Adjuvant Chemotherapy Guided by a 21-Gene Expression Assay in Breast Cancer

Lymph Node Status in Breast Cancer Does Not Predict Tumor Biology

BACKGROUND/OBJECTIVE

The 21-gene Oncotype DX® Breast Recurrence Score® (RS) assay has been prospectively validated as prognostic and predictive in node-negative, estrogen receptor-positive (ER+)/HER2- breast cancer patients. Less is known about its prognostic role in node-positive breast cancer. We compared RS results among patients with lymph node-negative (N0), micrometastatic (N1mi), and macrometastatic (N+) breast cancer to determine if nodal metastases are associated with more aggressive biology, as determined by RS.

METHODS

Overall, 610,350 tumor specimens examined by the Genomic Health laboratory from February 2004 to August 2017 were studied. Histology was classified centrally, while lymph node status was determined locally. RS distribution (low: < 18; intermediate: 18-30; high: ≥ 31) was compared by nodal status.

RESULTS

Eighty percent (n = 486,013) of patients were N0, 4% (n = 24,325) were N1mi, 9% (n = 56,100) were N+, and 7% (n = 43,912) had unknown nodal status. Mean RS result was 18, 16.7, 17.3 and 18.9 in the N0, N1mi, N+, and unknown groups, respectively. An RS ≥ 31 was seen in 10% of N0 patients, 7% of N1mi patients, and 8.0% of N+ patients. The likelihood of an RS ≥ 31 in N1mi and N+ patients varied with tumor histology, with only 2% of patients with classic infiltrating lobular cancer having an RS ≥ 31, versus 7-9% of those with ductal carcinoma.

CONCLUSIONS

RS distribution among N0, N1mi, and N+ patients is similar, suggesting a spectrum of biology and potential chemotherapy benefit exists among node-negative and node-positive ER+/HER2- breast cancer patients. If RxPONDER does not show a chemotherapy benefit in N+ patients with a low RS result, our findings indicate that substantial numbers of patients could be spared the burden of chemotherapy.

Validation of the 21-gene test as a predictor of clinical response to neoadjuvant hormonal therapy for ER+, HER2-negative breast cancer: the TransNEOS study

Purpose

The Recurrence Score test is validated to predict benefit of adjuvant chemotherapy. TransNEOS, a translational study of New Primary Endocrine-therapy Origination Study (NEOS), evaluated whether Recurrence Score results can predict clinical response to neoadjuvant letrozole.

Methods

NEOS is a phase 3 clinical trial of hormonal therapy ± adjuvant chemotherapy for postmenopausal patients with ER+, HER2-negative, clinically node-negative breast cancer, after six months of neoadjuvant letrozole and breast surgery. TransNEOS patients had tumors ≥ 2 cm and archived core-biopsy samples taken before neoadjuvant letrozole and subsequently sent for Recurrence Score testing. The primary endpoint was to evaluate clinical (complete or partial) response to neoadjuvant letrozole for RS < 18 versus RS ≥ 31. Secondary endpoints included evaluation of clinical response and rate of breast-conserving surgery (BCS) by continuous Recurrence Score result, ESR1 and PGR single-gene scores, and ER gene-group score.

Results

Of 295 TransNEOS patients (median age 63 years; median tumor size 25 mm; 66% grade 1), 53.2% had RS < 18, 28.5% had RS18–30, and 18.3% had RS ≥ 31. Clinical response rates were 54% (RS < 18), 42% (RS18–30), and 22% (RS ≥ 31). A higher proportion of patients with RS < 18 had clinical responses (p < 0.001 vs. RS ≥ 31). In multivariable analyses, continuous Recurrence Score result (p < 0.001), ESR1 score (p = 0.049), PGR score (p < 0.001), and ER gene-group score (p < 0.001) were associated with clinical response. Recurrence Score group was significantly associated with rate of BCS after neoadjuvant treatment (RS < 18 vs. RS ≥ 31, p = 0.010).

Conclusion

The Recurrence Score test is validated to predict clinical response to neoadjuvant letrozole in postmenopausal patients with ER+, HER2-negative, clinically node-negative breast cancer.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-4964-y) contains supplementary material, which is available to authorized users.

