Prognostic Significance of TOP2A Gene Dosage in HER‐2‐Negative Breast Cancer

Background.

Previous studies showed the prognostic and predictive impact of human epidermal growth factor receptor 2 (HER-2) gene alterations analyzed separately and jointly with topoisomerase II α (TOP2A) gene alterations; however, the role of TOP2A gene abnormalities alone has not been thoroughly investigated. Additionally, TOP2A aberrations were typically studied in HER-2-positive (HER-2⁺) tumors because these genes are frequently coamplified. Therefore, the knowledge concerning the impact of TOP2A abnormalities in HER-2-negative (HER-2⁻) patients is scarce. This study aimed to investigate the clinical significance of TOP2A anomalies in breast cancer patients with HER-2⁻ and HER-2⁺ tumors.

Materials and Methods.

Snap-frozen tumor samples from 322 consecutive stage I–III breast cancer patients were analyzed for TOP2A gene dosage using quantitative real-time PCR (qPCR).

Results.

A high TOP2A gene dosage was found in 94 tumors (29%)—32% and 27% of HER-2⁺ and HER-2⁻ tumors, respectively. The mean TOP2A gene dosages in the HER-2⁺ and HER-2⁻ groups were 1.49 ± 1.03 and 1.09 ± 0.35, respectively. High TOP2A gene dosage had an inverse prognostic impact in terms of shorter disease-free survival (DFS) and overall survival (OS) times in the entire group and in both the HER-2⁻ and HER-2⁺ subgroups. The unfavorable prognostic impact of TOP2A gene dosage was maintained in the multivariate Cox regression analysis in the entire group and in HER-2⁻ patients.

Conclusions.

A high gene dosage of TOP2A determined using qPCR occurs frequently both in HER-2⁺ and HER-2⁻ tumors and has a strong adverse prognostic impact.     

Moderate Immunohistochemical Expression of HER‐2 (2+) Without HER‐2 Gene Amplification Is a Negative Prognostic Factor in Early Breast Cancer

Background.

Human epidermal growth factor receptor (HER)-2 testing in patients with operable breast cancer is aimed at identifying candidates for adjuvant anti–HER-2 treatment. However, commonly defined “HER-2⁻” tumors express variable levels of the HER-2 protein, which can influence prognosis. We compared the clinical outcomes of operable breast cancer patients stratified according to a common HER-2 testing algorithm.

Methods.

We studied 1,150 women (median age, 58 years; range, 22–94 years) undergoing surgery for early breast cancer at our institution. HER-2 status was determined using the HercepTest™ (Dako, Glostrup, Denmark) and, when needed, by fluorescence in situ hybridization (FISH). Patients receiving adjuvant trastuzumab were excluded. The impact of HER-2 status on the disease-free survival (DFS) time was studied using multivariate Cox proportional regression analysis.

Results.

Four hundred-fifty seven (40%), 454 (39%), 116 (10%), and 123 (11%) patients were considered HER-2 0+, HER-2 1+, HER-2 2+/HER-2⁻ by FISH, and HER-2⁺ (3+ or HER-2⁺ by FISH), respectively. Compared with a HER-2 0 or 1+ status, a HER-2 2+/HER-2⁻ by FISH status was associated with a worse DFS outcome on multivariate analysis. Compared with a HER-2⁺ status, a HER-2 2+/HER-2⁻ status showed a time-dependent effect on the DFS probability, with an initial advantage that worsened every year by a factor of 1.649.

Conclusion.

A HER-2 2+/HER-2⁻ status is an adverse prognostic factor in patients with operable breast cancer. Because of suggestions from randomized trials that the benefits of adjuvant trastuzumab may not be limited to patients with HER-2⁺ tumors, patients with a HER-2 2+/HER-2⁻ status are ideal candidates for studies testing this hypothesis.     

Correlation between quantitative HER-2 protein expression and risk for brain metastases in HER-2+ advanced breast cancer patients receiving trastuzumab-containing therapy

Background.

Patients with human epidermal growth factor receptor (HER)-2⁺ breast cancer are at particularly high risk for brain metastases; however, the biological basis is not fully understood. Using a novel HER-2 assay, we investigated the correlation between quantitative HER-2 expression in primary breast cancers and the time to brain metastasis (TTBM) in HER-2⁺ advanced breast cancer patients treated with trastuzumab.

Methods.

