Abstract B21: Molecular epidemiological studies of breast cancer in Puerto Rican women and association with cancer health disparities
Authors: Matta Jaime , Ortiz Carmen , Bayona Manuel , Alvarez-Garriga Carolina , Morales Luisa 
Published: May 2015

Background: Breast cancer (BC) represents approximately 32% of the cancer cases diagnosed in Puerto Rican women and the principal cancer related death in women this population. BC is a complex disease whose risk is influenced by genetic, environmental and epigenetic factors. Although BC incidence among island Puerto Ricans is lower than in the USA, the rate incidence has been increasing 1.3% each year since 1987.

Objective: Our aim is to present key findings of a large population study on the molecular epidemiology of BC in Puerto Rican women. We recently completed the recruitment of nearly 1,200 women in a seven-year molecular epidemiology study focused on the role of DNA repair capacity (DRC) as a risk factor for BC. As part of that study, we gathered extensive epidemiological data on risk factors for BC in Puerto Rican women.

Methods: A 7-page epidemiological questionnaire was utilized for soliciting information on BC risk factors in relation to familial, occupational, and other variables. A total of 502 women with BC and 685 controls were studied. Crude and multiple logistic regression-derived adjusted odds ratios were used as indicators of the associations between BC and the variables under study. DRC was measured in lymphocytes using a host cell reactivation assay with a luciferase reporter gene.

Results: Age is an important risk factor for BC. Women of the 41-60 years of age group had the highest BC risk followed by women with 61 years or more (OR: 2.1, 95%CI 1.3-3.3, OR 1.6, 95%CI 1.2-2.2). Marital status also plays a role on BC risk with single women and widows being the higher risk groups (OR: 2.3 95% CI 1.3-4.0, and OR: 1.8 95%CI 0.9-3.5, respectively). Education was also an important risk factor; women with lower levels of education had a higher BC risk (OR: 3.5 95%CI 1.5- 7.8). Family history of cancer (non BC) and history of BC were both associated with an increase in BC risk (OR 1.8, 95% CI 1.3-2.5). Parity status was associated with a decreased BC risk in women who had at least three full term pregnancies. A higher protection was found in women who had given birth in the 20-29 years of age group (OR 0.6, 95% CI 0.4-0.9). This protection decreased as childbirth age increased. A low DRC was found to be a strong risk factor for BC. DRC was found to have a dose response relationship with women with the lowest levels being the ones with the higher risk (low DRC OR: 14.6 95% CI 9.7-21.9). Women with BC had a 30% reduced odds of multivitamin intake and 40% reduced odds of calcium intake as compared to controls (OR = 0.7; 95% CI: 0.5, 0.9 for multivitamins and OR = 0.6; 95% CI: 0.4, 0.9 for calcium). Women with low DRC had 50% lower odds of taking calcium and 30% lower odds of currently taking vitamins OR = 0.5 (95% CI, 0.4-0.7; P = .001) for calcium and (2) OR = 0.7 (95% CI, 0.5-0.9.1; P = .047) for vitamins. Women with low DRC had 50% lower odds of taking calcium and 30% lower odds of currently taking vitamins OR = 0.5 (95% CI, 0.4-0.7; P = .001) for calcium and (2) OR = 0.7 (95% CI, 0.5-0.9.1; P = .047) for vitamins.

Conclusions: Our study clearly shows the critical importance that DRC exerts as a risk factor for BC. Furthermore, the study provides a more comprehensive understanding of risk factors associated with BC in Puerto Rican women. The identification of higher risk individuals among our particular population can help target the population needing the most effective preventive measures. Supported by grants from the NCI Center to Reduce Health Disparities through the NIH-MBRS Program grants S06 GM008239-20, 1SCA157250 and 9SC1CA182846-04.

Citation Format: Jaime Matta, Carmen Ortiz, Manuel Bayona, Carolina Alvarez-Garriga, Luisa Morales. Molecular epidemiological studies of breast cancer in Puerto Rican women and association with cancer health disparities. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr B21. doi:10.1158/1538-7755.DISP13-B21