Prognostic utility of the 21-gene assay in hormone receptor-positive operable breast cancer compared with classical clinicopathologic features

Prognostic & predictive factors for planning adjuvant chemotherapy of early-stage breast cancer

Breast cancer is a heterogeneous disease and may present with different clinical and biological characteristics. At present, breast cancer is divided into molecular subgroups besides its histopathological classification. Decision for adjuvant chemotherapy is made based on not only histopathological characteristics but also molecular and genomic characteristics using indices, guidelines and calculators in early-stage breast cancer. Making a treatment plan through all these prognostic and predictive methods according to risk categories aims at preventing unnecessary or useless treatments. In this review, an attempt to make a general assessment of prognostic and predictive methods is made which may be used for planning individualized therapy and also the comments of the guidelines used by the oncologists worldwide on these methods.

Levels of uPA and PAI-1 in breast cancer and its correlation to Ki67-index and results of a 21-multigene-array

Background

Conventional parameters including Ki67, hormone receptor and Her2/neu status are used for risk stratification for breast cancer. The serine protease urokinase plasminogen activator (uPA) and the plasminogen activator inhibitor type-1 (PAI-1) play an important role in tumour invasion and metastasis. Increased concentrations in tumour tissue are associated with more aggressive potential of the disease. Multigene tests provide detailed insights into tumour biology by simultaneously testing several prognostically relevant genes. With OncotypeDX®, a panel of 21 genes is tested by means of quantitative real-time polymerase chain reaction.

The purpose of this pilot study was to analyse whether a combination of Ki67 and uPA/PAI-1 supplies indications of the result of the multigene test.

Methods

The results of Ki67, uPA/PAI-1 and OncotypeDX® were analysed in 25 breast carcinomas (luminal type, pT1/2, max pN1a, G2). A statistical and descriptive analysis was performed.

Results

With a proliferation index Ki67 of < 14%, the recurrence score (RS) from the multigene test was on average in the low risk range, with an intermediate RS usually resulting if Ki67 was > 14%. Not elevated values of uPA and PAI-1 showed a lower rate of proliferation (average 8.5%) than carcinomas with an increase of uPA and/or PAI-1 (average 13.9%); p = 0.054, Student’s t-test. When Ki67 was > 14% and uPA and/or PAI-1 was raised, an intermediate RS resulted. These differences were significant when compared to cases with Ki67 < 14% with non-raised uPA/PAI-1 (p < 0.03, Student’s t-test). Without taking into account the proliferative activity, an intermediate RS was also verifiable if both uPA and PAI-1 showed raised values.

Conclusion

A combination of the values Ki67 and uPA/PAI-1 tended to depict the RS to be expected. From this it can be deduced that an appropriate analysis of this parameter combination may be undertaken before the multigene test in routine clinical practice. The increasing cost pressure makes it necessary to base the implementation of a multigene test on ancillary variables and to potentially leave it out if not required in the event of a certain constellation of results (Ki67 raised, uPA and PAI-1 raised).

Practical Consequences Resulting from the Analysis of a 21-Multigene Array in the Interdisciplinary Conference of a Breast Cancer Center

During the multidisciplinary planning of postoperative therapy after breast cancer, borderline cases can arise with no clear rationale for or against adjuvant chemotherapy. In 50 hormone- receptor-positive, Her2neu-negative carcinomas of the breast with no or only minimal lymph node involvement (max. pT1a) we initiated an Oncotype DX® multigene assay in addition to the evaluation of usual parameters. In the oncology conference a vote for or against chemotherapy was taken on the basis of the conventional criteria for decision-making before the test results were available. The final recommendation was made after the multigene test. In 32 breast carcinomas (64%) a low recurrence score could be documented, while 26 (32%) showed an intermediate RS and 3 (6%) showed a high RS. In most cases the result of the test could validate the choice of therapy established using conventional criteria. In 5 cases the initial recommendation for adjuvant therapy was revised, and in 3 cases chemotherapy was secondarily recommended after evaluation of the test results. Conversely, in some cases a low or intermediate risk constellation did not argue against a recommendation for adjuvant chemotherapy. Altogether, the results of our study do not indicate that a multigene assay should be used as a routine diagnostic tool. Instead a thorough compilation and careful analysis of conventional parameters for therapeutic decision-making should take precedence, with special emphasis on histopathological and immunohistochemical results. In selected cases, however, a multigene assay can be a useful tool in the deliberation for or against a therapeutic pathway.

Integrating Radiosensitivity and Immune Gene Signatures for Predicting Benefit of Radiotherapy in Breast Cancer

Purpose: Breast cancer is a heterogeneous disease and not all patients respond equally to adjuvant radiotherapy. Predictive biomarkers are needed to select patients who will benefit from the treatment and spare others the toxicity and burden of radiation.Experimental Design: We first trained and tested an intrinsic radiosensitivity gene signature to predict local recurrence after radiotherapy in three cohorts of 948 patients. Next, we developed an antigen processing and presentation-based immune signature by maximizing the treatment interaction effect in 129 patients. To test their predictive value, we matched patients treated with or without radiotherapy in an independent validation cohort for clinicopathologic factors including age, ER status, HER2 status, stage, hormone-therapy, chemotherapy, and surgery. Disease-specific survival (DSS) was the primary endpoint.Results: Our validation cohort consisted of 1,439 patients. After matching and stratification by the radiosensitivity signature, patients who received radiotherapy had better DSS than patients who did not in the radiation-sensitive group [hazard ratio (HR), 0.68; P = 0.059; n = 322], whereas a reverse trend was observed in the radiation-resistant group (HR, 1.53; P = 0.059; n = 202). Similarly, patients treated with radiotherapy had significantly better DSS in the immune-effective group (HR, 0.46; P = 0.0076; n = 180), with no difference in DSS in the immune-defective group (HR, 1.27; P = 0.16; n = 348). Both signatures were predictive of radiotherapy benefit (P _interaction = 0.007 and 0.005). Integration of radiosensitivity and immune signatures further stratified patients into three groups with differential outcomes for those treated with or without radiotherapy (P _interaction = 0.003).Conclusions: The proposed signatures have the potential to select patients who are most likely to benefit from radiotherapy. Clin Cancer Res; 24(19); 4754-62. ©2018 AACR.

Heterogeneity in Outcomes of Pathologic T1-2N1 Breast Cancer After Mastectomy: Looking Beyond Locoregional Failure Rates

PURPOSE

A meta-analysis of 22 randomized trials accrued from 1964 to 1986 demonstrated significantly higher rates of locoregional failure (LRF) and breast-cancer mortality in women with 1-3 positive nodes without postmastectomy radiotherapy (PMRT) after mastectomy (mast.). Recent data demonstrate that PMRT reduces distant metastases (DM) in women with pN1 disease. The challenge today is whether all patients with pathologic T1-2pN1 disease have similar substantial LRF/DM risk that routinely warrants PMRT.

METHODS

We reviewed patients with pT1-2N1 breast cancer treated with mast. ± adjuvant systemic therapy without PMRT from 2000 to 2013. The endpoints were LRF and DM rates, estimated by cumulative incidence method.

