Extrafollicular PD1 and Intrafollicular CD3 Expression Are Associated With Survival in Follicular Lymphoma.
Introduction: Both microenvironment and tumor biomarkers impact outcome in follicular lymphoma (FL). We aimed to study the effect of Ki-67, CD3, CD68, and PD1 expression on outcome of FL. Materials and
Methods: Forty-eight patients were included. Stained slides were visually assessed and marker expression was correlated with outcome. Both intra- and extrafollicular expression of Ki-67, CD68, and PD1 were evaluated. CD3 was evaluated only in the intrafollicular area. The median values of expression served as a cutoff point for low- and high-expression groups.
Results: High extrafollicular PD1 expression predicted superior FFTF (freedom from treatment failure) compared with low expression (5-year 52% vs. 44%, P = .04). Five-year FFTF markedly increased from 37% to 67% (P = .057) in patients with low intrafollicular CD3 expression.
Conclusion: Our study supports the hypothesis that survival in FL depends on the immunologic cross talk between malignant cells and microenvironment; however, the specific types of cells that influence the clinical behavior of FL are still unknown.