A Study on the Prognosis of Patients Relapsing after Autologous Stem Cell Transplantation (auto-SCT) for Follicular Lymphoma (FL): The Impact of Remission Duration.

Although auto-SCT has been in use for treatment of advanced FL since many years, little is known about the course of those who relapse after this procedure. Because these patients may be candidates for aggressive salvage approaches, we sought to study the outcome of patients with FL relapsing after auto-SCT with particular focus on factors predicting for survival.

Methods: Relapse cases were identified retrospectively from 244 patients autografted for FL between August 1990 and November 2002 in 3 institutions. Overall survival after relapse (OS) was calculated according to Kaplan-Meier and analyzed for the prognostic impact of pre-relapse variables as well as of post-relapse salvage treatment by univariate log rank comparisons and Cox regression analyses.

Results: With a median follow-up of 88 (5–186) months post auto-SCT, 104 relapses occurred, corresponding to a 10-year relapse probability of 0.47 (95%CI 0.4–0.53). Median age of relapsed patients was 48 (22–65) years. FLIPI score at diagnosis was low in 18%, intermediate in 58%, and high in 24%. In 51%, auto-SCT had been given as part of first-line treatment, and 45% had been in complete remission at auto-SCT. Myeloablation included total body irradiation (TBI) in 57% of the cases. Median time from auto-SCT to relapse was 19 (2–128) months, with only 2 relapses occurring later than 6 years post transplant. Transformed FL was present in 14% of those 87 patients who had relapse histology available. Rituximab-containing salvage therapy was given to 50% of the patients after relapse. With 45 (1–139) months of follow-up, median OS after relapse was 100 months. Log rank comparisons identified auto-SCT as part of salvage treatment, time to relapse <12 months, and salvage without rituximab as factors adversely influencing OS, while all other variables listed above had no impact. Cox analysis considering sex, age, salvage auto-SCT, TBI, time to relapse, and rituximab salvage confirmed a possible adverse impact of time to relapse <12 months (hazard ratio 2.58 (95%CI 0.99–6.82); p 0.055) but none of the other covariates on OS.

Conclusions: The prognosis of patients relapsing after auto-SCT for FL is surprisingly good. However, those whose disease recurs within the first post-transplant year tend to have a dismal outcome and might benefit from experimental salvage approaches, such as allogeneic SCT.