The impact of adjuvant chemotherapy on overall survival in premenopausal (age ≤ 50 years) hormone and node positive breast cancer patients with an Oncotype Dx score of 25 or less. A NCDB analysis.

PURPOSE: The RxPONDER trial showed improved outcomes in premenopausal hormone positive breast cancer (BC) with 1-3 nodes and OncotypeDx (RS) score ≤ 25 with adjuvant chemotherapy (Chemo) use. This study aims to determine whether adjuvant chemotherapy improves survival outcomes in young women (≤ 50 years) with node positive, hormone receptor-positive breast cancer and oncotypeDx score ≤ 25.

METHODS

The 2010-2018 National Cancer Database was used to include M0 BC patients aged ≤ 50 years with N1-N3 lymph nodes stages, any T stage, and RS ≤ 25. Kaplan-Meier (KM) and multivariate (MV) propensity score (PS) weighted Cox model was used to compare survival between patients without and with chemo.

RESULTS

8628 women were included of which 3519 (40.8%) received chemo. KM curves showed that chemo use had better survival at 10 years (93 vs 91%) compared to hormonal therapy alone. Hazard Ratio (HR) comparison between the 2 groups favored chemo [0.602(0.482,0.751)]. Subgroup analysis for mortality benefits showed favorable results in Caucasian race [0.512(0.348,0.752)], both age groups of 18-40 years [0.429(0.217,0.847) and 41-50 years [0.585(0.394,0.869)], and RS 12-25 [0.549(0.379,0.795)].

CONCLUSIONS

Based on our analysis, chemo use was noted in 40.8% of young, lymph node + BC patients with an RS score of 0-25. This group of patients had a relative overall survival advantage of around 40% with chemo use, further supporting the findings of the RxPONDER trial. This benefit is of particular significance in patients with a RS of 12-25. The survival advantage was present in all patients less than 50 years, regardless of the age subgroups.