Young women who are treated for Hodgkin lymphoma with chest radiation therapy have a high cumulative absolute risk of developing breast cancer later in life. This risk increases with age at end of follow-up, time since diagnosis, and radiation dose, according to a new study in the October 5 issue of the Journal of the National Cancer Institute.
Due to advances in the treatment of Hodgkin lymphoma, there are now many long-term survivors who are at risk for the development of secondary cancers that frequently reflect the late side effects of treatment. Second primary cancers are the leading cause of death among long-term survivors, and breast cancer is the most common secondary cancer in female Hodgkin lymphoma survivors.
To estimate the future cumulative absolute risk of breast cancer for young women treated for Hodgkin lymphoma, Lois B. Travis, M.D., of the National Cancer Institute, and colleagues analyzed data from a case–control study within an international population-based cohort of 3,817 female 1-year survivors of Hodgkin lymphoma who had been diagnosed at age 30 or younger between 1965 and 1994.
The cumulative absolute risk of developing breast cancer increased with age at end of follow-up, time since diagnosis, and radiation dose. For example, a woman who was treated for Hodgkin lymphoma at age 20 with a chest radiation dose of at least 40 Gy without alkylating agents would have a 0.4% risk of developing breast cancer by age 30, a 4.9% risk by age 40, and a 19.1% risk by age 50. By comparison, for white women in the general population, the absolute risks of breast cancer from age 20 to ages 30, 40, and 50 are, respectively, 0.04%, 0.5%, and 2.0%.