ZIA CP010158 - 10477 (ZIA) | |||
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Title | Male Breast Cancer Pooling Project | ||
Institution | NCI, Bethesda, MD | ||
Principal Investigator | Brinton, Louise | NCI Program Director | N/A |
Cancer Activity | N/A | Division | DCEG |
Funded Amount | $60,702 | Project Dates | 05/05/2009 - 00/00/0000 |
Fiscal Year | 2015 | Project Type | Intramural |
Research Topics w/ Percent Relevance | Cancer Types w/ Percent Relevance | ||
Aging (50.0%) Biochemical Epidemiology (45.0%) Cancer (100.0%) |
Breast (100.0%) | ||
Research Type | |||
Exogenous Factors in the Origin and Cause of Cancer Endogenous Factors in the Origin and Cause of Cancer |
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Abstract | |||
The rarity of male breast cancer has posed difficulties for identifying etiologic factors. Although genetic factors have been shown to be important, they appear to explain only a small proportion of disease occurrence. To more fully understand the etiology of male breast cancers, we undertook a pooling project involving the majority of case-control studies published on the topic and cohort studies that could contribute a meaningful number of cases. This project assembled and harmonized data from 11 case-control and 10 cohort investigations, for a total of 2,405 cases and 52,013 controls. Analyses regarding anthropometric and hormonally-related risk factors showed significant independent associations with weight, body mass index (BMI), Klinefelter sydrome and gynecomastia. Diabetes, fractures, cryptorchidism and orchitis also showed some suggestive relationships with risk. Although age at onset of puberty and histories of infertility were unrelated to risk, never having had children was significantly related. Analyses regarding relations with alcohol consumption and cigarette smoking revealed no significant associations. In a third analysis, relations with physical activity levels were examined; this manuscript is currently under journal review. Biologic samples from a number of the cohorts have also been used to assess relations with endogenous estrogens and androgens. Hormone assays were conducted at Laval University for 101 cases and 217 controls. Although androgens appeared only weakly predictive of risk, estradiol levels were significantly related. The magnitude of association was similar to relations observed with postmenopausal female breast cancer risk seen in other populations. |