BACKGROUND: Because ionizing radiation is a known carcinogen, diligent long-term follow-up in @entity1 exposed to therapeutic radiation is required. The authors updated an earlier study on the nature and risk of second @entity5 (SN) in @entity1 treated with megavoltage radiotherapy as @entity1 . METHODS: The authors followed 446 @entity1 who were treated for a primary malignancy with megavoltage radiotherapy between January 16, 1954 and December 31, 1980. These @entity1 survived a minimum of 5 years. The nature and incidence of SNs were evaluated in this population. @entity1 with @entity995 or @entity4786 were excluded from the study due to their large genetically based predisposition for developing an SN. RESULTS: The Kaplan-Meier actuarial survival rate was 80% (95% confidence interval [CI] 74-85%) at 30 years for all @entity1 . Thirty-seven (8.3%) @entity1 developed SNs, most of which occurred within the original radiation treatment field, 3.8-31.8 years (median, 15.5 years) after radiotherapy. The cumulative risk of developing an SN was 13% (95% CI 9-19%) at 30 years and the standardized incidence ratio for the development of any SN was 5.2 (95% CI 3.4-7.6%). The most common SNs were @entity0 (n = 8), @entity1489 ( @entity1491 , two @entity320 , and one dermatosarcoma), and @entity1653 (n = 6). All eight @entity0 occurred after the treatment of @entity978 . Of the 37 @entity1 with SNs, 12 died of either the SN (n = 10) or of recurrent disease (n = 2). Risk factors associated with developing a SN included initial diagnosis of @entity978 (P = 0.0003), female gender (P = 0.008), and an initial diagnosis of @entity981 (P = 0.02). CONCLUSIONS: @entity1 in the radiation-treated cohort experienced increased mortality, were at an increased risk of developing an SN, and should undergo increased medical surveillance as adults. The cumulative probability of developing an SN has increased substantially at 30 years, largely due to an increase in follow-up time. In addition, the cumulative probability curve does not show evidence of plateau after increased duration of follow-up. Finally, the emergence of secondary @entity0 in the current study was not noted in the previous analysis.

Second @entity5 after megavoltage radiation for XXXX .

@entity1 :: ('9606', 'Species') :: ['children', 'Patients', 'patients'] @entity981 :: ('MESH:D054198', 'Disease') :: ['acute lymphoblastic leukemia'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast carcinoma', 'breast carcinomas'] @entity5 :: ('MESH:D009369', 'Disease') :: ['neoplasms'] @entity1489 :: ('MESH:D012878', 'Disease') :: ['skin carcinoma'] @entity1653 :: ('MESH:D008579', 'Disease') :: ['meningiomas'] @entity4786 :: ('MESH:D017253', 'Disease') :: ['neurofibromatosis'] @entity978 :: ('MESH:D006689', 'Disease') :: ['childhood Hodgkin disease', 'Hodgkin disease'] @entity320 :: ('MESH:D008545', 'Disease') :: ['malignant melanomas'] @entity1491 :: ('MESH:D002280', 'Disease') :: ['five basal cell carcinomas'] @entity995 :: ('MESH:D012175', 'Disease') :: ['bilateral retinoblastoma']
@entity5 :: (MESH:D009369,Disease) :: ['pediatric tumors']