The study group included 142 consecutive patients who were administered trastuzumab-based therapy for HER-2⁺ metastatic breast cancer. HER-2/neu gene copy number was quantified as the HER-2/centromeric probe for chromosome 17 (CEP17) ratio by central laboratory fluorescence in situ hybridization (FISH). HER-2 protein was quantified as total HER-2 protein expression (H2T) by the HERmark^® assay (Monogram Biosciences, Inc., South San Francisco, CA) in formalin-fixed, paraffin-embedded tumor samples. HER-2 variables were correlated with clinical features and TTBM was measured from the initiation of trastuzumab-containing therapy.

Results.

A higher H2T level (continuous variable) was correlated with shorter TTBM, whereas HER-2 amplification by FISH and a continuous HER-2/CEP17 ratio were not predictive (p = .013, .28, and .25, respectively). In the subset of patients that was centrally determined by FISH to be HER-2⁺, an above-the-median H2T level was significantly associated with a shorter TTBM (hazard ratio, [HR], 2.4; p = .005), whereas this was not true for the median HER-2/CEP17 ratio by FISH (p = .4). Correlation between a continuous H2T level and TTBM was confirmed on multivariate analysis (HR, 3.3; p = .024).

Conclusions.

These data reveal a strong relationship between the quantitative HER-2 protein expression level and the risk for brain relapse in HER-2⁺ advanced breast cancer patients. Consequently, quantitative assessment of HER-2 protein expression may inform and facilitate refinements in therapeutic treatment strategies for selected subpopulations of patients in this group.     

Triple-negative subtype predicts poor overall survival and high locoregional relapse in inflammatory breast cancer

Background.

Numerous studies have demonstrated that expression of estrogen/progesterone receptor (ER/PR) and human epidermal growth factor receptor (HER)-2 is important for predicting overall survival (OS), distant relapse (DR), and locoregional relapse (LRR) in early and advanced breast cancer patients. However, these findings have not been confirmed for inflammatory breast cancer (IBC), which has different biological features than non-IBC.

Methods.

We retrospectively analyzed the records of 316 women who presented to MD Anderson Cancer Center in 1989–2008 with newly diagnosed IBC without distant metastases. Most patients received neoadjuvant chemotherapy, mastectomy, and postmastectomy radiation. Patients were grouped according to receptor status: ER⁺ (ER⁺/PR⁺ and HER-2−; n = 105), ER⁺HER-2⁺ (ER⁺/PR⁺ and HER-2⁺; n = 37), HER-2⁺ (ER⁻/PR⁻ and HER-2⁺; n = 83), or triple-negative (TN) (ER⁻PR⁻HER-2⁻; n = 91). Kaplan–Meier and Cox proportional hazards methods were used to assess LRR, DR, and OS rates and their associations with prognostic factors.

Results.

The median age was 50 years (range, 24–83 years). The median follow-up time and median OS time for all patients were both 33 months. The 5-year actuarial OS rates were 58.7% for the entire cohort, 69.7% for ER⁺ patients, 73.5% for ER⁺HER-2⁺ patients, 54.0% for HER=2⁺ patients, and 42.7% for TN patients (p < .0001); 5-year LRR rates were 20.3%, 8.0%, 12.6%, 22.6%, and 38.6%, respectively, for the four subgroups (p < .0001); and 5-year DR rates were 45.5%, 28.8%, 50.1%, 52.1%, and 56.7%, respectively (p < .001). OS and LRR rates were worse for TN patients than for any other subgroup (p < .0001–.03).

Conclusions.

TN disease is associated with worse OS, DR, and LRR outcomes in IBC patients, indicating the need for developing new locoregional and systemic treatment strategies for patients with this aggressive subtype.     

Human responses against HER-2-positive cancer cells in human immune system-engrafted mice

Background:

Human immune system (HIS)-engrafted mice are new tools to investigate human immune responses. Here, we used HIS mice to study human immune responses against human HER-2-positive cancer cells and their ability to control tumour growth and metastasis.

Methods:

BALB/c Rag2^−/−, Il2rg^−/− mice were engrafted with CD34⁺ or CD133⁺ human cord blood hematopoietic stem cells (HSC) and vaccinated with human HER-2-positive cancer cells SK-OV-3 combined to human IL-12.

