Time interval to the development of breast carcinoma after treatment for Hodgkin disease

Women with Hodgkin disease (HD) who received mantle irradiation had an increased risk of developing breast carcinoma. The authors examined the influence of radiotherapy on the time interval to the development of breast carcinoma.

Using population, cancer incidence, and survival data from the Surveillance, Epidemiology, and End Results (SEER) registries, standardized incidence ratios (SIR) were calculated and Kaplan-Meier curves were constructed to estimate breast carcinoma-free survival in women with HD treated with and without radiotherapy. The log-rank test was utilized and multivariate proportional hazard regression analysis was performed. Multivariate analysis was also performed using the PHPH regression model.

In 9 SEER registries, 8036 females were identified who were diagnosed with HD between 1973 and 1999. Of these women, 183 (2.3%) were subsequently diagnosed with breast carcinoma. The use of radiotherapy in the treatment of HD resulted in an increased risk of development of breast carcinoma (SIR = 1.90, P < 0.01). The log-rank test and proportional hazard regression model failed to detect a difference (P = 0.79) in breast carcinoma-free survival for women treated with and without radiotherapy. The PHPH regression model revealed that the use of radiotherapy had an adverse effect on long-term survival (relative risk [RR] = 1.84, P = 0.01), but was associated with a short-term survival advantage (RR = 0.45, P = 0.01).

Use of the PHPH model indicated that the use of radiotherapy in the treatment of HD resulted in an increased long-term risk for the subsequent development of breast carcinoma, but conferred a short-term reduction.