The HER-2 receptor and breast cancer: ten years of targeted anti-HER-2 therapy and personalized medicine

Words matter: distinguishing "personalized medicine" and "biologically personalized therapeutics"

"Personalized medicine" has become a generic term referring to techniques that evaluate either the host or the disease to enhance the likelihood of beneficial patient outcomes from treatment interventions. There is, however, much more to personalization of care than just identifying the biotherapeutic strategy with the highest likelihood of benefit. In its new meaning, "personalized medicine" could overshadow the individually tailored, whole-person care that is at the bedrock of what people need and want when they are ill. Since names and definitional terms set the scope of the discourse, they have the power to define what personalized medicine includes or does not include, thus influencing the scope of the professional purview regarding the delivery of personalized care. Taxonomic accuracy is important in understanding the differences between therapeutic interventions that are distinguishable in their aims, indications, scope, benefits, and risks. In order to restore the due emphasis to the patient and his or her needs, we assert that it is necessary, albeit belated, to deconflate the contemporary term "personalized medicine" by taxonomizing this therapeutic strategy more accurately as "biologically personalized therapeutics" (BPT). The scope of truly personalized medicine and its relationship to biologically personalized therapeutics is described, emphasizing that the best of care must give due recognition and emphasis to both BPT and truly personalized medicine.

The efficacy of adjuvant trastuzumab in HER-2 positive breast cancer with axillary lymph node metastases according to the treatment duration

INTRODUCTION

Trastuzumab is the first anti-HER-2 humanized monoclonal antibody. The benefit of adjuvant trastuzumab has been shown in randomized phase III trials. Despite trastuzumab being recommended for 52 weeks in the adjuvant treatment of HER-2 positive breast cancer according to the current breast cancer guidelines, there is still no consensus on the optimal duration of adjuvant trastuzumab. The aim of our study is to investigate the efficacy and safety of adjuvant trastuzumab for 9 weeks and 52 weeks in axillary lymph node positive HER-2 positive breast cancer patients.

PATIENTS AND METHODS

A total of 271 HER-2 and axillary node positive breast cancer patients who received trastuzumab in adjuvant treatment between the years 2005 and 2013 were retrospectively analyzed. Patients with axillary node positive HER-2 positive breast cancer who were non-metastatic were enrolled to the study. Patients were allocated to the 9 week trastuzumab group (n = 155) or the 52 week trastuzumab group (n = 116). Kaplan-Meier survival analysis was carried out for disease free survival (DFS) and overall survival (OS). Two-sided p values of <0.05 were considered statistically significant. The most important limitation of our manuscript is the retrospective design.

RESULTS

The median follow-up time for this analysis was 34 (4-95) months. Patients' clinical and pathological characteristics were well balanced between the two treatment arms. In the 9 week trastuzumab treatment group, the DFS rate was 96.7%, 84.8% and 74.9% in the first, third and fifth years respectively, whereas in the 52 week trastuzumab treatment group it was 94.3%, 80.0% and 80.0% (P = 0.76). In the 9 week trastuzumab treatment group, the OS rate was 99.3%, 92.2% and 88.3% in the first, third and fifth years respectively, whereas in the 52 week trastuzumab treatment group it was 99.0%, 94.7% and 78.6% (P = 0.99). In both groups, symptomatic heart failure was not reported but asymptomatic left ventricular ejection fraction (LVEF) decline was observed 3 (1.9%) and 18 (15.5%) patients in the 9 week and 52 week trastuzumab treatment groups, respectively (P < 0.001).

CONCLUSION

In our study, the efficacy of trastuzumab for 52 weeks and 9 weeks was similar in node-positive HER-2 positive breast cancer. Cardiotoxicity was significantly increased in the 52 week trastuzumab arm compared to the 9 week trastuzumab arm.

A neoadjuvant, randomized, open-label phase II trial of afatinib versus trastuzumab versus lapatinib in patients with locally advanced HER2-positive breast cancer

BACKGROUND

Chemotherapy is standard neoadjuvant treatment of LA BC. Patients with HER2-positive BC require targeted therapy. Trastuzumab and pertuzumab, which target HER2, with chemotherapy are approved as neoadjuvant therapy, however, treatments with different mechanisms of action might provide a broader range of activity. In this study we evaluated the efficacy and safety of the irreversible ErbB family blocker afatinib, versus trastuzumab or lapatinib in the neoadjuvant treatment of HER2-positive, LA BC.

PATIENTS AND METHODS

Treatment-naive, HER2-positive BC patients with stage IIIA, B, C or inflammatory disease were randomized 1:1:1 to daily afatinib (50 mg), lapatinib (1500 mg), or weekly trastuzumab (4 mg/kg loading dose, then 2 mg/kg/wk) for 6 weeks until surgery or follow-up neoadjuvant treatment. The primary end point was objective response rate according to Response Evaluation Criteria in Solid Tumors (version 1.0).

RESULTS

Recruitment was stopped early because of slow patient enrollment; 29 patients were randomized to afatinib (n = 10), lapatinib (n = 8), or trastuzumab (n = 11). Objective response was seen in 8 afatinib-, 6 lapatinib-, and 4 trastuzumab-treated patients. Eleven patients had stable disease (best response); 1 lapatinib- and 1 trastuzumab-treated patient had progressive disease. All 10 afatinib-treated patients experienced drug-related adverse events (commonly diarrhea, dermatitis acneiform, and paronychia) versus 6 of 8 lapatinib- (diarrhea and rash) and 5 of 11 trastuzumab-treated patients (vomiting and arthralgia).

CONCLUSION

Afatinib demonstrated clinical activity that compared favorably to trastuzumab and lapatinib for neoadjuvant treatment of HER2-positive BC, with a safety profile consistent with epidermal growth factor receptor tyrosine kinase inhibitors.

Overexpression of HER2/neu as a Prognostic Value in Iranian Women With Early Stage Breast Cancer; A Single Institute Study

Background:

Patients with early stage breast cancer with same treatment strategy can have markedly different outcomes. Human epidermal growth factor receptor 2 (HER2/nue) gene amplification or the subsequent overexpression of protein has been proved to be associated with patient's outcome and response to anthracyclins-based regimens.

Objectives:

This study assessed prognostic value of HER2/nue marker in patients with early stage breast cancer who received adjuvant chemotherapy with anthracyclins-based regimens.

Materials and Methods:

Fifty tissue samples from patients with primary breast cancer of moderate risk receiving sequential adjuvant chemotherapy with anthracyclins-based regimens were assessed to evaluate HER2/nue gene status (quantified by Immunohistochemistry and fluorescence in situ hybridization) retrospectively. Besides, correlation of HER2/neu with patients' characteristics and outcome was studied.

Results:

HER2/neu amplification was identified in 19 (38%) of 50 patients. No significant difference regarding HER2/neu status was seen in clinic pathological characteristics of patients. Although Progression Free Survival (PFS) was shorter in HER2 overexpressed group, but uni/multivariate analysis adjusted for HER2 overexpression, nodal involvement, hormone receptor status, age and tumor size revealed no significant predictive and/or prognostic value for HER2 regarding PFS.

Conclusions:

This study on a limited number of patients treated with adjutant anthracyclins-based regimens, revealed that HER2/neu is not a unique strong predictor for outcome, thus according to combination of HER2/neu status and other clinical factors, it is necessary to distinguish patients at high risk of recurrence.

Comparison of the 2007 and 2013 ASCO/CAP evaluation systems for HER2 amplification in breast cancer

It has been proven that chromosome 17 centromere (CEP17) amplification causes misleading human epidermal growth factor receptor 2 (HER2) gene fluorescence in situ hybridization (FISH) results, precluding anti-HER2-based therapy in some patients with breast carcinoma. We used the 2013 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) scoring criteria to evaluate HER2 amplification status in 175 cases of breast carcinoma with chromosome 17 polysomy. We used immunohistochemistry (IHC) to determine the HER2 amplification status, and 2-color FISH to detect CEP17, and reviewed the results of initial evaluation using the 2007 ASCO/CAP criteria. Of the 175 cases, 17, 95, and 63 were IHC 0/1+, 2+, and 3+, respectively. Evaluation of IHC HER2 status according to the 2013 ASCO/CAP criteria identified significantly more HER2-positive cases compared to cases evaluated using the 2007 criteria (p<0.05). When the FISH results were evaluated in parallel with the 2013 criteria, we found that 22 cases were not HER2-negative despite the presence of polysomy 17, which, according to the 2013 criteria, indicates HER2-positive status. Our findings indicate that in breast carcinoma, HER2 status in the presence of polysomy 17 may vary with the scoring criteria used. In turn, performing FISH and evaluating samples using the 2013 ASCO/CAP criteria means that more patients with breast cancer may be appropriate for targeted treatment with trastuzumab, potentially improving their outcome.

