BACKGROUND: There is increasing concern regarding the risk of developing a second @entity5 in adjacent organs as a result of scattered radiation among @entity1 who have undergone radiotherapy (RT) for @entity0 . Previous studies have focused mainly on the possible increase in the incidence of @entity0 . To the authors' knowledge, the risk of @entity259 among these @entity1 has not been explored to date. METHODS: In this population-based, retrospective cohort study, the authors identified 194,798 @entity1 who were diagnosed with invasive @entity0 (exclusive of those with distant @entity3 ) between 1973 and 1993, and ascertained subsequent cases of @entity259 utilizing data from the Surveillance, Epidemiology, and End Results (SEER) program of the U.S. National @entity5 Institute. Poisson regression was used to calculate the age-standardized incidence ratio (SIR) of @entity259 and to model the influence of RT on the relative risk (RR) between the RT cohort (48,495 @entity1 ) and the non-RT cohort (146,303 @entity1 ). RESULTS: A total of 28 @entity1 in the RT cohort and 112 @entity1 in the non-RT cohort subsequently developed @entity259 . The distribution of @entity259 histologies in both the RT cohort and the non-RT cohort was similar to that in the female general population. Overall, there was no significant increase in the risk of @entity259 in either the RT cohort or the non-RT cohort compared with the general population; the SIR was 1.1 (95% confidence interval [95% CI], 0.8-1.6) for the RT cohort and 1.2 (95% CI, 1.0-1.4) for the non-RT cohort. When the RT cohort was compared with the non-RT cohort, the RR of @entity259 was 1.0 (95%CI, 0.7-1.5). CONCLUSIONS: The risk of radiation-associated @entity259 after initial RT for @entity0 was so low as to be undetectable in the current large population-based study. Continued monitoring of these @entity1 will be required to document that these findings are maintained with even longer follow-up periods. However, with 10,895 @entity1 having been followed for > 10 years at the time of last follow-up in the current study, these findings should be reassuring to @entity1 considering RT for their @entity0 . Therefore, @entity1 who have received RT for @entity0 require no special surveillance for their thyroid gland. Furthermore, previous breast radiation need not be a factor in determining the optimal management of thyroid nodules arising in @entity1 who received RT for @entity0 .

Risk of XXXX in a female population after radiotherapy for @entity0 .

@entity1 :: ('9606', 'Species') :: ['women', 'patients'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast carcinoma', 'contralateral breast carcinoma'] @entity5 :: ('MESH:D009369', 'Disease') :: ['primary tumor', 'Cancer'] @entity3 :: ('MESH:D009362', 'Disease') :: ['metastasis'] @entity259 :: ('MESH:D013964', 'Disease') :: ['thyroid carcinoma']
@entity259 :: (MESH:D013964,Disease) :: ['thyroid carcinoma']
