| This thesis examines the role of a family history of ovarian, breast, colorectal and testicular cancer on the risk of having a surgically diagnosed benign ovarian tumor (BOT). We based our hypothesis of an increase of specific cancers among first-degree relatives of women with BOTs on the multistage model of carcinogenesis which predicts that BOTs may be precursors of ovarian malignancies. This is analogous to the adenoma-colon cancer sequence. Seven hundred and forty-six cases and 404 controls were interviewed between August 1991 through July 1994. Cases were English-speaking women aged 18 to 74 who underwent surgery for a BOT in five New York metropolitan-area hospitals. Controls were frequency matched to cases by 10 year age groups and by hospital. One hundred and thirty-one cases reported 150 cancers of the ovary, breast, colorectal and testes. Fifty-seven controls reported 63 cancers. There was no statistically significant difference between cases and controls in the accuracy of their reporting of family history of cancer at initial versus reinterview, at initial interview versus affected relative diagnoses and at initial interview versus pathology report. Subject recall of specific cancers in first-degree relatives was highly reliable among this group of women. In order to assess the completeness of cancer reporting in first-degree relatives of controls, we compared their rates of cancer to expected population rates and found that controls reported rates of ovarian, breast, colorectal and testicular cancers similar to general population rates. The data were then analyzed using logistic regression (case-control design) (OROVERALL = 1.25, 95% CI = 0.89--1.75) and Cox proportional-hazards (reconstructed cohort design) (RROVERALL = 1.21, 95% CI = 0.89--1.65) techniques. When the data were analyzed by cancer site, both analyses showed no significant increased risk of breast, ovarian, colorectal, or testicular cancer among first-degree relatives of women with BOTs. These findings do not support the hypothesis that BOTs are precursors for the familial types of ovarian, breast, colorectal, and testicular cancers. |
