A national study on conditional survival, excess mortality and second cancer after high dose therapy with autologous stem cell transplantation for non-Hodgkin lymphoma

This national population-based study aimed to investigate conditional survival and standardized mortality ratios (SMR) after high-dose therapy with autologous stem-cell transplantation (HDT-ASCT) for non-Hodgkin lymphoma (NHL), and to analyse cause of death, relapses and second malignancies. All patients >= 18 years treated with HDT-ASCT for NHL in Norway between 1987 and 2008 were included (n = 578). Information from the Cause of Death Registry and Cancer Registry of Norway were linked with clinical data. The 5-, 10- and 20-year overall survival was 61% (95% confidence interval [CI] 56-64%), 52% (95% CI 48-56%) and 45% (95% CI 40-50%), respectively. The 5-year survival conditional on having survived 2, 5 and 10 years after HDT-ASCT was 81%, 86% and 93%. SMRs were 12.3 (95% CI 11.0-13.9), 4.9 (95% CI 4.1-5.9), 2.4 (95% CI 1.8-3.2) and 1.0 (95% CI 0.6-1.8) for the entire cohort and for patients having survived 2, 5 and 10 years after HDT-ASCT respectively. Of the 281 deaths observed, 77% were relapse-related. Treatment-related mortality was 3.6%. The 10-year cumulative incidence of second malignancies was 7.9% and standardized incidence ratio was 2.0 (95% CI 1.5-2.6). NHL patients treated with HDT-ASCT were at increased risk of second cancer and premature death. The mortality was still elevated at 5 years, but after 10 years mortality equalled that of the general population.