RESULTS

We identified 468 patients with median follow-up of 6.3 years. Most (71%) were estrogen receptor/progesterone receptor + human epidermal growth factor receptor 2 (HER2). There were 269 patients with 1+ node, 140 patients with 2+ nodes, and 59 patients with 3+ nodes. The 6-year LRF/DM rates were 4.1%/8.4%. Patients with 1+, 2+, and 3+ nodes had 6-year LRF of 2.3, 5.1 and 8.9%, respectively (p = 0.13). The 6-year DM rate was higher in patients with 3+ nodes versus 1-2+ nodes: 15.7% versus 7.4% (p = 0.02). Several subgroups had low 6-year LRF and DM rates, including T1/1+ node (0.8%/4.1% LRF/DM) and micrometastases (0%/5.8% LRF/DM).

CONCLUSIONS

Patients with pT1-2pN1 represent a heterogeneous group with a wide range of LRF/DM rates. In particular, patients with pT1 tumors and 1 + LN, and patients with micrometastases, had low event rates. These groups would derive small absolute reductions in LRF and DM with addition of PMRT, underscoring the importance of patient selection for PMRT in pT1-2pN1 breast cancer.

Distribution patterns of 21-gene recurrence score in 980 Chinese estrogen receptor-positive, HER2-negative early breast cancer patients

AIM

The current study aimed to explore the distribution patterns of 21-gene recurrence score (RS) assay in Chinese early breast cancer patients.

METHODS

Nine hundred and eighty consecutive estrogen receptor(ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer patients treated at Ruijin Hospital, Shanghai Jiaotong University, School of Medicine from 2009 to 2016 were retrospectively recruited. Reverse transcriptase-polymerase chain reaction (RT-PCR) assay of 21 genes were conducted in paraffin-embedded tumor tissue to calculate the RS. Co-relations of RS and clinico-pathologic factors were evaluated. Concordances of RT-PCR and immunohistochemistry (IHC) tests were measured. Logistic regression were applied to determine independent variables associated with RS.

RESULTS

The median RS of 980 patients was 23(0~90), and the proportions of patients categorized as having a low, intermediate, or high risk were 26.1%, 49.3% and 24.6%. The distribution of RS varied significantly according to different tumor grade, T stage, progesterone receptor(PR) status, Ki67 index and molecular subtypes (p<0.05). Grade, PR status and Ki67 index were identified as independent variables associated with RS. The concordance rates between RT-PCR and IHC test were 98.8% and 88.3% for ER and PR status, and there were weak to moderate correlation between IHC and RT-PCR tests for ER, PR expression and Ki67 index.

CONCLUSIONS

RS correlated significantly with grade, T stage, PR status, Ki67 index and molecular subtypes in Chinese early breast cancer patients. Grade, PR status and Ki67 index could independently predict RS. ER, PR status and Ki67 index between RT-PCR and IHC test had remarkable concordance.

Current issues with luminal subtype classification in terms of prediction of benefit from endocrine therapy in early breast cancer

Endocrine therapy for oestrogen receptor-positive (ER+) breast cancer (BC) is arguably the most successful targeted cancer therapy to date. Nevertheless, resistance to endocrine therapy still occurs in a significant proportion of patients, limiting its clinical utility. ER+ or luminal BC, which represents approximately three-quarters of all breast malignancies, are biologically heterogeneous, with no distinct, clinically defined subclasses able to predict the benefit of endocrine therapy in early settings. To improve patient outcomes there is a clear need for improved understanding of the biology of the luminal BC, with subsequent translation into more effective methods of diagnosis to identify potential predictive biomarkers for endocrine therapy. This review summarises current knowledge of factors predictive of benefit of endocrine therapy and discusses why molecular classification systems of BC have yet to be translated into the clinic.

The 21-gene Recurrence Score® assay predicts distant recurrence in lymph node-positive, hormone receptor-positive, breast cancer patients treated with adjuvant sequential epirubicin- and docetaxel-based or epirubicin-based chemotherapy (PACS-01 trial)

Background

The 21-gene Recurrence Score (RS) result predicts outcome and chemotherapy benefit in node-negative and node-positive (N+), estrogen receptor-positive (ER+) patients treated with endocrine therapy. The purpose of this study was to evaluate the prognostic impact of RS results in N+, hormone receptor-positive (HR+) patients treated with adjuvant chemotherapy (6 cycles of FEC100 vs. 3 cycles of FEC100 followed by 3 cycles of docetaxel 100 mg/m²) plus endocrine therapy (ET) in the PACS-01 trial (J Clin Oncol 2006;24:5664-5671).

Methods

The current study included 530 HR+/N+ patients from the PACS-01 parent trial for whom specimens were available. The primary objective was to evaluate the relationship between the RS result and distant recurrence (DR).

Results

There were 209 (39.4%) patients with low RS (< 18), 159 (30%) with intermediate RS (18-30) and 162 (30.6%) with high RS (≥ 31). The continuous RS result was associated with DR (hazard ratio = 4.14; 95% confidence interval: 2.67-6.43; p <  0.001), adjusting for treatment. In multivariable analysis, the RS result remained a significant predictor of DR (p <  0.001) after adjustment for number of positive nodes, tumor size, tumor grade, Ki-67 (immunohistochemical status), and chemotherapy regimen. There was no statistically significant interaction between RS result and treatment in predicting DR (p = 0.79).

Conclusions

After adjustment for clinical covariates, the 21-gene RS result is a significant prognostic factor in N+/HR+ patients receiving adjuvant chemoendocrine therapy.

Trial registration

Not applicable.

A 35-gene signature discriminates between rapidly- and slowly-progressing glioblastoma multiforme and predicts survival in known subtypes of the cancer

BACKGROUND

Gene expression can be employed for the discovery of prognostic gene or multigene signatures cancer. In this study, we assessed the prognostic value of a 35-gene expression signature selected by pathway and machine learning based methods in adjuvant therapy-linked glioblastoma multiforme (GBM) patients from the Cancer Genome Atlas.

METHODS

Genes with high expression variance was subjected to pathway enrichment analysis and those having roles in chemoradioresistance pathways were used in expression-based feature selection. A modified Support Vector Machine Recursive Feature Elimination algorithm was employed to select a subset of these genes that discriminated between rapidly-progressing and slowly-progressing patients.

RESULTS

Survival analysis on TCGA samples not used in feature selection and samples from four GBM subclasses, as well as from an entirely independent study, showed that the 35-gene signature discriminated between the survival groups in all cases (p<0.05) and could accurately predict survival irrespective of the subtype. In a multivariate analysis, the signature predicted progression-free and overall survival independently of other factors considered.

CONCLUSION

We propose that the performance of the signature makes it an attractive candidate for further studies to assess its utility as a clinical prognostic and predictive biomarker in GBM patients. Additionally, the signature genes may also be useful therapeutic targets to improve both progression-free and overall survival in GBM patients.

Spotlight on the utility of the Oncotype DX® breast cancer assay

The Oncotype DX^® assay was developed to address the need for optimizing the selection of adjuvant systemic therapy for patients with estrogen receptor (ER)-positive, lymph node-negative breast cancer. It has ushered in the era of genomic-based personalized cancer care for ER-positive primary breast cancer and is now widely utilized in various parts of the world. Together with several other genomic assays, Oncotype DX has been incorporated into clinical practice guidelines on biomarker use to guide treatment decisions. The Oncotype DX result is presented as the recurrence score which is a continuous score that predicts the risk of distant disease recurrence. The assay, which provides information on clinicopathological factors, has been validated for use in the prognostication and prediction of degree of adjuvant chemotherapy benefit in both lymph node-positive and lymph node-negative early breast cancers. Clinical studies have consistently shown that the Oncotype DX has a significant impact on decision making in adjuvant therapy recommendations and appears to be cost-effective in diverse health care settings. In this article, we provide an overview of the validation and clinical impact studies for the Oncotype DX assay. We also discuss its potential use in the neoadjuvant setting, as well as the more recent prospective validation trials, and the economic and utility implications of studies that use a lower cutoff score to define low-risk disease.

