Adjuvant trastuzumab with chemotherapy is effective in women with small, node-negative, HER2-positive breast cancer

BACKGROUND:

Several large, randomized trials established the benefits of adjuvant trastuzumab with chemotherapy. However, the benefit for women with small, node‐negative HER2‐positive (HER2+) disease is unknown, as these patients were largely excluded from these trials. Therefore, a retrospective, single‐institution, sequential cohort study of women with small, node‐negative, HER2+ breast cancer who did or did not receive adjuvant trastuzumab was conducted.

METHODS:

Women with ≤2 cm, node‐negative, HER2+ (immunohistochemistry 3+ or fluorescence in situ hybridization ≥2) breast cancer were identified through an institutional database. A “no‐trastuzumab” cohort of 106 trastuzumab‐untreated women diagnosed between January 1, 2002 and May 14, 2004 and a “trastuzumab” cohort of 155 trastuzumab‐treated women diagnosed between May 16, 2005 and December 31, 2008 were described. Survival and recurrence outcomes were estimated by Kaplan‐Meier methods.

RESULTS:

The cohorts were similar in age, median tumor size, histology, hormone receptor status, hormone therapy, and locoregional therapy. Chemotherapy was administered in 66% and 100% of the “no trastuzumab” and “trastuzumab” cohorts, respectively. The median recurrence‐free and survival follow‐up was: 6.5 years (0.7‐8.5) and 6.8 years (0.7‐8.5), respectively, for the “no trastuzumab” cohort and 3.0 years (0.5‐5.2) and 3.0 years (0.6‐5.2), respectively, for the “trastuzumab” cohort. The 3‐year locoregional invasive recurrence‐free, distant recurrence‐free, invasive disease‐free, and overall survival were 92% versus 98% (P = .0137), 95% versus 100% (P = .0072), 82% versus 97% (P < .0001), and 97% versus 99% (P = .18) for the “no trastuzumab” and “trastuzumab” cohorts, respectively.

CONCLUSIONS:

Women with small, node‐negative, HER2+ primary breast cancers likely derive significant benefit from adjuvant trastuzumab with chemotherapy. Cancer 2011;. © 2011 American Cancer Society.     

Incidence and risk of central nervous system metastases as site of first recurrence in patients with HER2-positive breast cancer treated with adjuvant trastuzumab

BackgroundCentral nervous system (CNS) disease as the site of first relapse after exposure to adjuvant trastuzumab has been reported. We carried out comprehensive meta-analysis to determine the risk of CNS metastases as the first site of recurrence in patients with HER2-positive breast cancer who received adjuvant trastuzumab.MethodsEligible studies include randomized trials of adjuvant trastuzumab administered for 1 year to patients with HER2-positive breast cancer who reported CNS metastases as first site of disease recurrence. Statistical analyses were conducted to calculate the incidence, relative risk (RR), and 95% confidence intervals (CIs) using fixed-effects inverse variance and random-effects models.ResultsA total of 9020 patients were included. The incidence of CNS metastases as first site of disease recurrence in HER2-positive patients receiving adjuvant trastuzumab was 2.56% (95% CI 2.07% to 3.01%) compared with 1.94% (95% CI 1.54% to 2.38%) in HER2-positive patients who did not receive adjuvant trastuzumab. The RR of the CNS as first site of relapse in trastuzumab-treated patients was 1.35 (95% CI 1.02–1.78, P = 0.038) compared with control arms without trastuzumab therapy. The ratio of CNS metastases to total number of recurrence events was 16.94% (95% CI 10.85% to 24.07%) and 8.33% (95% CI 6.49% to 10.86%) for the trastuzumab-treated and control groups, respectively. No statistically significant differences were found based on trastuzumab schedule or median follow-up time. No evidence of publication bias was observed.ConclusionsAdjuvant trastuzumab is associated with a significant increased risk of CNS metastases as the site of first recurrence in HER2-positive breast cancer patients.     

