RISK-FACTORS FOR FAMILIAL AND SPORADIC OVARIAN-CANCER AMONG FRENCH-CANADIANS - A CASE-CONTROL STUDY

OBJECTIVE: The objective was to compare risk factors between familial and sporadic ovarian cancer by means of a case-control approach. STUDY DESIGN: We conducted a case-control study among French Canadian women in Montreal during 1995-1996. One hundred seventy women 20 to 84 year s old with histologically confirmed diagnoses of primary ovarian carci nomas or borderline tumors were interviewed concerning their reproduct ive, family and medical histories. During the same period 170 randomly selected population control subjects, frequency-matched to the case p atients according to age and ethnic group, were also interviewed. Unco nditional logistic regression methods were used for data analysis. RES ULTS: The major factors influencing the risk of development of ovarian cancer were as follows: (1) family history of breast or ovarian cance r, (2) a late age at use of oral contraceptives (a protective effect), and (3) a late age at last childbirth (a protective effect for famili al case patients only). CONCLUSION: These factors had equally great im pacts in familiar and sporadic cases, implying that the underlying mec hanisms of carcinogenesis in sporadic and familiar ovarian cancer may be similar and that hereditary ovarian cancer may be preventable.