Prospective Evaluation of the Impact of the 21-Gene Recurrence Score Assay on Adjuvant Treatment Decisions for Women with Node-Positive Breast Cancer in Ontario, Canada

BACKGROUND

The 21-gene Recurrence Score (RS) assay is only reimbursed in Ontario for node-negative and micrometastatic node-positive (N+) early-stage breast cancer (EBC). We carried out a prospective study to evaluate the impact of the assay on treatment decisions for women with N+ EBC.

SUBJECTS, MATERIALS, AND METHODS

Women with estrogen receptor-positive, human epidermal growth receptor 2-negative EBC and one to three positive axillary lymph nodes, who were candidates for adjuvant chemotherapy in addition to hormonal treatment, but in whom the benefit of chemotherapy was uncertain, were eligible. The primary objective was to characterize how the results of the RS assay affected physicians' recommendations for adjuvant chemotherapy. Secondary objectives were to characterize changes in the physicians' and patients' level of confidence in treatment recommendations, to determine whether the results of the RS assay affected patients' treatment preferences, and to determine the final treatment administered.

RESULTS

Seventy-two patients were recruited; the mean age was 61. RS was <18 in 55%, between 18 and 30 in 36%, and ≥31 in 9% of patients. Treatment recommendations changed in 36% of all evaluable patients. The most significant change was in the group with a low RS. Physicians' and patients' confidence in treatment recommendations increased in 49% and 54% of cases, respectively. Upfront chemotherapy was recommended to 79% of patients before the assay; 42% ultimately received chemotherapy.

CONCLUSION

The RS assay resulted in a substantial decrease in the number of patients who received chemotherapy and in an increase in physicians' and patients' confidence in the adjuvant treatment recommendations.

IMPLICATIONS FOR PRACTICE

This is the first decision impact study to include exclusively women with ER-positive, HER2-negative, early-stage breast cancer with 1-3 positive lymph nodes, a population typically treated with adjuvant chemotherapy. This study provides evidence that, in these patients, the Oncotype Dx Recurrence Score assay influences systemic treatment decisions. Most of the changes in treatment recommendation resulted in withdrawal of chemotherapy or change in recommendation from a chemotherapy regimen with anthracyclines to a taxane-only regimen. If prospective studies confirm that these decisions result in good outcomes, a reduction in the use of chemotherapy might result in pharmacoeconomic savings.

Gene Expression Assays for Early-Stage Hormone Receptor-Positive Breast Cancer: Understanding the Differences

Biomarkers are frequently used to guide decisions for treatment of early-stage estrogen (ER) and progesterone (PR) receptor–positive (ER/PR+) invasive breast cancers and have been incorporated into guidelines. The American Society of Clinical Oncology (ASCO) 2016 guideline and a 2017 update were recently published to help clinicians use the tests available. ASCO currently recommends five tests that show evidence of clinical utility based on the parameters defined in the guideline. These include the 21-gene assay (Oncotype DX), Prediction of Analysis of Microarray-50 (PAM50), 12-gene risk score (Endopredict), Breast Cancer Index (BCI), and, most recently, the 70-gene assay (Mammaprint). However, discordance is often seen when the results of these gene assays are compared in a particular patient, for a number of reasons: the assays were initially developed to answer different questions, and the molecular makeup of each signature reflects this; the patient populations that were studied also differed and may not reflect the patient being tested; furthermore, the study design and statistical analysis varied between each test, leading to different scoring scales that may not be comparable. In this review, the background on the development and validation of these assays is discussed, and studies comparing them are reviewed. To provide guidance on which test to choose, the studies that support the level of evidence for clinical utility are presented. However, the choice of a particular test will also be influenced by socioeconomic factors, clinical factors, and patient preferences. We hope that a better understanding of the scientific and clinical rationale for each test will allow patients and providers to make optimal decisions for treatment of early-stage ER/PR+ breast cancer.

Germline variation in ADAMTSL1 is associated with prognosis following breast cancer treatment in young women

To identify genetic variants associated with breast cancer prognosis we conduct a meta-analysis of overall survival (OS) and disease-free survival (DFS) in 6042 patients from four cohorts. In young women, breast cancer is characterized by a higher incidence of adverse pathological features, unique gene expression profiles and worse survival, which may relate to germline variation. To explore this hypothesis, we also perform survival analysis in 2315 patients aged ≤ 40 years at diagnosis. Here, we identify two SNPs associated with early-onset DFS, rs715212 (P _meta = 3.54 × 10^-5) and rs10963755 (P _meta = 3.91 × 10^-4) in ADAMTSL1. The effect of these SNPs is independent of classical prognostic factors and there is no heterogeneity between cohorts. Most importantly, the association with rs715212 is noteworthy (FPRP <0.2) and approaches genome-wide significance in multivariable analysis (P _{multivariable} = 5.37 × 10^-8). Expression quantitative trait analysis provides tentative evidence that rs715212 may influence AREG expression (P _eQTL = 0.035), although further functional studies are needed to confirm this association and determine a mechanism.

21-Gene Recurrence Score for prognosis and prediction of taxane benefit after adjuvant chemotherapy plus endocrine therapy: results from NSABP B-28/NRG Oncology

BACKGROUND

The 21-gene recurrence score (RS) predicts outcome and benefit from adjuvant chemotherapy benefit in breast cancer patients treated with adjuvant endocrine therapy. In the NSABP B-28 study, we evaluated the 21-gene RS for its prognostic impact and its ability to predict benefit from paclitaxel (P) in node-positive, estrogen receptor-positive (ER+) breast cancer patients treated with adjuvant chemotherapy plus tamoxifen.

METHODS

The B-28 trial compared doxorubicin/cyclophosphamide (AC) with AC followed by P in 3060 patients. Tamoxifen for 5 years was also given to patients > 50 years and those < 50 years with ER+ and/or progesterone receptor-positive (PR+) tumors. The present study includes 1065 ER-positive, tamoxifen-treated patients with RS assessment. Median follow-up time was 11.2 years.

RESULTS

In univariate analyses, RS was a significant predictor of outcome. In multivariate analyses, RS remained a significant independent predictor of outcome beyond clinico-pathologic factors, age, and type of surgery (p < 0.001). In the study population (n = 1065), the disease-free survival (DFS) hazard ratio (HR) with adding P to AC was 0.87 (95% CI 0.72-1.05; p = 0.14). RS was not a significant predictor of P benefit: for DFS, HRs for adding P to AC in RS low, intermediate, and high subgroups were 1.01 (95% CI 0.69-1.47; p = 0.99), 0.84 (95% CI 0.62-1.14; p = 0.26), and 0.81 (95% CI 0.60-1.10; p = 0.21), respectively (interaction p = 0.64). Similar findings were observed for the other study endpoints.

CONCLUSIONS

RS maintains significant prognostic impact in ER-positive, node-positive patients treated with adjuvant chemotherapy plus tamoxifen. However, RS did not significantly predict benefit from adding paclitaxel to AC chemotherapy. (Trial Registration: PDQ: NSABP-B-28).

