Risk factors for epithelial ovarian cancer in Beijing, China
Chen, Y.; Wu, P.C.; Lang, J.H.; Ge, W.J.; Hartge, P.; Brinton, L.A.
International Journal of Epidemiology 21(1): 23-29
1992
ISSN/ISBN: 0300-5771 PMID: 1544753 DOI: 10.1093/ije/21.1.23Document Number: 317989
Data for 112 patients with epithelial ovarian cancer were compared with data for 224 age-matched community controls from the metropolitan area of Beijing, China to determine the role of risk factors in a low incidence area (5/100,000 in Shanghai, China compared with 12.9 in San Francisco, California) and whether these factors vary with those found elsewhere. Women who experienced 1, 2, and 3 full-term pregnancies had a 50%, 70%, and 90% reduced risk of ovarian cancer (p.01). Late age at 1st pregnancy appeared to have a strong effect on ovarian cancer, but after adjusting for parity and education its effect disappeared. Married nulliparous women were 5.7 time more likely to develop ovarian cancer than single nulliparous women (p=.01). Moreover married women who tried to conceive for 12 months had a relative risk (RR) for ovarian cancer of 5.6 (p=.01). Women who had experienced =or+ 30 ovulatory years were 2.6 times more likely to develop ovarian cancer than those who only experienced 10 years (p.01). Cases had significantly higher mumps antibody titers than did the controls (RR=1.8 for antibody titer of 1: 20; RR=3.6 for 1: 40; p.01) indicating that a mumps virus infection does not have a protective effect against ovarian cancer as reported in another study. Women who had applied talc powder to the lower abdomen and perineum for 3 months were 3.9 times at risk than those who did not. Women who used oral contraceptives (OCs) for 1 year had a decreased risk of ovarian cancer (RR=.7) and those who took OCs for 1-2 years and 3 years had an elevated risk (RR=1.4 and 1.1, respectively), but the trend was not significant (p=.75). The risk factors of ovarian cancer for Chinese women were comparable to those of western women.