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

Adjuvant Dose-Dense Chemotherapy in Hormone Receptor-Positive Breast Cancer

PURPOSE

In light of evolving evidence that some patients with node-positive estrogen receptor-positive (ER+) disease may receive less benefit from chemotherapy, this study reports 12-year outcomes of the C9741 trial overall, and by the sensitivity to endocrine therapy (SET2,3) test index, a biomarker measuring endocrine transcriptional activity, to identify patients most likely to benefit from dose-dense chemotherapy.

METHODS

In all, 1,973 patients were randomly assigned to dose-dense versus conventional chemotherapy. Hazard ratios (HRs) for prognosis and for predictive interaction with chemotherapy schedule were estimated from Cox models of long-term disease-free survival (DFS) and overall survival (OS). SET2,3 was tested on the 682 banked RNA samples from ER+ cancers.

RESULTS

Dose-dense chemotherapy improved DFS in the overall study population by 23% (HR, 0.77 [95% CI, 0.66 to 0.90]) and OS by 20% (HR, 0.80 [95% CI, 0.67 to 0.95]); the benefits of dose-dense therapy were seen for ER+ and ER-negative subsets, without significant interaction between treatment arm and ER status. Low SET2,3 status was highly prognostic, but also predicted improved outcomes from dose-dense chemotherapy (interaction P = .0998 for DFS; 0.027 for OS), independent of menopausal status. Specifically, low endocrine transcriptional activity predicted benefit from dose-dense chemotherapy, whereas tumor burden and proliferation-driven signatures for molecular subtype classification did not.

CONCLUSION

At 12-year follow-up, C9741 confirmed the sustained long-term benefit of adjuvant dose-dense chemotherapy for node-positive breast cancer. SET2,3 identified patients with ER+ breast cancer who benefited from dose-dense chemotherapy, and specifically, this benefit was predicted by low endocrine activity in the cancer, rather than tumor burden, molecular subtype, or menopausal status.

Gene expression profiling tests to guide adjuvant chemotherapy decisions in lymph node-positive early breast cancer: a systematic review

PURPOSE

To systematically review the effectiveness of gene expression profiling tests to inform adjuvant chemotherapy decisions in people with hormone receptor-positive (HR+), lymph node-positive (LN+) breast cancer.

METHODS

This systematic review assessed the effectiveness of Oncotype DX, Prosigna, EndoPredict and MammaPrint for guiding adjuvant chemotherapy decisions in HR+ early breast cancer with 1-3 positive nodes, in terms of prognostic ability, prediction of chemotherapy benefit, impact on chemotherapy decisions, quality of life and anxiety. Searches covered MEDLINE, EMBASE and Cochrane databases in April 2023.

RESULTS

Fifty-five articles were included. All four tests were prognostic for distant recurrence in LN+ patients. The RxPONDER trial reported no chemotherapy benefit in post-menopausal LN+ patients with low Oncotype DX (RS 0-25), whilst pre-menopausal patients had statistically significant chemotherapy benefit. An RCT reanalysis of Oncotype DX (SWOG-8814) suggested greater chemotherapy benefit with higher RS in post-menopausal LN+ patients. The MINDACT trial reported that LN+ patients with high clinical risk and low MammaPrint risk had a non-statistically significant chemotherapy benefit, but was not designed assess differential chemotherapy benefit per risk group. Decisions to undergo chemotherapy reduced by 12-75% following Oncotype DX testing in LN+ patients in the UK and Europe. No studies in LN+ populations were identified for prediction of chemotherapy benefit by Prosigna or EndoPredict; or for chemotherapy decisions for Prosigna, EndoPredict or MammaPrint; or for anxiety or quality of life impact for any test.

CONCLUSIONS

All four tests have prognostic ability in LN+ patients. Evidence on predictive benefit is weaker, with equivocal evidence that Oncotype DX may predict chemotherapy benefit in LN+ post-menopausal patients. Use of Oncotype DX leads to fewer patients being recommended chemotherapy.

Adjuvant endocrine therapy with cyclin-dependent kinase 4/6 inhibitor, ribociclib, for localized hormone receptor-positive/HER2- breast cancer (LEADER)

Optimal timing and dosing of adjuvant cyclin-dependent kinase (CDK) 4/6 inhibitor in early breast cancer is controversial. This prospective phase II clinical trial investigated tolerability and safety of two ribociclib dosing schedules. Patients with stage I-III hormone receptor-positive (HR+)/HER2- breast cancer on adjuvant endocrine therapy (ET) were randomized to two ribociclib dosing schedules: 400 mg continuous vs 600 mg intermittent, with initiation in early (prior ET < 2 years) vs delayed (prior ET ≥ 2 years) setting. Primary objective was to evaluate safety and tolerability of continuous vs intermittent schedule. Primary endpoint was proportion of patients who discontinued ribociclib before completion of all 12 cycles (measured at 12 months). Recurrence free survival (RFS) and circulating tumor DNA (ctDNA) detection were also evaluated. 81 patients were enrolled. Only six serious adverse events occurred, with no significant difference between treatment arms and no subject deaths. Twenty-five patients (31%) discontinued ribociclib before completion of 12 months, with no significant difference between treatment arms. Ribociclib discontinuation was higher in early vs delayed initiation (36% vs 21%). At median follow-up of 20 months, two patients in the intermittent arm (600 mg; Arm 2) experienced disease recurrence (2-year RFS 97%, 95%CI 88-99%), vs none in the continuous arm (400 mg; Arm 1) (2-year RFS 100%). ctDNA was only identified in the two subjects with recurrent disease at median of 7.5 months prior to radiological recurrence. Ribociclib is a safe and well-tolerated adjunct to adjuvant ET in early-stage breast cancer. Delayed initiation of ribociclib at 400 mg continuous dosing was feasible, better tolerated and associated with promising outcomes. ctDNA detection preceded clinical evidence of recurrence and may be considered as a surveillance tool in breast cancer.