Management of small HER2-positive breast cancers

Trastuzumab has revolutionised the treatment of HER2-positive early-stage breast cancer and is now standard of care in combination with chemotherapy for patients with tumours larger than 1 cm. However, 5 years after publication of the landmark trials establishing the efficacy of the drug, the management of small (≤1 cm), HER2-positive tumours remains difficult. Most small breast cancers have a good prognosis and adjuvant chemotherapy is not routinely recommended. However, retrospective data suggest that some small HER2-positive cancers might have a worse clinical outcome than others. This notion raises the key clinical question of whether patients with small HER2-positive cancers should be offered adjuvant trastuzumab and chemotherapy. The pivotal adjuvant trastuzumab trials did not include patients with tumours smaller than 1 cm, but a subset analysis of one trial showed that patients with tumours 1-2 cm in size derived at least as much clinical benefit from 1 year of adjuvant trastuzumab as did the overall cohort. Clinicians face the dilemma of whether the potential reduction in risk of recurrence in this patient group warrants the toxic effects and risks of adjuvant chemotherapy and trastuzumab. In this review, we discuss the evidence for prognosis of small HER2-positive cancers, and for possible benefit from adjuvant trastuzumab. We suggest potential treatment strategies and clinical trial designs to address this important issue. On the basis of present evidence, we recommend that the benefits and risks of adjuvant trastuzumab should be discussed with patients with small, HER2-positive breast cancer.     

High expression of lymphocyte-associated genes in node-negative HER2+ breast cancers correlates with lower recurrence rates

Gene expression analysis has identified biologically relevant subclasses of breast cancer. However, most classification schemes do not robustly cluster all HER2+ breast cancers, in part due to limitations and bias of clustering techniques used. In this article, we propose an alternative approach that first separates the HER2+ tumors using a gene amplification signal for Her2/neu amplicon genes and then applies consensus ensemble clustering separately to the HER2+ and HER2- clusters to look for further substructure. We applied this procedure to a microarray data set of 286 early-stage breast cancers treated only with surgery and radiation and identified two basal and four luminal subtypes in the HER2- tumors, as well as two novel and robust HER2+ subtypes. HER2+ subtypes had median distant metastasis-free survival of 99 months [95% confidence interval (95% CI), 83-118 months] and 33 months (95% CI, 11-54 months), respectively, and recurrence rates of 11% and 58%, respectively. The low recurrence subtype had a strong relative overexpression of lymphocyte-associated genes and was also associated with a prominent lymphocytic infiltration on histologic analysis. These data suggest that early-stage HER2+ cancers associated with lymphocytic infiltration are a biologically distinct subtype with an improved natural history.     

Non-initiation and early discontinuation of adjuvant trastuzumab in women with localized HER2-positive breast cancer

One year of trastuzumab therapy is recommended for women with HER2-positive breast cancer ≥1.0 cm in size to increase survival and is considered for women with tumors 0.5–0.9 cm in size. We analyzed compliance with trastuzumab among women with HER2-positive breast cancer in a prospective cohort study. Of 1145 recruited patients with breast cancer, 152 were HER2-positive (13.2 %), of whom 126 had tumors ≥1.0 cm; 110/126 (87.3 %) of these initiated trastuzumab. Non-receipt was associated with older age, better prognosis tumors, and with non-receipt of adjuvant chemotherapy. Of the 110 who initiated treatment, 18 (15 %) did not complete treatment, 15 (83 %) of them because of cardiotoxicity. Of 20 women with tumors 0.5–0.9 cm, 5 (25 %) initiated trastuzumab. Compliance with trastuzumab was very high among those with HER2-positive breast cancer, as was the completion of the recommended therapy.     

WEE1 inhibition reverses trastuzumab resistance in HER2-positive cancers

Gastric Cancer - To date, many efforts have been made to understand the resistance mechanism of trastuzumab in human epidermal growth factor receptor 2 (HER2)-positive breast and gastric cancer....     

Adjuvant trastuzumab therapy for HER2-positive breast cancer

HER2 is overexpressed or gene amplified in 20%-25% of breast cancers. The anti-HER2 monoclonal antibody trastuzumab targets HER2-positive tumors, inhibiting proliferation and inducing cell death via extracellular and intracellular mechanisms. The clinical benefits observed with trastuzumab in the metastatic setting provided the rationale for assessing trastuzumab in the treatment of early breast cancer. Four large phase III adjuvant trials (NSABP B-31, NCCTG N9831, HERA, and BCIRG 006) investigated the efficacy and safety of 1 or 2 years of trastuzumab given in combination with or after standard adjuvant chemotherapy. The addition of 1 year of trastuzumab to adjuvant chemotherapy significantly improved disease-free survival (DFS) by 33%-52% and overall survival by 34%-41% in the 4 trials. The DFS benefits were observed regardless of age, nodal status, hormonal status, or tumor size in all trials. The cumulative incidence of congestive heart failure or cardiac death ranged from 0-0.9% in the control arms and 0-3.8% in the trastuzumab-containing arms. These were below the safety cutoff points set by the individual studies' independent data monitoring committees, indicating acceptable cardiac safety. Risk factors associated with cardiac dysfunction included baseline left ventricular ejection fraction level, hypertension, and older age. The addition of trastuzumab to adjuvant chemotherapy provides significant survival benefits with a positive benefit/risk ratio. Ongoing and planned trials correlated with basic science will enhance our understanding of HER2-positive disease, leading to treatment optimization and further improvements in patient outcomes.     

