Quantitative proteomic analysis of HER2 expression in the selection of gastric cancer patients for trastuzumab treatment

BackgroundA wide range of response rates have been reported in HER2-positive gastric cancer (GC) patients treated with trastuzumab. Other HER2-targeted therapies for GC have yet to show efficacy in clinical trials. These findings raise question about the ability of standard HER2 diagnostics to accurately distinguish between GC patients who would and would not benefit from anti-HER2 therapies.Patients and methodsGC patients (n = 237), including a subset from the Trastuzumab in GC (ToGA) trial were divided into three groups based on HER2 status and history of treatment with standard chemotherapy or chemotherapy plus trastuzumab. We applied mass spectrometry-based proteomic analysis to quantify HER2 protein expression in formalin-fixed tumor samples. Using HER2 expression as a continuous variable, we defined a predictive protein level cutoff to identify which patients would benefit from trastuzumab. We compared quantitated protein level with clinical outcome and HER2 status as determined by conventional HER2 diagnostics.ResultsQuantitative proteomics detected a 115-fold range of HER2 protein expression among patients diagnosed as HER2 positive by standard methods. A protein level of 1825 amol/µg was predicted to determine benefit from the addition of trastuzumab to chemotherapy. Trastuzumab treated patients with HER2 protein levels above this cutoff had twice the median overall survival (OS) of their counterparts below the cutoff (35.0 versus 17.5 months, P = 0.011). Conversely, trastuzumab-treated patients with HER2 levels below the cutoff had outcomes similar to HER2-positive patients treated with chemotherapy. (Progression-free survival = 7.0 versus 6.5 months: P = 0.504; OS = 17.5 versus 12.6 months: P = 0.520). HER2 levels were not prognostic for response to chemotherapy.ConclusionsProteomic analysis of HER2 expression demonstrated a quantitative cutoff that improves selection of GC patients for trastuzumab as compared with current diagnostic methods.     

Circulating tumour cell increase as a biomarker of disease progression in metastatic castration-resistant prostate cancer patients with low baseline CTC counts

BackgroundThe development of treatment response and surrogate biomarkers for advanced prostate cancer care is an unmet clinical need. Patients with baseline circulating tumour cell (BLCTCs) counts <5/7.5 mL represent a good prognosis subgroup but are non-evaluable for response assessment (decrease in CTCs). The aim of the study is to determine the value of any increase in CTCs (CTC progression) as an indicator of progression in prostate cancer patients with low pre-treatment CTCs (<5).Patients and methodsWe carried out a post hoc analysis of patients with BLCTCs < 5 treated in the COU-AA-301 (abiraterone or placebo + prednisone) and IMMC-38 (chemotherapy) trials. The association of CTC progression (increase in CTCs at 4, 8 or 12 weeks) with overall survival (OS) was evaluated in multi-variable Cox regression models. Performance of survival models with and without CTC progression was evaluated by calculating ROC curve area under the curves (AUCs) and weighted c-indices.ResultsOverall, 511 patients with CTCs < 5 (421 in COU-AA-301 and 90 in IMMC-38) were selected; 212 (41.7%) had CTC progression at 4, 8 or 12 weeks after treatment initiation. CTC progression was associated with significantly worse OS [27.1 versus 15.1 m; hazard ratio (HR) 3.4 (95% confidence interval [CI] 2.5–4.5; P < 0.001)], independent of baseline CTCs and established clinical variables. Adding CTC progression to the OS model significantly improved ROC AUC (0.77 versus 0.66; P < 0.001). Models including CTC progression had superior ROC AUC (0.77 versus 0.69; P < 0.001) and weighted c-index [0.750 versus 0.705; delta c-index: 0.045 (95% CI 0.019–0.071)] values than those including CTC conversion (increase to CTCs ≥ 5). In COU-AA-301, the impact of CTC progression was independent of treatment arm.ConclusionsIncreasing CTCs during the first 12 weeks of treatment are independently associated with worse OS from advanced prostate cancer in patients with baseline CTCs < 5 treated with abiraterone or chemotherapy and improve models with established prognostic variables. These findings must be prospectively validated.     

A prospective examination of circulating tumor cell profiles in non-small-cell lung cancer molecular subgroups