Adjuvant treatment strategy evolution and risk stratification for hormone receptor-positive, human epidermal growth factor receptor-2 negative early breast cancer in China

BACKGROUND

Patients with hormone receptor-positive (HR+), human epidermal growth factor receptor-2 negative (HER2-) early breast cancer (EBC) with high-risk clinicopathological features face an increased risk of recurrence. This study explored the evolving treatment landscape and clinical outcomes in patients with EBC using a nationwide database.

PATIENTS AND METHODS

The study cohort comprised HR+/HER2-, stages 1-3, patients with EBC who underwent surgery and received adjuvant endocrine therapy (AET) from January 2013 to March 2021. High-risk patients were defined by ≥4 positive axillary lymph nodes, or 1-3 positive lymph node(s) with at least one high-risk feature (histologic grade 3, tumor size ≥5 cm, or Ki-67 ≥20%). A low-risk cohort included patients not meeting the criteria. Survival analysis was conducted with a cutoff of September 2021.

RESULTS

The study included 4088 eligible patients (1310 high-risk patients and 2778 low-risk patients). High-risk patients were more likely to receive adjuvant chemotherapy and radiotherapy compared to low-risk patients. From 2013 to 2021, an increasing proportion of patients received aromatase inhibitors and ovarian function suppression as part of their AET. The 2-, 5-, and 7-year invasive disease-free survival for high-risk cohort were 90.67%, 75.26%, and 57.10%, respectively, these rates were notably higher for low-risk cohort at 97.14%, 89.85%, and 84.83%. High-risk patients demonstrated a higher risk of recurrence or death compared with low-risk patients (hazard ratio, 2.38; 95% CI, 1.82-3.12).

CONCLUSION

In the setting of standard or even intensive AET, patients with EBC with high-risk features still present high recurrence risk, highlighting the urgent need for innovative adjuvant treatment strategies.

Selecting postoperative adjuvant systemic therapy for early-stage breast cancer: An updated assessment and systematic review of leading commercially available gene expression assays

Gene expression assays (GEAs) can guide treatment for early-stage breast cancer. Several large prospective randomized clinical trials, and numerous additional studies, now provide new information for selecting an appropriate GEA. This systematic review builds upon prior reviews, with a focus on five widely commercialized GEAs (Breast Cancer Index®, EndoPredict®, MammaPrint®, Oncotype DX®, and Prosigna®). The comprehensive dataset available provides a contemporary opportunity to assess each GEA's utility as a prognosticator and/or predictor of adjuvant therapy benefit.

A UK prospective multicentre decision impact, decision conflict and economic evaluation of the 21-gene assay in women with node+ve, hormone receptor+ve, HER2-ve breast cancer

BACKGROUND

For a tumour profiling test to be of value, it needs to demonstrate that it is changing clinical decisions, improving clinical confidence, and of economic benefit. This trial evaluated the use of the Oncotype DX Breast Recurrence Score® assay against these criteria in 680 women with hormone receptor-positive (HR+), HER2-negative early breast cancer with 1-3 lymph nodes positive (LN+) in the UK National Health Service (NHS).

METHODS

Prior to receipt of the Recurrence Score (RS) result, both the physician and the patient were asked to state their preference for or against chemotherapy and their level of confidence on a scale of 1-5. Following receipt of the RS result, the physician and patient were asked to make a final decision regarding chemotherapy and record their post-test level of confidence.

RESULTS

Receipt of the RS result led to a 51.5% (95% CI, 47.2-55.8%) reduction in chemotherapy, significantly increased the relative and absolute confidence for both physicians and patients and led to an estimated saving to the NHS of £787 per patient.

CONCLUSION

The use of the Oncotype DX assay fulfils the criteria of changing clinical decisions, improving confidence and saving money.

Costs of breast cancer recurrence after initial treatment for HR+, HER2-, high-risk early breast cancer: estimates from SEER-Medicare linked data

OBJECTIVE

To assess the costs of treated recurrence and survival in elderly patients with early breast cancer (EBC) at high risk of recurrence using Surveillance Epidemiology and End Results (SEER) registry-Medicare linked claims data.

METHODS

This retrospective study included patients aged ≥65 years with hormone receptor-positive (HR+), human epidermal growth factor receptor 2 negative (HER2-), node-positive EBC at high risk of recurrence. Treated recurrences were defined based on treatment events/procedure codes from claims. Primary outcomes were monthly total extra costs and cumulative extra costs of treated recurrence relative to patients with non/untreated recurrence. Costs were calculated using a Kaplan-Meier sampling average estimator method and inflated to 2021 US$. Secondary outcomes included analysis by recurrence type and overall survival (OS) after recurrence. Subgroup analysis evaluated costs in patients with Medicare Part D coverage.

RESULTS

Among 3,081 eligible patients [mean (SD) age at diagnosis was 74.5 (7.1) years], the majority were females (97.4%) and white (87.8%). Treated recurrence was observed in 964 patients (31.3%). The monthly extra cost of treated recurrence was highest at the beginning of the first treated recurrence episode, with 6-year cumulative cost of $117,926. Six-year cumulative extra costs were higher for patients with distant recurrences ($168,656) than for patients with locoregional recurrences ($96,465). Median OS was 4.34 years for all treated recurrences, 1.92 years for distant recurrence, and 6.78 years for locoregional recurrence. Similar cumulative extra cost trends were observed in the subgroup with Part D coverage as in the overall population.

