We used fluorescence in situ hybridization (FISH) assays to identify t(14;18) translocations in archival paraffin-embedded tumor sections from non-Hodgkin lymphoma (NHL) cases enrolled in a population-based study. t(14;18) was identified in 54% of 152 cases, including 39% of diffuse large cell lymphomas (26 of 66 cases) and 84% of follicular lymphomas (36 of 43 cases). Eighty-seven percent of t(14;18)-positive cases and 57% of t(14;18)-negative cases expressed bcl-2. FISH assays detected twice as many t(14;18)-positive follicular lymphomas as PCR assays. Overall, study findings support the use of FISH assays to detect t(14;18) in archival tumor samples for epidemiologic studies of NHL subtypes