Circulating Her-2/neu extracellular domain in breast cancer patients-correlation with prognosis and clinicopathological parameters including steroid receptor, Her-2/neu receptor coexpression

HER-2/neu extracellular domain (ECD) can be detected in blood as a soluble circulating protein. The aim of this study was to analyze the relationship between HER-2/neu extracellular domain in the serum and the prognosis in breast cancer patients. We also correlated HER-2/neu ECD with various clinicopathological factors including steroid receptor, HER-2/neu receptor coexpression. The serum from seventy nine patients with invasive breast cancer and twenty individuals without malignancy was analyzed using the enzyme-linked immune adsorbent assay method. The cut-off value was estimated by the ROC curve analysis (15.86 μg/L). HER-2/neu ECD values in the serum of patients with breast cancer were significantly higher than in control subjects. Circulating HER-2/neu ECD was significantly associated with the histological grade of tumors and the status of axillary lymph nodes. Negative correlation was observed between HER-2/neu ECD in the serum and estrogen receptor positivity. When we analyzed HER-2/neu ECD in relation with coexpression of steroid receptor and HER-2/neu receptor in tissue, statistically higher values were found in the subgroup of patients with steroid receptor negative, HER-2/neu negative tumors than in the other subgroups. HER-2/neu ECD was not an independent factor in the univariate and multivariate analysis. However, elevated HER-2/neu ECD levels were found in patients with breast cancer possessing more aggressive phenotype.

Phase I Study to Assess the Combination of Afatinib with Trastuzumab in Patients with Advanced or Metastatic HER2-Positive Breast Cancer

PURPOSE

The HER2 mAb, trastuzumab, is a standard therapy for patients with HER2-positive breast cancer before acquired resistance. Afatinib, an irreversible, oral, small-molecule ErbB family blocker, shows clinical activity in trastuzumab-refractory HER2-positive breast cancer.

EXPERIMENTAL DESIGN

This phase I study used a 3+3 dose escalation to determine the MTD of oral once-daily afatinib in combination with the recommended dose of intravenous trastuzumab (4 mg/kg week 1; 2 mg/kg/wk thereafter). Adult women with confirmed advanced/metastatic HER2-positive breast cancer were eligible.

RESULTS

Of 18 patients treated, 16 received daily afatinib 20 mg and two 30 mg. Overall, 4 of 13 and 2 of 2 patients receiving afatinib 20 mg and 30 mg, respectively, experienced dose-limiting toxicity (DLT; all CTCAE grade 3 diarrhea). Most frequent treatment-related adverse events were diarrhea (94%), rash (56%), and fatigue (56%). Overall, pharmacokinetic profiles of afatinib and trastuzumab in combination were consistent with the known characteristics of each alone. Overall, objective response and disease control rates were 11% and 39%, respectively, with median progression-free survival 111.0 days (95% confidence interval, 56.0-274.0).

CONCLUSIONS

The MTD of afatinib was 20 mg daily combined with the recommended weekly dose of trastuzumab, with 1 of 6 patients showing DLTs in the dose escalation. However, additional DLTs occurred in the dose-expansion phase meaning that this MTD cannot be recommended for phase II development without strict diarrhea management. There was no evidence suggesting relevant pharmacokinetic drug-drug interactions. Signs of clinical activity were seen in trastuzumab-resistant HER2-positive breast cancer, suggesting further investigation with optimal diarrhea management is warranted.

Trastuzumab, in combination with carboplatin and docetaxel, does not prolong the QT interval of patients with HER2-positive metastatic or locally advanced inoperable solid tumors: results from a phase Ib study

Purpose

This study evaluated the potential effect of trastuzumab on the electrocardiogram (ECG) QT interval and assessed the potential pharmacokinetic interaction between trastuzumab and carboplatin. Here, we report the QT and safety results.

Methods

Patients with metastatic or inoperable HER2-positive solid tumors received docetaxel and carboplatin on Day 1 of each 3-week (q3w) cycle. Trastuzumab was administered intravenously, as an accelerated loading dose regimen, on Cycle 1, Day 2 and Cycle 1, Day 8, and then on Day 1 of each subsequent q3w cycle. ECG assessments were performed pre- and posttrastuzumab infusion in the first two cycles. Fridericia’s correction was applied to QT intervals (QTcF). Baseline-adjusted QTcF intervals (the change from baseline) and their 90 % confidence intervals (CIs) were calculated.

Results

The study enrolled 59 patients. At all time points, the 90 % CI upper bound for the mean baseline-adjusted QTcF was <10 ms. At steady-state serum trastuzumab concentrations, the mean baseline-adjusted QTcF interval was −8.4 ms (90 % CI −11.1, −5.7). No patient exhibited an absolute QTcF interval of >480 ms. No relationship was observed between trastuzumab concentration and baseline-adjusted QTcF interval. At data cutoff, 84.5 % of patients had experienced grade ≥3 adverse events, the most common of which were hematologic and as expected. Left ventricular ejection fraction remained ≥45 % in all patients during the study.

Conclusions

The results suggest that trastuzumab had no clinically relevant effect on QTcF interval. The safety profile of trastuzumab in combination with carboplatin and docetaxel was consistent with the known safety profile of this combination.

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-014-2603-9) contains supplementary material, which is available to authorized users.

Neoadjuvant therapy of early stage human epidermal growth factor receptor 2 positive breast cancer: latest evidence and clinical implications

Neoadjuvant therapy in human epidermal growth factor receptor 2 (HER2)-positive breast cancer is exactly the paradigm of targeted therapy and a suitable setting to develop and test rapidly novel therapies in early stages. Moreover, neoadjuvant approaches provide a significant source of tumour tissue to identify molecular heterogeneity and potential predictive biomarkers of response. The addition of trastuzumab to primary chemotherapy revolutionized the treatment of this tumour subtype, increasing pathological complete response rate (pCR) that, even with its limitations, has also been shown to be an early marker of survival in HER2-positive disease. HER2-positive breast cancer is a biological heterogeneous disease with different characteristics and clinical outcomes. Multiple promising anti-HER2 drugs with nonoverlapping mechanisms of action have recently been developed. Combined administration of two different HER2-targeted agents, that is, trastuzumab with lapatinib or pertuzumab, and primary chemotherapy shows enhanced antitumour activity, with an increase in pCR to values never reached in the past. Moreover, results of recent studies show that the combination of targeted therapy alone (dual HER2 blockade with or without endocrine therapy) also has activity in a substantial percentage of patients, eradicating HER2-positive tumours without chemotherapy and with a favourable toxicity profile. It is still necessary to be able to select the appropriate group of patients who can avoid chemotherapy (approximately 25%), and to establish robust predictive biomarkers of response or resistance to the anti-HER2 approach. Neoadjuvant therapy represents an enormous step forward in HER2-positive breast cancer. The results of the most relevant neoadjuvant studies and latest evidence are described in this review, though new questions have emerged.

Inflammatory breast cancer: an overview

Inflammatory breast cancer (IBC) is the most aggressive entity of breast cancer. Management involves coordination of multidisciplinary management and usually includes neoadjuvant chemotherapy, ablative surgery if a tumor-free resection margin is expected and locoregional radiotherapy. This multimodal therapeutic approach has significantly improved patient survival. However, the median overall survival among women with IBC is still poor. By elucidating the biologic characteristics of IBC, new treatment options may become available. We performed a comprehensive review of the English-language literature on IBC through computerized literature searches. The objective of the current review is to present an overview of the literature related to the biology, imaging and multidisciplinary treatment of inflammatory breast cancer.

Biomarker testing for breast, lung, and gastroesophageal cancers at NCI designated cancer centers

BACKGROUND

Molecular biomarkers, a cornerstone of precision oncology, are critical in breast, gastroesophageal, and non-small cell lung cancer management (BC, GEC, NSCLC). Testing practices are intensely debated, impacting diagnostic quality and affecting pathologists, oncologists and patients. However, little is known about testing approaches used in practice. Our study described biomarker practices in BC, GEC, and NSCLC at the leading US cancer centers.

METHODS

We conducted a survey of the National Cancer Institute (NCI) designated centers on BC, GEC, and NSCLC biomarker testing. We used simple frequencies to describe practices, two-sided Fisher's exact test and two-sided McNemar's test for cross-cancer comparison. All statistical tests were two-sided.

RESULTS

For BC human epidermal growth factor receptor 2 (HER2), 39% of centers combine guidelines by using in situ hybridization (ISH) and immunohistochemistry (IHC) concurrently, and 21% reflex-test beyond guideline-recommended IHC2+. For GEC HER2, 44% use ISH and IHC concurrently, and 28% reflex-test beyond IHC2+. In NSCLC, the use of IHC is limited to 4% for epidermal growth factor receptor (EGFR) and 7% for anaplastic lymphoma kinase (ALK). 43.5% test NSCLC biomarkers on oncologist order; 34.5% run all biomarkers upfront, and 22% use a sequential protocol. NSCLC external testing is statistically significantly higher than BC (P < .0001) and GEC (P < .0001). NSCLC internally developed tests are statistically significantly more common than BC (P < .0001) and GEC (P < .0001).