BackgroundWe report the first study examining the clinical, numerical and biological properties of circulating tumor cells according to molecular subtypes of non-small-cell lung cancer.Patients and methods125 patients with treatment-naïve stage IIIb-IV NSCLC were prospectively recruited for CellSearch analysis. Anti-vimentin antibody was included for examination of CTCs to assess their mesenchymal character. Associations of total CTCs and vimentin-positive (vim +) CTCs with clinical characteristics, tumor genotype, and survival were assessed.Results51/125 patients (40.8%) were total CTC+ and 26/125 (20.8%) were vim CTC+ at baseline. Multivariate analysis showed patients with ≥5 total CTCs had significantly reduced OS (HR 0.55, 95% CI 0.33–0.92, P = 0.022) but not PFS (HR 0.68, 95% CI 0.42–1.1, P = 0.118) compared to patients with <5 total CTCs. No OS difference was evident between vim+ CTC and vim-negative CTC patients overall (HR 1.24, 95% CI 0.67–2.28, P = 0.494), but after subdivision according to NSCLC driver mutation, we found an increase of vim+ CTCs in the EGFR-mutated subgroup (N = 21/94 patients; mean 1.24 vs 1.22 vim+ CTCs, P = 0.013), a reduction of total CTCs in the ALK-rearranged subgroup (N = 13/90 patients; mean 1.69 vs 5.82 total CTCs, P = 0.029), and a total absence of vim+ CTCs in KRAS-mutated adenocarcinomas (N = 19/78 patients; mean 0 vs 1.4 vim+ CTCs, P = 0.006).ConclusionsWe validate that the baseline presence of ≥5 total CTCs in advanced NSCLC confers a poor prognosis. CTCs from EGFR-mutant NSCLC express epithelial–mesenchymal transition characteristics, not seen in CTCs from patients with KRAS-mutant adenocarcinoma.     

Very high quantitative tumor HER2 content and outcome in early breast cancer

BackgroundIt is unknown how a very high tumor total HER2 (human epidermal growth factor receptor-2) content (H2T) influences outcome in early breast cancer treated with adjuvant trastuzumab plus chemotherapy.Patients and methodsH2T was measured using a novel quantitative assay (HERmark®) from formalin-fixed tumor tissue of 899 women who participated in the FinHer trial (ISRCTN76560285). In a chromogenic in situ hybridization (CISH) test, 197 (21.9%) patients had HER2-positive cancer and were randomly assigned to receive trastuzumab or control.ResultsCancer H2T levels varied 1808-fold. High H2T levels were correlated with a positive HER2 status by CISH (P < 0.0001). A nonlinear association was present between H2T and the hazard of distant recurrence in a subpopulation treatment effect pattern plot analysis in CISH-positive disease. Patients with very high H2T (defined by ≥22-fold the median of HER2-negative cancers; 13% of CISH-positive cancers) did not benefit from adjuvant trastuzumab [hazard ratio (HR) 1.23; 95% confidence interval (CI) 0.33–4.62; P = 0.75], whereas the rest of the patients with HER2-positive disease by CISH (87%) did benefit (HR 0.52; 95% CI 0.28–1.00; P = 0.050).ConclusionPatients with HER2-positive breast cancer with very high tumor HER2 content may benefit less from adjuvant trastuzumab compared with those whose cancer has more moderate HER2 content.     

Circulating tumour cells and pathological complete response: independent prognostic factors in inflammatory breast cancer in a pooled analysis of two multicentre phase II trials (BEVERLY-1 and -2) of neoadjuvant chemotherapy combined with bevacizumab

BackgroundWe present a pooled analysis of predictive and prognostic values of circulating tumour cells (CTC) and circulating endothelial cells (CEC) in two prospective trials of patients with inflammatory breast cancer (IBC) treated with neoadjuvant chemotherapy combined with neoadjuvant and adjuvant bevacizumab.Patients and methodsNonmetastatic T4d patients were enrolled in two phase II multicentre trials, evaluating bevacizumab in combination with sequential neoadjuvant chemotherapy of four cycles of FEC followed by four cycles of docetaxel in HER2-negative tumour (BEVERLY-1) or docetaxel and trastuzumab in HER2-positive tumour (BEVERLY-2). CTC and CEC were detected in 7.5 and 4 ml of blood, respectively, with the CellSearch System.ResultsFrom October 2008 to September 2010, 152 patients were included and 137 were evaluable for CTC and CEC. At baseline, 55 patients had detectable CTC (39%). After four cycles of chemotherapy, a dramatic drop in CTC to a rate of 9% was observed (P < 0.01). Pathological complete response (pCR) rate was 40%. No correlation was found between CTC or CEC levels and pCR rate. Median follow-up was 43 months. CTC detection (≥1 CTC/7.5 ml) at baseline was associated with shorter 3-year disease-free survival (39% versus 70% for patients without CTC, P < 0.01, HR 2.80) and shorter 3-year overall survival (OS) (P < 0.01). In multivariate analysis, independent prognostic parameters for shorter survival were absence of hormonal receptors, no pCR and CTC detection at baseline. CEC level at baseline or variations during treatment had no prognostic value.ConclusionIn this pooled analysis of two prospective trials in nonmetastatic IBC, detection rate of CTC was 39% with a strong and independent prognostic value for survival. Combination of pCR after neoadjuvant treatment with no CTC detection at baseline isolated a subgroup of IBC with excellent OS (94% 3-year OS), suggesting that CTC count could be part of IBC stratification in prospective trials.     