LIMITATIONS

This study utilizes claims data to identify treated recurrence. Due to age constraints of the dataset, results may not extrapolate to a younger population where EBC is commonly diagnosed.

CONCLUSION

EBC recurrence in this elderly population has substantial costs, particularly in patients with distant recurrences. Therapies that delay or prevent recurrence may reduce long-term costs significantly.

Cost-effectiveness analysis of abemaciclib with endocrine therapy (ET) versus ET alone for HR+, HER2-, node-positive, high-risk early breast cancer in Italy

Background

Abemaciclib was recently approved by the European Medicines Agency in combination with adjuvant endocrine therapy (ET) for adult patients with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-), node-positive early breast cancer (EBC) at high risk of recurrence.

Objective

To evaluate the cost-effectiveness of abemaciclib plus ET vs. ET alone in patients with HR+, HER2-, node-positive EBC at high risk of disease recurrence, from the Italian healthcare system perspective.

Methods

A cohort state transition model was developed with five states: invasive disease-free survival (IDFS), nonmetastatic recurrence, remission, metastatic recurrence, and death. The analysis had a time horizon of 30 years. Individual patient-level data from the monarchE trial (NCT03155997) were used to generate IDFS estimates. Resource use included drug acquisition/administration, best supportive care, terminal care, adverse events, hospitalization, post-progression therapy, and associated resource use in the metastatic disease health state. Health state utilities were derived from monarchE patient-level data and other sources, applying Italian tariffs where feasible.

Results

The estimated total discounted costs (€39,249 vs. €16,806; difference: €22,443) and quality-adjusted life years (QALYs) (11.49 vs. 10.50; difference: 0.99) were higher for abemaciclib plus ET compared with ET alone. The incremental cost-effectiveness ratio was €22,651 per QALY gained. The likelihood of abemaciclib plus ET being cost-effective vs. ET alone was 99% at a willingness-to-pay threshold of €30,000 per QALY gained.

Conclusion

Abemaciclib plus ET is a cost-effective treatment option vs. ET alone for those with HR+, HER2- node-positive EBC at high risk of recurrence in Italy.

METTL3 depletion contributes to tumour progression and drug resistance via N6 methyladenosine-dependent mechanism in HR+HER2-breast cancer

BACKGROUND

Chemotherapy is an important strategy for the treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+HER2-) breast cancer (BC), but this subtype has a low response rate to chemotherapy. Growing evidence indicates that N⁶-methyladenosine (m⁶A) is the most common RNA modification in eukaryotic cells and that methyltransferase-like 3 (METTL3) participates in tumour progression in several cancer types. Therefore, exploring the function of METTL3 in HR+HER2- BC initiation and development is still important.

METHODS

mRNA and protein expression levels were analysed by quantitative real-time polymerase chain reaction and western blotting, respectively. Cell proliferation was detected by CCK-8 and colony formation assays. Cell cycle progression was assessed by flow cytometry. Cell migration and invasion were analysed by wound healing assays and transwell assays, respectively, and apoptosis was analysed by TUNEL assays. Finally, m⁶A modification was analysed by methylated RNA immunoprecipitation.

RESULTS

Chemotherapy-induced downregulation of the m⁶A modification is regulated by METTL3 depletion in HR+HER2- BC. METTL3 knockdown in MCF-7/T47D cells decreased the drug sensitivity of HR+HER2- BC cells by promoting tumour proliferation and migration and inhibiting apoptosis. Mechanistically, CDKN1A is a downstream target of METTL3 that activates the AKT pathway and promotes epithelial-mesenchymal transformation (EMT). Moreover, a decrease in BAX expression was observed when m⁶A modification was inhibited with METTL3 knockdown, and apoptosis was inhibited by the reduction of caspase-3/-9/-8.

CONCLUSION

METTL3 depletion promotes the proliferation and migration and decreases the drug sensitivity of HR+HER2- BC via regulation of the CDKN1A/EMT and m⁶A-BAX/caspase-9/-3/-8 signalling pathways, which suggests METTL3 played a tumour-suppressor role and it could be a potential biomarker for predicting the prognosis of patients with HR+HER2- BC.

Validation study of a nomogram for predicting probability of low risk of MammaPrint results in women with clinically high-risk breast cancer

BACKGROUND

MammaPrint (MMP) helps clinicians identify the ideal time for adjuvant treatment for patients with early HR+/HER2- breast cancer. We aimed to validate a nomogram designed to predict probability of low risk of MMP results and to evaluate the difference in survival outcome between two groups divided by nomogram score.

METHODS

In this retrospective cohort study, we evaluated 172 patients from Asan Medical Center, Seoul, Korea, who underwent breast cancer surgery and MMP during 2020-2021. First, we validated the nomogram by calculating the area under the curve (AUC) and using calibration. Additionally, with the data of 1,835 T1-3N0-1M0 HR+/HER2- patients from Asan Medical Center during 2010-2013, we compared the disease-free survival (DFS), overall survival (OS), and breast cancer-specific survival (BCSS) rates by Kaplan-Meier analysis between the two groups divided by nomogram total point (TP) of 183.

RESULTS

The AUC calculated by validation of 172 patients was 0.73 (95% confidence interval [CI], 0.66-0.81). The discrimination and calibration of the prediction model were satisfactory following additional validation of 1835 patients. The high-risk and low-risk groups had different 5-year OS (97.9% vs. 98.1%, p = 0.056), DFS (98.6% vs. 99.4%, p = 0.008), and BCSS rates (98.6% vs. 99.4%, p = 0.002).