CONCLUSIONS

At the NCI cancer centers, biomarker testing practices vary, but exceeding guidelines is a common practice for established biomarkers and emerging practice for newer biomarkers. Use of internally developed tests declines as biomarkers mature. Implementation of multibiomarker protocols is lagging. Our study represents a step toward developing a biomarker testing practice landscape.

Evaluation of HER2 Protein Expression Using 2 New Monoclonal Antibodies

This study describes the performance of 2 new mouse anti-HER2 monoclonal antibodies (Abs), clones 33F and 410G, in evaluating HER2 overexpression in a series of 123 invasive breast carcinoma cases. In-house immunohistochemistry (IHC) was performed and the results were compared with those for the SP3 and A0485 anti-HER2 Abs. Chromogenic in situ hybridization was used to detect ERBB2 amplification and its concordance with IHC was analyzed. Comparison of IHC results for 33F with SP3 and A0485 yielded concordance rates (K) of 0.81 and 0.75, respectively; the same concordance rates were found when comparing results for 410G with SP3 and A0485. Compared with SP3 and A0485, 33F and 410G specificities were 98.6% and 98.6%, and 100% and 100%, respectively, whereas the sensitivities were 80% and 74.1%, and 78% and 72.2%, respectively. The K values between 33F and 410G HER2+ expression and chromogenic in situ hybridization-positive amplification were 1 and 0.96, respectively. These concordance rates were reproduced in another production batch (K=0.96 and K=0.96). Together, these results show that the tested monoclonal Abs would be well suited for detecting HER2 protein overexpression by IHC.

Overexpression of ETV4 protein in triple-negative breast cancer is associated with a higher risk of distant metastasis

BACKGROUND

Patients with triple-negative breast cancer (TNBC) present a higher probability of distant metastasis and lack of effective targeted therapy. ETS translocation variant 4 (ETV4) is an ETS (E-26) transcription factor and has been associated with tumor metastasis. However, the clinical and functional significance of ETV4 in TNBC still remains unclear.

METHODS

A human tumor metastasis polymerase chain reaction array was used to profile differential expression of tumor metastasis-related genes in TNBC tissue. Real-time reverse transcription and Western blot analyses were performed to verify ETV4 expression in TNBC cells and tissue. Immunohistochemistry was used to detect expression of ETV4 protein in 135 TNBC tissue samples for association between ETV4 protein expression and clinical outcomes.

RESULTS

A total total of eight upregulated (CCL7, KISS1, MET, MMP7, NR4A3, ETV4, TIMP3, and TSHR) and three downregulated (ITGA7, SSTR, and MMP2) genes were identified between TNBC tissue and the luminal subtype of breast cancer tissue. ETV4 messenger ribonucleic acid was more than five-fold upregulated in TNBC tissue compared with the control tissue. ETV4 overexpression was found in 57.0% of 135 TNBC cases. Overexpression of ETV4 protein was associated with an advanced stage and a higher proportion of positive lymph node and lymphovascular invasion. Patients with an ETV4-overexpressed tumor had a significantly higher risk of developing distant metastasis (P<0.0001) and shorter overall survival and disease-free survival. Overexpression of ETV4 protein was an independent predictor of short disease-free survival of TNBC patients (P=0.021).

CONCLUSION

Overexpression of ETV4 protein increases risk of developing distant metastasis and results in a poor prognosis for TNBC patients. Thus, ETV4 might be a novel target for developing an alternative therapeutic strategy for prevention of TNBC distant metastasis.

Galectin-3 as a marker and potential therapeutic target in breast cancer

Galectin-3 has a relatively high level of expression in triple-negative breast cancers and is a potential marker for this disease. However, the clinical and prognostic implications of galectin-3 expression in breast cancer remain unclear. We examined mastectomy specimens from 1086 breast cancer cases and matching, adjacent non-cancerous tissues using immunohistochemistry. Overall, triple-negative breast cancers expressed galectin-3 more strongly than did other breast cancers types (63.59% vs 21.36%, P = 0.001). Galectin-3 expression was not found to be an independent prognostic factor for breast cancer by Cox regression analysis, but was associated with chemotherapeutic resistance. Apoptosis was only weakly induced by arsenic trioxide (ATO) treatment in galectin-3-positive breast cancer cells (MDA-MB-231 and MCF-7), although ATO treatment up-regulated galectin-3 expression. Knockdown of galectin-3 in MDA-MB-231 cells sensitized them to killing by ATO. These findings support a possible role for galectin-3 as a marker for triple-negative breast cancer progression and as a therapeutic target in combination with ATO treatment, although the mechanisms that underlie this synergy require further investigation.

Evaluation of a quantitative RT-PCR assay to detect HER2 mRNA overexpression for diagnosis and selection of trastuzumab therapy in breast cancer tissue samples

Breast cancer patients who have a positive result for HER2 overexpression are commonly treated with Herceptin, a HER2-targeted therapy. In the present study, the BrightGen HER2 RT-qDx (Syantra, Calgary, Canada), which is based on a one-tube nested RT-qPCR method that detects HER2 mRNA overexpression, was clinically evaluated in a total of 237 formalin-fixed paraffin-embedded (FFPE) tissue samples from breast cancer patients. Among the 38 HER2 positive samples, which were determined via IHC/FISH methods, 13 samples out of 16 (81.3%) that were IHC2+/FISH+ and 22 samples out of 22 (100%) that were IHC3+ have been decided positive for HER2 expression via the RT-qPCR method. The true positivity and false positivity results for the RT-qPCR were 92% (35/38) and 2% (1/65), respectively. The concordance between RT-qPCR and IHC results and RT-qPCR and IHC/FISH was 87.2% and 92.1%, respectively. Conclusively, the BrightGen HER2 RT-qDx may be a reliable and convenient method that can supplement traditional IHC and FISH methods for efficient use of trastuzumab.

Bispecific anti-CD3 x anti-HER2 antibody mediates T cell cytolytic activity to HER2-positive colorectal cancer in vitro and in vivo

Targeting HER2 overexpressed breast cancer cells with anti‑HER2 monoclonal antibodies inhibits tumor growth. Here we investigated whether HER2 can serve as a target for T cell-mediated immunotherapy of human colorectal carcinoma. Specific cytolytic activity of activated T cells (ATCs) armed with anti‑CD3 x anti‑HER2 bispecific antibody (HER2Bi-Ab) against HER2+ tumor cells was evaluated by bioluminescent signal generated by luciferase reporter on tumor cells in vitro and in vivo. In contrast to unarmed ATCs, increased cytotoxic activity of HER2Bi-armed ATCs against HER2+ tumor cells was observed. Moreover, HER2Bi-armed ATCs expressed higher level of activation marker CD69 and secreted significantly higher levels of IFN-γ than the unarmed ATC counterpart. In addition, compared with anti‑HER2 mAb (Herceptin®) or unarmed ATC, HER2Bi-armed ATCs showed significant suppression against colorectal carcinoma cells. In colorectal tumor cell xenograft mice, infusion of HER2Bi-armed ATCs successfully inhibited the growth of Colo205-luc cells. The HER2Bi-armed ATCs with anti-tumor effects may provide a promising immunotherapy for colorectal carcinoma in the future.

Comparative effectiveness of neoadjuvant therapy for HER2-positive breast cancer: a network meta-analysis

BACKGROUND

The growing number of antihuman epidermal growth factor receptor-2 (HER2) agents suggests the need for defining the optimal choice of neoadjuvant therapy for HER2-positive breast cancer. This study aims to assess the efficacy and safety of neoadjuvant therapy for HER2-positive breast cancer.

METHODS

Randomized trials that compared different anti-HER2 regimens in the neoadjuvant setting were included. The odds ratio (OR) for pathological complete response (pCR), treatment completion, and safety was utilized for pooling effect sizes. Network meta-analysis using a Bayesian statistical model was performed to combine the direct and indirect evidence of neoadjuvant therapy for HER2-positive breast cancer. All statistical tests were two-sided.

RESULTS

A database search identified 1047 articles, with 10 studies meeting the eligibility criteria. A total of 2247 patients in seven different treatment arms were assessed. Anti-HER2 agents evaluated included trastuzumab (tzmb), lapatinib (lpnb), and pertuzumab (pzmb). Network meta-analysis showed no statistically significant difference between dual targeting treatment arms; however, lpnb reduced treatment completion due to adverse events. Patients in dual targeting arms had statistically significantly more pCR than those in other treatment arms (chemotherapy [CT] + tzmb + pzmb vs CT + tzmb, OR = 2.29, 95% credibility interval = 1.02 to 5.02, P = .02). The surface under the cumulative ranking probability curve indicated that CT + tzmb + pzmb had the highest probability of being the best treatment arm in terms of pCR.

