Background: Marital status has long been related to cancer incidence and mortality rates. However, only few analytical studies have been conducted on this issue considering known or potential confounding factors.
Methods: We systematically examined the relation between marital status and cancer risk using data from a network of case-control studies conducted between 1983 and 2001, including a total of 17,976 incident cases with the following cancer sites: oral cavity and pharynx, esophagus, stomach, colon, rectum, liver, gallbladder, pancreas, larynx, breast, endometrium, ovary, prostate, bladder, kidney, thyroid, Hodgkin's disease, non-Hodgkin's lymphomas, multiple myelomas, and sarcomas. Controls were 15,345 patients admitted to the hospital for non-neoplastic conditions.
Results: As compared to married subjects, never married ones were at significantly increased risk of oral cavity and pharyngeal cancers and at reduced risk of cancer of the colon, liver, bladder, kidney, and thyroid. However, for other cancer sites considered, most odds ratios were close to unity. Likewise, there was no consistent excess risk for divorced or widowed subjects.
Conclusions: Despite some significant associations, our study suggests that marital status is not materially associated with cancer risk. Thus, the evidence that married subjects are at lower risk of several other major diseases may not be applicable to cancer.