An Update on Breast Cancer Multigene Prognostic Tests-Emergent Clinical Biomarkers

Multigene signatures generate crucial prognostic information particularly useful for cancer patients where clinical parameters and traditional immunohistochemical markers alone lead to equivocal prognosis. Clinicians are now provided with molecular tools that assist in the outline of adjuvant therapies, namely helping decide on the extension of adjuvant endocrine therapy or on suppressing adjuvant chemotherapy in patients were toxic effects are particularly deleterious or when this treatment is fundamentally not needed. The importance of cancer multigene prognostic signatures is well elucidated in the guidelines for adjuvant systemic therapy in early-stage breast cancer and the guidelines on disease staging that are progressively integrating gene expression assays as classification biomarkers. In addition to the predictive and prognostic value, some genetic tests provide intrinsic subtyping classification. Herewith, we compare the molecular tests OncotypeDX, MammaPrint, Prosigna, EndoPredict, Breast Cancer Index, Mammostrat, and IHC4 and report the eligibility of each one in the suitable setting. Through to now, there is not a commercially available multigene test that makes recommendations regarding adjuvant treatment for HER-2 and triple negative breast cancers. Thus, these patients still receive adjuvant chemotherapy. Importantly, triple negative carcinomas are very heterogeneous regarding prognosis and new molecular signatures that decipher this very heterogeneous subgroup of breast cancer may improve the clinical management of the disease.

RNAs as Candidate Diagnostic and Prognostic Markers of Prostate Cancer-From Cell Line Models to Liquid Biopsies

The treatment landscape of prostate cancer has evolved rapidly over the past five years. The explosion in treatment advances has been witnessed in parallel with significant progress in the field of molecular biomarkers. The advent of next-generation sequencing has enabled the molecular profiling of the genomic and transcriptomic architecture of prostate and other cancers. Coupled with this, is a renewed interest in the role of non-coding RNA (ncRNA) in prostate cancer biology. ncRNA consists of several different classes including small non-coding RNA (sncRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA). These families are under active investigation, given their essential roles in cancer initiation, development and progression. This review focuses on the evidence for the role of RNAs in prostate cancer, and their use as diagnostic and prognostic markers, and targets for treatment in this disease.

Predictive markers of endocrine response in breast cancer

Ongoing clinical and research efforts seek to optimise the use of endocrine therapy in the treatment of breast cancer. Accurate biomarkers are needed that predict response for individual patients. The presence of the estrogen receptor (ER) as the direct (for tamoxifen and fulvestrant) or indirect (for aromatase inhibitors) target molecule for endocrine therapy remains the foremost biomarker and determinant of response. However, ER expression only poorly predicts outcome and further indicators of response or resistance are required. The development and application of molecular signature assays such as Oncotype Dx, Prosigna, Mammaprint and Endopredict have provided valuable information on prognosis and these are being used to support clinical decision making on whether endocrine therapy alone alongside surgery is sufficient for ER-positive early stage breast cancers or whether combination of endocrine with chemotherapy are also warranted. Ki67, the proliferation marker, has been widely used in the neo-adjuvant (pre-operative) setting to help predict response and long term outcome. Gene expression studies within the same setting have allowed monitoring of changes of potential predictive markers. These have identified frequent changes in estrogen-regulated and proliferation genes. Specific molecules such as mutant ER may also prove helpful biomarkers in predicting outcome and monitoring response to treatment.

Mammaprint™: a comprehensive review

The number of breast cancer (BC) cases is growing worldwide, being most frequently diagnosed in the early-setting. Mammaprint™ is a 70-gene-expression signature, originally designed for selecting early BC patients with low risk of developing metastasis, so that they could be spared adjuvant chemotherapy. Its use as a prognostic biomarker has been extensively validated, both retrospectively and prospectively. However, its value as a predictive tool and as a clinically useful tool remains controversial. This review will describe how the test works, its application in the clinic and its limitations. Cost-effectiveness studies will be summarized. Finally, we will provide a perspective on the use of Mammaprint in the near future, as a valuable tool for personalizing the treatment of early BC patients.

[The major debate: Micrometastases and breast cancer - To be for nodal irradiation]

Standard of care in breast cancer management is well-defined. However, some gray zones still exist, in particular adjuvant radiotherapy indications in case of pN1mi breast cancer. Here we propose to define their prognosis, to underpin the benefit of adjuvant treatments in such patients' management and to define lymphedema risk, which is the most common late side effect of locoregional treatments.

Ten-year conditional recurrence risks and overall and relative survival for breast cancer patients in the Netherlands: Taking account of event-free years

BACKGROUND

Survival estimates from diagnosis are of limited importance for (ex-)breast cancer patients who survived several years, as it includes information on already deceased patients. This study analysed the 10-year conditional risk of recurrent breast cancer in specific prognostic subgroups. Second, we investigated 10-year conditional overall survival (OS) and relative survival (RS), adjusted for confounding.

