Prognostic Factors in Follicular Lymphoma Patients in Japan: Application of Follicular Lymphoma International Prognostic Index.

Background: By the new treatment approaches, such as anti-CD20 monoclonal antibody, purine analogues, high-dose therapy with SCT, the outcome of treatment for follicular lymphoma (FL) has been improved, but there is no consensus on any of these approaches except cases with early stage. Therefore, a reliable prognostic index would be needed in order to select the most appropriate treatment. Follicular Lymphoma International Prognostic Index (FLIPI) has recently been reported. We assessed characteristics at diagnosis and applied two prognostic models, the FLIPI and the IPI, to newly diagnosed Japanese patients (pts) with FL in this study.

Methods: Response rate, overall survival (OS), and progression free survival (PFS) were calculated by the FLIPI and the IPI. For two prognostic models, 5 factors were used, The IPI (age>60, EN≥2, LDH>N, PS≥2, CS≥3), and the FLIPI (age>60, Hb<12.0g/dl, LDH>N, CS≥3, nodal sites>4), respectively.

Results: Between 1988 and 2001, 107 pts of newly diagnosed FL (grade I-III) were analyzed. Patients characteristics were male/female 49/58, median age 54yr. (range 21–87yr.), and histological grade I, II/III 103/4. Initial therapy was CHOP-like regimen for 56 patients, ACOMP-B (the third generation regimen) for 44 patients, and another for 7 patients. The median follow-up of our series was 84 months (range 40–206 mo.). CR, PR was 60.7%, 31.8%, and response rate was 92.5%. Median OS at 15 years was 64.4%, and median PFS at 15 years was 28.5%. Patient distribution by the IPI and the FLIPI were the followings; the IPI (L/LI/HI/H 49/41/15/2), the FLIPI (L/I/H 41/29/37). There were few patients equivalent to high risk group in IPI, and it was the patient distribution which was more equal in FLIPI in comparison with IPI. OS by the IPI and the FLIPI risk group at 10 year were L: 85%, LI: 54%, HI: 44%, H: 50% (p=0.0088), and L: 87%, I: 66%, H: 47% (p<0.0001). PFS by the IPI and the FLIPI risk group at 10 year were L: 36%, LI: 23%, HI: 27%, H: 0% (p=0.0679), and L: 43%, I: 25%, H: 16% (p=0.0003). Correlation with a survival was recognized in FLIPI on OS, PFS more by significantly. In high-risk group of the FLIPI, PFS was significantly longer in pts treated with ACOMP-B, compared with pts treated with CHOP-like regimen (p=0.0015), and it tended to be better in OS, not so significant.

Conclusions: The FLIPI is a promising consequence prediction model in follicular lymphoma in Japan. Standard treatment of FL is one of the most controversial issues. Outcome of CHOP were poor in high-risk group of the FLIPI, so to improve survival new treatment strategy is needed. The therapeutic strategy on the basis of different risks by reliable prognostic index, such as the FLIPI is necessary in future, in order to select the most appropriate treatment. As for grade 3, there was a little number of patients in our series, but further examination is necessary for adaptation of the FLIPI about this group.