Estimating late adverse events using competing risks after autologous stem-cell transplantation in aggressive non-Hodgkin lymphoma patients.

Background: Consolidative autologous stem-cell transplantation (ASCT) is a valuable option in high-risk or disease recurrence large-cell non-Hodgkin lymphoma patients (NHL); however, its long-term toxicity must still be assessed.

Methods: Among the 439 lymphoma patients transplanted at our institution from January 1, 1993, to January 1, 2002, 158 exhibited aggressive NHL. The median age of the patients was 46 years (range, 18-69), 98 males and 60 females. Ninety (57%) patients received first-line ASCT. The median number of prior chemotherapy regimens was 2 (range, 1-10). Thirty-eight (24%) patients received total body irradiation conditioning. Here we report the adverse events which occurred at least 30 days after ASCT and before disease recurrence.

Results: After a median follow-up of 3 years, the overall and disease-free survival rates were 61% and 55%, respectively. Sixty-eight late adverse events affected 43 (27%) patients, leading to a cumulative incidence of 34% at 3 years. Infections were the most frequent adverse events (n = 13), followed by neurologic (n = 12), pulmonary (n = 6), or cardiovascular (n = 4). Eight malignancies were diagnosed (six solid, two hematologic), leading to a cumulative incidence of 3.7% at 3 years. Taking into account the competing risks, multivariate analysis revealed that the number of progressions (relative risk [RR] = 2.68) and a mitoxantrone-containing conditioning regimen (RR = 2.98) significantly increased the incidence of late toxicity.

Conclusion: ASCT is effective in patients with aggressive NHL with a poor prognosis. However, careful long-term follow-up of survivors is recommended because of the increase in malignant and nonmalignant toxicities.