ZIA CP010136-02340 (ZIA) | |||
---|---|---|---|
Title | Cancer Risk in Human Populations | ||
Institution | NCI, Bethesda, MD | ||
Principal Investigator | T Silverman, Debra | NCI Program Director | N/A |
Cancer Activity | N/A | Division | DCEG |
Funded Amount | $131,150 | Project Dates | 01/01/1989 - N/A |
Fiscal Year | 2009 | Project Type | Intramural |
Research Topics w/ Percent Relevance | Cancer Types w/ Percent Relevance | ||
Alcoholism Research (10.0%) Behavioral and Social Science (100.0%) Biochemical Epidemiology (45.0%) Cancer (100.0%) Digestive Diseases (100.0%) Sleep Disorders (30.0%) |
Colon/Rectum (50.0%) Esophagus (25.0%) Pancreas (25.0%) |
||
Research Type | |||
Normal Functioning Exogenous Factors in the Origin and Cause of Cancer |
|||
Abstract | |||
Estrogen has been suggested to play a role in the development of colorectal cancer (CRC). However, epidemiological evidence has been inconsistent. We evaluated the association between reproductive factors and oral contraceptive (OC) use and CRC risk in a population-based case-control study conducted in Shanghai, China from 1990 to 1993. A total of 880 female CRC cases (469 colon, 411 rectum) and 701 female controls aged 30-74 were included in this analysis. Odds ratios (OR) and 95% confidence intervals (CI) were used to estimate the relative risk, adjusting for age, education, income, marital status, BMI, CRC family history, and dietary factors. We found that age at first birth was inversely associated with the risk of colon cancer, particularly among postmenopausal women. Among postmenopausal women, having a first birth later than age 32 was associated with an OR of 0.46 (CI=0.21-1.01) as compared to having a first birth earlier than age 20. OC and estrogen use were associated with a non-significantly reduced risk of colon cancer. OC use for more than three years was associated with an OR of 0.68 (CI=0.35-1.31) for colon cancer for all women combined, and 0.62 (CI=0.29-1.34) for postmenopausal women. The OR of colon cancer associated with ever estrogen use was 0.31 (CI=0.08-1.25). We did not find that age at menarche, years of menstruation, or number of live births was related to the risk of colon cancer. The above mentioned factors did not appear to be related to the risk of rectal cancer. Overall, the data from our study tend to support the hypothesis that female hormones may play a role in the etiology of colon cancer. |