Is adjuvant chemotherapy omissible in women with T1-2 stage, node-positive, luminal A type breast cancer?

Risk of recurrence among patients with HR-positive, HER2-negative, early breast cancer receiving adjuvant endocrine therapy: A systematic review and meta-analysis

BACKGROUND

A systematic review and meta-analysis was conducted to assess breast cancer (BC) outcomes among patients with early-stage hormone receptor positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) BC, receiving adjuvant endocrine therapy.

METHODS

Randomized controlled trials (RCTs) and real-world evidence (RWE) studies were identified using Ovid MEDLINE®, Embase, and Evidence-Based Medicine Reviews. Clinical and methodological similarities including alignment of outcome definitions with standardized definitions for efficacy endpoints criteria were assessed to evaluate feasibility of conducting a meta-analysis. Where feasible, 5-year probabilities of BC recurrence or death were estimated using a Bayesian hierarchical arm-based model.

RESULTS

Of 21 included studies, 8 RCTs and 4 RWE studies reported outcome data of interest. There was heterogeneity in outcome reporting, as well as variation in recurrence risk amongst studies with aligned reporting. Of the 12 studies, 10 were considered for inclusion in a meta-analysis of BC recurrence or death. Only a subgroup analysis of node-positive patients (3 studies; n = 7307) was deemed feasible. The 5-year probability of BC recurrence or death was 17.2% (95% credible interval: 14.6%-20.3%).

CONCLUSION

Although studies reporting recurrence outcomes were limited, there remains a high risk of BC recurrence, especially among node-positive patients. Approximately 1 in 6 women with node-positive HR+/HER2- early-stage BC receiving endocrine therapy experience recurrence or death within 5-years of initiating treatment, suggesting a need for novel treatments for this population.

Efficacy of chemotherapy for lymph node-positive luminal A subtype breast cancer patients: an updated meta-analysis

Objective

To assess the association between chemotherapy and prognosis of patients with breast cancer of luminal A subtype and lymph node-positive, luminal A subtype breast cancer

Methods

Articles published between January 1, 2010, and May 1, 2020, were collected from PubMed, Embase, and Web of Science databases. On the basis of a test for heterogeneity, we selected the random effects model or fixed effects model for meta-analysis. Article quality was evaluated by sensitivity analysis, and Begg’s and Egger’s tests were used to measure publication bias.

Results

Six eligible articles were identified. The hazard ratio of overall survival of luminal A breast cancer patients who received both chemotherapy and endocrine therapy was 1.73 (95% CI 1.23, 2.43). The hazard ratio of overall survival for lymph node-positive, luminal A breast cancer patients who received chemotherapy and endocrine therapy was 1.86 and 95% CI 1.26, 2.81. The hazard ratio of relapse-free survival to disease-free survival was 1.30 (95% CI 0.85, 1.77). Tumor size, vascular invasion, and age did not show significant correlations with breast cancer prognosis.

Conclusion

Compared with endocrine therapy alone, the addition of chemotherapy did not improve the prognosis of patients with luminal type A and lymph node positive cancer; instead, side effects of the additional chemotherapy may have negatively affected prognosis. Prospective studies are needed to determine whether the number of positive lymph nodes also correlates with efficacy of chemotherapy of luminal type A breast cancer.

Does chemotherapy improve survival in patients with nodal positive luminal A breast cancer? A retrospective Multicenter Study

Background

In this study based on the BRENDA data, we investigated the impact of endocrine ± chemotherapy for luminal A, nodal positive breast cancer on recurrence free (RFS) and overall survival (OS). In addition, we analysed if tumor size of luminal A breast cancer influences survival in patients with the same number of positive lymph nodes.

Methods

In this retrospective multi-centre cohort study data of 1376 nodal-positive patients with primary diagnosis of luminal A breast cancer during 2001–2008 were analysed. The results were stratified by therapy and adjusted by age, tumor size and number of affected lymph nodes.

Results

In our study population, patients had a good to excellent prognosis (5-year RFS: 91% and tumorspecific 5-year OS 96.5%). There was no significant difference in RFS stratified by patients with only endocrine therapy and with endocrine plus chemo-therapy. Patients with 1–3 affected lymph nodes had no significant differences in OS treated only with endocrine therapy or with endocrine plus chemotherapy, independent of tumor size. Patients with large tumors and more than 3 affected lymph nodes had a significant worse survival as compared to the small tumors. However, despite the worse prognosis of those, adjuvant chemotherapy failed in order to improve RFS.

