Differences between Hispanic and non-Hispanic white women with breast cancer for clinical characteristics and their correlates.

PURPOSE: Body size and ethnicity may influence breast cancer tumor characteristics at diagnosis. We compared Hispanic and non-Hispanic white (NHW) cases for stage of disease, estrogen receptor (ER) status, tumor size, and lymph node status, and the associations of these with body size in the 4-Corners Breast Cancer Study.
METHODS: One thousand five hundred twenty-seven NHW and 798 Hispanic primary incident breast cancer cases diagnosed between October 1999 and May 2004 were included. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by multiple logistic regression.
RESULTS: Hispanic women were more likely to have larger (>1 cm) ER- tumors and more than four positive lymph nodes (P < .003). Lymph node status was not associated with body size. However, among NHW women, obesity (body mass index >30) and increased waist circumference (>38.5 inches) were significantly positively associated with ER- tumor status (OR, 1.87; 95% CI, 1.24-2.81 and OR, 2.59; 95% CI, 1.58-4.22, respectively). In contrast, among Hispanic women, obesity and waist circumference had inverse associations with ER- tumor status (OR, 0.49; 95% CI, 0.29-0.84 and OR, 0.56; 95% CI, 0.30-1.05, respectively).
CONCLUSIONS: Hispanic ethnicity may modify the association of body size and composition with ER- breast cancer. This finding could have relevance to clinical treatment and prognosis.