Effect of docetaxel duration on clinical outcomes: exploratory analysis of CLEOPATRA,a phase III randomized controlled trial

BackgroundCombination pertuzumab, trastuzumab, and docetaxel (D) is considered standard first-line treatment of human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. This post hoc, exploratory analysis of CLEOPATRA study data evaluated the clinical effects of D treatment duration within this regimen. The clinical benefits of pertuzumab and trastuzumab by different durations of D treatment were also evaluated.Patients and methodsPatients with HER2-positive metastatic breast cancer received trastuzumab and D plus pertuzumab or placebo. Clinical outcomes were analyzed by the number of D cycles that patients received (<6D, 6D, or >6D). Progression-free survival (PFS) and overall survival (OS) for each treatment arm within each D cycle group were estimated using the Kaplan–Meier approach. Time-dependent, multivariate Cox regression was applied to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for HER2-targeted therapy and D cycle groups.ResultsOverall, 804 patients received <6D (n = 119), 6D (n = 210), or >6D (n = 475) cycles. After adjusting for pertuzumab benefits versus placebo (PFS HR = 0.61, 95% CI 0.51–0.74, P < 0.0001; OS HR = 0.60, 95% CI, 0.49–0.74, P < 0.0001), >6D versus 6D cycles was not associated with statistically significant improvements in PFS (HR = 0.80, 95% CI 0.63–1.01, P = 0.0640) or OS (HR = 0.88, 95% CI 0.69–1.12, P = 0.3073). Consistent improvements in PFS and OS were observed with pertuzumab versus placebo, irrespective of D duration. The HRs for PFS were 0.395, 0.615, and 0.633 for <6D, 6D, and >6D cycles, respectively (P < 0.05 for all D cycle groups). Corresponding HRs for OS were 0.577, 0.700, and 0.612, respectively (P < 0.05 for <6D and >6D).ConclusionsAfter accounting for pertuzumab benefits, more than six cycles of D treatment was not associated with significant improvements in either PFS or OS compared with six cycles. The addition of pertuzumab to trastuzumab improved clinical outcomes versus trastuzumab plus placebo, regardless of D treatment duration.ClinicalTrials.gov identifierNCT00567190.     

Association between gain-of-function mutations in PIK3CA and resistance to HER2-targeted agents in HER2-amplified breast cancer cell lines

BackgroundThe mechanism of resistance to human epidermal growth factor receptor 2 (HER2)-targeted agents has not been fully understood. We investigated the influence of PIK3CA mutations on sensitivity to HER2-targeted agents in naturally derived breast cancer cells.Materials and methodsWe examined the effects of Calbiochem (CL)-387,785, HER2 tyrosine kinase inhibitor, and trastuzumab on cell growth and HER2 signaling in eight breast cancer cell lines showing HER2 amplification and trastuzumab-conditioned BT474 (BT474-TR).ResultsFour cell lines with PIK3CA mutations (E545K and H1047R) were more resistant to trastuzumab than the remaining four without mutations (mean percentage of control with 10 μg/ml trastuzumab: 58% versus 92%; P = 0.010). While PIK3CA-mutant cells were more resistant to CL-387,785 than PIK3CA-wild-type cells (mean percentage of control with 1 μm CL-387,785: 21% versus 77%; P = 0.001), CL-387,785 retained activity against BT474-TR. Growth inhibition by trastuzumab and CL-387,785 was more closely correlated with changes in phosphorylation of S6K (correlation coefficient, 0.811) than those of HER2, Akt, or ERK1/2. Growth of most HER2-amplified cells was inhibited by LY294002, regardless of PIK3CA genotype.Conclusions:PIK3CA mutations are associated with resistance to HER2-targeted agents. PI3K inhibitors are potentially effective in overcoming trastuzumab resistance caused by PIK3CA mutations. S6K phosphorylation is a possibly useful pharmacodynamic marker in HER2-targeted therapy.     

Multicenter phase II study of trastuzumab in combination with capecitabine and oxaliplatin for advanced gastric cancer

BackgroundTrastuzumab has been approved for use in combination with fluoropyrimidine plus cisplatin for the treatment of human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (AGC). Although capecitabine plus oxaliplatin (XELOX) is a standard first-line regimen for AGC, combination trastuzumab plus XELOX has not been studied.MethodsPatients with metastatic or unresectable HER2-positive AGC were diagnosed by either HER2 immunohistochemistry (IHC) 3+ or IHC 2+/fluorescence in-situ hybridisation (FISH)+ received intravenous trastuzumab (8 mg/kg for first cycle and 6 mg/kg for subsequent cycles on day 1) plus oral capecitabine (1000 mg/m² twice daily on days 1–14) and intravenous oxaliplatin (130 mg/m² on day 1), every 3 weeks. The primary end-point was the objective response rate, and secondary end-points included progression-free survival (PFS), overall survival (OS) and toxicity profiles.ResultsFifty-five HER2-positive AGC patients were enrolled between August 2011 and February 2013. The median age was 57 years (range = 29–74). The confirmed objective response rate was 67% (95% confidence interval (CI) = 54–80%). After a median follow-up period of 13.8 months (range = 6.1–23.9), the median PFS and OS were 9.8 months (95% CI = 7.0–12.6) and 21.0 months (95% CI = 6.4–35.7), respectively. Frequently encountered grade 3–4 toxicities included neutropenia (18%), anaemia (11%), and peripheral neuropathy (11%). There was a treatment-related death caused by severe diarrhoea and complicated sepsis.ConclusionCombination of trastuzumab and XELOX is well tolerated and highly effective in patients with HER2-positive AGC.     