CONCLUSION

For treatment decision-making among clinically high-risk patients with HR+/HER2- and node-positive disease, the nomogram showed satisfactory performance in predicting patients with low genomic risk. Survival outcome significantly differed between two groups divided by nomogram TP. More studies are needed to validate this model in international cohorts and large prospective cohorts from other institutions.

Impact of the 21-Gene Recurrence Score Assay on Treatment Decisions and Cost in Patients with Node-Positive Breast Cancer: A Multicenter Study in Quebec

BACKGROUND

The 21-gene Breast Recurrence Score (RS) assay, "the assay", has led to a paradigm shift for patients with hormone receptor-positive, node-negative early breast cancer and is emerging as an important tool to assist physician-patient decisions in foregoing chemotherapy in node-positive patients. We wanted to better understand the impact of the RS assay in node-positive patients upon physician treatment decisions and treatment cost in Quebec, Canada.

PATIENTS AND METHODS

We conducted a multicenter, prospective observational trial for Estrogen/Progesterone Receptor (ER/PR)- positive, Human Epidermal Growth Factor Receptor 2 (HER2)-negative breast cancer patients with 1-3 positive lymph nodes. Physicians completed a questionnaire indicating treatment choice prior to and post availability of RS results. The primary endpoint was change in the physician's recommendation for chemotherapy prior to and post assay results. Secondary endpoints included change in physician's expressed level of confidence, and changes in estimated cost of recommended treatments prior to and post assay results.

RESULTS

For the entire cohort, physician recommendation for chemotherapy was reduced by an absolute 67.1% by knowledge of the RS assay result (P < .0001). Physician recommendation of chemotherapy was decreased by 75.9% for patients RS result <14 (P < .0001); and 67.5% for patients with RS result 14-25 (P < .0001). Changes in treatment recommendations were associated with an overall reduction in cost by 73.7% per patient, and after incorporating the cost of the RS test, a cost benefit of $823 CAN at 6-month follow-up.

CONCLUSION

Altogether, we established that the assay led to a two-third reduction in the use of chemotherapy, and was a cost-effective approach for hormone receptor-positive, node-positive breast cancer.

Two Instrument Comparison of Reagents From a US FDA-Approved Assay for the Assessment of Ki-67 in High-Risk Early Breast Cancer

The objective of this study was to measure concordance of results obtained from the US Food and Drug Administration-approved Ki-67 immunohistochemistry MIB-1 pharmDx assay performed on the Dako Omnis automated staining instrument (Omnis) versus results produced from the assay reagents applied using an optimized protocol on the more widely available Autostainer Link 48 (ASL48) platform. Tissue sections obtained from 40 formalin-fixed paraffin-embedded breast carcinoma samples, with available Oncotype DX Breast Recurrence Score (RS) results, were stained. Three certified pathologists scored slides at 3 timepoints, totaling 360 observations for each instrument (N=720 total) using the approved scoring approach. Using the ≥20% cutoff, agreement was calculated with corresponding 2-sided 95% percentile bootstrap confidence intervals (CIs). Pairwise comparisons (N=360) from the interinstrument evaluation, performed with all observers, resulted in 325 (90.3%) concordant outcomes (244 negative and 81 positive) and 35 (9.7%) discordant outcomes. The overall agreement was 90.3% (95% confidence interval, 85.6% to 94.4%). No significant systematic differences were observed between instruments. Specimens scored from the Omnis were on average <1% higher than ASL48, with high correlation and little bias between the continuous Ki-67 scores (concordance correlation coefficient=0.916). Most specimens with a Ki-67 score ≥20% had a RS >25. This study demonstrated that good concordance can be achieved with the reagents run on the ASL48 instrument when using an optimized protocol and standardized scoring.

Clinical and Biological Aspects of Disseminated Tumor Cells and Dormancy in Breast Cancer

Progress in detection and treatment have drastically improved survival for early breast cancer patients. However, distant recurrence causes high mortality and is typically considered incurable. Cancer dissemination occurs via circulating tumor cells (CTCs) and up to 75% of breast cancer patients could harbor micrometastatses at time of diagnosis, while metastatic recurrence often occurs years to decades after treatment. During clinical latency, disseminated tumor cells (DTCs) can enter a state of cell cycle arrest or dormancy at distant sites, and are likely shielded from immune detection and treatment. While this is a challenge, it can also be seen as an outstanding opportunity to target dormant DTCs on time, before their transformation into lethal macrometastatic lesions. Here, we review and discuss progress made in our understanding of DTC and dormancy biology in breast cancer. Strides in our mechanistic insights of these features has led to the identification of possible targeting strategies, yet, their integration into clinical trial design is still uncertain. Incorporating minimally invasive liquid biopsies and rationally designed adjuvant therapies, targeting both proliferating and dormant tumor cells, may help to address current challenges and improve precision cancer care.

Comparison of CTS5 risk model and 21-gene recurrence score assay in large-scale breast cancer population and combination of CTS5 and recurrence score to develop a novel nomogram for prognosis prediction

Background

Breast cancer is the most common malignancy in women. Clinical models such as Oncotype DX recurrence score (RS) and Clinical Treatment Score post–5 years (CTS5) model for survival prediction are crucial for clinical practice. However, it remains unclear whether CTS5 or RS would be a more powerful clinical model for recurrence risk evaluation. Therefore, we conducted the present study to compare the performance of CTS5 risk model and RS on different recurrence evaluation. And we further integrated the two models into a novel nomogram to improve the power for prognosis prediction.

