The danger of extrapolation. Humans and rodents differ in response to PCBs.
Authors: Mary Eubanks
Journal: Environmental Health Perspectives (2004)

Sport-Caught Fish and Breast CancerAngling for More DataThe U.S. Food and Drug Administration inspects fish sold at market for environmental contaminants and removes tainted seafood from sale.But consumption of sport-caught fish by fishing enthusiasts and those with whom they share their catch may expose these people to chemicals that affect development of breast cancer in some women, according to a study by University of Wisconsin Comprehensive Cancer Center staff scientist Jane McElroy and colleagues [EHP 112:156-162].Despite advisories warning anglers away from contaminated fishing spots, consumption of sport-caught fish remains an important route of human exposure to halogenated hydrocarbons thought to be risk factors for breast cancer.Several of these agents-including polychlorinated biphenyls (PCBs), oily liquids not manufactured since the 1970s but once used as industrial lubricants and coolants; the U.S.-banned pesticide DDT and its most stable metabolite, DDE; and polybrominated diphenyl ethers (PBDEs), which are currently used as flame retardants in textiles, furniture, and other household and office items-accumulate in lake fish.And although recall of eating behaviors over time is imperfect, studies have shown that self-reported histories of the amount of fish consumed correlate with body burdens of PCBs, DDT/DDE, and PBDEs.McElroy's group has been studying risk factors related to breast cancer as part of an ongoing population-based case-control study.Along with fish consumption, the researchers are also looking at how factors such as physical activity, family history, alcohol consumption, hormone use, and reproductive history impact a woman's chances of developing breast cancer.The team used telephone interviews of patients newly diagnosed with the disease between 1998 and 2000 to gather data on 1,481 Wisconsin women aged 20-69.A control group of 1,301 randomly selected Wisconsin women with a similar age distribution also was interviewed.The women were asked how often they ate sport-caught fish-and whether any of this fish had been caught in the Great Lakes-over a 12-month period five years before the interviewee's cancer diagnosis or five years before a control's matched reference age.Consistent with other studies, the survey revealed that the women with breast cancer had gained more weight after age 18 than women without.They were also, as a group, younger at menarche and older at menopause, and were more likely to be older at first fullterm pregnancy, consume more alcohol, and have a family history of breast cancer.But women with breast cancer and their age-matched controls were similarly likely to have eaten sport-caught fish, from the Great Lakes as well as from other fishing spots.Overall, the team found that sport-caught fish consumption was not associated with breast cancer risk in Wisconsin women.But there were two potentially troubling findings specifically regarding premenopausal women under age 40: those who ate any sport-caught fish had almost double the risk of developing breast cancer, and those who ate Great Lakes sport-caught fish had a 74% greater risk.Although the study makes the link between cancer and consumption of sport-caught fish-a food potentially high in PCBs,