- During a 2-decade span, the incidence of distant-relapse metastatic breast cancer (rMBC) declined by more than half in patients with stage I-III invasive breast cancer, yet there was no corresponding improvement in distant disease-specific survival (DDSS).
- Possible explanations include a shift to more triple-negative breast cancer (TNBC) subtype, 2 or more metastatic sites, and more visceral metastases.
Why this matters
- Better therapies are needed for TNBC at initial diagnosis, and for rMBC.
- Retrospective cohort of early BC (n=8292) at a community-based institutional registry (1990-2011).
- 12% of the cohort developed rMBC (n=964).
- Funding: Kaplan Center Research Fund; Metastatic Breast Cancer Alliance; NIH.
- The proportion of rMBC cases declined from 19% (1990-1998) to 11% (1999-2004) to 7% (2005-2011; P<.001>
- There was a shift among the rMBC cases over time:
- from stage I/II at initial BC diagnosis to stage III (P=.002); and
- from HER2+ subtype, which declined from 21% (1999-2004) to 13% (2005-2001), to TNBC, which increased from 19% to 27% (P=.011).
- There was also an increase over time in the proportion of simultaneous local/regional/distant recurrence at first recurrence, ≥2 metastatic sites, and more visceral metastasis (P<.001>
- No improvement in DDSS over time.
- Single institution.
- Observational design.