Comparative Genomic Hybridization Studies on Mesothelioma Show a Parallel Fate of 1p21-1p22 and 9p21 Bands and a Chromosomally Stable Sub-Group

Abstract

Malignant Pleural Mesothelioma (MPM) is a cancer whit a poor prognosis. The landscape of the chromosomal rearrangements in MPM was approached by several authors but robust conclusions could not be made, given the limited sample sets analyzed within each study. In order to improve the knowledge on the field, we retrieved and pooled all the results deriving from published studies where comparative genomic hybridization (CGH) was employed. A total of 283 tissues (149 epithelioid, 53 sarcomatoid, 78 biphasic, and 3 unclassified) were analysed, 179 with classical chromosome CGH (cCGH), and 104 with arrayed-CGH (aCGH). Some chromosomal bands were involved in aberrations with a frequency exceeding 20% (-1p21, -9p, -14q, and -22q for the epithelioid, -4, +5p, +8q21ter, -9p, -13, and -14q for the sarcomatoid, and -9p, -14q, and -22q for the biphasic type). We found a statistical significant association between contemporary losses at 9p21 and 1p21-1p22 (21% of the samples showed losses at both bands, P=7.74x10-8), whose significance should be elucidated with further studies. Candidate cancer genes involved in MPM were suggested. Finally, 15% of epithelioid, 13% of sarcomatoid, and 13% of biphasic MPM tissues did not show any genomic alteration. Only two previous studies suggested a less aggressive behavior of MPM in relation to a low degree of chromosomal alterations. Thus, more work is warranted to understand whether chromosomal rearrangements could be included as prognostic biomarker in the clinical practice.