Results:

Both CD34⁺ or CD133⁺ human HSC gave long-term engraftment and differentiation, both in peripheral blood and in lymphoid organs, and production of human antibodies. Vaccinated mice produced specific anti-HER-2 human IgG. An s.c. SK-OV-3 challenge was significantly inhibited (but not abolished) in both vaccinated and non-vaccinated HIS mice. Tumours were heavily infiltrated with human and murine cells, mice showed NK cells and production of human interferon-γ, that could contribute to tumour growth inhibition. Vaccinated HIS mice showed significantly inhibited lung metastases when compared with non-vaccinated HIS mice and to non-HIS mice, along with higher levels of tumour-infiltrating human dendritic cells.

Conclusion:

Anti-HER-2 responses were elicited through an adjuvanted allogeneic cancer cell vaccine in HIS mice. Human immune responses elicited in HIS mice effectively inhibited lung metastases.     

Carbonic anhydrase IX is a predictive marker of doxorubicin resistance in early-stage breast cancer independent of HER2 and TOP2A amplification

Background:

In early-stage breast cancer, adjuvant chemotherapy is associated with significant systemic toxicity with only a modest survival benefit. Therefore, there is considerable interest in identifying predictive markers of response to therapy. Doxorubicin, one of the most common drugs used to treat breast cancer, is an anthracycline chemotherapeutic agent, a class of drugs known to be affected by hypoxia. Accordingly, we examined whether expression of the endogenous hypoxia marker carbonic anhydrase IX (CA IX) is predictive of outcome in early-stage breast cancer patients treated with doxorubicin.

Methods:

We obtained 209 early-stage pre-treatment surgically-resected breast tumours from patients, who received doxorubicin in their chemotherapeutic regimen and had >10 years of follow-up. Immunohistochemistry was used to detect CA IX, and we used fluorescence in situ hybridisation to detect both human epidermal growth factor receptor (HER2) and DNA topoisomerase II-alpha (TOP2A) gene amplification.

Results:

Carbonic anhydrase IX intensity was significantly correlated with progression-free survival (PFS) and overall survival (OS) in patients receiving 300 mg m⁻² of doxorubicin (HR=1.82 and 3.77; P=0.0014 and 0.010, respectively). There was a significant, inverse correlation between CA IX score and oestrogen receptor expression, but no significant correlations were seen with either HER2 or TOP2A ratio.

Conclusion:

We demonstrate that CA IX expression is correlated with worse PFS and OS for breast cancer patients treated with doxorubicin, independent of HER2 or TOP2A gene amplification. This study provides evidence that using CA IX to detect hypoxia in surgically-resected breast tumours may be of clinical use in choosing an appropriate chemotherapy regimen.     

HER-2 and HER-3 expression in liver metastases of patients with colorectal cancer

Objective

In this study, we evaluate the frequency of HER-2 and HER-3 expression in liver metastases from patients with colorectal cancer (CRLM). We analyzed the potential of HER-2 and HER-3 as therapeutic targets and evaluated their prognostic value.

Patients and Methods

Overall 208 patients with CRLM were enrolled. HER-2 and HER-3 expression were determined in metastatic tissue of diagnostic punch biopsies (n = 29) or resection specimens (n = 179). The results of immunohistochemistry (IHC) scoring and In-situ-hybridization (ISH)-amplification were correlated with clinical parameters and for the 179 resected patients with cancer-specific (CSS) and overall survival (OS). The mean follow-up time was 56.7 months.

Results

Positivity of HER-2 status (IHC score 2+/ISH+ and IHC 3+) was found in 8.2% of CRLM. High expression of HER-3 (IHC score 2+ and IHC 3+) was detected in 75.0% of liver metastases. CSS after liver surgery was determined and was independent from the HER-2 status (p = 0.963); however HER-3 was prognostic with a favorable course for patients showing an overexpression of HER-3 (p = 0.037).

Conclusions

HER-2 overexpression occurs in only 8% of patients with CRLM but with 75% of cases HER-3 is frequently overexpressed in CRLM. Therefore, HER-2 and particularly HER-3 could serve as novel targets to be addressed within multimodal treatment approaches.     

Prognostic impact of phosphorylated HER-2 in HER-2+ primary breast cancer

Purpose.

Tyrosine 1248 is one of the autophosphorylation sites of human epidermal growth factor receptor (HER)-2. We determined the prognostic value of the expression level of tyrosine 1248–phosphorylated HER-2 (pHER-2) in patients with HER-2⁺ primary breast cancer using a reverse-phase protein array.