Systematic review of the clinical and economic value of gene expression profiles for invasive early breast cancer available in Europe

Gene expression profiles with prognostic capacities have shown good performance in multiple clinical trials. However, with multiple assays available and numerous types of validation studies performed, the added value for daily clinical practice is still unclear. In Europe, the MammaPrint, OncotypeDX, PAM50/Prosigna and Endopredict assays are commercially available. In this systematic review, we aim to assess these assays on four important criteria: Assay development and methodology, clinical validation, clinical utility and economic value. We performed a literature search covering PubMed, Embase, Web of Science and Cochrane, for studies related to one or more of the four selected assays. We identified 147 papers for inclusion in this review. MammaPrint and OncotypeDX both have evidence available, including level IA clinical trial results for both assays. Both assays provide prognostic information. Predictive value has only been shown for OncotypeDX. In the clinical utility studies, a higher reduction in chemotherapy was achieved by OncotypeDX, although the number of available studies differ considerably between tests. On average, economic evaluations estimate that genomic testing results in a moderate increase in total costs, but that these costs are acceptable in relation to the expected improved patient outcome. PAM50/prosigna and EndoPredict showed comparable prognostic capacities, but with less economical and clinical utility studies. Furthermore, for these assays no level IA trial data are available yet. In summary, all assays have shown excellent prognostic capacities. The differences in the quantity and quality of evidence are discussed. Future studies shall focus on the selection of appropriate subgroups for testing and long-term outcome of validation trials, in order to determine the place of these assays in daily clinical practice.

Web-Based Tool to Facilitate Shared Decision Making With Regard to Neoadjuvant Chemotherapy Use in Muscle-Invasive Bladder Cancer

PURPOSE

Level 1 evidence supports the use of neoadjuvant chemotherapy (NAC) for the treatment of muscle-invasive bladder cancer (MIBC), but observational data demonstrate that this approach is underused. A barrier to shared decision making is difficulty in predicting and communicating survival estimates after cystectomy with or without NAC.

METHODS

We included patients with MIBC from the National Cancer Database treated with cystectomy. A state-transition model was constructed for calculating 5-year death risk using baseline patient-, tumor-, and facility-level variables. Internal-external cross-validation by geographic region was performed. The effect of NAC was integrated using a literature-derived hazard ratio. Bladder cancer-specific and other-cause mortality was estimated from all-cause mortality rates from US life tables. From the state-transition model, a Web-based tool was developed and pilot usability testing performed.

RESULTS

A total of 9,824 patients with MIBC who underwent cystectomy were eligible for inclusion. Median overall survival was 39.6 months (95% CI, 37.4 to 42.4 months). Increasing age, higher clinical T stage, higher comorbidity index, and black race were associated with shorter survival. Private insurance, higher income, and cystectomy at a high-volume facility were associated with longer survival. The prediction model was well calibrated across geographic regions, with observed-to-predicted 5-year death risks ranging from 0.85 to 1.17. Absolute risk reductions with NAC varied from 8.6% to 10.1%. The Web-based tool allowed input of the predictor variables and a user-defined hazard ratio associated with the effect of NAC to generate individualized survival estimates. The tool demonstrated good usability with clinicians.

CONCLUSION

A Web-based tool was developed to individualize outcome prediction and communication in patients with MIBC treated with cystectomy with or without NAC to facilitate shared decision making.

Impacts of Early Guideline-Directed 21-Gene Recurrence Score Testing on Adjuvant Therapy Decision Making

PURPOSE

The 21-gene recurrence score (RS) assay is used to help formulate adjuvant chemotherapy recommendations for patients with estrogen receptor-positive, early-stage breast cancer. Most frequently, medical oncologists order RS after surgery. Results take an additional 2 weeks to return, which can delay decision making. We conducted a prospective quality-improvement project to assess the impact of early guideline-directed RS ordering by surgeons before the first visit with a medical oncologist on adjuvant therapy decision making.

MATERIALS AND METHODS

Surgical oncologists ordered RS testing following National Comprehensive Cancer Network guidelines at time of diagnosis or at time of surgery between July 1, 2015 and December 31, 2015. We measured the testing rate of patients eligible for RS, time to chemotherapy decisions, rates of chemotherapy use, accrual to RS-based clinical trials, cost, and physician acceptance of the policy and compared the results to patients who met eligibility criteria for early guideline-directed testing during the 6 months before the project.

RESULTS

Ninety patients met eligibility criteria during the testing period. RS was ordered for 91% of patients in the early testing group compared with 76% of historical controls ( P < .001). Median time to chemotherapy decision was significantly shorter in the early testing group (20 days; 95% CI, 17 to 23 days) compared with historical controls (32 days; 95% CI, 29 to 35 days; P < .001). There were no significant differences in time to chemotherapy initiation, chemotherapy use, RS-based trial enrollment, or calculated costs between the groups.

CONCLUSION

Early guideline-directed RS testing in selected patients is an effective way to shorten time to treatment decisions.

Exploitation of Gene Expression and Cancer Biomarkers in Paving the Path to Era of Personalized Medicine

Cancer therapy agents have been used extensively as cytotoxic drugs against tissue or organ of a specific type of cancer. With the better understanding of molecular mechanisms underlying carcinogenesis and cellular events during cancer progression and metastasis, it is now possible to use targeted therapy for these molecular events. Targeted therapy is able to identify cancer patients with dissimilar genetic defects at cellular level for the same cancer type and consequently requires individualized approach for treatment. Cancer therapy begins to shift steadily from the traditional approach of “one regimen for all patients” to a more individualized approach, through which each patient will be treated specifically according to their specific genetic defects. Personalized medicine accordingly requires identification of indicators or markers that guide in the decision making of such therapy to the chosen patients for more effective therapy. Cancer biomarkers are frequently used in clinical practice for diagnosis and prognosis, as well as identification of responsive patients and prediction of treatment response of cancer patient. The rapid breakthrough and development of microarray and sequencing technologies is probably the main tool for paving the way toward “individualized biomarker-driven cancer therapy” or “personalized medicine”. In this review, we aim to provide an updated knowledge and overview of the current landscape of cancer biomarkers and their role in personalized medicine, emphasizing the impact of genomics on the implementation of new potential targeted therapies and development of novel cancer biomarkers in improving the outcome of cancer therapy.

Do online prognostication tools represent a valid alternative to genomic profiling in the context of adjuvant treatment of early breast cancer? A systematic review of the literature

INTRODUCTION

Decision-making regarding adjuvant chemotherapy has been based on clinical and pathological features. However, such decisions are seldom consistent. Web-based predictive models have been developed using data from cancer registries to help determine the need for adjuvant therapy. More recently, with the recognition of the heterogenous nature of breast cancer, genomic assays have been developed to aid in the therapeutic decision-making.

METHODS

We have carried out a comprehensive literature review regarding online prognostication tools and genomic assays to assess whether online tools could be used as valid alternatives to genomic profiling in decision-making regarding adjuvant therapy in early breast cancer.

RESULTS AND CONCLUSIONS

Breast cancer has been recently recognized as a heterogenous disease based on variations in molecular characteristics. Online tools are valuable in guiding adjuvant treatment, especially in resource constrained countries. However, in the era of personalized therapy, molecular profiling appears to be superior in predicting clinical outcome and guiding therapy.