Tumor-infiltrating lymphocytes in patients with HER2-positive breast cancer treated with neoadjuvant chemotherapy plus trastuzumab,lapatinib or their combination: A meta-analysis of randomized controlled trials

BackgroundA relationship between baseline tumor-infiltrating lymphocytes (TIL) and outcomes has been described in HER2-positive breast cancer. Nevertheless, the magnitude of this association and whether this effect differs based on the type of anti-HER2 agent remain controversial. This meta-analysis investigated the association between baseline TIL and pathologic complete response (pCR) rates in HER2-positive breast cancer patients treated with neoadjuvant chemotherapy plus trastuzumab and lapatinib either alone or in combination.MethodsA literature search covering PubMed, Embase and the Cochrane library up to October 31, 2016 identified randomized, controlled trials investigating neoadjuvant chemotherapy plus trastuzumab and lapatinib either alone or in combination where published data for pCR based on pre-treatment TIL scores were available. Two subgroups were considered: high baseline TIL vs. non-high TIL, according to each study definition. Summary risk estimates (odds ratio) and 95% confidence intervals (CI) were calculated for pCR using pre-treatment TIL levels for each trial. Pooled analyses were conducted using random and fixed effects models. Interaction P-values were computed using a Monte Carlo permutation test.ResultsA total of 5 studies (N = 1256 patients) were included. Overall, high TIL subgroup was associated with a significantly increased pCR rate (OR 2.46; 95% CI 1.36–4.43; P = 0.003). No interaction was observed between TIL subgroup (high vs. non-high TIL) and response to anti-HER2 agent(s) (trastuzumab vs. lapatinib vs. their combination; P = 0.747) and chemotherapy (anthracycline and taxanes vs. taxanes only; P = 0.201). A stronger association between high TIL subgroup and pCR rates was observed when examining only the 4 studies using anthracycline- and taxane- based neoadjuvant chemotherapy and the 60% cut-off for high TIL (N = 869, NeoALTTO excluded) with an OR of 2.88 (95% CI 2.03–4.08; P < 0.001).ConclusionsIn HER2-positive breast cancer, high baseline TIL are associated with increased pCR probability irrespective of neoadjuvant anti-HER2 agent(s) and chemotherapy regimens used.     

Does HER2 status influence locoregional failure rates in breast cancer patients treated with mastectomy for pT1–2pN0 disease?

Background: The impact of HER2 overexpression on the locoregional control of breast cancer is controversial.Patients and methods: Data on 906 women diagnosed with pT_1–2pN₀ breast cancer from 1986 to 1992 with known HER2 status and treated with a modified radical mastectomy without adjuvant radiotherapy or adjuvant trastuzumab were analyzed with respect to local relapse-free survival (LRFS), regional relapse-free survival (RRFS) and distant relapse-free survival (DRFS). Log-rank statistics were used to compare 10-year Kaplan–Meier curves of LRFS, RRFS and DRFS in HER2+ and HER2- patients.Results: Median follow-up was 12.8 years. HER2+ patients had a worse DRFS (P = 0.028) but there was no statistically significant difference in LRFS or RRFS between HER2+ and HER2- patients (P = 0.32 and 0.24 for LRFS and RRFS, respectively). Ten-year LRFS estimates among HER2+ patients was 91.3% and 86.9% for HER2- patients. Ten-year RRFS estimates for HER2+ and HER2- patients were 88.0% and 93.0%, respectively.Conclusion: HER2 overexpression was not associated with higher local or regional recurrence risk in subjects with pT_1–2pN₀ breast cancer following mastectomy and nodal dissection after a median follow-up of >12 years.     

Defining prognosis for women with breast cancer and CNS metastases by HER2 status

BackgroundThe purpose of this retrospective study was to determine, in a cohort of patients with breast cancer and central nervous system (CNS) metastases, the effect of trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)-positive disease and to compare this with that of patients with HER2-negative disease.MethodsFive hundred and ninety-eight patients with invasive breast cancer, CNS metastases and known HER2 status were identified. Time to CNS metastases and survival after CNS metastases were estimated by the Kaplan–Meier method, and Cox models were fitted to determine the association between HER2 status, trastuzumab treatment and outcomes after adjustment for other patient characteristics.ResultsIn the multivariable model, patients with HER2-negative disease [Hazard ratio (HR) 1.50, 95% confidence interval (CI) 1.15–1.95, P = 0.003] and patients with HER2-positive disease who did not receive trastuzumab (HR 2.13, 95% CI 1.51–3.00, P < 0.0001) had shorter times to CNS metastases compared with patients with HER2-positive disease who had received trastuzumab as first-line therapy for metastases. Furthermore, patients with HER2-negative disease (HR 1.66, 95% CI 1.31–2.12, P < 0.0001) and patients with HER2-positive disease who had never received trastuzumab (HR 1.34, 95% CI 0.78–2.30, P = 0.28) had an increased hazard of death compared with patients with HER2-positive disease who had received trastuzumab before or at the time of CNS metastases diagnosis.ConclusionIn our cohort of patients with breast cancer and CNS metastases, patients with HER2-positive disease treated with trastuzumab had longer times to development of and better survival from CNS metastases compared with patients with HER2-positive disease who had never received trastuzumab and patients with HER2-negative breast cancer.     

