First-line real-world treatment patterns and survival outcomes in women younger or older than 40 years with metastatic breast cancer in the real-life multicenter French ESME cohort

Abstract

Aim

To describe first-line treatment patterns, overall survival (OS) and real-world progression-free survival (rwPFS) in young women (<40) with metastatic breast cancer (mBC), as compared to women aged 40–69.

Materials and Methods

Data on adult women diagnosed with mBC (2008–2017) were extracted from the ESME mBC database (NCT03275311) which includes consecutive patients starting first-line metastatic treatment in one of the 18 French Comprehensive cancer centers. We reported first-line therapeutic strategy and prognostic factors of OS and rwPFS for women aged < 40 and 40–69.

Results

In total, 14,897 mBC women were included (1512 aged <40). HR+ /HER2- mBC was the most frequent subtype. First-line treatment differed between young patients and older ones for HR+ /HER2- and Triple Negative (TN) mBC. Median OS for women aged < 40 and 40–69, respectively, was 46.9 and 46.2 months for HR+ /HER2- mBC; 13.5 and 15.2 for TN mBC; and, 60.7 and 55.1 for HER2 + mBC. Median rwPFS under first line treatment was 11.6 and 11.9 months for HR+ /HER2- in women aged < 40 and 40–69, respectively; 5.5 and 5.9 for TN, and, 13.3 and 12.9 for HER2 + . Factors associated with shorter OS and rwPFS were similar for both women aged < 40 and 40–69 and included ≥ 3 metastatic sites, visceral metastases, and longer MFI, with time-varying effects observed for several prognostic factors.

Conclusion

Young women presented more frequently with TN and HER2 + subtypes and aggressive mBC than women aged 40–69 did. Prognostic factors of OS and rwPFS were quite similar between age groups and mBC subtypes.