Secondary Breast Cancer (S-Bc) After Hematopoietic Cell Transplantation (Hct) For Leukemia: Role Of Total Body Irradiation (Tbi).

1592 Background: s-BC after conventional chest radiation for histologically distinct cancer is well-recognized, and has resulted in radiologic screening recommendations by American Cancer Society. However, risk of s-BC after TBI is not well-defined. Methods: We determined the risk of s-BC in 648 consecutive females transplanted for leukemia (ALL [19%], AML/MDS [57%], CML [24%]) between 1976 and 2008 with a post-HCT survival of ≥2 years. The study was restricted to leukemia to understand the role of TBI without the influence of pre-HCT chest radiation. Near-complete ascertainment of s-BC was assured by combining institutional follow-up with California Cancer Registry data. Results: Median age at HCT was 38 years (range, 0-71); 14% had received autologous HCT, 64% related and 22% unrelated donor HCT; 70% had received TBI for myeloablative conditioning. After 5,675 person-years of observation, 16 patients developed s-BC (14 after TBI). Median latency from HCT to s-BC was 16y (2-27). Median age at s-BC was 50...