Clinical utility of gene-expression signatures in early stage breast cancer

Breast cancer is a heterogeneous disease, with different subtypes having a distinct biological, molecular, and clinical course. Assessments of standard clinical and pathological features have traditionally been used to determine the use of adjuvant systemic therapy in patients with early stage breast cancer; however, the ability to identify those who will benefit from adjuvant chemotherapy remains a challenge, leading to the overtreatment of some patients. Advances in molecular medicine have substantially improved the accuracy of gene-expression profiling of breast tumours, resulting in improvements in the ability to predict a patient's risk of breast cancer recurrence and likely response to endocrine therapy and/or chemotherapy. These genomic assays, several of which are commercially available, have aided physicians in tailoring treatment decisions for patients at the individual level. Herein, we describe the available data on the clinical validity of the most widely available assays in patients with early stage breast cancer, with a focus on the development, validation, and clinical application of these assays, in addition to the anticipated outcomes of ongoing prospective trials. We also review data from comparative studies of these assays and from cost-effectiveness analyses relating to their clinical use.

Clinical use of the Oncotype DX genomic test to guide treatment decisions for patients with invasive breast cancer

Implementation of the Oncotype DX assay has led to a change in the manner in which chemotherapy is utilized in patients with early stage, estrogen receptor (ER)-positive, node-negative breast cancer; ensuring that patients at highest risk of recurrence are prescribed systemic treatment, while at the same time sparing low-risk patients potential adverse events from therapy unlikely to influence their survival. This test generates a recurrence score between 0 and 100, which correlates with probability of distant disease recurrence. Patients with low-risk recurrence scores (0–17) are unlikely to derive significant survival benefit with adjuvant chemotherapy and hormonal agents derived from using adjuvant hormonal therapy only. Conversely, adjuvant chemotherapy has been shown to significantly improve survival in patients with high-risk recurrence scores (≥31). Trials are ongoing to determine how best to manage patients with recurrence scores in the intermediate range. This review outlines the introduction and impact of Oncotype DX testing on practice; ongoing clinical trials investigating its utility; and challenging clinical scenarios where the absolute recurrence score may require careful interpretation. We also performed a bibliometric analysis of publications on the topics of breast cancer and Oncotype DX as a surrogate marker of acceptability and incorporation of the assay into the management of patients with breast cancer.

Towards decision-making using individualized risk estimates for personalized medicine: A systematic review of genomic classifiers of solid tumors

Recent advances in the understanding of the genetic underpinnings of cancer offer the promise to customize cancer treatments to the individual through the use of genomic classifiers (GCs). At present, routine clinical utilization of GCs is uncommon and their current scope and status, in a broad sense, are unknown. As part of a registered review (PROSPERO 2014:CRD42014013371), we systematically reviewed the literature evaluating the utility of commercially available GCs by searching Ovid Medline (PubMed), EMBASE, the Cochrane Database of Systematic Reviews, and CINAHL on September 2, 2014. We excluded articles involving pediatric malignancies, non-solid or non-invasive cancers, hereditary risk of cancer, non-validated GCs, and GCs involving fewer than 3 biomarkers. A total of 3,625 studies were screened, but only 37 met the pre-specified inclusion criteria. Of these, 15 studies evaluated outcomes and clinical utility of GCs through clinical trials, and the remainder through the use of mathematical models. Most studies (29 of 37) were specific to hormone-receptor positive breast cancer, whereas only 4 studies evaluated GCs in non-breast cancer (prostate, colon, and lung cancers). GCs have spurred excitement across disciplines in recent decades. While there are several GCs that have been validated, the general quality of the data are weak. Further research, including prospective validation is needed, particularly in the non-breast cancer GCs.

The Era of Multigene Panels Comes? The Clinical Utility of Oncotype DX and MammaPrint

The AJCC Cancer Staging Manual, eighth edition published in late 2016, will become the new global guideline for cancer diagnosis and treatment from January 1, 2018. The new edition for the tumor staging system has numerous updates, including building up the prognostic stage group of tumors for the first time and adding a large number of non-anatomical factors into the prognostic evaluation. Oncotype DX and MammaPrint are two of the genomic predictors that will be part of routine clinical practice in the future. Numerous studies have proved the clinical utility of multigene panels in predicting clinical outcome and treatment response. Here we present our review of the studies on these multigene panels and their application to breast cancer.

Pathologic diagnosis of breast cancer patients: evolution of the traditional clinical-pathologic paradigm toward "precision" cancer therapy

We present an updated account of breast cancer treatment and of progress toward "precision" cancer therapy; we focus on new developments in diagnostic molecular pathology and breast cancer that have emerged during the past 2 years. Increasing awareness of new prognostic and predictive methodologies, and introduction of next generation sequencing has increased understanding of both tumor biology and clinical behavior, which offers the possibility of more appropriate therapeutic choices. It remains unclear which of these testing methodologies provides the most informative and cost-effective actionable results for predictive and prognostic pathology. It is likely, however, that an integrated "step-wise" approach that uses the traditional clinical-pathologic paradigms coordinated with molecular characterization of breast tumor tissue, will offer the most comprehensive and cost-effective options for individualized, "precision" therapy for patients with breast cancer.

Precision medicine for early breast cancer radiotherapy: Opening up new horizons?

So far most efforts put forth to test the value of predictive and prognostic tools in the field of breast radiotherapy remained globally disappointing, or at least below the convincing levels reached for systemic therapy. Nevertheless the addition of predictive tools to the clinical armament tends to prevail over the use of the sole prognostic factors, also in radiotherapy. A number of predictive assays, clinically validated or not, have recently elicited significant associations between molecular profiles and tumor biological aggressiveness and/or radiosensitivity levels. Will it take a long time for these radiation-specific assays to provide added value to the - already crowded - constellation of predictive tools in the breast cancer? On the one hand, optimizing radiotherapy through the integration of precision medicine into the breast cancer management still remains a challenging issue. On the other hand, recent advances in predictive assays aimed at distinguishing patients with a more radioresistant tumor that necessitates radiation dose escalation or a switch to therapeutic approaches other than radiotherapy, plea in favor of an increasing role, in a near future, for radiation-specific molecular signatures. Streamlining predictive assays platforms via concerted actions should imperatively be given high priority, also in terms of health economics.

Second Opinions From Medical Oncologists for Early-Stage Breast Cancer: Prevalence, Correlates, and Consequences

IMPORTANCE

Advances in the evaluation and treatment of breast cancer have made the clinical decision-making context much more complex. A second opinion from a medical oncologist may facilitate decision making for women with breast cancer, yet little is known about second opinion use.

OBJECTIVE

To investigate the patterns and correlates of second opinion use and the effect on chemotherapy decisions.

DESIGN, SETTING, AND PARTICIPANTS

A total of 1901 women newly diagnosed with stages 0 to II breast cancer between July 2013 and September 2014 (response rate, 71.0%) were accrued through 2 population-based Surveillance, Epidemiology, and End Results registries (Georgia and Los Angeles County, California) and surveyed about their experiences with medical oncologists, decision making, and chemotherapy use.

MAIN OUTCOMES AND MEASURES

Factors associated with second opinion use were evaluated using logistic regression. Also assessed was the association between second opinion and chemotherapy use, adjusting for chemotherapy indication and propensity for receiving a second opinion. Multiple imputation and weighting were used to account for missing data.