CONCLUSIONS

This study indicates that combining two anti-HER2 agents with CT is the most effective treatment modality in the neoadjuvant setting for HER2-positive breast cancer.

HER2/neu testing in primary colorectal carcinoma

Background:

Anti-HER2/neu therapy is well-established in breast and gastric carcinoma. The increased understanding of this pathway led to the identification of new promising drugs in addition to trastuzumab, offering further perspectives. The role of HER2/neu in colorectal carcinoma is controversially discussed, as discrepant data has been reported.

Methods:

Here, we retrospectively assessed the prevalence of HER2/neu positivity in a large series of colorectal carcinoma, testing HER2/neu status according to current recommendations. We correlated the results to clinico-pathological data and patient survival.

Results:

Overall, in 1645 primary colorectal carcinoma cases, 1.6% of the cases were HER2/neu positive. HER2/neu positivity significantly correlated with higher UICC stages (P=0.017) and lymph node metastases (P=0.029). In the subgroup of sigmoideal and rectal carcinomas, positive HER2/neu status was associated with T-category (P=0.041) and higher UICC stages (P=0.022). Although statistically not significant, HER2/neu-positive colorectal carcinomas displayed a tendency to poorer overall survival.

Conclusions:

These results illustrate the importance of testing HER2/neu by approved diagnostic techniques and scoring systems. We assume that although the prevalence of HER2/neu positivity in colorectal carcinoma is low, HER2/neu testing in advanced, nodal-positive colorectal carcinoma is reasonable, offering a potential target in high risk colorectal carcinoma.

The sensitivity of gastric cancer to trastuzumab is regulated by the miR-223/FBXW7 pathway

A recent large-scale phase III study (the ToGA trial) demonstrated the significant efficacy of trastuzumab combined with chemotherapy in patients with HER2-positive gastric cancer. Although trastuzumab has become a key drug in cancer treatment, the resistance of breast cancer to trastuzumab is a major problem in clinical practice. However, it is unclear whether similar mechanisms of trastuzumab resistance are involved in gastric cancer (GC). The aim of the current study was to identify a novel micro-RNA (miR)/gene pathway that regulates the sensitivity of HER2-positive GC cells to trastuzumab. We focused on F-box and WD repeat domain-containing 7 (FBXW7), which is one of the major causes of drug resistance. We also identified miR-223, which can regulate FBXW7, using miR quantitative reverse transcription-PCR array analysis using by resistance cell line, which we established. Overexpression of miR-223 decreased FBXW7 expression and the sensitivity of GC cells to trastuzumab, while suppression of miR-223 restored FBXW7 expression and the sensitivity of GC cells to trastuzumab. Moreover, overexpression of miR-223 significantly suppressed trastuzumab-induced apoptosis. This study is the first report to reveal that the miR-223/FBXW7 pathway regulates the sensitivity of a HER2-positive GC cell line to trastuzumab through the modulation of apoptosis. These findings suggest that this pathway can be crucial for the mechanism of trastuzumab resistance in GC, which may lead to the development of individualized treatment in clinical practice.

Intratumoral heterogeneity impacts the response to anti-neu antibody therapy

BACKGROUND

Along with de novo resistance, continued exposure to trastuzumab, an anti-human epidermal growth factor receptor 2 (HER2/neu) antibody, can lead to acquired resistance. In this study, we characterize a new anti-HER2/neu antibody resistant and metastatic mouse breast carcinoma cell line, TUBO-P2J. This cell line was developed during in vivo experiments using the antibody sensitive and non-metastatic tumor line TUBO. In addition, TUBO-P2J was used to establish an intratumoral HER2 heterogenous animal tumor model to evaluate the therapeutic effects of anti-HER2/neu antibody.

METHODS

After establishing the cell line, TUBO-P2J was characterized regarding its susceptibility to anti-neu antibody and chemotherapeutics, as well as its metastatic potential in vitro and in vivo. In addition, expression profiles of metastasis related genes were also evaluated. A clinically relevant intratumoral HER2 heterogenous tumor model was established by inoculating mice with tumor cells consisting of TUBO and TUBO-P2J at a ratio of 1,000:1 or 10,000:1. Tumor growth and mouse survival were used to evaluate the therapeutic effects of anti-neu antibody.

RESULTS

The TUBO-P2J cell line is a HER2/neu negative and highly metastatic variant of TUBO. This cell line was resistant to anti-neu antibody therapy, and when inoculated subcutaneously, metastasized to the lungs within 14 days. Compared to the parental TUBO cell line, TUBO-P2J displayed an epithelial-mesenchymal transition (EMT) related gene expression profile including: the loss of E-cadherin, and increased Vimentin, Snail, and Twist1 expression. In addition, TUBO-P2J exhibited increased invasion and migration activity, and was resistant to chemotherapy drugs. Finally, mixed tumor implantations experiments revealed that an increased percentage of TUBO-P2J rendered tumors less responsive to anti-neu antibody therapy.

CONCLUSION

This study describes a novel model of intratumoral heterogenous metastatic breast cancer in immune competent mice that can be used to develop novel or combined immunotherapies to overcome antibody resistance.

Effect and safety of dual anti-human epidermal growth factor receptor 2 therapy compared to monotherapy in patients with human epidermal growth factor receptor 2-positive breast cancer: a systematic review

Background

Dual anti-human epidermal growth factor receptor 2 (HER2) therapies have been shown to improve outcomes of HER2-positive breast cancer patients. We undertook a systematic review to compare treatment outcomes for patients who received single or combined anti-HER2 therapies.

Methods

We identified randomized control trials that compared dual anti-HER2 therapy and anti-HER2 monotherapy in patients with HER2-positive breast cancer. Outcomes included pathologic complete response (pCR), overall survival (OS), progression-free survival (PFS), and adverse events. Included in the analysis were seven trials that recruited 2,609 patients.

Results

In the neoadjuvant setting, the pooled pCR rate in the dual anti-HER2 therapy and monotherapy groups in combination with chemotherapy was 54.8% and 36%, respectively. This difference was statistically significant (relative risk, 1.56; 95% confidence interval (CI), 1.23–1.97; p < 0.001). In the metastatic setting, dual anti-HER2 therapy demonstrated significant benefits in both PFS (hazard ratio (HR), 0.71; 95% CI, 0.62–0.81; p < 0.001) and OS (HR, 0.68; 95% CI, 0.57–0.82; p < 0.001). Subgroup analyses indicated that the addition of chemotherapy to dual anti-HER2 therapy could greatly improve pCR in the neoadjuvant settings. However, in the metastatic setting, similar PFS and OS were found in patients receiving dual anti-HER2 therapy with or without chemotherapy. Dual anti-HER2 therapy was associated with more frequent adverse events than monotherapy, but no statistical differences were observed in cardiac toxicity.

Conclusions

This systematic review provides a summary of all the data currently available, and confirms the benefits and risks of dual anti-HER2 therapy for HER2-positive breast cancer.

Lapatinib for the treatment of breast cancer in the People's Republic of China

Lapatinib is an oral, small-molecule, reversible inhibitor of both epidermal growth factor receptor and human epidermal growth factor receptor-2 (HER2) tyrosine kinases. In March 2007, the US Food and Drug Administration approved lapatinib for use in combination with capecitabine for the treatment of women with HER2-overexpressing, advanced or metastatic breast cancer. This review discusses the available information of lapatinib in Chinese breast cancer patients, focusing on its effectiveness and clinical application against advanced or metastatic breast cancer. In pivotal phase III trials, a combination of lapatinib and capecitabine significantly decreased the risk of disease progression compared to capecitabine alone in women with HER2-positive advanced or metastatic breast cancer. Other trials were used to evaluate lapatinib in combination with hormone therapy, in combination with trastuzumab, and as an adjunct to adjuvant therapy for early-stage disease. Preclinical data have revealed that lapatinib is active in trastuzumab-resistant cell lines as well as synergistic with trastuzumab. In clinical trials, lapatinib has not been associated with serious or symptomatic cardiotoxicity. Further, it can cross the blood-brain barrier and may therefore have a role in preventing cancer progression in the central nervous system. Thus, lapatinib warrants further evaluation in HER2-positive metastatic and early-stage breast cancer patients.

Current Approaches and Emerging Directions in HER2-resistant Breast Cancer

Human epidermal growth factor receptor-2 (HER2) is overexpressed in up to 30% of breast cancers; HER2 overexpression is indicative of poor prognosis. Trastuzumab, an anti-HER2 monoclonal antibody, has led to improved outcomes in patients with HER2-positive breast cancer, including improved overall survival in adjuvant and first-line settings. However, a large proportion of patients with breast cancer have intrinsic resistance to HER2-targeted therapies, and nearly all become resistant to therapy after initial response. Elucidation of underlying mechanisms contributing to HER2 resistance has led to development of novel therapeutic strategies, including those targeting HER2 and downstream pathways, heat shock protein 90, telomerase, and vascular endothelial growth factor inhibitors. Numerous clinical trials are ongoing or completed, including phase 3 data for the mammalian target of rapamycin inhibitor everolimus in patients with HER2-resistant breast cancer. This review considers the molecular mechanisms associated with HER2 resistance and evaluates the evidence for use of evolving strategies in patients with HER2-resistant breast cancer.

