A Prospective Cohort Study of Occupational Exposures and Cancer Risk Among Women

A prospective cohort study is proposed to evaluate occupational and environmental risk factors for cancer among women in Shanghai, China. Approximately 75,000 women aged 40-69 who reside in eight geographically defined communities in two urban districts of Shanghai will be recruited via a community-based cancer education program. All eligible subjects will be invited by local health workers from the neighborhood health station to the clinic for an interview and selected anthropometric measurements. The interview will elicit information on demographic background, diet, lifestyle factors, medical history, lifetime occupational history and residential history for the past 20 years. In addition, the women will be asked for information on their husbands' current and usual occupations, and demographic and a few other exposure factors. A spot urine sample and 10 ml of blood will be collected from all cohort members and stored at -70 degrees C for future assays of urine metabolites and DNA and hemoglobin adducts of selected occupational and environmental carcinogens, and polymorphic genes encoding enzymes that are involved in metabolism of relevant carcinogens. Cohort members and their husbands will be followed for cancer outcomes through biennial recontact and linkage with files of the population-based Shanghai Cancer Registry, of the Shanghai Vital Statistics, and of the Shanghai Resident Registry. Medical records and pathology slides will be reviewed for all cancer cases to verify their diagnosis. Post-diagnostic blood samples will be obtained from all cohort members diagnosed with cancer during the follow-up period and stored for future methodologic and etiologic studies. The proposed initial study period is 5 years, with an average follow-up of about 3.5 years. We anticipate, however, that follow-up will continue for 10 years or more.