RESULTS

A total of 1901 patients with stage I to II breast cancer (mean [SD] age, 61.6 [11.0] years; 1071 [56.3%] non-Hispanic white) saw any medical oncologist. Analysis of multiply imputed, weighted data (mean n = 1866) showed that 168 (9.8%) (SE, 0.74%) received a second opinion and 54 (3.2%) (SE, 0.47%) received chemotherapy from the second oncologist. Satisfaction with chemotherapy decisions was high and did not differ between those who did (mean [SD], 4.3 [0.08] on a 1- to 5-point scale) or did not (4.4 [0.03]) obtain a second opinion (P = .29). Predictors of second opinion use included college education vs less education (odds ratio [OR], 1.85; 95% CI, 1.24-2.75), frequent use of internet-based support groups (OR, 2.15; 95% CI, 1.12-4.11), an intermediate result on the 21-gene recurrence score assay (OR, 1.85; 95% CI, 1.11-3.09), and a variant of uncertain significance on hereditary cancer genetic testing (OR, 3.24; 95% CI, 1.09-9.59). After controlling for patient and tumor characteristics, second opinion use was not associated with chemotherapy receipt (OR, 1.04; 95% CI, 0.71-1.52).

CONCLUSIONS AND RELEVANCE

Second opinion use was low (<10%) among patients with early-stage breast cancer, and high decision satisfaction regardless of second opinion use suggests little unmet demand. Along with educational level and use of internet support groups, uncertain results on genomic testing predicted second opinion use. Patient demand for second opinions may increase as more complex genomic tests are disseminated.

Neoadjuvant therapy for treatment of breast cancer: the way forward, or simply a convenient option for patients?

The complexity of managing early stage breast cancer is well known. Optimal treatment is increasingly multidisciplinary and in the modern era informed by sophisticated molecular tools to help select and guide therapy. Major phase III trials have determined that the order of systemic therapy relative to surgery does not influence important endpoints such as event free survival and overall survival (OS), but questions remain as to how best to utilize these most essential services. For example, there is still uncertainty regarding the ideal timing, intensity, and duration of proposed therapy. For treating physicians, evidence based standardization of these practices is both possible and critically important. Optimization of care will increasingly rely on well-designed studies that have addressed the choice as well as the timing of the steps involved in multidisciplinary breast cancer treatment. Understanding when factors under the oncologist's control will influence outcome, cost and convenience is essential in the era of quality and value-based medical decision making. The timing of surgery before or after chemotherapy for breast cancer is one such factor. Investigators are to be commended for addressing these questions, which may generate additional hypotheses concerning the biology of metastasis and the nature of recurrence.

A metastasis biomarker (MetaSite Breast™ Score) is associated with distant recurrence in hormone receptor-positive, HER2-negative early-stage breast cancer

Metastasis is the primary cause of death in early-stage breast cancer. We evaluated the association between a metastasis biomarker, which we call "Tumor Microenviroment of Metastasis" (TMEM), and risk of recurrence. TMEM are microanatomic structures where invasive tumor cells are in direct contact with endothelial cells and macrophages, and which serve as intravasation sites for tumor cells into the circulation. We evaluated primary tumors from 600 patients with Stage I-III breast cancer treated with adjuvant chemotherapy in trial E2197 (NCT00003519), plus endocrine therapy for hormone receptor (HR)+ disease. TMEM were identified and enumerated using an analytically validated, fully automated digital pathology/image analysis method (MetaSite Breast™), hereafter referred to as MetaSite Score (MS). The objectives were to determine the association between MS and distant relapse free interval (DRFI) and relapse free interval (RFI). MS was not associated with tumor size or nodal status, and correlated poorly with Oncotype DX Recurrence Score (r = 0.29) in 297 patients with HR+/HER2- disease. Proportional hazards models revealed a significant positive association between continuous MS and DRFI (p = 0.001) and RFI (p = 0.00006) in HR+/HER2- disease in years 0-5, and by MS tertiles for DRFI (p = 0.04) and RFI (p = 0.01), but not after year 5 or in triple negative or HER2+ disease. Multivariate models in HR+/HER- disease including continuous MS, clinical covariates, and categorical Recurrence Score (<18, 18-30, > 30) showed MS is an independent predictor for 5-year RFI (p = 0.05). MetaSite Score provides prognostic information for early recurrence complementary to clinicopathologic features and Recurrence Score.

How could breast cancer molecular features contribute to locoregional treatment decision making?

Systemic treatments are tailored to breast cancer (BC) heterogeneity, which is not yet taken into account for radiotherapy (RT) personalization. The primary objective of this review is to summarize existing data suggesting BC subtypes and genetic assays are prognostic and predictive biomarkers useful for RT decision-making and to provide implications for their incorporation into future translational and clinical research. The evidence suggesting that BC subtypes also exhibit distinct "locoregional recurrence (LRR)" patterns is retrospective but consistent and validated in over fifteen studies. The HER-2 positive and triple negative subtypes are the most susceptible to locoregional failure. The high risk of the HER-2 positive subtype can be reversed with trastuzumab administration. Very little is known on the subtypes' intrinsic radiosensitivity properties. Genetic assays have assessed retrospectively signatures' prognostic and predictive value in patients' cohorts (several coming from prospective studies) for LRR risk and radiotherapy (RT) benefit. Further confirmation is needed before their introduction into clinical routine. Evidence on the use of molecular biomarkers for adjuvant RT tailoring is emerging but needs validation and introduction into prospective studies. The plethora of modern RT options (partial breast irradiation, hypofractionation), as well as recent evidence pointing towards more extensive radiotherapy, demand introduction of biological features into clinical trials to improve therapeutic decisions. Open questions, such as tailoring of irradiation after neo-adjuvant chemotherapy in complete responders and the understanding of the interplay between local control, systemic recurrence and survival given modern systemic treatments, need to be addressed under the prism of biology within this heterogeneous disease. Intrinsic radiobiological properties within this heterogeneity need to be highlighted in order to further improve outcomes.

Hormonal Modulation of Breast Cancer Gene Expression: Implications for Intrinsic Subtyping in Premenopausal Women

Clinics are increasingly adopting gene-expression profiling to diagnose breast cancer subtype, providing an intrinsic, molecular portrait of the tumor. For example, the PAM50-based Prosigna test quantifies expression of 50 key genes to classify breast cancer subtype, and this method of classification has been demonstrated to be superior over traditional immunohistochemical methods that detect proteins, to predict risk of disease recurrence. However, these tests were largely developed and validated using breast cancer samples from postmenopausal women. Thus, the accuracy of such tests has not been explored in the context of the hormonal fluctuations in estrogen and progesterone that occur during the menstrual cycle in premenopausal women. Concordance between traditional methods of subtyping and the new tests in premenopausal women is likely to depend on the stage of the menstrual cycle at which the tissue sample is taken and the relative effect of hormones on expression of genes versus proteins. The lack of knowledge around the effect of fluctuating estrogen and progesterone on gene expression in breast cancer patients raises serious concerns for intrinsic subtyping in premenopausal women, which comprise about 25% of breast cancer diagnoses. Further research on the impact of the menstrual cycle on intrinsic breast cancer profiling is required if premenopausal women are to benefit from the new technology of intrinsic subtyping.

