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Incidence of thyroid and other tumors associated with radiation therapy exposure in childhood
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INCIDENCEOF THYROIDAND OTHER TUMORS ASSOCIATED WITH RADIATION THERAPY EXPOSURE IN CHILDHOOD M. Colman, M.D. Division of Radiation Oncology Department of Radiological Sciences University of California, Irvine, CA 92717 and M. Kirsch, M.D. and M. Creditor, M.P.H. Department of Radiation Oncology Michael Reese Hospital and Medical Center Chicago, Illinois 60616 Supported by grants from the Michael Reese Research Foundation, the Illinois Division of the American Cancer Society and the National Cancer Institute (CA 22037)
5166 persons who were exposed to limited field (80-100 cmL) x-irradiation to the head, neck, and upper chest reqion during childhood and adolescence have provided an outstanding opportunity for the study of tumor incidence following medical x-ray therapy. Initial observation of thyroid cancer were reported at the ASTR meeting in 1974. An extensive follow-up effort has continued and 3254 subjects have completed questionnaires eliciting information on tumor incidence. 1539 of these were subjected to a thorough Careful clinical screening procedure which included a thyroid scintigram. comparison of the screened subgroup with the total population at risk demonstrated them to be essentially similar in respect of sex distribution, age at the time of irradiation, radiation dose and year of treatment. The prevalence of thyroid tumors in the 1539 clinically screened subjects and the prevalence of all other tumors in the 3254 traced subjects can therefore be assumed to reflect the risks in the group of irradiated subjects as a whole. Median age at irradiation was 3.5 years, mediation radiation dose was 790 rads (7.9 Gy). Thyroid tumor was diagnosed in 413 subjects. Of these undergoing surgery (273), 30.3% were found to have thyroid cancer. A total of 366 surgical pathology specimens of the thyroid, including 93 from subjects who were diagnosed at other hospitals, were examined revealing 73 papillary carcinomas. One hundred and eighty-seven other (non-thyroid) neoplasms identified included 27 benign and 10 malignant salivary gland tumors, 16 benign and seven malignant tumors of neural origin (brain, spinal cord, cranial and peripheral nerves), 37 skin tumors, 9 lymphomas, 8 gonadal tumors, 45 breast tumors and 28 tumors of miscellaneous sites. The incidence of thyroid tumors, salivary gland tumors and primary brain tumors was considerably in excess of the expected incidence (p values 0.0001) and a radiation dose-effect correlation was observed for thyroid and brain tumors. Comparable incidence rates for many of the benign tumors which we observed are not available but gonadal tumors and lymphomas did not occur in excess of the expected incidence.
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INCIDENCEOF THYROIDAND OTHER TUMORS ASSOCIATED WITH RADIATION THERAPY EXPOSURE IN CHILDHOOD M. Colman, M.D. Division of Radiation Oncology Department of Radiological Sciences University of California, Irvine, CA 92717 and M. Kirsch, M.D. and M. Creditor, M.P.H. Department of Radiation Oncology Michael Reese Hospital and Medical Center Chicago, Illinois 60616 Supported by grants from the Michael Reese Research Foundation, the Illinois Division of the American Cancer Society and the National Cancer Institute (CA 22037)
5166 persons who were exposed to limited field (80-100 cmL) x-irradiation to the head, neck, and upper chest reqion during childhood and adolescence have provided an outstanding opportunity for the study of tumor incidence following medical x-ray therapy. Initial observation of thyroid cancer were reported at the ASTR meeting in 1974. An extensive follow-up effort has continued and 3254 subjects have completed questionnaires eliciting information on tumor incidence. 1539 of these were subjected to a thorough Careful clinical screening procedure which included a thyroid scintigram. comparison of the screened subgroup with the total population at risk demonstrated them to be essentially similar in respect of sex distribution, age at the time of irradiation, radiation dose and year of treatment. The prevalence of thyroid tumors in the 1539 clinically screened subjects and the prevalence of all other tumors in the 3254 traced subjects can therefore be assumed to reflect the risks in the group of irradiated subjects as a whole. Median age at irradiation was 3.5 years, mediation radiation dose was 790 rads (7.9 Gy). Thyroid tumor was diagnosed in 413 subjects. Of these undergoing surgery (273), 30.3% were found to have thyroid cancer. A total of 366 surgical pathology specimens of the thyroid, including 93 from subjects who were diagnosed at other hospitals, were examined revealing 73 papillary carcinomas. One hundred and eighty-seven other (non-thyroid) neoplasms identified included 27 benign and 10 malignant salivary gland tumors, 16 benign and seven malignant tumors of neural origin (brain, spinal cord, cranial and peripheral nerves), 37 skin tumors, 9 lymphomas, 8 gonadal tumors, 45 breast tumors and 28 tumors of miscellaneous sites. The incidence of thyroid tumors, salivary gland tumors and primary brain tumors was considerably in excess of the expected incidence (p values 0.0001) and a radiation dose-effect correlation was observed for thyroid and brain tumors. Comparable incidence rates for many of the benign tumors which we observed are not available but gonadal tumors and lymphomas did not occur in excess of the expected incidence.
163