Paclitaxel,carboplatin, and trastuzumab in HER2-positive metastatic breast cancer

Conclusions The regimen of weekly paclitaxel plus carboplatin and trastuzumab seems to have promising activity and is better tolerated than the 3-weekly schedule.     

Subcutaneous trastuzumab: a review of its use in HER2-positive breast cancer

Trastuzumab (Herceptin®) is a humanized IgG₁ monoclonal antibody that is an efficacious treatment for HER2-positive breast and gastric cancers. Subcutaneous trastuzumab is a new formulation approved in the European Union for use in patients with early or metastatic breast cancer. In the randomized, open-label, multinational HannaH (enHANced treatment with NeoAdjuvant Herceptin) study of neoadjuvant/adjuvant trastuzumab in patients with early HER2-positive breast cancer, the pharmacokinetics of neoadjuvant subcutaneous trastuzumab were similar to those after intravenous administration, meeting the noninferiority criterion for mean predose trough concentrations, as assessed prior to surgery (primary pharmacokinetic endpoint). Trastuzumab blood concentrations throughout the dosing interval remained above those considered necessary for anticancer activity. In this study, the pathologic complete response rates (primary efficacy endpoint) were 45.4 and 40.7 % in the subcutaneous and intravenous administration groups, respectively, meeting a study noninferiority criterion. In the randomized, open-label, crossover, multinational PrefHer study of neoadjuvant/adjuvant or adjuvant trastuzumab in early HER2-positive breast cancer, subcutaneous administration of trastuzumab was preferred over intravenous administration by >85 % of patients, most commonly because it was time saving and induced less pain and discomfort. In the HannaH study, the tolerability profile of subcutaneous trastuzumab was similar to that of intravenous trastuzumab, except that the rate of serious adverse events was 21 % (vs. 12 % with intravenous administration), partly because of more infections with subcutaneous administration. Whether this finding is of any clinical significance should emerge from ongoing studies. On the evidence, subcutaneous trastuzumab is an effective and generally well-tolerated treatment option that is preferred by patients over intravenous administration.     

Cost-effectiveness analysis of trastuzumab in the adjuvant setting for treatment of HER2-positive breast cancer

BACKGROUND: Adding trastuzumab to adjuvant chemotherapy provides significant clinical benefit in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. A cost-effectiveness analysis was performed to assess clinical and economic implications of adding trastuzumab to adjuvant chemotherapy, based upon joint analysis of NSABP B-31 and NCCTG N9831 trials. METHODS: A Markov model with 4 health states was used to estimate the cost utility for a 50-year-old woman on the basis of trial results through 4 years and estimates of long-term recurrence and death based on a meta-analysis of trials. From 6 years onward, rates of recurrence and death were assumed to be the same in both trastuzumab and chemotherapy-only arms. Incremental costs were estimated for diagnostic and treatment-related costs. Analyses were from payer and societal perspectives, and these analyses were projected to lifetime and 20-year horizons. RESULTS: Over a lifetime, the projected cost of trastuzumab per quality-adjusted life year (QALY; discount rate 3%) gained was 26,417 dollars (range 9,104 dollars-69,340 dollars under multiway sensitivity analysis). Discounted incremental lifetime cost was 44,923 dollars, and projected life expectancy was 3 years longer for patients who received trastuzumab (19.4 years vs 16.4 years). During a 20-year horizon, the projected cost of adding trastuzumab to chemotherapy was 34,201 dollars per QALY gained. Key cost-effectiveness drivers were discount rate, trastuzumab price, and probability of metastasis. The cost-effectiveness result was robust to sensitivity analysis. CONCLUSIONS: Trastuzumab for adjuvant treatment of early stage breast cancer was projected to be cost effective over a lifetime horizon, achieving a cost-effectiveness ratio below that of many widely accepted oncology treatments.     

Factors influencing survival among patients with HER2-positive metastatic breast cancer treated with trastuzumab

Background

Intergroup Exemestane Study (IES) was a randomised study that showed a survival benefit of switching adjuvant endocrine therapy after 2–3 years from tamoxifen to exemestane. This PathIES aimed to assess the role of immunohistochemical (IHC)4 score in determining the relative sensitivity to either tamoxifen or sequential treatment with tamoxifen and exemestane.