'Omics Approaches in Breast Cancer Research and Clinical Practice

Our understanding of the natural history of breast cancer has evolved alongside technologies to study its genomic, transcriptomic, proteomic, and metabolomics landscapes. These technologies have helped decipher multiple molecular pathways dysregulated in breast cancer. First-generation 'omics analyses considered each of these dimensions individually, but it is becoming increasingly clear that more holistic, integrative approaches are required to fully understand complex biological systems. The 'omics represent an exciting era of discovery in breast cancer research, although important issues need to be addressed to realize the clinical utility of these data through precision cancer care. How can the data be applied to predict response to molecular-targeted therapies? When should treatment decisions be based on tumor genetics rather than histology? And with the sudden explosion of "big data" from large 'omics consortia and new precision clinical trials, how do we now negotiate evidence-based pathways to clinical translation through this apparent sea of opportunity? The aim of this review is to provide a broad overview of 'omics technologies used in breast cancer research today, the current state-of-play in terms of applying this new knowledge in the clinic, and the practical and ethical issues that will be central to the public discussion on the future of precision cancer care.

The analytical validation of the Oncotype DX Recurrence Score assay

In vitro diagnostic multivariate index assays are highly complex molecular assays that can provide clinically actionable information regarding the underlying tumour biology and facilitate personalised treatment. These assays are only useful in clinical practice if all of the following are established: analytical validation (i.e., how accurately/reliably the assay measures the molecular characteristics), clinical validation (i.e., how consistently/accurately the test detects/predicts the outcomes of interest), and clinical utility (i.e., how likely the test is to significantly improve patient outcomes). In considering the use of these assays, clinicians often focus primarily on the clinical validity/utility; however, the analytical validity of an assay (e.g., its accuracy, reproducibility, and standardisation) should also be evaluated and carefully considered. This review focuses on the rigorous analytical validation and performance of the Oncotype DX^® Breast Cancer Assay, which is performed at the Central Clinical Reference Laboratory of Genomic Health, Inc. The assay process includes tumour tissue enrichment (if needed), RNA extraction, gene expression quantitation (using a gene panel consisting of 16 cancer genes plus 5 reference genes and quantitative real-time RT-PCR), and an automated computer algorithm to produce a Recurrence Score^® result (scale: 0–100). This review presents evidence showing that the Recurrence Score result reported for each patient falls within a tight clinically relevant confidence interval. Specifically, the review discusses how the development of the assay was designed to optimise assay performance, presents data supporting its analytical validity, and describes the quality control and assurance programmes that ensure optimal test performance over time.

Molecular Phenotype, Multigene Assays, and the Locoregional Management of Breast Cancer

Molecular profiling has revealed that breast cancer is not a single disease entity, but rather a class of heterogeneous subtypes, each with its own inherent biology and natural history. As a result, different treatment approaches have been optimized for the various subtypes and, in turn, the ability to identify subtypes has become a critical element in the management of breast cancer. Comprehensive transcriptional profiling studies have revealed at least 4 principal subtypes that, in practice, are often distinguished by immunohistochemical staining of the estrogen receptor (ER), progesterone receptor (PR), and HER2, along with a determination of histologic grade or Ki-67 staining: luminal A (ER+/HER2-/grade 1 or 2), luminal B (ER+/HER2-/grade 3), HER2 enriched (any HER2+ tumor), and basal like (ER-/PR-/HER2-). Although these immunohistochemically derived subtypes show robust prognostic and predictive ability, there remain many cases that demand profiling that more closely approximates the original transcriptionally derived definitions of the intrinsic subtypes. The need for improved prognostication and risk stratification has led to the development of several multigene assays in breast cancer. Although there is little molecular overlap between current assays, they all rely heavily on quantifying the transcriptional output of ER signaling and proliferation-related genes. These data are typically then used in multivariate prediction models that incorporate other canonical risk factors such as the tumor size, lymph node involvement, and patient demographic parameters, among others. Indeed, the advent of scalable molecular profiling technologies has brought a number of assays into routine clinical use for optimizing risk prediction and treatment assignment. The landscape of these assays and the clinical utility of contemporary molecular profiles are the main focus of this overview. In addition to the clinical advances in transcriptional subtyping, recent reports have characterized the most common genomic and epigenomic alterations that are likely to drive certain breast cancers. The identification of these "driver" lesions has heralded an era of precision medicine in which vulnerable oncogenic pathways may be targeted to disrupt the etiologic lesion(s) of a specific tumor. A number of such early targeted approaches have yielded success in treating breast cancer, demonstrating the critical need for molecular diagnostics in this disease.

Clinical evidence supporting genomic tests in early breast cancer: Do all genomic tests provide the same information?

Breast cancer (BC) has historically been treated as a single disease entity; however, in the last decade, insights into its molecular heterogeneity have underpinned the development/commercialisation of several genomic tools whose goal is to guide patient management in early BC. These include the Oncotype DX^® Breast Recurrence Score™ assay, MammaPrint^®, Prosigna^®, and EndoPredict^®. Although these assays are similar in that they are all multigene assays reflecting risk of recurrence, they differ substantially in the technological platform used to measure gene expression; the number and identity of genes assessed; the patient populations used for development and validation; and the level of evidence supporting clinical utility. They also differ in the amount of evidence demonstrating their impact on treatment decisions and cost effectiveness in different countries. This review discusses these 4 assays, highlighting the clinical evidence that supports each of them, while focussing on the Recurrence Score assay. This assay has the greatest body of evidence supporting its clinical utility and decision impact/effectiveness, and currently is the only one validated as a predictor of response to adjuvant chemotherapy in hormone-receptor positive early BC patients treated with endocrine therapy and to be included as such in international/national BC treatment guidelines. The review also discusses ongoing prospective trials investigating the 4 assays, recent outcome studies, as well as analyses comparing different assays on the same tumour blocks.

Molecular Mechanisms of Bone Metastasis: Which Targets Came from the Bench to the Bedside?

Bone metastases ultimately result from a complex interaction between cancer cells and bone microenvironment. However, prior to the colonization of the bone, cancer cells must succeed through a series of steps that will allow them to detach from the primary tumor, enter into circulation, recognize and adhere to specific endothelium, and overcome dormancy. We now know that as important as the metastatic cascade, tumor cells prime the secondary organ microenvironment prior to their arrival, reflecting the existence of specific metastasis-initiating cells in the primary tumor and circulating osteotropic factors. The deep comprehension of the molecular mechanisms of bone metastases may allow the future development of specific anti-tumoral therapies, but so far the approved and effective therapies for bone metastatic disease are mostly based in bone-targeted agents, like bisphosphonates, denosumab and, for prostate cancer, radium-223. Bisphosphonates and denosumab have proven to be effective in blocking bone resorption and decreasing morbidity; furthermore, in the adjuvant setting, these agents can decrease bone relapse after breast cancer surgery in postmenopausal women. In this review, we will present and discuss some examples of applied knowledge from the bench to the bed side in the field of bone metastasis.

Adoption of Gene Expression Profiling for Breast Cancer in US Oncology Practice for Women Younger Than 65 Years

BACKGROUND

A number of practice guidelines incorporate the use of gene expression profiling (GEP) tests for early-stage, hormone receptor-positive, HER2-negative breast tumors. Few studies describe factors associated with GEP testing in US oncology practice. We assessed the relationship between clinical, demographic, and group-level socioeconomic variables and test use in women younger than 65 years.

PATIENTS AND METHODS

Data from 5 state cancer registries were linked with insurance claims data and GEP test results. We assessed rates of testing and variables associated with test use in an incident cohort of 9,444 commercially insured women younger than 65 years, newly diagnosed with stage I or II hormone receptor-positive breast cancer from 2006 through 2012.