Patients and Methods.

The optimal cutoff value of pHER-2 for segregating disease-free survival (DFS) was determined by receiver operating characteristic (ROC) curve analysis. Five-year DFS for pHER-2 expression level was estimated with the Kaplan-Meier method using both derivation (n = 162) and validation (n = 227) cohorts.

Results.

Of the 162 patients in the derivation cohort, 26 had high HER-2 expression levels. The area under the ROC curve for pHER-2 level and DFS was 0.662. Nineteen of the 162 patients (11.7%) had high pHER-2 expression levels (pHER-2^high); 143 patients (88.3%) had low pHER-2 expression levels (pHER-2^low). Among the 26 patients with high HER-2 expression levels, the 17 pHER-2^high patients had a significantly lower 5-year DFS rate than the nine pHER-2^low patients (23.5% versus 77.8%). On multivariate analysis, only pHER-2^high independently predicted DFS in the Cox proportional hazards model. In the validation cohort, among 61 patients with high HER-2 expression, the difference in 5-year DFS rates between pHER-2^high (n = 7) and pHER-2^low (n = 54) patients was marginal (57.1% versus 81.5%).

Conclusion.

In patients with HER-2⁺ primary breast cancer, pHER-2^high patients had a lower 5-year DFS rate than pHER-2^low patients. Quantification of pHER-2 expression level may provide prognostic information beyond the current standard HER-2 status.     

Molecular alterations between the primary breast cancer and the subsequent locoregional/metastatic tumor

Background.

Metastatic breast cancers have historically been presumed to have the same predictive biomarkers as the initial primary tumor. We compared the expression of these biomarkers in a large paired tissue microarray (TMA) series of primary and subsequent relapsed tumors.

Methods.

Using the British Columbia Cancer Agency Breast Cancer Outcomes Unit database, patients with biopsy-proven relapses were identified and linked to a large TMA series of primary breast cancers from 1986–1992. Charts were reviewed, and tissue blocks of the metastatic cancer were collected to create a separate TMA. Immunohistochemical assessment with the same antibodies and conditions was performed for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER)-2 on both the primary and relapsed tumors.

Results.

One hundred sixty cases were received that had tumor adequate for analyses. Of these, 71.9% had no changes in either the ER or PR status or HER-2 status. Of the 45 (28.1%; 95% confidence interval [CI], 21.2%–35.1%) tumors that did have changes in receptor status, 7.5% were in-breast recurrences or new breast primaries, 4.4% had changes in PR status only and were therefore deemed clinically irrelevant, and 19.4% (95% CI, 13.3%–25.5%) had changes in either the ER or HER-2 status from regional or distant relapses. Five percent of tumors had a receptor status change going from ER⁺ or PR⁺ to ER⁻ or PR⁻; 9.4% went from ER⁻ or PR⁻ to ER⁺ or PR⁺. With regard to HER-2 status, 3.8% of tumors went from positive to negative and 1.3% went from negative to positive. For all discordant cases, biopsies of the relapsed lesion were obtained prior to initiation of first-line treatment for metastatic disease. In the primary tumors that were ER⁺, time to relapse was significantly shorter in the discordant relapsed cases than in the concordant ones (p = .0002). Changes in loss or gain of either biomarker were seen across the discordant cases.

Conclusions.

A significant proportion of relapsed tumors had changes in either ER or HER-2 status, which would dramatically alter treatment recommendations and clinical behavior. This study suggests that biopsies of relapsed and metastatic breast cancers should be performed routinely in clinical practice.     

Advances in first-line treatment for patients with HER-2+ metastatic breast cancer

Background.

The prognosis for breast cancer patients overexpressing human epidermal growth factor receptor (HER)-2 has changed with anti–HER-2–targeted therapy. Although anti–HER-2 therapy with trastuzumab and chemotherapy is the standard first-line treatment, the best therapeutic regimen has yet to be defined, and new strategies are evolving.

Methods.

A literature review of well-established and recently published trials, reviews, and ongoing clinical trials addressing first-line treatment for HER-2⁺ metastatic breast cancer patients was performed.

Results.