Role of trastuzumab emtansine in the treatment of HER2-positive breast cancer

Trastuzumab is a monoclonal antibody that is used in the treatment of breast cancer. Trastuzumab targets the human epidermal growth factor receptor 2 (HER2) receptor on breast cancer cells that express this tyrosine kinase receptor. These cancers are referred to as HER2-positive breast cancer. The original studies of trastuzumab showed improved survival in metastatic breast cancer; however, resistance often develops. In the adjuvant setting, women often progress despite therapy that includes trastuzumab. Antibody-drug conjugates are a new class of powerful drugs designed to target high-dose chemotherapy directly to the cancer cells. Trastuzumab emtansine is one of these antibody-drug conjugates and was the first Food and Drug Administration approved drug for a solid tumor. Emtansine is a potent antimicrotubule agent. Trastuzumab is used to target this potent chemotherapy agent directly to the HER2-expressing cancer cells. This review article will summarize the evidence from the preclinical studies, summarize evidence from the clinical trials, discuss current clinical trials, discuss current approval of trastuzumab emtansine, and discuss future directions of research.

Evaluating the predictive value of biomarkers for efficacy outcomes in response to pertuzumab- and trastuzumab-based therapy: an exploratory analysis of the TRYPHAENA study

INTRODUCTION

Molecular markers that predict responses to particular therapies are invaluable for optimization of patient treatment. The TRYPHAENA study showed that pertuzumab and trastuzumab with chemotherapy was an efficacious and tolerable combination for patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer in the neoadjuvant setting. We analyzed whether particular biomarkers correlated with the responses observed and therefore may predict outcomes in patients given pertuzumab plus trastuzumab.

METHODS

We describe the analysis of a panel of biomarkers including HER2, human epidermal growth factor receptor 3 (HER3), epidermal growth factor receptor (EGFR), phosphatase and tensin homolog (PTEN), and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) by qRT-PCR, immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), enzyme-linked immunosorbent assay (ELISA), and PCR-based mutational analyses as appropriate. For each marker analyzed, patients were categorized into 'low' (generally below median) or 'high' (generally above median) subgroups at baseline and post-treatment.

RESULTS

Correlation of marker subgroups with the achievement of a pathological complete response (pCR) (ypT0/is) was analyzed. HER2 protein and mRNA expression levels were associated with pCR rate in two of the three study arms and the pooled analyses. Correlations of biomarker status with pCR occurred in one individual arm only and the pooled analyses with EGFR and PTEN; however, interpretation of these results is limited by a strong imbalance in patient numbers between the high and low subgroups and inconsistency between arms. We also found no association between expression levels of TOP2A and pCR rate in either the anthracycline-containing or free arms of TRYPHAENA.

CONCLUSIONS

According to these analyses, and in line with other analyses of pertuzumab and trastuzumab in the neoadjuvant setting, we conclude that HER2 expression remains the only marker suitable for patient selection for this regimen at present.

TRIAL REGISTRATION

The TRYPHAENA study was registered with ClinicalTrials.gov, NCT00976989, on September 14 2009.

The challenge of intratumour heterogeneity in precision medicine

Cells within tumours have diverse genomes and epigenomes and interact differentially with their surrounding microenvironment generating intratumour heterogeneity, which has critical implications for treating cancer patients. Understanding the cellular and microenvironment composition and characteristics in individual tumours is critical to stratify the patient population that is likely to benefit from specific treatment regimens. Here, we will review the current understanding of intratumour heterogeneity at the genomic, epigenomic and microenvironmental levels. We will also discuss the clinical implications and the challenges posed by intratumour heterogeneity and evaluate noninvasive methods such as circulating biomarkers to characterize the cellular diversity of tumours. Comprehensive assessment of the molecular features of patients based on tumour specimen characterization (including intratumour spatial and temporal variations), ancillary noninvasive methods (such as circulating biomarkers and molecular imaging approaches) and the correct design of clinical trials are required to guide administration of targeted therapy and to control therapeutic resistance. Finding the means to accurately determine and effectively control tumour heterogeneity and translate these achievements into patient benefit are major goals in modern oncology.

Heat Shock Protein 90 (HSP90) and Her2 in Adenocarcinomas of the Esophagus

Her2 overexpression and amplification can be found in a significant subset of esophageal adenocarcinomas. The activity of Her2 has been shown to be modulated by molecular chaperones such as HSP90. We analyzed expression/amplification data for HSP90 and Her2 on 127 primary resected esophageal adenocarcinomas in order to evaluate a possible relationship between these two molecules. HSP90 expression determined by immunohistochemistry was observed in various levels. Thirty nine (39) tumors (30.7%) were classified as Her2-positive according to their immunoreactivity and amplification status. There was a significant correlation between HSP90 expression and Her2-status (p = 0.008). This could also be demonstrated by quantitative protein expression analysis with reverse phase protein arrays (r = 0.9; p < 0.001). Her2-status was associated withpT-category (p = 0.041), lymph node metastases (p = 0.049) and tumor differentiation (p = 0.036) with a higher percentage of cases with negative Her2 status in lower tumor stagesA negative Her2-status was also associated with better survival in univariate and multivariate analysis (p = 0.001 and p = 0.014). For HSP90, no associations between clinical and pathological parameters were found. The observed association between HSP90 expression and Her2 suggests a co-regulation of these molecules in at least a subset of esophageal adenocarcinomas. Anti-HSP90 drugs, which recently have been introduced in cancer treatment, may also be an option for these tumors by targeting HSP90 alone or in combination with Her2.

Choosing inclusion criteria that minimize the time and cost of clinical trials

AIM: To present statistical tools to model and optimize the cost of a randomized clinical trial as a function of the stringency of patient inclusion criteria.

METHODS: We consider a two treatment, dichotomous outcome trial that includes a proportion of patients who are strong responders to the tested intervention. Patients are screened for inclusion using an arbitrary number of test results that are combined into an aggregate suitability score. The screening score is regarded as a diagnostic test for the responsive phenotype, having a specific cutoff value for inclusion and a particular sensitivity and specificity. The cutoff is a measure of stringency of inclusion criteria. Total cost is modeled as a function of the cutoff value, number of patients screened, the number of patients included, the case occurrence rate, response probabilities for control and experimental treatments, and the trial duration required to produce a statistically significant result with a specified power. Regression methods are developed to estimate relevant model parameters from pilot data in an adaptive trial design.

RESULTS: The patient numbers and total cost are strongly related to the choice of the cutoff for inclusion. Clear cost minimums exist between 5.6 and 6.1 on a representative 10-point scale of exclusiveness. Potential cost savings for typical trial scenarios range in millions of dollars. As the response rate for controls approaches 50%, the proper choice of inclusion criteria can mean the difference between a successful trial and a failed trial.

CONCLUSION: Early formal estimation of optimal inclusion criteria allows planning of clinical trials to avoid high costs, excessive delays, and moral hazards of Type II errors.

Trastuzumab Administration in Patients with Metastatic Breast Cancer - Experience of a Large University Breast Center

Background: Administered either alone or in combination with various cytostatic, endocrine or targeted therapies, trastuzumab significantly improves the prognosis of patients with HER2-positive breast cancer. As trastuzumab is effective across multiple lines of therapy in the metastatic setting (treatment beyond progression: TBP), it is often administered over a long period of time. The aim of this study was to evaluate the tolerability and clinical practice of long-term trastuzumab administration (> 1 year) in metastatic breast cancer patients treated in a large university breast center. Methods: Metastatic breast cancer patients who received at least 18 cycles of trastuzumab administered every three weeks at the University Gynecological Hospital of Tuebingen between 1999 and 2012 were included in this retrospective study. Typical combination drugs, side effects, and the impact of administration on left ventricular ejection fraction (LVEF) were investigated. Results: 72 patients were eligible for inclusion in the study. The mean number of administrations was 50.14 (SD: 27.51). In 53 patients the principle of TBP was followed across an average of 2.4 therapy lines. Classic cardiac risk factors were present at the beginning of trastuzumab treatment in 34 patients (47 %). Seven patients (10 %) experienced a decrease in LVEF during treatment, 9 patients (13 %) had hypersensitivity reactions. Treatment was discontinued in two patients due to side effects (1 × progressive LVEF decrease, 1 × intolerance). Summary: The administration of trastuzumab across multiple lines of therapy was generally tolerated well. Cardiac risk factors were not a limiting factor. If regular cardiac monitoring is done, trastuzumab appears not only to improve survival but also helps preserve the quality of life of patients with HER2-positive metastatic breast cancer.