RESULTS

Rates of testing for women with N0 disease increased from 20.4% in 2006 to 35.2% in 2011. Variables associated with higher rates of testing, beyond clinical factors such as nodal status (P<.001), included being diagnosed from 2008 through 2012 versus 2006 through 2007 (adjusted odds ratio [OR], 1.67; 95% CI, 1.47-1.90), having preexisting comorbidities (adjusted OR, 1.35; 95% CI, 1.14-1.59), and higher out-of-pocket pharmacy costs (adjusted OR, 1.66; 95% CI, 1.40-1.97). Women younger than 50 years were more likely to be tested if they had stage I versus stage II disease (P<.0001).

CONCLUSIONS

In an insured population of women younger than 65 years, GEP testing increased after its inclusion in clinical practice guidelines and mounting evidence. Additional research is needed to better understand oncologists' decision not to order GEP testing for their patients who are otherwise eligible.

Prognostic Impact of the Combination of Recurrence Score and Quantitative Estrogen Receptor Expression (ESR1) on Predicting Late Distant Recurrence Risk in Estrogen Receptor-Positive Breast Cancer After 5 Years of Tamoxifen: Results From NRG Oncology/National Surgical Adjuvant Breast and Bowel Project B-28 and B-14

PURPOSE

We determined the utility of the 21-Gene Recurrence Score (RS) in predicting late (> 5 years) distant recurrence (LDR) in stage I and II breast cancer within high and low-ESR1-expressing groups.

PATIENTS AND METHODS

RS was assessed in chemotherapy/tamoxifen-treated, estrogen receptor (ER) -positive, node-positive National Surgical Adjuvant Breast and Bowel Project B-28 patients and tamoxifen-treated, ER-positive, node-negative B-14 patients. The association of the RS with risk of distant recurrence (DR) 0 to 5 years and those at risk > 5 years was assessed. An ESR1 expression cut point was optimized in B-28 and tested in B-14.

RESULTS

Median follow-up was 11.2 years for B-28 and 13.9 years for B-14. Of 1,065 B-28 patients, 36% had low (< 18), 34% intermediate (18 to 30), and 30% high (≥ 31) RS. Of 668 B-14 patients, 51% had low, 22% intermediate, and 27% high RS. Median ESR1 expression by reverse transcriptase polymerase chain reaction was: B-28, 9.7 normalized expression cycle threshold units (CT) and B-14, 10.7 CT. In B-28, RS was associated with DR 0 to 5 years (log-rank P < .001) and > 5 to 10 years (log-rank P = .02) regardless of ESR1 expression. An ESR1 expression cut point of 9.1 CT was identified in B-28. It was validated in B-14 patients for whom the RS was associated with DR in years 5 to 15: 6.8% (95% CI, 4.4% to 10.6%) versus 11.2% (95% CI, 6.2% to 19.9%) versus 16.4% (95% CI, 10.2% to 25.7%) for RS < 18, RS 18 to 30, and RS ≥ 31, respectively (log-rank P = .01).

CONCLUSION

For LDR, RS is strongly prognostic in patients with higher quantitative ESR1. Risk of LDR is relatively low for patients with low RS. These results suggest the value of extended tamoxifen therapy merits evaluation in patients with intermediate and high RS with higher ESR1 expression at initial diagnosis.

Utilization and impact of 21-gene recurrence score assay for breast cancer in clinical practice across the United States: lessons learned from the 2010 to 2012 National Cancer Data Base analysis

The aim of our study is to investigate patient selection for the 21-gene recurrence score assay (RS) for breast cancer (BC) and the RS impact on chemotherapy administration (Chemo) in clinical practice across the United States through the retrospective observational study of National Cancer Data Base (NCDB) patients from 2010 to 2012. NCDB captures ~70 % of all newly diagnosed malignancies in the USA annually. The 2010–2012 period depicts data from the beginning of the NCDB that required recording of molecular assays and their data release in April 2015. De-identified demographic and clinical variables of patients that had RS results were analyzed. 513,080 patients had BC; 406,525 were estrogen receptor-positive (ER+). 74,334/91,651 patients with RS recorded as a numerical value (0–100) were analyzed (18.2 % of ER+). Patients’ ages ranged from 18 to 90 (mean = 58.8, median = 59); 99.1 % were females. Patients of Caucasian race, from regions with <7 % having no high school education, and >$63,000 median household income were more likely to be tested than patients of other races, education, or income (p < 0.001). 58.1 % of tests were performed in ER+/lymph node-negative/>1 cm tumors; 16.4 % included ≥N1 disease; 9.9 % included T1a, T3, Stage III and IV, or HER2-positive cancers. Low-risk RS result had 92.2 % negative predictive value for no Chemo. Intermediate-risk RS result had 40.1 % positive predictive value (PPV); high-risk RS had 81.2 % PPV for Chemo. RS is obtained in ~1/5 of ER + BC patients across the USA. Further studies investigating influence and implementation of the newest evidence-based management guidelines regarding patients’ selection for RS test and chemotherapy administration upon obtaining of test results are warranted.

The impact of the 21-gene assay on adjuvant treatment decisions in oestrogen receptor-positive early breast cancer: a prospective study

BACKGROUND

International guidelines, including NICE, recommend using the 21-gene Recurrence Score assay for guiding adjuvant treatment decisions in ER+, HER2-negative early breast cancer (BC). We investigated the impact of adding this assay to standard pathological tests on clinicians'/patients' treatment decisions and on patients' decisional conflict in the United Kingdom.

METHODS

In this prospective multicentre study, eligibility criteria included: ER+ HER2-negative BC (N0/Nmic for patients ⩽50 years; ⩽3 positive lymph nodes for patients >50 years) and being fit for chemotherapy. Physicians'/patients' treatment choices and patients' decisional conflict were recorded pre- and post testing.

RESULTS

The analysis included 137 patients. Overall, adjuvant treatment recommendations changed in 40.7% of patients, with the direction of the change consistent with the Recurrence Score results (net decrease in chemotherapy recommendation rate in low Recurrence Score patients and net increase in high Recurrence Score patients). Patients' choices were generally consistent with physicians' recommendations. Post-testing, patients' decisional conflict decreased significantly (P<0.0001). In the 67 patients meeting the NICE criteria for testing, the recommendation change rate was 49.3%.

CONCLUSIONS

Recurrence Score testing significantly influenced treatment recommendations overall and in the subgroup of patients meeting the NICE criteria, suggesting that this test could substantially alter treatment patterns in the United Kingdom.

[Molecular pathology for breast cancer: Importance of the gene expression profile]

Gene expression arrays are currently used to guide therapy decisions in breast cancer. The indications for gene expression tests are especially important in the group of hormone receptor negative, HER2 positive tumors to decide whether endocrine therapy alone is sufficient or additional chemotherapy is necessary. In this group of luminal tumors conventional clinicopathological parameters are often not suitable to select patients who would benefit from an endocrine therapy alone. Gene expression tests can provide additional information and, therefore, support decision-making and avoid unnecessary chemotherapy. There are a variety of test systems available which poses the questions of which tests should be selected for which patients and how the test results should be evaluated in a direct comparison. This report provides information about three currently available gene expression tests (i.e. OncotypeDx®, Endopredict® and PAM50/Prosigna®), comments on similarities and differences and discusses the impact on therapy decisions. The focus of this article is on a discussion of clinical studies that have compared the different molecular tests in the same clinical study cohort. These investigations allow a first comparative evaluation of the various assays for breast cancer.