Taxanes are the agents most commonly used in combination with trastuzumab, but other chemotherapy drugs, such as anthracyclines, vinorelbine, and gemcitabine and triple-combination therapies including platinum compounds, capecitabine, and taxanes have been studied. The combination of aromatase inhibitors with anti–HER-2 therapies is a new therapeutic option for some patients who coexpress HER-2 and hormone receptors, although its activity observed in randomized clinical trials seems to be inferior to that of chemotherapy plus anti–HER-2 therapies. In addition, new anti–HER-2 therapies have shown activity in HER-2⁺ tumors, both alone and in combination with trastuzumab.

Conclusions.

Trastuzumab plus chemotherapy is the current standard of care for the upfront treatment of HER-2⁺ breast cancer patients, though other anti–HER-2–targeting agents may appear as new standards in the upcoming years.     

Impact of HER-2 overexpression/amplification on the prognosis of gastric cancer patients undergoing resection: a single-center study of 1,036 patients

Background.

Opinions regarding the impact of human epidermal growth factor receptor (HER)-2 overexpression or HER-2 amplification on the prognosis of gastric cancer patients are mixed. The present study attempted to clarify this issue by investigating a large cohort of surgical patients.

Methods.

We investigated 1,036 gastric cancer patients undergoing curative-intent resection. Their surgical specimens were evaluated for HER-2 expression by immunohistochemistry (IHC), and those with HER-2 expression levels of 2+ were additionally subjected to fluorescence in situ hybridization (FISH). Data on demographic and clinicopathological features and relevant prognostic factors in these patients were analyzed.

Results.

HER-2 positivity was noted in 64 (6.1%) of 1,036 gastric cancer patients, including 46 patients whose HER-2 expression level was 3+ on IHC and 18 patients whose FISH results were positive. On univariate analysis, HER-2 positivity was more often associated with differentiated histology, intestinal type, and negative resection margins, whereas only differentiated histology was independently associated with HER-2 positivity in a logistic regression model. For stage I–IV gastric cancer, HER-2 was not a prognostic factor. In a subpopulation study, although HER-2 positivity emerged as a favorable prognostic factor for stage III–IV gastric cancer on univariate analysis, it failed to be an independent prognostic factor after multivariate adjustment.

Conclusions.

The prevalence of HER-2 positivity, determined using standardized assays and scoring criteria in a large cohort of gastric cancer patients after resection, was 6.1%. HER-2 positivity was phenotypically associated with differentiated histology. HER-2 is not an independent prognostic factor for gastric cancer.     

Lapatinib plus Letrozole as First‐Line Therapy for HER‐2+ Hormone Receptor–Positive Metastatic Breast Cancer

Objective.

To evaluate the efficacy and tolerability of letrozole plus lapatinib versus letrozole plus placebo in women with hormone receptor (HR)⁺ human epidermal growth factor receptor (HER)-2⁺ tumors receiving first-line therapy for metastatic breast cancer (MBC).

Patients and Methods.

Postmenopausal women (n = 1,286) with HR⁺ MBC were randomized to daily oral treatment with letrozole (2.5 mg) plus lapatinib (1,500 mg) versus letrozole (2.5 mg) plus placebo. Of the 1,286 patients enrolled in the phase III study, 219 had HER-2⁺ tumors. The primary endpoint was progression-free survival (PFS) in HER-2⁺ patients.

Results.

Results in the HR⁺ HER-2⁺ population (n = 219) are presented. The addition of lapatinib to letrozole resulted in a significantly lower risk for disease progression than with letrozole alone (hazard ratio, 0.71; 95% confidence interval, 0.53–0.96). The PFS time was 8.2 months, versus 3.0 months. The objective response rate (ORR) (28% versus 15%) and clinical benefit rate (CBR) (48% versus 29%) were also significantly greater in lapatinib-treated women. The most common adverse events in the lapatinib group were diarrhea (68%) and rash (46%), primarily grade 1 and 2.

Conclusions.

The addition of lapatinib to letrozole is well tolerated and leads to a significantly greater PFS time, ORR, and CBR than with letrozole alone in women with MBC who coexpress HR and HER-2.     

Pathological complete response and survival according to the level of HER-2 amplification after trastuzumab-based neoadjuvant therapy for breast cancer

Background:

We analysed whether the level of human epidermal growth factor receptor-2 (HER-2) amplification significantly influenced either pathological complete response (pCR) or recurrence-free survival (RFS) and overall survival (OS) after trastuzumab-based neoadjuvant therapy.