Patients and methods

Primary tumour samples were available for 1274 patients (27% of IES population). Only patients for whom the IHC4 score could be calculated (based on oestrogen receptor, progesterone receptor, HER2 and Ki67) were included in this analysis (N = 430 patients). The clinical score (C) was based on age, grade, tumour size and nodal status. The association of clinicopathological parameters, IHC4(+C) scores and treatment effect with time to distant recurrence-free survival (TTDR) was assessed in univariable and multivariable Cox regression analyses. A modified clinical score (PathIEscore) (N = 350) was also estimated.

Results

Our results confirm the prognostic importance of the original IHC4, alone and in conjunction with clinical scores, but no significant difference with treatment effects was observed. The combined IHC4 + Clinical PathIES score was prognostic for TTDR (P < 0.001) with a hazard ratio (HR) of 5.54 (95% CI 1.29–23.70) for a change from 1st quartile (Q1) to Q1–Q3 and HR of 15.54 (95% CI 3.70–65.24) for a change from Q1 to Q4.

Conclusion

In the PathIES population, the IHC4 score is useful in predicting long-term relapse in patients who remain disease-free after 2–3 years. This is a first trial to suggest the extending use of IHC4+C score for prognostic indication for patients who have switched endocrine therapies at 2–3 years and who remain disease-free after 2–3 years.

     

Hormone-receptor expression and activity of trastuzumab with chemotherapy in HER2-positive advanced breast cancer patients

BACKGROUND:

The relationship between quantitative immunohistochemical hormone receptor expression and response to the combination of trastuzumab with chemotherapy in HER2‐positive advanced breast cancer is currently unknown.

METHODS:

Estrogen receptor (ER) and progesterone receptor expression was studied both as a dichotomous variable (positivity set at ≥1% of positive cells) and as a continuous variable. The effect of hormone receptor expression on overall response rate and progression‐free survival in patients receiving trastuzumab‐based treatment was studied by univariate and multivariate analysis.

RESULTS:

One hundred eleven of 227 consecutive advanced breast cancer patients treated at 2 Institutions had hormone receptor‐positive tumors (49%). High expression of ER (≥30% of tumor cells) predicted reduced probability of tumor response to trastuzumab plus chemotherapy (multivariate odds ratio, 0.422; 95% confidence interval [CI], 0.222‐0.803; P = .009). In patients with hormone receptor‐positive tumors (≥1% of tumor cells), maintenance endocrine therapy added to trastuzumab upon the completion of chemotherapy was associated with a significant progression‐free survival benefit (hazard ratio, 0.521; 95% CI, 0.3325‐0.836; P = .007).

CONCLUSIONS:

Our results suggest a predictive role of hormone receptor expression in HER2‐positive tumors. Further investigation in this patient subset is warranted to optimize the use of HER2‐targeting agents, chemotherapy, and endocrine therapy. Cancer 2012;. © 2011 American Cancer Society.     

Concurrent trastuzumab with adjuvant radiotherapy in HER2-positive breast cancer patients: acute toxicity analyses from the French multicentric study

BackgroundTrastuzumab (T) combined with chemotherapy has been recently shown to improve outcome in HER2-positive breast cancer (BC). The aim of this study was to evaluate the toxic effects of concurrent radiation therapy (RT) and T administration in the adjuvant setting.Patients and methodsData of 146 patients with stages II–III HER2-positive BC were recorded. Median age was 46 years. In all, 32 (23%) and 114 (77%) patients received a weekly and a 3-week T schedule, respectively. A median dose of 50 Gy was delivered after surgery. Internal mammary chain (IMC) was irradiated in 103 (71%) patients.ResultsGrade >2 dermatitis and esophagitis were noted in 51% and 12%, respectively. According to the Common Toxicity Criteria v3.0 scale and HERA (HERceptin Adjuvant) trial criteria, respectively, 10% and 6% of the patients had a grade ≥2 of left ventricular ejection fraction (LVEF) decrease after RT. Multivariate analyses revealed two independent prognostic factors: weekly T administration (for LVEF decrease) and menopausal status (for dermatitis). Higher level of T cumulative dose (>1600 mg) was only borderline of statistical significance for acute esophagitis toxicity.ConclusionWe showed that weekly concurrent T and RT are feasible in daily clinical practice with, however, a decrease of LVEF. Cardiac volume sparing and patient selections for IMC irradiation are highly recommended. Longer follow-up is warranted to evaluate late toxic effects.