PATIENTS AND METHODS

All women diagnosed in 2005 with operated T1-2N0-1 breast cancer were selected from the Netherlands Cancer Registry. Patients were classified into T1N0, T1N1, T2N0 and T2N1 stage. Ten-year conditional recurrence rates were calculated from diagnosis, and for patients without an event (local [LR], regional recurrence [RR], distant metastasis [DM] or death) every year following diagnosis. Ten-year conditional OS was calculated using multivariable Cox regression. RS was estimated by dividing patient survival rates by those of the general Dutch population.

RESULTS

We included 7969 patients: 52.3% had T1N0, 15.3% T1N1, 19.9% T2N0 and 12.5% T2N1 stage. For T1N0, 10-year LR rates changed from 4.6% at diagnosis to 0.5% in year 10. RR rates changed from 2.3% to 0.2%, and DM rates changed from 7.8% to 0.6%. For T2N1 stage, the LR, RR and DM rates changed from 6.2% to 0.8%, 5.2%-0.4% and 19.6%-1.5%, respectively. For the luminal A subtype, LR, RR and DM rates changed from 3.9% to 0.4%, 1.7%-0.5% and 7.3%-1.1%, while for triple negative, these rates changed from 5.6% to 0.7%, 4.9%-0.2% and 16.7%-0%, respectively. Differences between subgroups attenuated over time, and all recurrence rates became ≤1.5% in year 10. Ten-year OS and RS, adjusted for confounding, showed declining risk differences between subgroups over time.

CONCLUSION

Differences in recurrence rates, OS and RS between prognostic subgroups declined as years passed by. These results highlight the importance of taking into account disease-free years to more accurately predict (ex-)breast cancer patients' prognosis over time.

Clinical relevance of the 21-gene Recurrence Score® assay in treatment decisions for patients with node-positive breast cancer in the genomic era

In contemporary management of early-stage breast cancer, clinical decisions regarding adjuvant systemic therapy are increasingly made after considering both genomic assay results and clinico-pathologic features. Genomic information augments the prognostic information gleaned from clinico-pathologic features by providing risk estimates for distant recurrence and/or breast cancer-specific survival based on individual tumor biology. The 21-gene Oncotype DX Breast Recurrence Score^® (RS) assay is validated to be prognostic and predictive of chemotherapy benefit in patients with hormone receptor-positive (HR+), HER2-negative early-stage breast cancer, regardless of nodal status. Because patients frequently are recommended to receive adjuvant chemotherapy based on the perceived poor prognosis related to a positive nodal status, inconsistent use of any prognostic genomic assay in the node-positive (N+) setting likely results in overtreatment of some patients, particularly those with a low genomic risk as defined by the RS test. This comprehensive review of the evidence for the RS assay in patients with N+, HR+, HER2-negative early-stage breast cancer focuses on outcomes of patients with low RS results treated with hormonal therapy alone. Aggregate findings show that the RS assay consistently identifies patients with low genomic risk N+ breast cancer, in whom adjuvant chemotherapy can be avoided without adversely affecting outcomes. This evidence suggests that HR+ patients with limited nodal involvement and low RS results should discuss with their physicians the pros and cons of adjuvant chemotherapy at the time their treatment plans are being decided.

Balancing the Economics and Ethics of Personalised Oncology

The cost of personalised medicine in oncology is increasing. The varied and contrasting priorities of the pharmaceutical industry, local and national governments, international medical community, and patients need to be reviewed and balanced. In addition to the economic and political standpoints on this issue, the ethical considerations from physicians' viewpoints need to be considered to optimise cancer patients' care. In this paper we discuss the way research and development (R&D) of these drugs is carried out and reimbursed, and how this needs to change. We describe frameworks assessing the value of these treatments which been developed. Physicians need to develop their knowledge and understanding of these issues to best meet their dual responsibilities of advocating for their patients and promoting public health.

Optimizing adjuvant endocrine therapy for early ER+ breast cancer: An update for surgeons

INTRODUCTION

The optimal duration of adjuvant endocrine therapy in early ER + breast cancer has been controversial. This article aims to provide an overview of the evidence.

METHODS

A search of the literature was conducted via MEDLINE using appropriate keywords. Eligible studies were screened and relevant articles were selected for this report.

RESULTS

Studies investigating the role of extended adjuvant tamoxifen beyond 5 years have revealed mixed results depending on the proportion of node positivity. In postmenopausal women, aromatase inhibitors (AIs) for 5 years are superior to tamoxifen. Extending the use of AIs beyond 5 years seem to reduce the risk of relapse in postmenopausal women with node positive disease. The addition of bisphosphonates to counteract AI-related osteopenia may further improve overall and disease-free survival. Women younger than 40 years seem to benefit from ovarian suppression combined with tamoxifen or exemestane.