Methods

Female patients with invasive hormone receptor positive breast cancer in the Surveillance, Epidemiology, and End Results Program (SEER) database with RS data available were included. The clinicopathological data were directly extracted from SEER database. Participants were divided into three subsets according to recurrence timing (<36 months, between 36 and 60 months, and >60 months) for model evaluation. Survival receiver operating characteristic curve and C-index were calculated to evaluate discrimination. Calibration curve were used to visual inspection for calibration. Model comparison was assessed by net reclassification index (NRI) method. Nomogram prognostic model was developed with the combination of CTS5 score and RS and also included other critical clinicopathological parameters.

Results

In total, 64044 breast cancer patients were enrolled for analysis. The number of patients with survival <36 months (early recurrence subset), 36–60 months (intermediate recurrence subset) and >60 months (late recurrence subset) were 64044, 36878 and 15926, respectively. For model discrimination, CTS5 model was superior to RS for overall survival (OS) prediction (likelihood ratio test P < 0 0.001). RS model showed better performance for breast cancer specific survival (BCSS) in late recurrence subsets and worse performance in early and intermediate recurrence subsets than CTS5 (likelihood ratio test P < 0 0.001). For calibration, CTS5 model was superior to RS model for OS, which overestimated the recurrence risk in low-risk subgroup. Both models overestimated the risk for BCSS. In either early/intermediate/late recurrence patient subsets, there was no significant difference in NRI between two models in terms of both BCSS and OS, indicating the two models had comparable prognostic value. The nomogram which combined these two models largely improved the discrimination and calibration power (C-index 0.70–0.72).

Conclusions

Our study proved the CTS5 risk model had comparable prognostic value as RS in HR + breast cancer patients. And the novel nomogram model had better discrimination and calibration than both CTS5 and RS, and future large-scale clinical trials are warranted for further validation.

A real-world US study of recurrence risks using combined clinicopathological features in HR-positive, HER2-negative early breast cancer

Aim: To assess invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in hormone receptor-positive, HER2-negative early breast cancer with combined clinicopathological criteria from monarchE, a phase III study of abemaciclib. Methods: US electronic health records were used to compare outcomes between high-risk (≥4 lymph nodes, or 1-3 lymph nodes and grade 3, tumor ≥5 cm, or Ki-67 ≥20%) versus nonhigh-risk groups using Kaplan-Meier methods and Cox regression models. Results: The high-risk group (n = 557) was at higher risk for IDFS and DRFS events than the nonhigh-risk group (n = 3471). IDFS events (hazard ratio: 3.07; 95% CI: 2.45-3.83) and DRFS events (hazard ratio: 3.15; 95% CI: 2.49-3.97) were significantly higher for the high-risk group. Conclusion: Risk of recurrence was three-times greater in the high-risk group, highlighting the need for better therapies.

Breast-conserving therapy is associated with better survival than mastectomy in Early-stage breast cancer: A propensity score analysis

Background

Recent retrospective studies have reported that breast‐conserving therapy (BCT) led to improved overall survival (OS) than mastectomy in some populations. We aimed to compare the efficacy of BCT and mastectomy using the SEER database.

Materials and methods

Between 2010 and 2015, 99,790 eligible patients were identified. We included early‐stage breast cancer patients with 5cm or smaller tumors and three or fewer positive lymph nodes in our study. We compared the OS and breast cancer‐specific survival (BCSS) results among patients with BCT and those with mastectomy. Kaplan‐Meier plots, Cox proportional hazard regressions, competing risk analysis, and multivariate regressions were used to evaluate the outcomes. Propensity‐score matching was used to assemble a cohort of patients with similar baseline characteristics.

Results

In our study, 77,452 (77.6%) patients underwent BCT and 22,338 (22.4%) underwent mastectomy. The 5‐year OS rate was 94.7% in the BCT group and 87.6% in the mastectomy group, and the 5‐year BCSS was 97.2% in the BCT and 94.3% in the mastectomy group. Multivariate analysis in the matched cohort showed that women underwent mastectomy was associated with worse OS (Hazard ratio (HR) = 1.79; 95% confidence intervals (CIs) = 1.59–2.02, p < 0.001) and BCSS (HR = 1.88; 95% CIs = 1.61–2.18, p < 0.001) results compared with those underwent BCT. Patients with different subtypes and age group (>50 years old; ≤50 years old) received BCT showed significantly better OS and BCSS results than those received mastectomy. The effect of surgery choice on survival yielded similar results either for all patients or matched cohorts.

Conclusions

Our study showed that BCT was associated with improved survival compared with mastectomy in early‐stage breast cancer patients. It seems advisable to encourage patients to receive BCT rather than mastectomy in early‐stage patients when feasible and appropriate.

Breast cancer-specific mortality in early breast cancer as defined by high-risk clinical and pathologic characteristics

OBJECTIVES

To investigate breast cancer-specific mortality by early breast cancer (EBC; Stages I-IIIC) subtype; incidence of high-risk indicators for recurrence (defined in monarchE trial); and mortality risk difference by those who did/did not meet these criteria.

MATERIALS AND METHODS

Analyses included patients with initial EBC diagnosis between 2010-2015 from Surveillance, Epidemiology, and End Results (SEER) data (n = 342,149). Cox proportional hazards models and Kaplan-Meier estimates examined mortality among 228,031 patients, by subtype (hormone receptor [HR]-positive [+], human epidermal growth factor receptor-2 [HER2] negative [-]; triple negative [TNBC]; HR+, HER2+; HR-, HER2+). Incidence and mortality among patients who did/did not meet monarchE clinicopathological high-risk criteria were examined.

