As part of an ongoing large scale population study funded by the Minority Biomedical Research Support (MBRS) Support of Competitive R esearch (SCORE) Program and the National Institute of General Medical Sciences (NIGMS), we are currently pursuing the following Specific Aims in breast cancer:

Aim 1. Compare the DNA repair capacity (DRC) in women with and without breast carcinoma in Puerto Rico using a host cell reactivation assay that provides a direct measurement. It is hypothesized that participants with breast carcinoma have a lower age-adjusted DRC than women without breast carcinoma.

Aim 2. Obtain epidemiological data from participants in order to determine risk factors for breast carcinoma. Each participant (controls and cases) will be administered an epidemiological questionnaire soliciting information on variables that can provide an estimate of breast carcinoma risk in relation to familial, genetic, hormonal and environmental factors. Statistical correlations between the various study variables and risk of developing breast carcinoma will provide valuable information for the development of effective strategies for cancer prevention and control for future studies.

Aim 3. Compare whether the levels of expression of DNA repair genes is correlated with the DNA repair capacity of women with breast carcinoma. It is hypothesized that women with BC have an altered expression of key DNA repair genes. The expression of DNA repair genes in BC tumors will be analyzed in women with low, normal, and high DRC. Microarray analysis will be utilized to identify potential DNA repair genes associated with the risk of breast carcinoma and to test whether candidate DNA repair genes can be utilized to predict DNA repair capacity of women with breast carcinoma.

Aim 4. Examine whether tumor grade and size and presence of axillary lymph node metastasis are associated with the level of DNA repair capacity and levels of expression of DNA repair genes. The pathology report will be analyzed for the presence of axillary lymph node metastasis, the size of the tumor, the histological grade, and type and sub-type of breast carcinoma. It is hypothesized that BC cases with a lower DRC have a higher tumor grade, larger size, and positive axillary lymph node metastasis when compared with BC cases with higher DRC. It is also hypothesized that BC cases with a significant alteration in the expression of DNA repair genes have a higher tumor grade, larger size, and positive axillary lymph node metastasis than BC cases with a normal expression of DNA repair genes.