(ChemotherapyAdvisor) – A 40-year follow-up has found breast cancer risk to be 48% for women who received ≥40 Gy mantle radiotherapy for Hodgkin lymphoma at a young age, a study in the Journal of Clinical Oncology published June 25 online has found.
These results underscore the necessity to follow this population for 40 years or longer “and may require more intensive screening regimens than those in national general population programs,” the national cohort study in England and Wales pointed out.
Breast cancer risk was assessed in 5,002 women younger than 36 years of age in England and Wales treated for Hodgkin lymphoma with supradiaphragmatic radiotherapy from 1956 to 2003 who underwent follow-up. As of December 31, 2008, data were 97% complete.
They found breast cancer or ductal carcinoma in situ had developed in 373 patients, with a standardized incidence ratio of 5.0 (95% CI, 4.5–5.5). Standardized incidence ratios were greatest for those treated at age 14 years (47.2 [95% CI, 28.0–79.8]) and continued to remain high for at least 40 years.
“The maximum absolute excess risk was attained at ages 50 to 59 years,” they observed. “Alkylating chemotherapy or pelvic radiotherapy diminished the risk, but only for women treated at age ≥20 years, not for those treated when younger.”
Special consideration is needed “of potential measures to reduce breast cancer risk for girls treated with supradiaphragmatic radiotherapy at pubertal ages,” they concluded.