Studies to be presented at ISEE

By LOIS BAKER
News Services Editor

University researchers studying the effects of a gene on breast cancer and the consumption of pesticide-contaminated fish on lactation will present the results of their findings next week in Athens at the annual meeting of the International Society for Environmental Epidemiology.

UB researchers have shown for the first time that a variant of the apolipoprotein E (apoE) gene, known as apoE 4, may increase the risk of breast cancer by inhibiting the elimination of serum triglycerides from the bloodstream.

While women with the highest triglyceride levels had a slight increase in risk of breast cancer, those with the highest levels, plus the apoE 4 genotype, had a four-fold increase in risk.

"We think that apoE 4 keeps serum triglyceride levels elevated by reducing their clearance," said Kirsten Moysich, a molecular epidemiologist at UB and Roswell Park Cancer Institute. "Triglycerides themselves appear to be a risk factor for breast cancer by reducing sex-hormone-binding globulin levels, which may lead to higher endogenous estrogen levels. This genotype seems to keep levels of triglycerides constantly high."

Moysich will present her findings Sept. 6. The study also has been accepted for publication.

The results showed no relationship between increased breast-cancer risk and apoE genotype when comparing only genotypes. Women with the highest levels of triglycerides were found to be at a 70-percent-greater risk than women with the lowest levels. But when comparing triglyceride levels and breast-cancer risk among apoE genotypes, triglycerides were associated with elevated risk only in women with the e4 genotype.

Moysich said that if these results can be replicated, researchers will gain further understanding of the role of dietary factors and serum lipids in breast-cancer development.

Also contributing to the study were Julie Baker, a doctoral student, and Jo L. Freudenheim, professor, both in the Department of Social and Preventive Medicine; Christine Ambrosone, formerly with UB and now a molecular epidemiologist with the Food and Drug Administration, and Elise Bowman and Peter G. Shields, both of the National Cancer Institute.

In a second study, UB reproductive epidemiologists found no association between eating DDE-contaminated sport fish from Lake Ontario and the length of lactation in nursing mothers.

The research is part of the New York State Angler Study, which is assessing the health effects of eating sport fish from Lake Ontario, the most contaminated of the Great Lakes. UB's portion of the study concentrates on the relationship between sport-fish consumption and adverse reproductive events.

"DDE is a potential endocrine disrupter, which means it could interfere with production of hormones that control lactation," said Bridget McGuinness, UB project coordinator for the New York State Angler Study and principal author of the lactation study. She presented results Sept. 7 at the joint meeting of the ISEE and the International Society of Exposure Analysis.

Results showed that women who had eaten sport fish during the study period did lactate for a shorter period than women who had not eaten sport fish, she said. But they had lower levels of DDE in their breast milk than their non-fish-consuming colleagues.

The study cohort was composed of 54 first-time mothers enrolled in the New York State Angler Study who gave birth between 1991 and 1993. During the initial data collection, which ended in 1991, enrollees provided information on consumption of sport fish from Lake Ontario and their intentions to conceive.

"Our study suggests no direct relationship between DDE concentrations in breast milk of first-time mothers who eat sport fish and a shortened duration of lactation," McGuinness said.

Also contributing to the study were John Vena, Germaine Buck, and John Weiner, of the Department of Social and Preventive Medicine; Pauline Mendola, formerly of UB, now with the Environmental Protection Agency, and Hebe Greizerstein and Paul Kostyniak of the Department of Pharmacology and Toxico