Low-scale phosphoproteome analyses identify the mTOR effector p70 S6 kinase 1 as a specific biomarker of the dual-HER1/HER2 tyrosine kinase inhibitor lapatinib (Tykerb®) in human breast carcinoma cells

BackgroundDiscovery of key proliferative and/or survival cascades closely linked to the biological effects of human epidermal growth factor receptor (HER) 1 (erbB-1) and/or HER2 (erbB-2) inhibitors may identify a priori mechanisms responsible for the development of acquired resistance in breast cancer disease. Here, we took advantage of a semiquantitative protein array technology to identify intracellular oncogenic kinases that distinctively correlate with breast cancer cell sensitivity/resistance to the dual-HER1/HER2 tyrosine kinase inhibitor lapatinib (Tykerb®).Materials and methodsMCF-7 cells were forced to overexpress HER2 following stable transduction with pBABE-HER2 retroviruses. The Human Phospho-MAPK Array Proteome Profiler™ (R&D Systems) was used to molecularly assess the effects of both the mono-HER2 inhibitor trastuzumab (Herceptin™) and the dual-HER1/HER2 inhibitor lapatinib on 21 different oncogenic kinases. A model of acquired resistance to lapatinib (MCF-7/HER2-Lap10 cells) was established by chronically exposing MCF-7/HER2 cells to increasing concentrations of lapatinib for >10 months.ResultsTreatment of MCF-7/HER2 cells with either trastuzumab or lapatinib similarly impaired HER2-enhanced activation status (i.e. phosphorylation) of the mitogen-activated protein kinases, c-Jun N-terminal kinases 1–3 and p38α/β/γ/δ and of the serine/threonine kinases AKT, glycogen synthase kinase-3, p90 ribosomal s6 kinase1/2, and mitogen- and stress-activated protein kinase1/2. Trastuzumab was less effective than lapatinib at blocking extracellular-signal regulated kinase (ERK) 1/2 and, notably, it failed to deactivate the mammalian target of rapamycin (mTOR) effector p70S6K1. Conversely, lapatinib treatment caused a drastic decrease in the phosphorylation of p70S6K1 at ERK1/2-regulated sites (Thr⁴²¹/Ser⁴²⁴) and, as a consequence, p70S6K1 activity measured by its phospho-Thr³⁸⁹ levels was abolished. The mTOR inhibitor rapamycin was found to supraadditively increase lapatinib efficacy in MCF-7/HER2 cells [∼10-fold enhancement; combination index (CI₅₀) = 0.243 < 1.0 = additivity, P < 0.001] but not in p70S6K1 gene-amplified MCF-7 parental cells (∼1.3-fold enhancement; CI₅₀ = 0.920 ≅ 1.0 = additivity). Lapatinib-resistant MCF-7/HER2-Lap10 cells, which are capable of growing in the continuous presence of 10 μm lapatinib without significant effects on cell viability, notably exhibited a lapatinib-insensitive hyperphosphorylation of p70S6K1. Rapamycin cotreatment suppressed p70S6K1 hyperactivation and synergistically resensitized MCF-7/HER2-Lap10 cells to lapatinib (>20-fold increase in lapatinib-induced cytotoxicity; CI₅₀ = 0.175 < 1.0 = additivity).ConclusionsSerine–threonine kinase p70S6K1, a marker for mTOR activity that regulates protein translation, constitutes a specific biomarker for the biological effects of the dual-HER1/HER2 inhibitor lapatinib. The clinical implications of our data are that the efficacy of lapatinib might be enhanced with therapies that target the mTOR pathway. Rapamycin analogues such as CCI-779 (Temsirolimus) and RAD001 (Everolimus) may warrant further clinical evaluation to effectively delay or prevent the development of acquired resistance to lapatinib in HER2-positive breast cancer patients.     

Preliminary safety and efficacy of first-line pertuzumab combined with trastuzumab and taxane therapy for HER2-positive locally recurrent or metastatic breast cancer (PERUSE)

