INCIDENCE OF SALIVARY-GLAND TUMORS AMONG ATOMIC-BOMB SURVIVORS, 1950-1987 - EVALUATION OF RADIATION-RELATED RISK

A wide-ranging search for benign and malignant tumors of the major and minor salivary glands among members of the Life Span Study sample of the Radiation Effects Research Foundation identified 41 malignant and 94 benign incident tumors, including 14 malignant and 12 benign tumors of the minor salivary gland, plus 10 major gland tumors of unknown be havior. Dose-response analyses found statistically significant increas es in risk with increasing A-bomb dose for both cancer and benign tumo rs. Estimated relative risks at 1 Sv weighted tissue kerma (RR(1Sv), w ith 90% confidence interval in parentheses) were 4.5 (2.5-8.5) for can cer and 1.7 (1.1-2.7) for benign tumors. When analyzed by histological subtype within these two broad groups, it appeared that most of the d ose response for malignant tumors was provided by an exceptionally str ong dose response for mucoepidermoid carcinoma [11 exposed cases with dose estimates, RR(1Sv) = 9.3 (3.5-30.6)], and most or all of that for benign tumors corresponded to Warthin's tumor [12 cases, RR(1Sv) = 4. 1 (1.6-11.3)]. There was a marginal dose response for malignant tumors other than mucoepidermoid carcinoma [RR(1Sv) = 2.4 (0.99-5.7)] but no significant trend for benign tumors other than Warthin's tumor [RR(1S v) = 1.3 (0.9-2.2)]. Re-examination of the original data from publishe d studies of other irradiated populations may shed new light on the re markable type specificity of the salivary tumor dose response observed in the present study. (C) 1996 by Radiation Research Society