by I-Chun Chen, Fu-Chang Hu, Ching-Hung Lin, Shu-Min Huang,
Dwan-Ying Chang, Ann-Lii Cheng, Yen-Shen Lu
The Breast: VOLUME
59, P211-220, OCTOBER 01, 2021
Background
This meta-analysis aimed to test the hypothesis that the
HER2-positive metastatic breast cancer (mBC) patients treated with anti-HER2
antibodies in trial intervention arms have a greater prolongation of overall
survival (OS) than of progression-free survival (PFS) and this
extra-prolongation of median survival time in OS relates specifically to the
anti-HER2 antibody.
Methods
The NCBI/Pubmed and Cochrane databases were searched
systematically for HER2-positive or mBC trials published in English during
January 1999–November 2017. Treatment arms with shorter PFS were considered as
the “control” arm, whereas those with longer PFS as the “test” arm. The
between-treatment drug differences were grouped into nine categories. Groups
with or without anti-HER2 antibodies were pooled respectively for comparisons.
The interrelationships between PFS and OS hazard ratios (HRs) and median
survival time differences were investigated by conducting fixed-effects and
mixed-effects linear meta-regression analyses.
Results
Twenty-eight trials (10,928 patients) from 438 articles were
collected, and four with missing data were excluded in meta-regression
analysis. Overall median PFS (HR = 0.73, 95% CI: 0.68–0.78) and
median OS (HR = 0.82, 95% CI: 0.77–0.87) weakly favored the longer
PFS arm with a weak correlation between the PFS and OS HRs. However, the
between-treatment drug difference was anti-HER2 antibody, the absolute
increment in median OS time was double that of median PFS time (p < 0.001)
and linearly correlated, which was not found with any non-anti-HER2 antibody
drug differences.
Conclusions
Anti-HER2 antibody in patients with HER2-positive mBC
prolonged OS more than PFS and mandates further investigation.