BackgroundPertuzumab combined with trastuzumab and docetaxel is the standard first-line therapy for HER2-positive metastatic breast cancer, based on results from the phase III CLEOPATRA trial. PERUSE was designed to assess the safety and efficacy of investigator-selected taxane with pertuzumab and trastuzumab in this setting.Patients and methodsIn the ongoing multicentre single-arm phase IIIb PERUSE study, patients with inoperable HER2-positive advanced breast cancer (locally recurrent/metastatic) (LR/MBC) and no prior systemic therapy for LR/MBC (except endocrine therapy) received docetaxel, paclitaxel or nab-paclitaxel with trastuzumab [8 mg/kg loading dose, then 6 mg/kg every 3 weeks (q3w)] and pertuzumab (840 mg loading dose, then 420 mg q3w) until disease progression or unacceptable toxicity. The primary end point was safety. Secondary end points included overall response rate (ORR) and progression-free survival (PFS).ResultsOverall, 1436 patients received at least one treatment dose (initially docetaxel in 775 patients, paclitaxel in 589, nab-paclitaxel in 65; 7 discontinued before starting taxane). Median age was 54 years; 29% had received prior trastuzumab. Median treatment duration was 16 months for pertuzumab and trastuzumab and 4 months for taxane. Compared with docetaxel-containing therapy, paclitaxel-containing therapy was associated with more neuropathy (all-grade peripheral neuropathy 31% versus 16%) but less febrile neutropenia (1% versus 11%) and mucositis (14% versus 25%). At this preliminary analysis (52 months’ median follow-up), median PFS was 20.6 [95% confidence interval (CI) 18.9–22.7] months overall (19.6, 23.0 and 18.1 months with docetaxel, paclitaxel and nab-paclitaxel, respectively). ORR was 80% (95% CI 78%–82%) overall (docetaxel 79%, paclitaxel 83%, nab-paclitaxel 77%).ConclusionsPreliminary findings from PERUSE suggest that the safety and efficacy of first-line pertuzumab, trastuzumab and taxane for HER2-positive LR/MBC are consistent with results from CLEOPATRA. Paclitaxel appears to be a valid alternative taxane backbone to docetaxel, offering similar PFS and ORR with a predictable safety profile.ClinicalTrials.govNCT01572038.     

Lapatinib versus lapatinib plus capecitabine as second-line treatment in human epidermal growth factor receptor 2-amplified metastatic gastro-oesophageal cancer: A randomised phase II trial of the Arbeitsgemeinschaft Internistische Onkologie

IntroductionHuman epidermal growth factor receptor 2 (HER2) amplification is present in a subgroup of gastroo-esophageal cancers (GCs). HER2 inhibition with trastuzumab has shown to improve outcomes in advanced disease. Lapatinib ditosylate (LAP), a dual anti-epidermal growth factor receptor (EGFR) and anti-HER2 tyrosine kinase inhibitor with preclinical activity against GC, has been approved in HER2-positive breast cancer. We aimed to study the activity of LAP in HER2-amplified GC.Materials and methodsPatients (pts) with HER2-positive (gene amplification or increased copy numbers based on predefined criteria) advanced GC were randomly allocated 1:1 to receive LAP 1250 mg per day 1–21 plus capecitabine (CAP) 2000 mg/m² on days 1–14 of a 21-day cycle or LAP 1500 mg monotherapy day 1–21 after having failed on a platinum-based first-line therapy. HER2 status was assessed centrally. The primary end-point was the objective response rate (ORR) as assessed by the investigator using Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1). We aimed to include 38 pts per arm to show an interesting response rate of ⩾20% in either of the two arms.Results37 pts were enrolled (18 to LAP + CAP, 19 to LAP). Pts had received a median of three prior treatment lines. 12 pts in the LAP + CAP group (67%) and 12 pts in the LAP group (63%) had received prior trastuzumab. Only two pts (11.1%; 95% confidence interval (CI): 1.37–34.7), both in the LAP + CAP arm, achieved an objective response. The study was closed prematurely for futility. Median time to progression was 42 (95% CI: 38–61) days in the LAP group and 83 (95% CI: 42–86) days in the LAP + CAP group. Other secondary efficacy end-points (progression-free and overall survival) were comparable in the two treatment groups. Rates of diarrhoea were higher with LAP + CAP (61%; 95% CI: 35–83) compared to 26% (95% CI 9–51) with LAP mono, whereas other adverse events were mostly similar between the groups (18 [100%] versus 17 [90%]).DiscussionLapatinib showed insufficient activity in HER2-amplified pretreated advanced GC. The safety profile of LAP or LAP + CAP was as expected with some more toxicity in the combination arm. (ClinicalTrials.gov Identifier, NCT01145404).     

An exploratory analysis of the factors leading to delays in cancer drug reimbursement in the European Union: The trastuzumab case

BackgroundThe European Union (EU) has adopted a common procedure for granting marketing authorisation for cancer drugs. Nevertheless, pricing and reimbursement decisions are a competency of EU national governments, and their policies are diverse. We aimed to evaluate the time for trastuzumab reimbursement approval and its association to health expenditure, to health policy performance, to the availability of cost-effectiveness studies and to breast cancer outcome.MethodsBreast cancer outcome was estimated by the mortality/incidence (M/I) ratio. Trastuzumab reimbursement approval dates were provided by Roche. Spearman’s rank correlation and Wilcoxon rank-sum test were used to evaluate associations and/or differences between the variables studied. Additional analyses were made by grouping countries according to compliance to the 180 day timeframe stipulated in the EU 89/105/EEC Directive for drug pricing and reimbursement.ResultsA statistically significant inverse and strong correlation between breast cancer M/I ratio and health expenditure (r_s = –0.730, p < 0.001) and health policy performance (r_s = –0.711, p < 0.001) was found, meaning the better the score and the higher the expenditure, the fewer patients died after a breast cancer diagnosis. Factors associated with trastuzumab faster reimbursement and compliance to the 89/105/EEC Directive were better health policy score, higher health expenditure and availability of cost-effectiveness studies.ConclusionHigher health policy scores and health expenditure are associated with faster reimbursement of trastuzumab and better breast cancer outcome. Although the study design does not allow inference of causal associations, a marked difference is observed between Eastern and Western Europe, with long delays and increased breast cancer mortality identified in Eastern European countries.     