Conclusions

According to our data, nodal positive patients with luminal A breast cancer have, if any, a limited benefit of adjuvant chemotherapy. Tumor size and nodal status seem to be of prognostic value in terms of survival, however both tumor size as well as nodal status were not predictive for a benefit of adjuvant chemotherapy.

Adjuvant endocrine therapy alone in patients with node-positive, luminal A type breast cancer

Luminal A breast cancer has a much better prognosis than other subtypes, with a low risk of local or regional recurrence. However, there is controversy around under- versus overtreatment with regard to adjuvant treatment of node-positive, luminal A breast cancer. The purpose of this study was to identify whether adjuvant systemic chemotherapy has any benefit in node-positive, luminal A breast cancer and to evaluate feasibility of endocrine therapy without chemotherapy in this group.This was a retrospective study of 11,025 patients who were surgically treated for invasive breast cancer at Samsung Medical Center between January 2004 and December 2013. Luminal A subtype was defined as ER+, HER2-, and Ki-67 < 14%. We compared AC based (AC: doxorubicin or epirubicin, plus cyclophosphamide) adjuvant chemotherapy versus endocrine therapy without chemotherapy in patients with node-positive, luminal A breast cancer.We performed 1: n matching, with a maximum n of 8 on endocrine therapy group (n = 50) to chemotherapy group (n = 642). The median age of the patients in each group at the time of surgery was 58.3 ± 9.5 years in the chemotherapy group and 58.7 ± 11.7 in the endocrine therapy only group. The median follow-up time was 51.9 months (range, 1-125 months). In multivariable analysis, omission of adjuvant chemotherapy in luminal A cancer had no influence on OS and DFS. Axillary lymph node metastasis and progesterone receptor (PR) status were significantly different between the endocrine therapy alone group and the chemotherapy group in terms of OS. Nuclear grade, PR status, and adjuvant radiotherapy were significantly different between the endocrine therapy alone group and the chemotherapy group with regard to DFS. In survival analysis, there were no differences in OS (P = .137) and DFS (P = .225) between the 2 groups.Adjuvant chemotherapy could provide little benefit to postmenopausal patients with luminal A, node-positive breast cancer, and endocrine therapy alone may help reduce morbidity. Future studies with a large number of patients and longer follow-up time are necessary to determine whether chemotherapy might be avoided in this patient population.

Do Patients with Luminal A Breast Cancer Profit from Adjuvant Systemic Therapy? A Retrospective Multicenter Study

BACKGROUND

Luminal A breast cancers respond well to anti-hormonal therapy (HT), are associated with a generally favorable prognosis and constitute the majority of breast cancer subtypes. HT is the mainstay of treatment of these patients, accompanied by an acceptable profile of side effects, whereas the added benefit of chemotherapy (CHT), including anthracycline and taxane-based programs, is less clear-cut and has undergone a process of critical revision.

METHODS

In the framework of the BRENDA collective, we analyzed the benefits of CHT compared to HT in 4570 luminal A patients (pts) with primary diagnosis between 2001 and 2008. The results were adjusted by nodal status, age, tumor size and grading.

RESULTS

There has been a progressive reduction in the use of CHT in luminal A patients during the last decade. Neither univariate nor multivariate analyses showed any statistically significant differences in relapse free survival (RFS) with the addition of CHT to adjuvant HT, independent of the nodal status, age, tumor size or grading. Even for patients with more than 3 affected lymph nodes, there was no significant difference (univariate: p = 0.865; HR 0.94; 95% CI: 0.46-1.93; multivariate: p = 0.812; HR 0.92; 95% CI: 0.45-1.88).

CONCLUSIONS

The addition of CHT to HT provides minimal or no clinical benefit at all to patients with luminal A breast cancer, independent of the RFS-risk. Consequently, risk estimation cannot be the initial step in the decisional process. These findings-that are in line with several publications-should encourage the critical evaluation of applying adjuvant CHT to patients with luminal A breast cancer.