Long-term survey of survival time, histological transformation, and secondary malignancies in Japanese patients with advanced-stage follicular lymphoma in the rituximab era: Hokkaido Hematology Study Group

Following the introduction of rituximab, the long-term overall survival (OS) rate of advanced-stage follicular lymphoma (FL) cases was expected to improve after the introduction of rituximab: however, there is a lack of large-scale survey data in Asia due to the relatively low incidence of FL. We conducted a retrospective survey to assess the treatment outcomes in patients with newly diagnosed advanced-stage FL in 29 institutions in Hokkaido from January 2001 to December 2010. The total number of patients was 443 (men 47.6 %, women 52.4 %), with a median age of 55 years (range 20–80 years). Of the cases examined, 42.2 % had stage III and 57.8 % had stage IV disease. Furthermore, 62.5, 19.7, 9.2, 5.2, and 3.4 % had performance statuses of 0, 1, 2, 3, and 4, respectively. The 5-year OS was 91.2 %, and no survival plateau was observed. Seventeen patients experienced secondary malignancies (six hematological diseases and 11 solid cancers; 5-year probability, 4.2 %). Eighteen patients experienced transformation (5-year probability, 4.5 %). The overall survival at 5 years after therapy for transformation was 50 %. Before the introduction of rituximab, the 5- to 10-year OS of advanced-stage FL patients in Japan was reported to be about 30–60 %. Although these data are limited, improvement in OS has been observed in Japan during the rituximab era.