Overcoming chemoresistance of small-cell lung cancer through stepwise HER2-targeted antibody-dependent cell-mediated cytotoxicity and VEGF-targeted antiangiogenesis

Small-cell lung cancer (SCLC) easily recurs with a multidrug resistant phenotype. However, standard therapeutic strategies for relapsed SCLC remain unestablished. We found that human epidermal growth factor receptor 2 (HER2) is not only expressed in pretreated human SCLC specimens, but is also upregulated when HER2-positive SCLC cells acquire chemoresistance. Trastuzumab induced differential levels of antibody-dependent cell-mediated cytotoxicity (ADCC) to HER2-positive SCLC cells. Furthermore, as a mechanism of the differential levels of ADCC, we have revealed that coexpression of intracellular adhesion molecule (ICAM)-1 on SCLC cells is essential to facilitate and accelerate the trastuzumab-mediated ADCC. Although SN-38-resistant SCLC cells lacking ICAM-1 expression were still refractory to trastuzumab, their in vivo growth was significantly suppressed by bevacizumab treatment due to dependence on their distinctive and abundant production of vascular endothelial growth factor. Collectively, stepwise treatment with trastuzumab and bevacizumab is promising for the treatment of chemoresistant SCLC.

A comparison of Bayesian adaptive randomization and multi-stage designs for multi-arm clinical trials

When several experimental treatments are available for testing, multi-arm trials provide gains in efficiency over separate trials. Including interim analyses allows the investigator to effectively use the data gathered during the trial. Bayesian adaptive randomization (AR) and multi-arm multi-stage (MAMS) designs are two distinct methods that use patient outcomes to improve the efficiency and ethics of the trial. AR allocates a greater proportion of future patients to treatments that have performed well; MAMS designs use pre-specified stopping boundaries to determine whether experimental treatments should be dropped. There is little consensus on which method is more suitable for clinical trials, and so in this paper, we compare the two under several simulation scenarios and in the context of a real multi-arm phase II breast cancer trial. We compare the methods in terms of their efficiency and ethical properties. We also consider the practical problem of a delay between recruitment of patients and assessment of their treatment response. Both methods are more efficient and ethical than a multi-arm trial without interim analyses. Delay between recruitment and response assessment attenuates this efficiency gain. We also consider futility stopping rules for response adaptive trials that add efficiency when all treatments are ineffective. Our comparisons show that AR is more efficient than MAMS designs when there is an effective experimental treatment, whereas if none of the experimental treatments is effective, then MAMS designs slightly outperform AR.

Assessing the discordance rate between local and central HER2 testing in women with locally determined HER2-negative breast cancer

BACKGROUND

The importance of human epidermal growth factor receptor 2 (HER2) as a prognostic and predictive marker in invasive breast cancer is well established. Accurate assessment of HER2 status is essential to determine optimal treatment options.

METHODS

Breast cancer tumor tissue samples from the VIRGO observational cohort tissue substudy that were locally HER2-negative were retested centrally with both US Food and Drug Administration (FDA)-approved immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assays, using FDA-approved assay cutoffs; results were compared.

RESULTS

Of the 552 unique patient samples centrally retested with local HER2-negative results recorded, tumor samples from 22 (4.0%) patients were determined to be HER2-positive (95% confidence interval [CI] = 2.5%-5.7%). Of these, 18 had been tested locally by only one testing methodology; 15 of 18 were HER2-positive after the central retesting, based on the testing methodology not performed locally. Compared with the 530 patients with centrally confirmed HER2-negative tumors, the 22 patients with centrally determined HER2-positive tumors were younger (median age 56.5 versus 60.0 years) and more likely to have ER/PR-negative tumors (27.3% versus 22.3%). These patients also had shorter median progression-free survival (6.4 months [95% CI = 3.8-15.9 months] versus 9.1 months [95% CI = 8.3-10.3 months]) and overall survival (25.9 months [95% CI = 13.8-not estimable] versus 27.9 months [95% CI = 25.0-32.9 months]).

CONCLUSIONS

This study highlights the limitations of employing just one HER2 testing methodology in current clinical practice. It identifies a cohort of patients who did not receive potentially efficacious therapy because their tumor HER2-positivity was not determined by the test initially used. Because of inherent limitations in testing methodologies, it is inadvisable to rely on a single test to rule out potential benefit from HER2-targeted therapy. Cancer 2014;120:2657–2664.

Optimal sequencing of anti-HER2 therapy throughout the continuum of HER2-positive breast cancer: evidence and clinical considerations

With the advent of the monoclonal antibody trastuzumab over 2 decades ago for breast cancer therapy, the outcome of patients with human epidermal growth factor receptor (HER) 2-positive disease has improved dramatically. Based on its substantial efficacy and good tolerability, trastuzumab has become the therapeutic gold standard for early as well as advanced breast cancer. Nevertheless, despite adjuvant trastuzumab, patients do experience recurrence and require further anti-HER2-targeted therapy. Next to the small molecule tyrosine kinase inhibitor lapatinib, which was the first approved therapy option after trastuzumab failure, several new anti-HER2 agents are currently already available for clinical use [i.e. pertuzumab, T-DM1 (trastuzumab emtansine)] or are still being evaluated (e.g. afatinib, neratinib). Recent evidence from neoadjuvant as well as metastatic therapy suggests that dual blockade may be superior to single-agent HER2 blockade. While the number of available or potential therapies has increased considerably, no additional predictive biomarkers beyond HER2 have been validated for the use of the different anti-HER2 therapies. Moreover, novel therapeutic concepts such as the antibody-drug conjugate T-DM1 warrant excellent determination methodology for HER2 and suggest re-evaluation of tumor biology upon first metastasis. The clinical challenge remains to optimally choose, utilize, and sequence anti-HER2 therapy in early as well as metastatic breast cancer. This article will provide evidence-based guidance for sequencing anti-HER2 therapy throughout the continuum of breast cancer therapy.

C-FLIP(L) contributes to TRAIL resistance in HER2-positive breast cancer

Breast cancers with HER2 amplification have a poorer prognosis than the luminal phenotypes. TRAIL activates apoptosis upon binding its receptors in some but not all breast cancer cell lines. Herein, we investigated the expression pattern of c-FLIP(L) in a cohort of 251 invasive breast cancer tissues and explored its potential role in TRAIL resistance. C-FLIP(L) was relatively high-expressed in HER2-positive breast cancer in comparison with other molecular subtypes, co-expressed with TRAIL death receptors, and inversely correlated with the apoptosis index. Downregulation of c-FLIP(L) sensitized SKBR3 cells to TRAIL-induced apoptosis in a concentration- and time-dependent manner and enhanced the activities and cleavages of caspase-8 and caspase-3, without altering the surface expression of death receptors. Together, our results indicate that c-FLIP(L) promotes TRAIL resistance and inhibits caspase-3 and caspase-8 activation in HER2-positive breast cancer.

Luciferase fragment complementation imaging in preclinical cancer studies

The luciferase fragment complementation assay (LFCA) enables molecular events to be non-invasively imaged in live cells in vitro and in vivo in a comparatively cheap and safe manner. It is a development of previous enzyme complementation assays in which reporter genes are split into two, individually enzymatically inactive, fragments that are able to complement one another upon interaction. This complementation can be used to externally visualize cellular activities. In recent years, the number of studies which have used LFCAs to probe questions relevant to cancer have increased, and this review summarizes the most significant and interesting of these. In particular, it focuses on work conducted on the epidermal growth factor, nuclear and chemokine receptor families, and intracellular signaling pathways, including IP3, cAMP, Akt, cMyc, NRF2 and Rho GTPases. LFCAs which have been developed to image DNA methylation and detect RNA transcripts are also discussed.

Revising the role of the androgen receptor in breast cancer

Breast cancer (BC) is traditionally viewed as an oestrogen-dependent disease in which the androgen receptor (AR) is inhibitory, counteracting the oncogenic activity of oestrogen receptor α (ERα (ESR1)). Most probably as a result of this crosstalk, the AR has prognostic value in ER-positive disease, with AR positivity reported to correlate with a better prognosis. Activation of the AR pathway has been previously used as a therapeutic strategy to treat BC, but its usage declined following the introduction of the anti-oestrogen tamoxifen. More recently, it has been demonstrated that a subset of triple-negative BCs (molecular apocrine) are dependent upon androgen signalling for growth and therapies that inhibit androgen signalling, currently used for the treatment of prostate cancer, e.g. the antiandrogen bicalutamide and the CYP17 inhibitor abiraterone acetate are undergoing clinical trials to investigate their efficacy in this BC subtype. This review summarises the current knowledge of AR activity in BC.

