Radiosensitivity of normal tissues in ataxia-telangiectasia heterozygotes.
OBJECTIVE
Approximately 5% of cancer patients given radiation therapy exhibit severe injuries to the noncancerous tissue in the radiation field. Striking clinical sensitivity to ionizing radiation has been observed frequently in ataxia-telangiectasia (A-T) homozygotes. This study was undertaken to test the hypothesis that heterozygous carriers of a mutated gene for A-T may represent a substantial proportion of all patients who suffer severe radiation toxicity.


METHODS
The medical records of all A-T heterozygotes treated with radiation therapy for breast or prostate cancer were compiled from an ongoing study of mortality and cancer incidence in A-T families. Diagnostic, treatment, and follow-up records were reviewed. Acute and long-term radiation complications were scored according to Radiation Therapy and Oncology Group criteria.


RESULTS
There were no instances of soft tissue necrosis or other apparent serious injuries to normal tissues of two A-T heterozygotes with prostate carcinoma and 11 with breast carcinoma who received moderate-to-high doses of conventionally fractionated radiation therapy by megavoltage techniques.


CONCLUSIONS
There is no evidence that abnormal clinical radiosensitivity occurs in A-T heterozygotes receiving conventionally fractionated radiation therapy for breast or prostate cancer.
Weissberg
J B
JB
Department of Radiation Oncology, Middlesex Hospital, Middletown, CT, USA.
Huang
D D
DD
Swift
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001260:Ataxia Telangiectasia / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics / Q000532:radiotherapy; D005260:Female; D005819:Genetic Markers; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000235:genetics / Q000532:radiotherapy; D011832:Radiation Injuries / Q000235:genetics*; D011836:Radiation Tolerance / Q000235:genetics*; D011855:Radiodermatitis / Q000209:etiology / Q000235:genetics
D005819:Genetic Markers