Effects of anthropometric characteristics on racial differences in stage at diagnosis among younger women with invasive breast cancer

• Main Author: Monteilh, Carolyn Patricia
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01.01.2000
• Subjects: Breast cancer; Medical diagnosis; Nutrition; Oncology; Public health; Racial differences; Young adults
• ISBN: 9780599889934; 0599889934

This study examined relations between tumor stage and a number of anthropometric characteristics among 858 women aged 20–55 when diagnosed with invasive breast cancer during 1990–1992 in Atlanta, Georgia and examined whether differences in body size may explain differences in stage between 253 African-American and 591 European-American women in the study cohort. Anthropometry was collected during in-person interviews and information on tumor characteristics was abstracted from medical records. In polytomous logistic regression models adjusted for race/ethnicity, grade, detection method, and other non-anthropometric stage determinants, odds of stage III/IV vs. stage I disease in women in the highest quartile relative to those in the lowest were 4.3 (95% confidence interval (CI) = 1.1–16.5) for waist circumference, adjusted for body mass index (BMI); 1.6 (95% CI = 0.5–5.2) for BMI, adjusted for waist; and 1.6 (95% CI: 0.5–5.3) for brassiere cup size, adjusted for waist. Other anthropometric characteristics were not associated with stage independent of BMI or waist. Adipose tissue, especially at the waist, was the body compartment most clearly associated with stage. These relations may be explained in part by effects of adiposity on serum insulin levels and, hence on breast tumor cell proliferation. In polytomous logistic regression models adjusted for other non-anthropometric stage determinants, odds for stage III/IV disease versus stage I among African-American women were 2.1 (95 percent CI: 1.1, 4.0) times those for European-Americans. Further adjustment for BMI reduced the OR to 1.6 (95 percent CI: 0.8, 2.8). Similarly, the prevalence ratio for stage III/IV disease was reduced from 1.7 to 1.4 (1.0, 2.4) when BMI was added to the model. Adjustment for waist circumference had an effect similar to that of BMI, but breast size did not alter the relationship. These findings indicate that overweight may increase the likelihood that younger women with breast cancer will be diagnosed at a later stage. The findings also suggest that, among women under age 55, adiposity, a factor potentially amenable to intervention, may account for 15–20 percent of the excess prevalence of late stage disease among African-American women.