Molecular implications of recurrent cytogenetic alterations in human small cell lung cancer.

This article describes cytogenetic findings in human small cell lung cancer (SCLC). Included is a summary of analyses performed by the authors on 17 tumors, each of which displayed numerous chromosomal alterations. Many of the recurrent changes involve losses at the locations of tumor suppressor genes, whose loss and/or inactivation may play a crucial role in tumorigenesis. Deletions of the short arm of chromosome 3 (particularly 3p21-25) were found in every case, providing additional evidence in support of the notion that this region harbors a tumor suppressor gene(s) critical in the pathogenesis of SCLC. Cytogenetic losses of 5q21, 13q14, and 17p13 (sites of the APC, RB1, and TP53 suppressor loci, respectively) also are common in SCLC. Double minutes are found in a minority of these tumors and are associated with oncogene amplification. The genetic complexity in SCLC underscores the need for greater preventive measures and early detection.