Examining social and clinical characteristics of breast cancer among black women in Trinidad and Tobago: Impact of treatment modalities on survival

Background: While studies have shown that Trinidad and Tobago experiences the highest breast cancer mortality in the Caribbean, the effects of traditional clinical characteristics on treatment and survival have not been analyzed. Methods: We analyzed 2,614 incident breast cancer cases diagnosed between 1995 and 2005 and followed until 2009. Multivariate logistic regression models were fit to examine the effects of race/ethnicity, age, socioeconomic status, place of birth, stage, hormone receptor (HR) status and histology on the likelihood of receiving surgery, radiation, or chemotherapy. Differences in overall survival by treatment were assessed using Cox proportional hazards models. Results: Nine percent of women were diagnosed with distant stage; 54% were identified as HR negative. 95% of women undergo treatment, with nearly 65% receiving at least a combination of two therapies. Women of advanced stage or with HR negative tumors were significantly more likely to undergo chemotherapy but experienced poorer survival (hazard ratio 4.30; 95% CI 3.42-5.41; HR negative 1.22; 95% CI 1.05-1.42), regardless of treatment. Carcinoma not otherwise specified cases were significantly less likely to undergo surgery but had better survival outcomes compared to ductal (hazard ratio 0.81; 95% CI 0.67-0.99). Women having undergone surgery alone, a combination of two therapies, or all therapies had prolonged survival compared to those who received no treatment, after adjustment for other clinical characteristics. Discussion: Although treatment strategies are similar to those reported in the US, disparities in survival remain. Future studies should analyze health care institutional factors which may influence timing and quality of treatment.