The cumulative experience of benign plus malignant nodule development as a function of age at exposure shows clearly the increased susceptibility of the vounger population to nodule induction (Fig. 3). Most benign nodules and all the thyroid carcinomas nave occurred in femaies. It was noted (Robbins and Adams. 1989) that the prevalence of thyroid carcinomas compared to benign nodules (15'.) was lower than that reported following medical x-ray therapy (about 30'%). i st Zz ~ = F4PILLARY ~ "CER ‘ — = « "7 FOL ClLLe = CANCER I = © tn u TIRIK 1201 1 ece — = = = >4 - a e } ’ a j L ni . — "0-18 YR a 75 - ~ . > = ; 37%1 | Sf A ’ ‘ oS = — 4 ‘ oO 25%) 2 . —. “ >1a YR x 14% }) x 10% 11 _ “4 directly with age at exposure. Nonthyroidal tumors During the period 1985 through 1987, deaths attributable to cancer occurred in three exposed persons. all from Utirik. The types of tumors were: lung cancer, hepatoma. and meningioma. During the same period there were three cancerrelated deathsin the unexposed population, the tumor types being: colon carcinoma. hepatoma, and mvelodysplastic svndrome. Additional tumor diagnoses resulted from clinical investigation initiated at the time of medical team visits. These included a case of breast carcinoma (detected by mammography) and a case of colon carcinoma. both diagnosed in exposed Utirik women. Bothlesions were surgically resected and have a high probability of being cured. In addition, an epithelioma was removed from the skin of an exposed Rongelap woman, the site of the lesion being in the approximatearea of a beta burn that developed soon after the 1954 exposure. This type oflesion, also termed basal cell carcinoma. is very common in the United States and is not included in the detailed cancer statistics published by the American Cancer Society (Silverberg and Lubera, 1987). However, its frequency in Marshal- lese is unknown. The development of two cases of hepatoma i 3 adults). another interpretation of Fig. + is that the time for development of adenomatous nodules following radiation exposure varies 20 20.09 a) ae 29 YEARS AFTER °354 Fig. 3: The accrual of cases with thyroid nodules and thyroid cancer in the exposed Rongelap population as a function of age at the time of exposure in 1954. The <!0 year group inciudes exposure tn utero. Two cases of thyroid atrophy without nodule formation (2 Rongelap bovs, <10 years of age) are excluded. (Figure taken from Robbins and Adams, 1989). It appears that thereis an inversecorrelation between the radiation dose absorbed by thethyroid and the time after exposure for development of the benign adenomatous nodules( Fig. 4}. However, since the thyroid-absorbed radiation dose was determined primarily by age at exposure (children receiving greater doses than F008 TTI among the population served by the medical team requires comment. Two persons. one each from the Utirik and the Comparison groups, died from this tumor during the period covered by this report. To this number should be added the death of another Utirik man who died in 1984 from complicationsof cirrhosis (Adams et al, 1985), for he, like one of the hepatoma patients. had hepatitis B surface antigen detected in his serum. Studies have demonstrated an association between hepatitis B surface antigenemia and hepatoma.cirrhosis, and chronic active hepatitis (Beasley et al., 1981). Early BNL observations revealed that infection with hepatitis B virusis nearly universal among Marshallese,as it is among many tropical popu- lations. and that serological evidence of the infection is common in childhood. In view of the