Pertuzumab in human epidermal growth-factor receptor 2-positive breast cancer: clinical and economic considerations

In the absence of specific therapy, the 15%–20% of breast cancers demonstrating human epidermal growth-factor receptor 2 (HER2) protein overexpression and/or gene amplification are characterized by a more aggressive phenotype and poorer prognosis compared to their HER2-negative counterparts. Trastuzumab (Herceptin), the first anti-HER2-targeted therapy, has been associated with improved survival outcomes in HER2-positive breast cancer. However, many patients with early stage disease continue to relapse, and metastatic disease remains incurable. In order to further improve these outcomes, several novel HER2-targeted agents have recently been developed. Pertuzumab (Perjeta), a monoclonal antibody against the HER2 dimerization domain, has also been associated with improved patient outcomes in clinical trials, and has recently been approved in combination with chemotherapy and trastuzumab for neoadjuvant therapy of early stage, HER2-positive breast cancer and first-line treatment of metastatic disease. This review briefly summarizes pertuzumab’s clinical development as well as the published evidence supporting its use, and highlights some of the currently unanswered questions that will influence pertuzumab’s incorporation into clinical practice.

FDA approval: ado-trastuzumab emtansine for the treatment of patients with HER2-positive metastatic breast cancer

On February 22, 2013, the FDA licensed ado-trastuzumab emtansine (Kadcyla; Genentech, Inc.) for use as a single agent for the treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) who previously received trastuzumab and a taxane, separately or in combination. The clinical basis for licensure was a phase III trial in 991 patients with HER2-positive MBC that randomly allocated patients to receive ado-trastuzumab emtansine (n=495) or lapatinib in combination with capecitabine (n=496). The coprimary endpoints were progression-free survival (PFS) based on tumor assessments by an independent review committee and overall survival (OS). Statistically significant improvements in PFS and OS were observed in patients receiving ado-trastuzumab emtansine compared with patients receiving lapatinib plus capecitabine [difference in PFS medians of 3.2 months, HR, 0.65 (95% confidence interval, CI, 0.55-0.77), P<0.0001 and difference in OS medians of 5.8 months, HR, 0.68 (95% CI, 0.55-0.85), P=0.0006]. The most common adverse reactions in patients receiving ado-trastuzumab emtansine were fatigue, nausea, musculoskeletal pain, thrombocytopenia, headache, increased aminotransferase levels, and constipation. Other significant adverse reactions included hepatobiliary disorders and left ventricular dysfunction. Given the PFS and OS results, the benefit-risk profile was considered favorable.

Changing histopathological diagnostics by genome-based tumor classification

Traditionally, tumors are classified by histopathological criteria, i.e., based on their specific morphological appearances. Consequently, current therapeutic decisions in oncology are strongly influenced by histology rather than underlying molecular or genomic aberrations. The increase of information on molecular changes however, enabled by the Human Genome Project and the International Cancer Genome Consortium as well as the manifold advances in molecular biology and high-throughput sequencing techniques, inaugurated the integration of genomic information into disease classification. Furthermore, in some cases it became evident that former classifications needed major revision and adaption. Such adaptations are often required by understanding the pathogenesis of a disease from a specific molecular alteration, using this molecular driver for targeted and highly effective therapies. Altogether, reclassifications should lead to higher information content of the underlying diagnoses, reflecting their molecular pathogenesis and resulting in optimized and individual therapeutic decisions. The objective of this article is to summarize some particularly important examples of genome-based classification approaches and associated therapeutic concepts. In addition to reviewing disease specific markers, we focus on potentially therapeutic or predictive markers and the relevance of molecular diagnostics in disease monitoring.

Safety profile of Pertuzumab with Trastuzumab and Docetaxel in patients from Asia with human epidermal growth factor receptor 2-positive metastatic breast cancer: results from the phase III trial CLEOPATRA

INTRODUCTION

We report detailed safety analyses by geographic region from the phase III study CLEOPATRA with pertuzumab, trastuzumab, and docetaxel in patients with human epidermal growth factor receptor 2 (HER2)-positive first-line metastatic breast cancer.

PATIENTS AND METHODS

Patients received pertuzumab/placebo at 840 mg in cycle 1 and 420 mg in subsequent cycles, and trastuzumab at 8 mg/kg in cycle 1 and 6 mg/kg in subsequent cycles; docetaxel was initiated at 75 mg/m(2). All study drugs were given intravenously, 3 times weekly.

RESULTS

Docetaxel dose reductions below 75 mg/m(2) were more common in patients from Asia (47.0%) than other regions (13.4%); docetaxel dose escalations to 100 mg/m(2) were less frequent in Asia (2.4%) than other regions (18.7%). Rates of edema (26.1% and 5.4% for Asia and other regions, respectively), myalgia (42.3%, 14.7%), nail disorder (39.9%, 15.1%), febrile neutropenia (18.6%, 7.1%), upper respiratory tract infection (25.7%, 10.2%), decreased appetite (47.0%, 19.1%), and rash (44.3%, 22.0%) were at least twice as high in Asia as in other regions. Adverse events did not result in a reduction in the median number of study treatment cycles administered in patients from Asia. Efficacy analyses per region showed hazard ratios similar to those of the whole intention-to-treat (ITT) population for progression-free survival (ITT: 0.63; Asia: 0.68; other regions: 0.61) and overall survival (ITT: 0.66; Asia: 0.64; other regions: 0.66).

CONCLUSION

Despite a higher proportion of docetaxel dose reductions in patients from Asia, survival benefits were comparable between regions. The benefit-risk profile of pertuzumab, trastuzumab, and docetaxel supports this regimen as the first-line therapy for patients with HER2-positive metastatic breast cancer from all geographic regions.

Pharmacogenomics: Current State-of-the-Art

The completion of the human genome project 10 years ago was met with great optimism for improving drug therapy through personalized medicine approaches, with the anticipation that an era of genotype-guided patient prescribing was imminent. To some extent this has come to pass and a number of key pharmacogenomics markers of inter-individual drug response, for both safety and efficacy, have been identified and subsequently been adopted in clinical practice as pre-treatment genetic tests. However, the universal application of genetics in treatment guidance is still a long way off. This review will highlight important pharmacogenomic discoveries which have been facilitated by the human genome project and other milestone projects such as the International HapMap and 1000 genomes, and by the continued development of genotyping and sequencing technologies, including rapid point of care pre-treatment genetic testing. However, there are still many challenges to implementation for the many other reported biomarkers which continue to languish within the discovery phase. As technology advances over the next 10 years, and the costs fall, the field will see larger genetic data sets, including affordable whole genome sequences, which will, it is hoped, improve patient outcomes through better diagnostic, prognostic and predictive biomarkers.

Lessons learned from the intrinsic subtypes of breast cancer in the quest for precision therapy

BACKGROUND

Wide variability in breast cancer, between patients and within each individual neoplasm, adds confounding complexity to the treatment of the disease. In clinical practice, hormone receptor status has been used to classify breast tumours and to guide treatment. Modern classification systems should take the wide tumour heterogeneity into account to improve patient outcome.

METHODS

This article reviews the identification of the intrinsic molecular subtypes of breast cancer, their prognostic and therapeutic implications, and the impact of tumour heterogeneity on cancer progression and treatment. The possibility of functionally addressing tumour-specific characteristics in in vivo models to inform decisions for precision therapies is also discussed.

RESULTS

Despite the robust breast tumour classification system provided by gene expression profiling, heterogeneity is also evident within these molecular portraits. A complicating factor in breast cancer classification is the process of selective clonality within developing neoplasms. Phenotypically and functionally distinct clones representing the intratumour heterogeneity might confuse molecular classification. Molecular portraits of the heterogeneous primary tumour might not necessarily reflect the subclone of cancer cells that causes the disease to relapse. Studies of reciprocal relationships between cancer cell subpopulations within developing tumours are therefore needed, and are possible only in genetically engineered mouse models or patient-derived xenograft models, in which the treatment-induced selection pressure on individual cell clones can be mimicked.

CONCLUSION

In the future, more refined classifications, based on integration of information at several molecular levels, are required to improve treatment guidelines. Large-scale translational research efforts paved the way for identification of the intrinsic subtypes, and are still fundamental for ensuring future progress in cancer care.

Pertuzumab in Combination with Trastuzumab and Chemotherapy in the Treatment of HER2-Positive Metastatic Breast Cancer: Safety, Efficacy, and Progression Free Survival

Tyrosine kinase inhibitors have revolutionized the oncology community and were pioneered by the use in HER2-targeted therapies. Improved outcomes were seen with the advent of trastuzumab, leading investigators to develop newer agents to target the HER2 pathway such as the novel monoclonal antibody pertuzumab. In this paper, we describe the attributes of pertuzumab including: mechanism of action, pharmacokinetics and metabolism, safety/cardiotoxicity, drug interactions, efficacy, and role in HER2-positive breast cancer management. Newly reviewed here versus previously published reviews on pertuzumab oriented therapy are data of pertuzumab monotherapy as it is used in combination with other anti-HER2 agents derived from preclinical research and ongoing clinical trials.

