Offsprings of preconceptionally irradiated parents. Final report of a longitudinal study 1976-1994 and recommendations for patients' advisory

Abstract

Many young adults with cancer of good prognosis seek advice from their doctors, because they are concerned about their ability to have children and about potential hereditary diseases in the children conceived or fathered after cancer therapy. Results of repeated examinations of 61 children over a period of 20 years are reported. One of their parents had received radiotherapy for malignant disease (only three had additional chemotherapy). Radiation doses to the gonads ranged from 0.01 to 2 Gy. The most frequent indications for radiotherapy were Hodgkin's disease (n=25), seminomas (n=7), thyroid cancer (n=3), and malignant melanomas (n=3) There was a trend to premature birth with 52.5% of the babies born before term. Yet, all had normal birth weight and delivery was inconspicuous. The skeletal maturation was retarded, but development was still in the normal range of German children. There were no chromosome aberrations, normal mental and intellectual development, and no malignancy among these children. A trend to an increased frequency of developmental disturbances and four moderately severe malformations were observed; however, no direct association with radiation treatment could be demonstrated. One child had a balanced translocation (5;17) which it inherited from the unirradiated parent. During the first consultation of young adult cancer patients, before the start of treatment, the problems of fertility and of therapy-induced mutations and hereditary diseases as well as developmental damage of the offspring need to be addressed directly by the radiation oncologist. Decisions on cryoconservation of sperm, fixation of the ovaries and dosimetry of the gonads during radiotherapy have to be made before the start of treatment. The rate of radiation-induced hereditary diseases and developmental damage in the children conceived or fathered after curative radiotherapy of one parent is estimated to increase by <0.1% (after gonadal exposure of 1 Gy). However, at present, heritable damage potentially induced by chemotherapy cannot be adequately quantified yet.