Methods:

In all, 99 patients with an HER-2-amplified breast tumour treated with trastuzumab-based neoadjuvant therapy were included. Tumours were classified as low amplified (LA; 6–10 signals per nuclei) or highly amplified (HA; >10 signals). Pathological response was assessed according to Chevallier''s classification (pCR was defined as grade 1 or 2). Median follow-up lasted 46 months (6–83). Cox uni- and multivariate analyses were performed.

Results:

In all, 33 tumour samples were LA and 66 were HA. The pCR in HA tumours was significantly higher than in LA tumours (55% vs 24%, P=0.005), whereas no association was found between the pCR rate and tumour stage, grade or hormone receptor status. In multivariate analysis, the pathological nodal status (P=0.005) and adjuvant trastuzumab (P=0.037) were independently associated with RFS, whereas the level of HER-2 amplification nearly reached statistical significance (P=0.057). There was no significant difference between LA and HA tumours for OS (P=0.22, log-rank).

Conclusion:

The level of HER-2 gene amplification significantly influenced pCR but not RFS or OS in non-metastatic breast cancer treated with trastuzumab-based neoadjuvant therapy. However, RFS in patients with HA tumours tended to be shorter.     

Lapatinib Plus Capecitabine in Women with HER‐2–Positive Advanced Breast Cancer: Final Survival Analysis of a Phase III Randomized Trial

Objectives.

A planned interim analysis of study EGF100151 prompted early termination of enrollment based on a longer time to progression with lapatinib and capecitabine than with capecitabine alone in patients with human epidermal growth factor receptor (HER)-2⁺ previously treated advanced breast cancer or metastatic breast cancer (MBC). Here, we report final analyses of overall survival.

Patients and Methods.

Women with HER-2⁺ MBC who progressed after regimens that included, but were not limited to, anthracyclines, taxanes, and trastuzumab, were randomized to lapatinib (1,250 mg/day) plus capecitabine (2,000 mg/m²) or capecitabine monotherapy (2,500 mg/m²) on days 1–14 of a 21-day cycle.

Results.

At enrollment termination, 399 patients were randomized, and nine were being screened and were offered combination treatment. In total, 207 and 201 patients were enrolled to combination therapy and monotherapy, respectively. Thirty-six patients receiving monotherapy crossed over to combination therapy following enrollment termination. The median overall survival times were 75.0 weeks for the combination arm and 64.7 weeks for the monotherapy arm (hazard ratio [HR], 0.87; 95% confidence interval [CI], 0.71–1.08; p = .210). A Cox regression analysis considering crossover as a time-dependent covariate suggested a 20% lower risk for death for patients treated with combination therapy (HR, 0.80; 95% CI, 0.64–0.99; p = .043). The low incidence of serious adverse events was consistent with previously reported rates.

Conclusions.

Although premature enrollment termination and subsequent crossover resulted in insufficient power to detect differences in overall survival, exploratory analyses demonstrate a trend toward a survival advantage with lapatinib plus capecitabine. These data continue to support the efficacy of lapatinib in patients with HER-2⁺ MBC.     

Immunohistochemical and molecular analyses of HER2 status in breast cancers are highly concordant and complementary approaches

Background:

Immunohistochemistry (IHC) and fluorescent in situ hybridisation (FISH) are currently the most commonly used methods to assess HER2 status. PCR-based assays allow quantitative determination of HER2 amplification (Q-PCR) or overexpression (Q-RT–PCR), but are not routinely used. We evaluated the relevance of Q-RT–PCR for HER2 status determination.

Methods:

We compared IHC and Q-RT–PCR in 466 breast tumours. In discordant or equivocal cases, five additional methods (IHC with two other antibodies, FISH, silver in situ hybridisation (SISH) and Q-PCR) were combined to determine HER2 status. Two cases with HER2 intra-tumour heterogeneity were further explored by allelic profiles analysis and HUMARA clonality determination after microdissection.

Results:

We observed 97.3% concordance between Q-RT–PCR and non-equivocal IHC. Twelve out of 466 cases (3%) revealed discordances between the two methods. The power of Q-RT–PCR to predict HER2 status (defined by seven methods) was similar to that of IHC. Although rare, some discordances between techniques might be due to HER2 intra-tumour heterogeneity and we report two examples, one tumour containing two distinct clones, another tumour consisting of HER2 amplified and non-amplified subclones.

Conclusion:

Q-RT–PCR and IHC are highly concordant methods for HER2 status assessment, and Q-RT–PCR allows a highly reliable quantitative assessment and could be a useful adjunct to IHC.     

