OCCUPATIONAL RISK-FACTORS FOR FEMALE BREAST-CANCER - A REVIEW

Objectives-Although progress has been made in identifying personal ris k factors and in improving treatment for female breast cancer, inciden ce rates continue to increase. With women now occupying a sizable frac tion of the workforce, it is worth inquiring whether there are occupat ional risk factors for breast cancer. This is a review of occupational studies on female breast cancer. Methods-Suitable reports and publish ed articles with associations of female breast cancer and occupation w ere identified from technical reports, by searching the MEDLINE biblio graphic data base, and by reviewing each paper on cancer that was publ ished in 20 major journals during the period from about 1971-94. Resul ts-A total of 115 studies were identified; 19 studies relied exclusive ly on data collected for administrative purposes, and there were four incident case-control studies and 92 cohort studies. Although data for individual industries, occupations, and exposures were sparse, there was limited evidence of an association with employment in the pharmace utical industry and among cosmetologists and beauticians. Associations were also found for chemists and occupations with possible exposure t o extremely low frequency electromagnetic fields, but potential method ological weaknesses preclude drawing any definite conclusions. There w as little support for increased risks among textiles workers, dry clea ning workers, and nuclear industry workers. Conclusions-Few high quali ty occupational studies directed specifically toward women have been c arried out to allow the unambiguous identification of occupational ris k factors for breast cancer. It is suggested that investigations that account for non-occupational risk factors and that assess exposure in a more detailed way be carried out. One strategy already suggested is to conduct population based, case-control studies in which subjects ar e interviewed about their occupational histories and exposure to chemi cal and physical agents which are then attributed from the job descrip tions by a team of experts. These studies can then be supplemented whe n necessary with cohort studies of specific populations.