RESULTS

Among patients with HR+, HER2- EBC, histologic Grade 3 (vs. Grade 1) was the most influential factor on mortality (hazard ratio, 3.61; 95%CI, 3.27, 3.98). Among patients with TNBC, ≥4 ipsilateral axillary positive nodes (vs. node negative) was the most influential factor on mortality (hazard ratio, 3.46; 95%CI, 2.87, 4.17). For patients with HR-, HER2+ or HR+, HER2+ EBC, tumor size ≥5 cm (vs. <1 cm) and ≥4 ipsilateral axillary positive nodes were the most influential factors on mortality. The 60-month mortality rate for the 12% of patients within the HR+, HER2- EBC group meeting monarchE clinicopathological high-risk criteria was 16.5%, versus 7.0% (Stage II-III and node positive) and 2.8% (Stage I or node negative) for those not meeting criteria. The 60-month mortality rate for patients with TNBC was 18.5%.

CONCLUSION

Mortality risk and the relative importance of risk factors varied by subtype. monarchE clinicopathological high-risk criteria were associated with increased mortality risk among patients with HR+, HER2- EBC. Patients with HR+, HER2- EBC, and monarchE clinicopathological high-risk criteria experienced risk of mortality similar to patients with early TNBC. These data highlight a high unmet need in this select patient population who may benefit most from therapy escalation.

Abemaciclib: The First FDA-Approved CDK4/6 Inhibitor for the Adjuvant Treatment of HR+ HER2- Early Breast Cancer

OBJECTIVE

To review the new indication of cyclin-dependent kinase (CDK4/6) inhibitor abemaciclib for the adjuvant treatment of hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-), axillary lymph node (LN) positive early breast cancer (EBC) at high risk of recurrence and a Ki-67 ≥20%.

DATA SOURCES

A literature search was performed through PubMed, ClinicalTrials.gov, and Food and Drug Administration (FDA) website (February 1, 2018, to December 23, 2021) to identify relevant information.

STUDY SELECTION AND DATA EXTRACTION

Human and animal studies related to pharmacology, pharmacokinetics, efficacy, and safety of abemaciclib were identified.

DATA SYNTHESIS

Addition of abemaciclib to standard of care endocrine therapy (ET) for patients with high-risk clinicopathologic features and Ki-67 ≥20% demonstrated 30% reduction in the risk of developing invasive disease and distant recurrence. At 15.5 months, abemaciclib + ET demonstrated a significant improvement in invasive disease-free survival (IDFS) vs ET alone (hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.60-0.93, P = 0.01). At 27 months, IDFS benefit was maintained (HR, 0.70; 95% CI, 0.59-0.82, P < 0.0001). Diarrhea occurred in more than 80% of patients in the abemaciclib arm.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review describes the clinical applicability of adjuvant abemaciclib for patients with HR+, HER2- EBC at high risk for recurrence.

CONCLUSION

Adjuvant abemaciclib significantly reduces the risk for early development of invasive disease and distant recurrence in patients with HR+, HER2- node positive EBC. Longer follow-up is needed to determine the impact of adjuvant abemaciclib on late disease recurrence and survival outcomes.

The clinician's perspective on the 21-gene assay in early breast cancer

Most patients with early HR+ and HER2- breast cancer receive a hormone therapy; the clinical question still open is how to identify patients who can really benefit from adjuvant chemotherapy. The accurate identification of these patients is essential to avoid an over-treatment, increasing the risk of an unnecessary toxicity; on the contrary, the omission of chemotherapy can deprive high risk patients of a potential life-saving treatment (under-treatment). Several multigene assays (MGAs), assessing the risk of relapse according to the biological characteristics of the tumor, have been developed. To date, the 21-gene assay (Oncotype DX Breast Recurrence Score^®) is the only test developed and validated to be actionable, i.e., able to predict the benefit of adjuvant chemotherapy. The different available tests can be classified according to their clinical utility based on their prognostic and predictive value. A prognostic test gives information about the outcome of the disease, regardless of the administered therapy. When the aim of the test is to drive the treatment decisions, the predictive component, and therefore the ability to accurately identify which patients could benefit from chemotherapy, is essential. This review summarizes the clinical evidences of the Oncotype DX^® test supporting its clinical utility.

Adjuvant abemaciclib combined with endocrine therapy for high-risk early breast cancer: updated efficacy and Ki-67 analysis from the monarchE study

BACKGROUND

Adjuvant abemaciclib combined with endocrine therapy (ET) previously demonstrated clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer at the second interim analysis, however follow-up was limited. Here, we present results of the prespecified primary outcome analysis and an additional follow-up analysis.

PATIENTS AND METHODS

This global, phase III, open-label trial randomized (1 : 1) 5637 patients to adjuvant ET for ≥5 years ± abemaciclib for 2 years. Cohort 1 enrolled patients with ≥4 positive axillary lymph nodes (ALNs), or 1-3 positive ALNs and either grade 3 disease or tumor ≥5 cm. Cohort 2 enrolled patients with 1-3 positive ALNs and centrally determined high Ki-67 index (≥20%). The primary endpoint was IDFS in the intent-to-treat population (cohorts 1 and 2). Secondary endpoints were IDFS in patients with high Ki-67, DRFS, overall survival, and safety.

RESULTS

At the primary outcome analysis, with 19 months median follow-up time, abemaciclib + ET resulted in a 29% reduction in the risk of developing an IDFS event [hazard ratio (HR) = 0.71, 95% confidence interval (CI) 0.58-0.87; nominal P = 0.0009]. At the additional follow-up analysis, with 27 months median follow-up and 90% of patients off treatment, IDFS (HR = 0.70, 95% CI 0.59-0.82; nominal P < 0.0001) and DRFS (HR = 0.69, 95% CI 0.57-0.83; nominal P < 0.0001) benefit was maintained. The absolute improvements in 3-year IDFS and DRFS rates were 5.4% and 4.2%, respectively. Whereas Ki-67 index was prognostic, abemaciclib benefit was consistent regardless of Ki-67 index. Safety data were consistent with the known abemaciclib risk profile.

