Purpose: The records of 557 consecutive adult recipients of allogeneic-related and -unrelated and syngeneic bone marrow transplants (BMTs) were reviewed to determine the incidence of secondary cancers.
Patients and methods: Four hundred fifty-six patients were transplanted for acute lymphocytic leukemia (ALL; n = 79), acute myelogenous leukemia (AML; n = 182), and chronic myelogenous leukemia (CML; n = 195); 42 patients were transplanted for aplastic anemia (AA) and 59 for a variety of other hematologic and nonhematologic disorders, malignant and nonmalignant. Conditioning regimens included high-dose chemotherapy with or without total-body irradiation (TBI). Statistical analyses determined the cumulative incidence of developing a secondary cancer and elucidated the associated risk factors. Complete records (1 to 24 years of follow-up) on all patients were available.
Results: Nine patients developed 10 secondary cancers for a cumulative actuarial risk of 12% (95% confidence interval [CI], 4.3 to 23.0) 11 years after transplant. The age-adjusted incidence of secondary cancer was 4.2 times higher than that of primary cancer in the general population. Eight of the 10 were epithelial in origin and three were cutaneous. TBI and acute graft-versus-host disease (GVHD) with a severity > or = grade II were associated with the development of any secondary cancer. On the other hand, chronic GVHD was a risk factor only for the development of secondary skin neoplasms.
Conclusion: Adult recipients of BMT face a significant risk of developing a secondary malignancy. Their risk is similar to that of other patients with hematologic malignancies who are treated with chemoradiotherapy only. Epithelial tumors, rather than the more commonly reported Epstein-Barr virus (EBV)-associated lymphomas, were most common. The fact that we did not routinely use T-cell-depleted marrow grafts nor anti-T-cell immunoglobulin for the treatment of acute GVHD may explain this variance.