A 1993 study (Rubin CH, Burnett CA, Halperin WE, et al. Occupation as a risk identifier for breast cancer. American Journal of Public Health, 1993;83:1311-15) suggested that teachers had twice the risk of dying of breast cancer than other women; this study prompted significant concern because of the magnitude of the suggested increased risk and because teachers comprise one of the largest single occupational groups among women in the US.

To determine the risk of breast cancer by occupation group and specifically among teachers, the researchers analyzed data on more than 563,395 women who were among the female participants in the Cancer Prevention Study II (CPS II). CPS II, a prospective mortality study of about 1.2 million Americans, was begun by the American Cancer Society in 1982.

After nine years of follow-up, the researchers identified 1,780 cases of fatal breast cancer After adjusting for established breast cancer risk factors, the results revealed little variability in breast cancer mortality by occupation. According to the study, in comparison with housewives, women in administrative support, including clerical occupations, were at a small increased risk. Women classified as executives were at an increased risk, based on 10 breast cancer deaths. No significant increases were seen for teachers, librarians, nurses, managers, or women employed in sales or service occupations.

"In this large, prospective mortality study, the mortality from breast cancer experienced by teachers was similar to, and even slightly lower than, breast cancer mortality in housewives," says Eugenia E. Calle, PhD, director of analytic epidemiology for the American Cancer Society and principal investigator for the study. "These results agree with those from two recent, well-conducted, case-control studies of occupation and breast cancer. Together, these studies suggest that teachers do not have any unique occupationally-related exposure that puts them at increased risk of breast cancer. However, similar to other professional women, teachers may have sociodemographic and reproductive profiles that increase their risk for breast cancer, and studies must be able to control for these factors in the analysis," says Dr. Calle. Cont.

The authors caution that the lack of an observed association between occupation and breast cancer mortality does not invalidate efforts to implement workplace screening programs.

"Age-appropriate mammography screening should take place among all women, whether or not their occupation puts them at higher risk. If the workplace offers an opportunity for screening, then such programs should be encouraged," notes Dr. Calle. The American Cancer Society recommends annual mammography for women aged 40 and over.

The American Cancer Society is the nationwide, community-based voluntary health organization dedicated to eliminating cancer as a major health problem by preventing cancer, saving lives and diminishing suffering from cancer, through research, education, advocacy, and service. For more information about cancer or the American Cancer Society and its programs, contact your local American Cancer Society at 1-800-ACS-2345.

Joann Schellenbach
National Director Media Relations
American Cancer Society
212-382-2169
jschelle@cancer.org