Women In Professional And Executive Positions Have Lower Breast-Cancer Risk

SNOWBIRD, UTAH -- A study of a possible link between breast cancer and occupation, conducted by University at Buffalo epidemiologists, shows that premenopausal women who work in professional or executive positions appear to be at lower risk of developing the disease than women who do not.

Sandra Petralia, a doctoral candidate in the UB Department of Social and Preventive Medicine and lead author on the study, said the findings diverge from the small number of earlier studies on the subject, which indicated that women in professional positions were more likely to develop breast cancer.

Results of the research were presented here today at the annual meeting of the Society for Epidemiologic Research.

Little is known about the relationship between the risk of breast cancer and lifetime work history. Researchers at UB sought to learn more about a possible link by analyzing data from the Western New York Breast Cancer Study, a body of health, lifestyle and demographic information obtained through interviews with 617 pre-menopausal and 933 postmenopausal women from 1986-91.

Researchers examined the data for evidence of a breast cancer-job link by comparing cancer cases and controls with the job of longest duration. The data showed that 78 percent of the premenopausal and 42 percent of postmenopausal women were employed at the time of their interview. Thirty-one percent of the first group and 28 percent of the second group reported having five or more jobs in their lifetime.

Results using job of longest duration showed that premenopausal women whose longest job was in the category of "craftsman" were at increased risk of developing breast cancer. This census-bureau category includes jobs such as dressmaker, pattern maker, lab and medical technicians and equipment assemblers. The researchers now are clarifying potential carcinogenic exposures in these jobs.

No effect was found for pre- or postmenopausal women whose longest jobs were in professional fields. Some of the jobs in this category were executives, administrators, accountants, engineers, nurses, teachers, writers and lawyers.

When the researchers analyzed breast-cancer risk and lifetime history of ever holding a professional job, they found that for premenopausal women, having held such a job was associated with a lower risk of developing breast cancer. The effect remained after controlling for other factors known to influence risk of breast cancer, including age at first pregnancy, education and age at menarche.

Results showed no relationship between breast-cancer risk and professional employment among postmenopausal women in the study.

Petralia said more research on the relationship between lifetime occupation and breast cancer is needed to determine if women in professional occupations are, in fact, at lower risk of developing cancer compared to other women.

Also contributing to the study were John Vena, Ph.D.; Jo Freudenheim, Ph.D.; Mya Swanson; Saxon Graham, Ph.D., and John Brasure, all of the UB Department of Social and Preventive Medicine.