A clinicopathologic and molecular study of follicular lymphoma in Taiwan

The clinicopathologic and molecular features of follicular lymphoma (FL) in Taiwan have not been well defined. We conducted a retrospective study including history review, immunohistochemistry, and molecular study for the major breakpoint region (MBR) of t(14;18) and correlated these findings with survival.

Sixty-five FLs were identified, with a male to female ratio of 1.9:1 and a median age of 63 years (mean, 60 years). Sixty cases (92%) were nodal, 4 (6%) were extranodal, and 1 (2%) was indeterminate. The median ages of the nodal and extranodal cases were 63 years and 44 years, respectively. Disease staging in 59 patients included 15 patients (25%) with stage I disease, 14 (24%) with stage II, 20 (34%) with stage III, and 10 (17%) with stage IV. Forty-four patients received chemotherapy, 2 patients received chemotherapy with palliative radiation therapy, and 13 patients received supportive treatment/observation.

The 5-year survival rate was 52.6%. The cases were classified as grades 1 (n = 27; 42%), 2 (n = 22; 34%), 3A (n = 13; 20%), and 3B (n = 3; 5%). Twenty cases (31%) were positive for MBR, including 19 of 57 (33%) nodal cases and 1 of 4 (25%) primary extanodal FLs. Patients with low-stage disease (stages I/II) had a better survival rate than patients with high-stage disease (III/IV; log-rank test, P = 0.012).

This is the largest series of Taiwanese FLs with immunophenotypes and MBR detection rates similar to those of the West. Disease stage was statistically significant with regard to survival. Although the number of extranodal FLs cases was small, the patients were younger, their tumors had lower CD10 expression, and they had more favorable survival rates than patients with nodal disease.