CONCLUSIONS

An individualised approach is required for every patient. The adverse effects of endocrine therapy should be weighed against the potential benefits of extended therapy to better inform decision-making.

Pathologist's health-care value in the triage of Oncotype DX® testing: a value-based pathology study of tumour biology with outcomes

AIMS

Pathologists provide expert tissue assessment of breast cancer, yet their value to guide the appropriate use of breast cancer gene expression profile tests (GEPT) is underutilised. The specific aims of this study are to report morpho-immunohistological characteristics of breast tumours with Oncotype DX^® (ODx) recurrence scores (RS) of 10 or fewer (ultra-low risk) and 25 or fewer (low risk) in order to determine if pathologists can identify prospectively patient tumours that do not require ODx testing.

METHODS AND RESULTS

Oncotype DX^® cases with RS < 10 from 2005 to 2010 comprised 441 of 2594 (17%) of clinical cases; this cohort had 5 years' follow-up and was treated with endocrine therapy alone. Tumours were analysed for tumour type, Nottingham grade, mitosis score (MS) semi-quantitative (H-score) hormone receptor content and Magee equation 3. Knowledge derived from this data set was used to develop algorithms in order to identify prospectively tumours with RS of 10 or fewer or 25 or fewer. Thirty-four per cent of tumours were low-grade special types, while the remainder were enriched with high hormone receptor content with MS of 1. These algorithmic selection criteria identified correctly all patient cases below the chemotherapy cut-point, i.e. RS < 25, indicating that these oncotype test orders were an unnecessary cost.

CONCLUSIONS

This unique study demonstrates that (i) pathologists add great value to triage breast cancer for GEPT; and (ii) can identify prospectively low-grade tumour biology with high sensitivity and high specificity for those cases which do not require chemotherapy (RS < 25) using MS and hormone receptor content.

Distribution and Clinical Utility of the 21-gene Recurrence Score in Pure Mucinous Breast Cancer Patients: a case-control study

The 21-gene recurrence score (RS) is increasingly being used for patients with early stage, hormone receptor-positive, Her-2-negative breast cancer. However, these results are largely from populations with infiltrating ductal carcinoma (IDC). The clinical value of RS testing in mucinous carcinoma has not been well investigated. Pure mucinous breast cancer (PMBC) and paired pure IDC patients who underwent 21-gene RS were retrospectively reviewed and matched with tumor stage and molecular subtype. Clinic-pathological factors, treatment strategies, and RS distribution were compared between the PMBC and IDC patients. A total of 35 PMBC and 70 IDC patients were included. We found that RS was lower in the PMBC as compared with the IDC group: 21.26 vs. 24.40 (P=0.037). Regarding RS categories, PMBC patients had a relatively lower percentage of high RS patients than the IDC group: 8.57% vs. 22.86% (P = 0.048). Multivariate analysis showed that histologic type was an independent factor predicting RS distribution: IDC patients were associated with a higher RS as compared with PMBC patients (OR: 1.27, 95% CI: 1.03-2.13; P=0.014). Among genes in 21-gene RS testing, HER2, STMY3, STK15, and BAG1 were significantly different between the PMBC and IDC groups (P < 0.05). Two patients (5.71%) in the PMBC group, both with high RS, were recommended to receive adjuvant chemotherapy, much lower than patients with IDC (57.14%, P < 0.001). In multivariate analysis, histologic type of IDC was an independent factor for chemotherapy recommendation (OR = 22.00, 95% CI: 4.89-98.97, P<0.001). With a medium follow-up time of 24 months, one IDC patient had ipsilateral axillary lymph nodes recurrence and one PMBC patient had contralateral breast cancer. In conclusion, PMBC patients, mostly classified with low or intermediate RS category, were associated with lower RS as compared with IDC patients. PMBC and IDC had different genes expression patterns. Patients with high RS in the PMBC group might be recommended to receive adjuvant chemotherapy, which deserves further clinical evaluation.

Molecular subtypes of screen-detected breast cancer

BACKGROUND

Detection of breast cancers by mammographic screening confers a survival advantage of 20-50% compared to symptomatic presentations. The improved prognosis is only partly explained by stage migration. The distribution of the molecular subtypes of screen-detected breast cancer (SDBC) or their HER2 status has not been studied extensively. We wished to address these issues through the study of a large series of SDBC, with other presentations serving as controls.

