Abstract A common treatment for follicular lymphoma is rituximab monotherapy. To identify patients for whom this regimen is adequate as first-line therapy, we applied the World Health Organization (WHO) classification for grading follicular lymphoma in a prospective central pathology review of the biopsies of previously untreated patients in two randomized trials of rituximab without chemotherapy. In the first trial (n₁ = 53), higher WHO grades correlated with longer time to next treatment, independently of clinical prognostic factors (p = 0.030); the finding was replicated in the second trial (n₂ = 221; p = 0.019). Higher grades were associated with better treatment responses (p = 0.018). Furthermore, also grades externally confirmed by independent local pathologists correlated with time to next treatment (p = 0.048). Flow cytometry in a separate patient series showed that the intensity of CD20 increased with the malignant cell size (p < 0.00005). In conclusion, WHO grade 1 follicular lymphoma correlates with inferior outcome after rituximab monotherapy. WHO grading might provide a clinically useful tool for personalized therapy.
Leukemia and Lymphoma, 2014, Vol 55, Issue 2, p. 288-95
Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal, Murine-Derived; Antigens, CD20; Denmark; Female; Finland; Humans; Lymphoma, Follicular; Male; Middle Aged; Multivariate Analysis; Neoplasm Grading; Norway; Prospective Studies; Randomized Controlled Trials as Topic; Survival Analysis; Sweden; Treatment Outcome; World Health Organization; Young Adult; Journal Article; Research Support, Non-U.S. Gov't