CONCLUSION

Abemaciclib + ET significantly improved IDFS in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer, with an acceptable safety profile. Ki-67 index was prognostic, but abemaciclib benefit was observed regardless of Ki-67 index. Overall, the robust treatment benefit of abemaciclib extended beyond the 2-year treatment period.

Adjuvant CDK4/6 inhibitors combined with endocrine therapy in HR-positive, HER2-negative early breast cancer: A meta-analysis of randomized clinical trials

BACKGROUND

The benefit of adjuvant cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors with endocrine therapy (ET) in hormone receptor-positive, human epidermal growth factor 2 receptor-negative (HR+/HER2-) early breast cancer (EBC) is uncertain. Hence, we performed a meta-analysis to determine the efficacy and safety of adjuvant CDK4/6 inhibitors plus ET and to identify potential preferred subpopulations for this regimen.

METHODS

A literature search was conducted in PubMed, Embase, Cochrane databases up to Jan 15, 2021. Hazard ratios (HRs) for invasive disease-free survival (IDFS) and risk ratios (RRs) for grade 3/4 adverse events (AEs) and treatment discontinuation were extracted. Analysis with predefined subgroup variables was done. Trial sequential analysis (TSA) was performed to assess the conclusiveness of survival outcomes.

RESULTS

Three trials were eligible (N = 12647). Compared with ET, adjuvant CDK4/6 inhibitors with ET prolonged IDFS in patients with HR+/HER2- EBC (HR 0.87, 95% CI 0.76-0.98, p = 0.03, I2 = 19%), with positive therapeutic responses observed in patients with N2/N3 nodal status (HR 0.83, 95% CI 0.71-0.97, p = 0.02, I2 = 0%). None of the cumulative z-curves crossed the trial monitoring boundaries in TSA, and no reliable conclusion could be drawn. The combination treatment carried a higher risk of grade 3/4 AEs (RR 4.14, 95% CI 3.33-5.15, p < 0.00001) and an increase in treatment discontinuation due to AEs (RR 19.16, 95% CI 9.27-39.61, p < 0.00001).

CONCLUSIONS

Adjuvant CDK4/6 inhibitors with ET might provide survival benefit in HR+/HER2- EBC. A statistically significantly improved IDFS was only observed in N2/N3 subgroup. However, overall evidence favoring the use of this combination regimen was inadequate.

The role of CDK4/6 inhibitors in early breast cancer

The use of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) has proven to be a successful strategy in the treatment of advanced hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) breast cancer (BC), leading to a strong interest in their possible role in the treatment of early luminal BC. In this review we collect the most relevant and recent information on the use of CDK4/6i for the treatment of early BC in the neoadjuvant and adjuvant settings. Specifically, we evaluate the results of the large phase 3 adjuvant trials recently released, which have yielded apparently divergent results. We also examine the relevance of biomarkers as response predictive factors for CDI4/6i, the combination between radiotherapy and CDK4/6i, and provide a critical discussion on the evidence that we have so far and future directions of the role of these drugs in the treatment of early BC.

Abemaciclib Combined With Endocrine Therapy for the Adjuvant Treatment of HR+, HER2-, Node-Positive, High-Risk, Early Breast Cancer (monarchE)

PURPOSE

Many patients with HR+, HER2- early breast cancer (EBC) will not experience recurrence or have distant recurrence with currently available standard therapies. However, up to 30% of patients with high-risk clinical and/or pathologic features may experience distant recurrence, many in the first few years. Superior treatment options are needed to prevent early recurrence and development of metastases for this group of patients. Abemaciclib is an oral, continuously dosed, CDK4/6 inhibitor approved for HR+, HER2- advanced breast cancer (ABC). Efficacy and safety of abemaciclib in ABC supported evaluation in the adjuvant setting.

METHODS

This open-label, phase III study included patients with HR+, HER2-, high-risk EBC, who had surgery and, as indicated, radiotherapy and/or adjuvant/neoadjuvant chemotherapy. Patients with four or more positive nodes, or one to three nodes and either tumor size ≥ 5 cm, histologic grade 3, or central Ki-67 ≥ 20%, were eligible and randomly assigned (1:1) to standard-of-care adjuvant endocrine therapy (ET) with or without abemaciclib (150 mg twice daily for 2 years). The primary end point was invasive disease-free survival (IDFS), and secondary end points included distant relapse-free survival, overall survival, and safety.

RESULTS

At a preplanned efficacy interim analysis, among 5,637 randomly assigned patients, 323 IDFS events were observed in the intent-to-treat population. Abemaciclib plus ET demonstrated superior IDFS versus ET alone (P = .01; hazard ratio, 0.75; 95% CI, 0.60 to 0.93), with 2-year IDFS rates of 92.2% versus 88.7%, respectively. Safety data were consistent with the known safety profile of abemaciclib.

CONCLUSION

Abemaciclib when combined with ET is the first CDK4/6 inhibitor to demonstrate a significant improvement in IDFS in patients with HR+, HER2- node-positive EBC at high risk of early recurrence.

Oncotype DX testing in node-positive breast cancer strongly impacts chemotherapy use at a comprehensive cancer center

PURPOSE

In 2016, we initiated standardized "reflex" Oncotype DX Recurrence Score (RS) testing for patients ≤ 65 years with pT1-2N0-1 HR⁺/HER2^- breast cancer. Here, we examine RS testing patterns, RS distribution, and factors associated with chemotherapy use in patients with pN1 breast cancer.

