ABO blood groups and salivary gland tumors (Alabama, United States).

Studies of associations between various diseases and the ABO blood groups have shown elevated relative risks for some categories of disease. A strong association between salivary gland tumors and blood group A has been reported, but studies are few and have yielded contradictory results. To investigate this association, we conducted an epidemiologic study of salivary gland tumors diagnosed in Jefferson Country, Alabama (United States), 1968-89. All tumors were histologically confirmed. Blood group information was obtained for 200 individuals with salivary gland tumors, and the distribution of ABO and Rh blood type for cases was compared with that of 52,118 healthy blood donors from the same geographic area. The 38.5 percent of salivary gland tumors in cases with blood group A was similar to the 39.0 percent observed for controls (P = 0.95). No differences were observed when benign and malignant tumors were considered separately, nor for any of the major histologic types of tumor. The distribution of Rh factor among cases and controls also did not differ significantly (P = 0.08).