Comparison of HER2 status in primary and paired metastatic sites of gastric carcinoma

Background:

Trastuzumab has recently shown efficacy in the treatment of HER2-positive advanced gastric adenocarcinoma. Although antibody-based therapies target the metastatic disease, HER2 status is usually evaluated in the primary tumour because metastatic sites are rarely biopsied. The aim of this study was to compare HER2 status in primary and paired metastatic sites of gastric adenocarcinoma.

Methods:

The HER2 status was assessed by fluorescence in situ hybridisation (FISH) and immunohistochemistry (IHC) in 72 secondary lesions of gastric adenocarcinoma and in the corresponding primary tumours.

Results:

Concordance of FISH results, evaluable in 68 primary and matched metastatic sites, was 98.5%. Concordance of IHC results, available in 39 of the 72 paired cases, was 94.9%. Only one case showed discordance between primary tumour and metastasis, being negative by both IHC and FISH in the primary and showing HER2 overexpression and amplification in the corresponding pancreatic lymph node metastasis.

Conclusion:

The high concordance observed between HER2 results obtained by both IHC and FISH on primary tumours and corresponding metastases suggests that in gastric cancer HER2 status is maintained in most cases unchanged during the metastatic process.     

Validation of UBE2C protein as a prognostic marker in node-positive breast cancer

Background:

We recently identified and validated UBE2C RNA as a prognostic marker in 252 node-positive (N+) breast cancers by means of a microarray study. The aim of this study was to validate UBE2C protein as a prognostic marker in N+ breast cancer by immunohistochemistry (IHC).

Methods:

To this end, 92 paraffin-embedded blocks were used. The impact of UBE2C IHC value on metastasis-free survival (MFS) and overall survival (OS) was evaluated and compared with Ki-67 and Nottingham prognostic index (NPI) performances.

Results:

In accordance with genomic data, UBE2C IHC had a significant impact both on MFS and OS (hazard ratio=6.79 – P=0.002; hazard ratio=7.14 – P=0.009, respectively). Akaike information criterion proved that the prognostic power of UBE2C IHC was stronger than that of Ki-67 (and close to that of NPI). Furthermore, multivariate analyses with NPI showed that, contrary to Ki-67 IHC, UBE2C IHC remained an independent factor, both for MFS (adjusted P=0.02) and OS (adjusted P=0.04).

Conclusion:

We confirmed that UBE2C protein measured by IHC could be used as a prognostic marker in N+ breast cancer. The potential predictive interest of UBE2C as a marker of proteasome activity needs further investigations.     

Predictive value of HER2 serum levels in patients treated with lapatinib or trastuzumab - a translational project in the neoadjuvant GeparQuinto trial

Background:

We were able to demonstrate a predictive value of serum HER2 (sHER2) in patients receiving trastuzumab in the neoadjuvant GeparQuattro trial. However, the role of sHER2 in patients receiving neoadjuvant therapy (NT) with lapatinib is still unclear.

Methods:

The neoadjuvant GeparQuinto trial compared trastuzumab vs lapatinib in addition to chemotherapy in HER2-positive primary breast cancer patients. The sHER2 levels were measured by enzyme-linked immunosorbant assay in 210 patients, of whom 109 (52%) patients received trastuzumab and 101 (48%) lapatinib at three different time points.

Results:

Twenty-two percent of patients had elevated baseline sHER2 levels (>15 ng ml⁻¹). A decrease of sHER2 levels (>20%) in the trastuzumab and lapatinib-treated group during NT was seen in 44% and 24% of the patients, an increase of sHER2 levels (>20%) was seen in 6% and 41% of patients, respectively. Higher pre-chemotherapy sHER2 levels were associated with higher pathological complete remission (pCR) rates in the entire study cohort (OR 1.8, 95% CI 1.02–3.2, P=0.043). A decline of sHER2 levels (>20%) during NT was a predictor for pCR in the lapatinib-treated patient group (OR: 11.7, 95% CI 1.3–110, P=0.031).

Conclusion:

Results of this study demonstrate that sHER2 levels change differently during NT depending on the anti-HER2 treatment strategy. Elevated baseline sHER2 levels (>15 ng ml⁻¹) and a decrease of sHER2 levels (>20%) early after therapy initiation are both relevant criteria to predict response to lapatinib-based treatment.