REPRODUCTIVE AND OTHER FACTORS AND RISK OF EPITHELIAL OVARIAN-CANCER - AN AUSTRALIAN CASE-CONTROL STUDY

Of the few factors known to be associated with epithelial ovarian canc er, the most consistently observed relate to women's reproductive func tion, although even here uncertainties remain. We have undertaken a ca se control study involving personal interviews with over 1,600 women, the largest of its kind to date, to investigate further the associatio ns between women's reproductive histories and other factors and the de velopment of ovarian cancer. Cases were drawn from women diagnosed wit h epithelial ovarian cancer in 3 Australian states, Queensland, New So uth Wales and Victoria, between August 1990 and December 1993, and con trols were drawn at random from the electoral roll, stratified by age and geographic region. Trained interviewers administered standard ques tionnaires to obtain detailed information about women's reproductive a nd contraceptive histories and other factors of interest, such as smok ing and family history of ovarian or other cancer. Findings were based on data from 824 cases and 860 controls and confirmed the reduced ris k of ovarian cancer associated with increasing parity and duration of use of the oral contraceptive pill (OCP), hysterectomy and tubal ligat ion. The strongest association of all was seen with use of the OCP for 10 years or more. An inverse association between ovarian cancer and a ge at first birth was observed, but this was not statistically signifi cant. There were no associations between development of ovarian cancer and number of incomplete pregnancies, use of hormone replacement ther apy or menstrual history. Among other factors considered, education af ter leaving school was negatively associated and high body mass index, family history of ovarian cancer, use of talc in the abdominal or per ineal region and smoking were positively associated with occurrence of ovarian cancer. (C) 1995 Wiley-Liss, Inc