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APHA Scientific Session and Event Listing

Brian Kunkle, MPH and Deodutta Roy, PhD. Robert Stempel School of Public Health, Florida International University, 10440 SW 41 St., Miami, FL 33165, 570-436-0293, brkunk@gmail.com

Interaction between environment and genetics may cause a large proportion of breast cancers. The strong link between hormonal factors and risk of breast cancer has increased attention on metabolic pathways and their possible role in breast cancer etiology. Reactive oxygen species (ROS), natural byproducts of cellular metabolism, have been suggested as plausible agents in the development of cancer because of their ability to damage cell membranes, mitochondria, and DNA. Because manganese superoxide dismutase (MnSOD) removes ROS, a decreased risk of breast cancer among MnSOD Val genotypes compared to the less active Ala variant is hypothesized. To investigate this relationship, published epidemiological studies on MnSOD genotype and risk of breast cancer were evaluated and pooled for analysis. We calculated odds ratios for genotype and exposure status. In a pooled analysis of 10 case-control studies (n=7,010 cases; n=7,491 controls), a slight increased risk for breast cancer was observed in women with MnSOD^Val/Ala and MnSOD^Ala/Ala genotype (OR=1.08, 95% CI:1.00-1.16; OR=1.15, 95% CI:1.04-1.26). Select studies pooled by exposure data found a higher increase in risk for women exposed to hormonal contraceptives with MnSOD^Val/Ala and MnSOD^Ala/Ala genotype (OR=2.18, 95% CI:1.46-3.28; OR=172, 95% CI:1.08-2.76). Women exposed to hormone replacement therapy with MnSOD^Val/Ala and MnSOD^Ala/Ala genotype were also at increased risk (OR=1.18, 95% CI:0.74-1.88; OR=1.31, 95% CI:0.76-2.28), though not significantly. These results suggest carriers of the Ala allele of MnSOD, especially those exposed to hormonal contraceptives, may be at increased risk of breast cancer.

Learning Objectives:

• Recognize possible interactions between genetics, environmental exposures, and risk of breast cancer.
• Describe metabolic pathways linked to environmental exposures and possible increase in breast cancer risk.
• Conduct a pooled analysis of data from several studies.

Keywords: Breast Cancer, Genetics

Presenting author's disclosure statement:

Not Answered