Quantitative measurements of HER2 and phospho-HER2 expression: correlation with pathologic response to neoadjuvant chemotherapy and trastuzumab

Background

Preoperative therapy with chemotherapy and the HER2-targeted monoclonal antibody trastuzumab is valuable for patients with large or locally advanced HER2-positive (HER2+) breast cancers but traditional methods of measuring HER2 expression do not accurately stratify patients for likelihood of response. Quantitative immunofluorescent approaches have the potential to provide a mathematically continuous measure of HER2. Here we seek to determine whether quantitative measurement of HER2 or phospho-HER2 correlates with likelihood of response to trastuzumab- containing neoadjuvant therapy.

Methods

We evaluated core biopsy samples from 27 HER2+ breast cancer patients enrolled in a preoperative clinical trial using trastuzumab, nab-paclitaxel and carboplatin combination therapy (BrUOG BR-211B (NCT00617942)). Tumor core biopsies were taken before initiation of treatment and 9–13 days after patients received "run-in" doses of either single agent trastuzumab or nab-paclitaxel. The AQUA method of quantitative immunofluorescence was used for analysis of in situ protein expression. Patients then received 18 weeks of treatment, followed by surgery to assess pathologic response to the neoadjuvant regimen.

Results

A HER2 score of 2111 by AQUA analysis has been shown to be equivalent to HER2 3+ by immunohistochemical staining in previous studies. Of 20 evaluable patients, 10 cases who achieved a pathologic complete response (pathCR) with neoadjuvant treatment had a mean HER2 level of 10251 compared with 4766 in the patients without pathCR (p = 0.0021). Measurement of phospho-HER2 showed no difference in pathCR vs non-pathCR groups. In 9 patients who had HER2 levels repeated after a single treatment with trastuzumab there was no evidence of a reduction in the HER2 or phospho-HER2 levels following that exposure.

Conclusions

High levels of HER2 are associated with achievement of a pathCR in the preoperative setting, while levels of Phospho-HER2 were not predictive of response. This data suggests that accurate measurement of HER2 may help determine the likelihood of response in the pre-surgical setting. Further validation in larger cohorts is required, but this pilot data shows the feasibility of this approach.

Identification of prolidase as a high affinity ligand of the ErbB2 receptor and its regulation of ErbB2 signaling and cell growth

ErbB2, an important membrane-bound receptor tyrosine kinase, was discovered nearly 30 years ago, but a natural ligand has never been found previously. ErbB2 is also an important oncogene and anticancer target, and its overexpression in cancer is associated with poor disease prognosis. Here, we report that human prolidase (PEPD) is a high affinity ligand of ErbB2 and binds as a homodimer to subdomain 3 in the extracellular domain of this receptor. In ErbB2-overexpressing cells, both ErbB2 monomers and activated dimers exist. PEPD bound to ErbB2 monomers relatively slowly but caused ErbB2 dimerization, ErbB2 phosphorylation and downstream signaling. In contrast, PEPD bound rapidly to ErbB2 homodimers and rapidly silenced ErbB2 dimer-Src signaling, a key oncogenic pathway of ErbB2, by disrupting the association of Src with ErbB2. PEPD also caused pronounced ErbB2 depletion, resulting from ErbB2 internalization and degradation. Moreover, PEPD strongly inhibited the DNA synthesis, anchorage-independent growth and invasion and migration of cells that overexpressed ErbB2 but had no effect on cells without ErbB2 overexpression. Cells became sensitized to PEPD upon achieving stable ErbB2 overexpression. Thus, the impact of PEPD on ErbB2 is predominantly inhibitory, and PEPD targets cells addicted to ErbB2. PEPD is also a dipeptidase, but its enzymatic function is not involved in ErbB2 modulation. These findings revise our understanding of ErbB2 and PEPD and may be especially important for combating ErbB2-positive cancers.

BMP9 inhibits proliferation and metastasis of HER2-positive SK-BR-3 breast cancer cells through ERK1/2 and PI3K/AKT pathways

Bone morphogenetic protein 9 (BMP9), a member of TGF-β superfamily, is reported to inhibit the growth and migration of prostate cancer, osteosarcoma and triple-negative MDA-MB-231 breast cancer cells. However, little is known about the effect of on the biological behaviors of HER2-positive SK-BR-3 breast cancer cells and the underlying mechanisms. This study aimed to investigate the effects of BMP9 on the proliferation and metastasis of SK-BR-3 cells with BMP9 over-expression or BMP9 down-regulated expression. Results indicated that exogenously expressed BMP9 inhibited the proliferation and metastasis of SK-BR-3 cells while decreased endogenous BMP9 expression in SK-BR-3 cells promoted the proliferation and migration of breast cancer cells in vitro and in vivo. In SK-BR-3 cells with BMP9 over-expression, the phosphorylation of HER2, ERK1/2 and AKT was markedly suppressed and the HER2 expression decreased at both mRNA and protein levels, while opposite results were observed in SK-BR-3 cells with BMP9 knock down. When the phosphorylation of ERK1/2 and PI3K/AKT was inhibited by PD98059 and LY294002, respectively, the decreased proliferation and invasion induced by BMP9 knock down were eliminated. These findings suggest that BMP9 can inhibit the proliferation and metastasis of SK-BR-3 cells via inactivating ERK1/2 and PI3K/AKT signaling pathways. Thus, BMP9 may serve as a useful agent in the treatment of HER-2 positive breast cancer.

The SystHERs registry: an observational cohort study of treatment patterns and outcomes in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer

Background

Amplification of the human epidermal growth factor receptor 2 (HER2) gene occurs in approximately 20% of invasive breast cancer cases and is associated with a more aggressive disease course than HER2-negative breast cancer. HER2-targeted therapies have altered the natural history of HER2-positive breast cancer, a trend that will likely further improve with the recent approval of new agents. A prospective, observational cohort study was designed and initiated to provide real-world insights into current treatment patterns, long-term survival, and patients’ experiences with initial and subsequent treatments for HER2-positive metastatic breast cancer (MBC).

Methods/Design

The Systematic Therapies for HER2-positive Metastatic Breast Cancer Study (SystHERs) is a US-based prospective observational cohort study enrolling patients ≥18 years of age with recently diagnosed HER2-positive MBC not previously treated with systemic therapy in the metastatic setting. The primary objective of the study is to identify treatment patterns and clinical outcomes in recently diagnosed patients in a variety of practice settings. Secondary objectives include comparative efficacy, safety, and patient-reported outcomes (PROs). Healthcare resource utilization is an exploratory end point. Tumor tissue and blood sample collection is optional.

The SystHERs registry will enroll approximately 1000 patients over a 3-year period, after which the study will continue for ≥5 years, allowing for a maximum follow-up of 8 years. The treating physician will determine all care and the frequency of visits. PRO measures will be completed at study enrollment and every 90 days. Clinical data will be abstracted quarterly from patient records. The first patient was enrolled in June 2012, and preliminary descriptive data based on 25% to 30% of the final study population are expected at the end of 2013, and as of April 25, 2014, 386 patients are enrolled.

Discussion

SystHERs is expected to provide in-depth data on demographic, clinicopathological, and treatment patterns and their associations with clinical outcomes, PROs, and healthcare resource utilization. Tumor tissue and DNA repositories will also be established for use in future translational research.

Trial registration number

NCT01615068 (ClinicalTrials.gov identifier).

Development of an easy method to test for HER2 in breast cancer using dual-color in situ hybridization

BACKGROUND

Although human epidermal growth factor receptor 2 (HER2) is a significant clinical biomarker for breast cancer, the HER2 testing involves a complicated evaluation process. We devised an easy method for HER2 gene testing and investigated its utility.

METHODS

HER2 testing was performed by immunohistochemistry (IHC) and dual-color in situ hybridization (DISH) on surgical specimens from 50 patients with invasive breast cancer. DISH was evaluated by two methods. One was the DISH count method in which the HER2 and CEP17 signals were counted and the HER2/CEP17 signal ratio was calculated. The other was the DISH-easy method in which pathologists only observed slices without counting the signals. The DISH-easy method was performed by two pathologists. We analyzed the correlations between the DISH-easy method and the DISH count method by each pathologist and calculated the inter-observer concordance rate of the DISH-easy method.

RESULTS

The results from two pathologists using the DISH-easy method corresponded to the IHC results (P < 0.01) and the DISH count method results (P < 0.01). All cases determined to be negative using the DISH-easy method were also negative via the DISH count method with a corresponding rate of 100 % for both pathologist A (34/34) and B (32/32). Most of the results for the positive cases also corresponded; the correspondence rate of pathologist A was 100 % (8/8) and 89 % for B (8/9). The inter-observer concordance rate was 81 % (κ = 0.65).

CONCLUSIONS

The DISH-easy method is simple and useful for HER2 testing regardless of proficiency of the evaluators.