The Southern Medical Journal (SMJ) is the official, peer-reviewed journal of the Southern Medical Association. It has a multidisciplinary and inter-professional focus that covers a broad range of topics relevant to physicians and other healthcare specialists.

SMJ // Article

Original Article

Does the Number of Positive Nodes in pN1 Premenopausal HR+/HER2− Breast Cancer Patients with a Low 21-Gene Recurrence Score Predict Chemotherapy Benefit?

Authors: Kelly Kapp, MD, Austin D. Williams, MD, MSEd, Nathan Wong, MD, Carmen de Carvajal, MD, Jennifer D. Son, MD, Lucy De La Cruz, MD

Abstract

Objectives: The RxPONDER trial showed premenopausal patients with pT1-2 N1 hormone receptor-positive (HR+)/HER2− breast cancer benefit from chemotherapy regardless of 21-gene recurrence score (RS), but it did not analyze whether the number of positive lymph nodes (+LNs) was correlative of outcomes. Our study sought to evaluate whether the number of +LNs predicted chemotherapy benefit in pN1 premenopausal women with a low RS.

Methods: Using the National Cancer Database, we identified females younger than 50 years with HR+/HER2− invasive breast cancer, stratified by RS (<25 and > 25) and number of +LNs. We analyzed clinicopathologic features, adjuvant therapies received, and overall survival (OS).

Results: Within the cohort of 12,017 patients, 86% had a RS ≤25, whereas 77% had 1 +LN, 18% had 2 +LNs, and only 5% had three +LNs. Of patients with RS ≤25, 57% had endocrine therapy alone and 38% had combination chemoendocrine therapy. Chemotherapy omission was associated with worse unadjusted OS in the overall cohort and in the subgroup with only 1 +LN (both P < 0.001). Factors associated with worse adjusted OS were Black race (hazard ratio 1.91), intermediate/high tumor grade (hazard ratios 1.93 and 3.75), T2 tumors (hazard ratio 1.59), having 2 or 3 +LNs (hazard ratios 1.53 and 2.17), the use of endocrine therapy alone (hazard ratio 1.64), and increasing RS (hazard ratio 1.08; all P < 0.05).

Conclusions: Chemotherapy was omitted in more than half of the patients younger than 50 years with RS ≤25 during the study period, and omission was associated with worse OS in every LN category. These findings confirm the benefit of chemotherapy even in patients with limited nodal disease.
Posted in: Breast Cancer21

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