DESIGN

Deidentified cases of female invasive cancer, diagnosed in Australia and New Zealand during 2005-2015, were retrieved from the BreastSurgANZ Quality Audit (BQA). Method of detection and selected patient, tumour and treatment data were assessed. Immunohistochemical surrogates for molecular subtypes were defined as Luminal A (ER+ and/or PR+, HER2-), Luminal B (ER+ and/or PR+, HER2+), HER2-enriched (ER-, PR- and HER2+) and basal-like (triple negative). Results were compared with the findings of controls and previous studies.

RESULT

100983 invasive cancers were diagnosed, including 32493 (32.7%) SDBC and 66907 (67.3%) with other presentations. The biomarker profile for SDBC versus other presentations in the same population was ER 89.3 versus 80.3%, PR 78.8 versus 69.8% and for HER2 11 versus 15.6%. The distribution of molecular subtypes was Luminal A 81.9 versus 70.74%, Luminal B 7.39 versus 9.52%, HER2-enriched 3.63 versus 6.06% and Basal-like 7.08 versus 13.68%. These differences were significant (p < 0.0001).

CONCLUSION

Molecular profiles of SDBC are significantly different from those of symptomatic cancers, with over-representation of the Luminal A and proportionately lower rates of all other subtypes. We have shown, for the first time, significantly lower rates of HER2 positivity in SDBC. These differences may contribute to the better survival of SDBC and have implications for prognostication, targeted therapy decisions and for laboratory quality assurance programs in setting target ranges for proportions of ER-positive and HER2 results in heavily screened populations.

Using Probability for Pathological Complete Response (pCR) as a Decision Support Marker for Neoadjuvant Chemotherapy in HER2 Negative Breast Cancer Patients - a Survey Among Physicians

BACKGROUND

In women with early breast cancer, a pathological complete response (pCR) after neoadjuvant chemotherapy is reported to be associated with an improvement of the survival. The aim of this survey among physicians was to investigate whether the probability of achieving pCR in patients with a hormone receptor-positive, HER2-negative disease encourages physicians to recommend neoadjuvant chemotherapy.

METHODS

The study was conducted via an online survey that was sent to 493 physicians, who were either known as members of national guideline committees, heads of breast cancer centers, being high recruiters in clinical trials or leading a private practice. Participants were asked about a specific case that should resemble patients for whom it is unclear, whether they should be treated with chemotherapy.

RESULTS

113 (24.5%) physicians participated at the survey, out of which 96.5% had a work experience of more than 10 years and 94.7% were board certified in their specialty. A total of 84.1% would consider pCR for a decision concerning neoadjuvant chemotherapy. With regard to the pCR probability, 2.7 and 10.6% of the participants demanded at least a pCR rate of 5 and 10%, respectively, while 25.7% were satisfied with 20% probability, and another 25.7% with a pCR rate of 30%.

CONCLUSIONS

The vast majority of the long-term experienced physicians would embrace the implementation of a further method such as the prediction of pCR probability in clinical routine to support decision making regarding the necessity of neoadjuvant chemotherapy. The cut-off of around 30% pCR probability seems to be a realizable rate to distinguish patient groups.

Development of an e-health app to support women prescribed adjuvant endocrine therapy after treatment for breast cancer

BACKGROUND

Adjuvant endocrine therapy (AET) is prescribed to women for 5-10 years after treatment for estrogen receptor positive (ER+ve), early-stage breast cancer. AET has proven effectiveness in reducing the risk of recurrence of breast cancer and mortality. However, adherence is known to be suboptimal with around 20% discontinuing by 2 years and up to 50% discontinuing by 5 years. Interventions are needed to support women taking AET after breast cancer. The aim of this study was to develop and pilot test an e-health app for this population.

METHODS

Two focus groups (n=15) and five interviews were conducted with women following treatment for early-stage breast cancer to assess the likely acceptability of an e-health app and to inform the content (Phase I). Following development of a prototype e-health app, a simple heuristic usability test was completed by five women in order to identify any design usability problems (Phase II). A further 18 women used the app for 1 month between July and August 2016, after which they were interviewed by telephone to collect their experiences and views of the app (Phase III).

RESULTS

The prototype e-health app included evidence-based information on effectiveness of AET, an electronic side-effects diary, a peer support forum, a repeat prescription reminder, suggested strategies for facilitating adherence and managing any side effects that occur, and a link to further evidence and useful organizations for further information and support. The app was received positively by women. Women found the app useful as it emphasized the importance of taking AET, helped them manage their side effects and provided details of support organizations, while offering empathy and exchange of suggestions for self-management strategies through the peer support forum.

CONCLUSION

Overall, findings suggest that this novel e-health app has potential as a feasible medium for promoting adherence to AET. Future research should evaluate the efficacy of the app in supporting women and promoting adherence.