METHODS

Patients with stage I-III HR⁺/HER2^- pN1 breast cancer treated with upfront surgery from February 2016 to March 2019 were identified. Clinical characteristics were compared between patients meeting reflex RS testing criteria, those with RS ordered outside of reflex criteria, and those without RS testing. RS was categorized as low (< 18), intermediate (18-30), and high (≥ 31). Multivariate logistic regression was performed to identify factors associated with adjuvant chemotherapy receipt. We examined 3-year recurrence-free survival (RFS) and overall survival (OS) stratified by chemotherapy use.

RESULTS

We identified 347 HR⁺/HER2^- pN1 patients; 272 (78.4%) received RS testing, and 194 (71.3%) met reflex criteria. RS was < 18 in 164 (61.4%) patients, 18-30 in 89 (32.7%) patients, and ≥ 31 in 16 (5.9%) patients. On multivariate analysis, RS < 18 (OR 0.47, 95% CI 0.24-0.92) was associated with lower odds of chemotherapy use, whereas presence of lymphovascular invasion (OR 1.77, 95% CI 1.03-3.07) and lobular subtype (OR 2.40, 95% CI 1.21-4.78) were associated with higher odds. No differences in 3-year RFS (p = 0.97) or OS (p = 0.19) based on chemotherapy receipt were observed.

CONCLUSION

Most RS-tested HR⁺/HER2^- pN1 patients at our center had low genomic risk. A low RS independently influenced chemotherapy omission and in RS-tested patients, short-term outcomes were excellent. Our study demonstrates increased use of RS in guiding adjuvant treatment decisions in node-positive disease.

Impact of the 21-gene recurrence score assay on chemotherapy decision making and outcomes for breast cancer patients with four or more positive lymph nodes

BACKGROUND

To assess the impact of the 21-gene recurrence score (RS) on chemotherapy decision making and survival outcomes for breast cancer patients with >4 positive lymph nodes.

METHODS

Patients with non-metastatic estrogen receptor-positive breast cancer with >4 positive lymph nodes diagnosed between 2004 and 2013 were identified using the Surveillance, Epidemiology, and End Results database. The relationships between the 21-gene RS value and survival outcomes, chemotherapy decision-making, and chemotherapy benefit were analyzed.

RESULTS

A total of 410 patients were identified, including 191 (46.6%), 164 (40.0%), and 55 (13.4%) in the low-, intermediate-, and high-risk RS groups, respectively. The 21-gene RS assay results were independently related to chemotherapy receipt. A total of 59.0%, 68.0%, and 78.0% of patients received chemotherapy in the low-, intermediate-, and high-risk RS groups, respectively. The 21-gene RS was an independent indicator of breast cancer specific survival (BCSS) and overall survival (OS). Intermediate-risk [BCSS: hazards ratio (HR), 2.832, 95% confidence interval (CI): 1.160-6.910, P=0.022; OS: HR, 3.704, 95% CI: 1.750-7.836, P=0.001] and high-risk RS (BCSS: HR, 6.440, 95% CI: 2.597-15.974, P<0.001; OS: HR, 5.053, 95% CI: 2.199-11.608, P<0.001) cohorts had significantly lower survival outcomes compared to low-risk RS cohort. The 5-year BCSS were 92.7%, 88.3%, and 70.7% in patients in the low-, intermediate-, and high-risk RS cohorts, respectively (P<0.001), and the 5-year OS were 92.1%, 80.6%, and 66.6%, respectively (P<0.001).

CONCLUSIONS

The 21-gene RS is an independent predictor of chemotherapy receipt and survival outcomes for breast cancer patients with > 4 positive lymph nodes.

Prediction of chemotherapy benefit by EndoPredict in patients with breast cancer who received adjuvant endocrine therapy plus chemotherapy or endocrine therapy alone

Purpose

EndoPredict (EPclin) is a prognostic test validated to inform decisions on adjuvant chemotherapy to endocrine therapy alone for patients with oestrogen receptor-positive, HER2-negative breast cancer. Here, we determine the performance of EPclin for estimating 10-year distant recurrence-free interval (DRFI) rates for those who received adjuvant endocrine therapy (ET) alone compared to those with chemotherapy plus endocrine therapy (ET + C).

Methods

A total of 3746 women were included in this joint analysis. 2630 patients received 5 years of ET alone (ABCSG-6/8, TransATAC) and 1116 patients received ET + C (GEICAM 2003-02/9906). The primary objective was to evaluate the ability of EPclin to provide an estimate of the 10-year DR rate as a continuous function of EPclin separately for ET alone and ET + C. Cox proportional hazard models were used for these analyses.

Results

EPclin was highly prognostic for DR in women who received ET alone (HR 2.79 (2.49–3.13), P < 0.0001) as well as in those who received ET + C (HR 2.27 (1.99–2.59), P < 0.0001). Women who received ET + C had significantly smaller increases in 10-year DR rates with the increasing EPclin score than those receiving ET alone (EPclin = 5; 12% ET + C vs. 20% ET alone). We observed a significant positive interaction between EPclin and treatment groups (P-_interaction = 0.022).

Conclusions

In this comparative non-randomised analysis, the rate of increase in DR with EPclin score was significantly reduced in women who received ET + C versus ET alone. Our indirect comparisons suggest that a high EPclin score can predict chemotherapy benefit in women with ER-positive, HER2-negative disease.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05226-8) contains supplementary material, which is available to authorized users.

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.