Study Identifies Patients With Breast Cancer Who Don’t Benefit From Adjuvant Chemo

Breast cancer patients who had a pathologic complete response (pCR) after neoadjuvant chemotherapy may not benefit from adjuvant chemotherapy, according to a meta-analysis presented at the 2018 San Antonio Breast Cancer Symposium (SABCS) in San Antonio, Texas.¹

“While the prognostic significance of pCR after neoadjuvant chemotherapy is relatively well established, the impact of adjuvant therapy in modulating the relationship between pCR and long-term outcomes is less clear,” said the study presenter Laura Spring, MD, medical oncologist at Massachusetts General Hospital Cancer Center and instructor in medicine at Harvard Medical School, Boston, Massachusetts. “Furthermore, the relationship between the magnitude of pCR change and corresponding change in long-term clinical outcomes has not been well established.”

A meta-analysis of 52 studies encompassing 27,895 breast cancer patients was conducted to establish the following relationships: association between pCR and survival outcomes by breast cancer subtype, impact of adjuvant chemotherapy on the association between pCR and survival outcomes, and the magnitude of change in pCR and corresponding change in survival outcomes.

Compared with breast cancer patients with residual disease, patients who achieved a pCR after neoadjuvant chemotherapy had an improved event-free survival (EFS; hazard ratio [HR] = 0.31, 95% PI: 0.24–0.39, 26,378 participants) and overall survival (HR = 0.22; 95% PI, 0.15–0.30, 23,329 participants). The 5-year EFS for patients who achieved pCR was similar regardless of whether adjuvant chemotherapy was given (86% for those with adjuvant chemotherapy vs 88% without adjuvant chemotherapy). Further, based on a model, the magnitude of pCR change was predictive of EFS.

“Achieving pCR following neoadjuvant chemotherapy is associated with significantly improved event-free survival and overall survival, particularly for triple-negative and HER2-positive breast cancer,” concluded Dr Spring. “The similar outcomes with or without adjuvant chemotherapy in patients who obtained pCR after neoadjuvant chemotherapy likely reflects tumor biology [and] suggests adjuvant chemotherapy can potentially be omitted in certain circumstances.”

Read more of Cancer Therapy Advisor‘s coverage of the SABCS 2018 meeting by visiting the conference page.

Reference

1. Spring LM, Fell G, Arfe A, et al. Pathological complete response after neoadjuvant chemotherapy and impact on breast cancer recurrence and mortality, stratified by breast cancer subtypes and adjuvant chemotherapy usage: Individual patient-level meta-analyses of over 27,000 patients. Oral presentation at: 2018 San Antonio Breast Cancer Symposium; December 4-8, 2018; San Antonio, TX. GS2-03.