Duration of adjuvant trastuzumab in HER2 positive breast cancer: Overall and disease free survival results from meta-analyses of randomized controlled trials

BackgroundOne year of trastuzumab, chosen empirically, improves survival of women with early-stage, HER2-positive breast cancer but also adds substantially to cost, toxicity, and inconvenience. Longer treatment does not improve outcomes, but potentiates toxicities.MethodsMedline, Embase, and major conference proceedings were searched systematically in June 2017 to identify Randomized Controlled Trials (RCTs) comparing one year versus shorter durations of trastuzumab in adjuvant treatment of breast cancer. Reported Hazard-Ratios (HR) for Overall Survival (OS) and Disease-Free Survival (DFS), and Odds-Ratio for cardiac events, with respective 95% Confidence Intervals (CI) from each study was weighted using generic inverse-variance, and pooled in a meta-analysis. Inter-study heterogeneity and sub-group difference (based on hormone-receptors and node-positivity) were assessed using I², and chi² statistics, respectively.ResultsFour studies (n = 7614) satisfied inclusion criteria. Individual RCTs had diverse pre-specified upper-limits of 95% CI for declaring non-inferiority (range: <1.15 to <1.53). Pooled results demonstrated significant improvements in OS (HR 1.28, p = 0.04), and DFS (HR 1.24, p = 0.005) with 1 year of trastuzumab compared to shorter durations. Absence of multiplicity argument allowed for declaring superiority of 1 year of trastuzumab based on our results despite non-inferiority designs of individual trials. No influence on overall effect by duration of trastuzumab in experimental arm (9 weeks versus 6 months) was noted. No statistical interaction by hormone-receptor status and node-positivity on overall results was noticed [p(sub-group difference) 0.73, and 0.52, respectively]. Odds-Ratio for cardiac events was 2.65 (p < 0.001) favoring shorter duration.ConclusionOne year of trastuzumab prolongs overall, and disease-free survivals in women with early-stage HER2 positive breast cancer compared to shorter durations and this should remain as the standard of care. Cardiotoxicity increased significantly with the 1-year treatment.     

Incidence of central nervous system metastases in patients with HER2-positive metastatic breast cancer treated with pertuzumab,trastuzumab, and docetaxel: results from the randomized phase III study CLEOPATRA

BackgroundResults from the phase III trial CLEOPATRA in human epidermal growth factor receptor 2-positive first-line metastatic breast cancer demonstrated significant improvements in progression-free and overall survival with pertuzumab, trastuzumab, and docetaxel over placebo, trastuzumab, and docetaxel. We carried out exploratory analyses of the incidence and time to development of central nervous system (CNS) metastases in patients from CLEOPATRA.Patients and methodsPatients received pertuzumab/placebo: 840 mg in cycle 1, then 420 mg; trastuzumab: 8 mg/kg in cycle 1, then 6 mg/kg; docetaxel: initiated at 75 mg/m². Study drugs were administered i.v. every 3 weeks. The log-rank test was used for between-arm comparisons of time to CNS metastases as first site of disease progression and overall survival in patients with CNS metastases as first site of disease progression. The Kaplan–Meier approach was used to estimate median time to CNS metastases as first site of disease progression and median overall survival.ResultsThe incidence of CNS metastases as first site of disease progression was similar between arms; placebo arm: 51 of 406 (12.6%), pertuzumab arm: 55 of 402 (13.7%). Median time to development of CNS metastases as first site of disease progression was 11.9 months in the placebo arm and 15.0 months in the pertuzumab arm; hazard ratio (HR) = 0.58, 95% confidence interval (CI) 0.39–0.85, P = 0.0049. Overall survival in patients who developed CNS metastases as first site of disease progression showed a trend in favor of pertuzumab, trastuzumab, and docetaxel; HR = 0.66, 95% CI 0.39–1.11. Median overall survival was 26.3 versus 34.4 months in the placebo and pertuzumab arms, respectively. Treatment comparison of the survival curves was not statistically significant for the log-rank test (P = 0.1139), but significant for the Wilcoxon test (P = 0.0449).ConclusionsWhile the incidence of CNS metastases was similar between arms, our results suggest that pertuzumab, trastuzumab, and docetaxel delays the onset of CNS disease compared with placebo, trastuzumab, and docetaxel.ClinicalTrials.govNCT00567190.     

