Distinct HR expression patterns significantly affect the clinical behavior of metastatic HER2+ breast cancer and degree of benefit from novel anti-HER2 agents in the real world setting.

ABSTRACT: We analyzed data from 738 HER2-positive metastatic breast cancer (mbc) patients treated with pertuzumab-based regimens and/or T-DM1 at 45 Italian centers. Outcomes were explored in relation to tumor subtype assessed by immunohistochemistry (IHC). The median progression-free survival at first-line (mPFS1) was 12 months. Pertuzumab as first-line conferred longer mPFS1 compared to other first-line treatments (16 vs. 9 months, p = 0.0001), regardless of IHC subtype. Median PFS in second-line (mPFS2) was 7 months, with no difference by IHC subtype, but it was more favorable with T-DM1 compared to other agents (7 vs. 6 months, p = 0.03). There was no PFS2 gain in patients with tumors expressing both hormonal receptors (HRs; p = 0.17), while a trend emerged for tumors with one HR (p = 0.05). Conv

SUBMITTER: Pizzuti L 

PROVIDER: S-EPMC7027476 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature