Geographic variance in the frequency of the t(14;18) translocation in follicular lymphoma: an Israeli series compared to the world.

ABSTRACT

It has been suggested that differences in the frequency of the t(14;18) translocation in follicular lymphoma might explain ethno-geographic variation in the incidence of these tumors. We tested Israeli follicular lymphoma patients for the frequency of the t(14;18) translocation, and reviewed the published literature, comparing the frequency in our series with data from different parts of the world. Tissue specimens from 36 Israeli follicular lymphoma patients were tested for presence of the translocation by PCR amplification of the MBR breakpoint. Twenty-two of the 36 patients (61%) tested positive. A systematic search of the literature yielded 35 papers reporting the frequency of the t(14;18) translocation in follicular lymphoma. We analyzed cytogenetic data and molecular data separately. For each method, data were pooled from all studies within each of three geographical regions - USA, East Asia and Europe. Pooled data from cytogenetic studies show a low frequency of the translocation in the Far East (38%) compared to the USA (71%), with an intermediate frequency found in Europe (61%). Molecular studies show a similar frequency of the translocation in the Far East and Europe, significantly lower than the frequency in pooled data from American studies. The frequency in our Israeli series is relatively high, comparable to that detected in the USA. We suggest that the apparent geographical differences we describe are unlikely to be caused by a difference in the biology of the tumor, and are more likely due to technical and methodological factors. We conclude that it is unlikely that differences in the frequency of the t(14;18) translocation explain the difference in the epidemiology of lymphoma between East and West.