Prognostic value of event-free survival at 12 and 24 months and long-term mortality for non-Hodgkin follicular lymphoma patients: A study report from the Spanish Lymphoma Oncology Group

Abstract

BACKGROUND: Relatively few studies have analyzed the mortality of follicular lymphoma (FL) patients in comparison with a sex- and age-matched general population. This study analyzed the overall survival (OS) of patients with FL and compared their survival with the expected survival of a general population. METHODS: Patients diagnosed with FL were prospectively enrolled from 1980 to 2013. Standardized mortality ratios (SMRs) were obtained from yearly sex- and age-specific mortality rates in Spain, and OS was compared with age- and sex-matched general population data. RESULTS: A total of 1074 patients with newly diagnosed FL were enrolled. The median OS was 231 months (95% confidence interval [CI], 195-267 months). Event-free survival at 12 months (EFS12) and event-free survival at 24 months (EFS24) were associated with an increased probability of early death, with an SMR of 10.27 (95% CI, 8.26-12.77) for EFS12. The overall SMR, including all causes of death, was 2.55 (95% CI, 2.23-2.92), and it was higher for women (SMR, 3.02; 95% CI, 2.48-3.67) and young adults (SMR, 6.01; 95% CI, 3.13-11.55). More than 10 years after the diagnosis, mortality rates for FL patients were lower than those for the general population (SMR, 0.47; 95% CI, 0.28-0.78). When FL was excluded as a cause of death, the overall SMR was 1.35 (95% CI, 1.11-1.65) without a statistically significant mortality increase in the >60-year-old group in comparison with age- and sex-matched general population data. More than 15% of the patients included in the study (n = 158) had more than 10 years of follow-up. CONCLUSIONS: EFS12 and EFS24 predict an early increase in mortality. The long-term SMR, over the course of 10 years of follow-up, shows that patients with FL have a risk of dying similar to that of a sex- and age-matched general population. Cancer 2017;123:3709–3716. © 2017 American Cancer Society.