Single circulating tumor cell detection and overall survival in nonmetastatic breast cancer

BackgroundCirculation of cancer cells in the blood is a mandatory step for metastasis, but circulating tumor cells (CTC) have a low metastatic efficiency in preclinical animal models. In this prospective study, we reported the clinical outcome of nonmetastatic breast cancer patients according to CTC detection.Patients and methodsIn 115 nonmetastatic patients diagnosed with large operable or locally advanced breast cancer, we prospectively detected CTC using the CellSearch system before and after neoadjuvant chemotherapy in a phase II trial (REMAGUS02).ResultsAt baseline, 23% of patients were CTC positive, but only 10% had >1 CTC/7.5 ml of blood. After a median follow-up of 36 months, CTC detection before chemotherapy was an independent prognostic factor for both distant metastasis-free survival [DMFS; P = 0.01, relative risk (RR) = 5.0, 95% confidence interval (CI) 1.4–17] and overall survival (OS; P = 0.007, RR = 9, 95% CI 1.8–45). CTC detection after chemotherapy was of less significance (P = 0.07 and 0.09, respectively). Moreover, CTC detection showed interesting characteristics as an individual predictive test for metastatic relapses (sensibility 55%, specificity 81%, and global accuracy 77%).ConclusionsDetection of ≥1 CTC/7.5 ml before neoadjuvant chemotherapy can accurately predict OS. Our findings may change the clinical management of nonmetastatic breast cancer and indicate that the metastatic efficiency of CTC could be higher than previously reported.     

A randomized phase II study evaluating different maintenance schedules of nab-paclitaxel in the first-line treatment of metastatic breast cancer: final results of the IBCSG 42-12/BIG 2-12 SNAP trial

BackgroundThe phase II SNAP trial was designed to evaluate the efficacy of alternative chemotherapy schedules for prolonged administration in HER2-negative metastatic breast cancer (MBC), after a short induction at conventional doses.Patients and methodsBetween April 2013 and August 2015, 258 women untreated with chemotherapy for MBC were randomly assigned to receive three different maintenance chemotherapy schedules after three cycles of identical induction chemotherapy: arm A, nab-paclitaxel 150 mg/m² days 1 and 15 Q28; arm B, nab-paclitaxel 100 mg/m² days 1, 8 and 15 Q28; arm C, nab-paclitaxel 75 mg/m² days 1, 8, 15 and 22 Q28. Induction was three cycles nab-paclitaxel 150/125 mg/m², days 1, 8 and 15 Q28. The primary objective was to evaluate the efficacy of each maintenance schedule, in terms of progression-free survival (PFS), as compared with the historical reference of 7-month median PFS reported by previous studies with first-line docetaxel. One-sample, one-sided log-rank tests were utilized. Quality-of-life (QoL) evaluation was carried out, and the global indicator for physical well-being was defined as the primary QoL end point; completion rates of QoL forms were >90%.ResultsIn total, 255 patients were assessable for the primary end point. After 18.2-month median follow-up, 182 PFS events were observed. Median PFS was 7.9 months [90% confidence interval CI 6.8–8.4] in arm A, 9.0 months (90% CI 8.1–10.9) in arm B and 8.5 months (90% CI 6.7–9.5) in arm C. PFS in arm B was significantly longer than the historical reference of first-line docetaxel (P = 0.03). Grade ≥2 sensory neuropathy was reported in 37.9%, 36.1% and 31.2% of the patients in arm A, B and C, respectively (Grade ≥3 in 9.1%, 5.6% and 6.6% of the patients, respectively). Noteworthy, the QoL scores for sensory neuropathy did not worsen with prolonged nab-paclitaxel administration in any of the maintenance arms.ConclusionThe SNAP trial demonstrated that alternative nab-paclitaxel maintenance schedules with reduced dosages after a short induction at conventional doses are feasible and active in the first-line treatment of MBC.Registration: ClinicalTrials.gov NCT01746225     

Obesity increases the incidence of distant metastases in oestrogen receptor-negative human epidermal growth factor receptor 2-positive breast cancer patients

BackgroundObesity is a major negative determinant of breast cancer outcome. However, there are contrasting data on the differential impact of obesity on specific breast cancer subtypes. In particular, very little is known on human epidermal growth factor receptor 2-positive (HER2+) tumours.Patients and methodsWe assessed the prognostic role of increased body mass index (BMI) on a consecutive series of non-metastatic HER2+ patients treated at our institution before the introduction of adjuvant Trastuzumab. We separately analysed oestrogen receptor-positive (ER+) and -negative (ER?) HER2+ cases.ResultsIn ER?/HER2+ tumours we observed a significantly worse overall survival (Hazard ratio (HR) 1.79, p-value 0.041) and cumulative incidence of distant metastases (HR 2.03, p-value 0.019) in obese (BMI > 30) versus normal/underweight (BMI < 25) patients. Local relapses appeared to be non-significantly reduced in obese patients, masking the overall effect on disease-free survival. Outcome in ER+ tumours, instead, was not significantly different between BMI groups.ConclusionsObesity significantly correlates with worse overall survival and cumulative incidence of distant metastases in ER?/HER2 positive breast cancer. Differences in the biology of breast tumours may determine individual susceptibility to obesity. The biology of the underlying tumour should be taken into account in the design of dietary intervention trials in breast cancer.