Diagnostic and Prognostic Utility of t(14;18) in Follicular Lymphoma

Background: Follicular lymphoma (FL) is one of the most common non-Hodgkin’s lymphomas of B cells, being closely associated with a t(14;18) translocation. Detection of t(14;18), which is present in 70–95% of FL, might aid in FL diagnosis. Objective: To compare the efficacy of routine polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) techniques in detecting t(14;18) in paraffin-embedded tissue samples of FL patients at different stages. Combined with other immunophenotypic biological determinants, detection of t(14;18) might help to determine patients at increased risk according to the FL International Prognostic Index (FLIPI) and therefore facilitate appropriate treatment. Design and Methods: This study was mainly based on a retrospective examination of formalin-fixed, paraffin-embedded lymph nodes. We selected fixed tissue samples of 21 FL patients treated at the National Cancer Institute Center in the period from 2000 to 2001. Results: FISH techniques could detect 14 of 18 FL cases with a sensitivity of 77.8%, while the PCR technique could detect only 11 of 18 FL cases with a sensitivity of 61.1%, resulting in a statistically significant difference between both techniques (p = 0.004). According to the FLIPI index, 9 of the 18 FL patients were categorized into the high-risk group (50%), 5 in the intermediated-risk group (27.8%) and 4 in the low-risk group (22.2%). Conclusion: The sensitivity of FISH is superior to that of PCR in the detection of the t(14;18) translocation in paraffin-embedded tissue samples. There is a statistically significant correlation between both CD10 and FISH with FLIPI.