Published in:
01-05-2016 | Original paper
Mortality risk from comorbidities independent of triple-negative breast cancer status: NCI-SEER-based cohort analysis
Published in: Cancer Causes & Control | Issue 5/2016
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Purpose
A comparatively high prevalence of comorbidities among African-American/Blacks (AA/B) has been implicated in disparate survival in breast cancer. There is a scarcity of data, however, if this effect persists when accounting for the adverse triple-negative breast cancer (TNBC) subtype which occurs at threefold the rate in AA/B compared to white breast cancer patients.
Methods
We reviewed charts of 214 white and 202 AA/B breast cancer patients in the NCI-SEER Connecticut Tumor Registry who were diagnosed in 2000–2007. We employed the Charlson Co-Morbidity Index (CCI), a weighted 17-item tool to predict risk of death in cancer populations. Cox survival analyses estimated hazard ratios (HRs) for all-cause mortality in relation to TNBC and CCI adjusting for clinicopathological factors.
Results
Among patients with SEER local stage, TNBC increased the risk of death (HR 2.18, 95 % CI 1.14–4.16), which was attenuated when the CCI score was added to the model (Adj. HR 1.50, 95 % CI 0.74–3.01). Conversely, the adverse impact of the CCI score persisted when controlling for TNBC (Adj. HR 1.49, 95 % CI 1.29–1.71; per one point increase). Similar patterns were observed in SEER regional stage, but estimated HRs were lower. AA/B patients with a CCI score of ≥3 had a significantly higher risk of death compared to AA/B patients without comorbidities (Adj. HR 5.65, 95 % CI 2.90–11.02). A lower and nonsignificant effect was observed for whites with a CCI of ≥3 (Adj. HR 1.90, 95 % CI 0.68–5.29).
Conclusions
comorbidities at diagnosis increase risk of death independent of TNBC, and AA/B patients may be disproportionately at risk.