Chromosomal aberrations in a series of large-cell neuroendocrine carcinomas: Unexpected divergence from small-cell carcinoma of the lung

Large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCL C) are high-grade neuroendocrine tumors of the lung. Despite different morp hologic appearances, loss of heterozygosity and oncogene studies on LCNEC t o date suggest genetic similarities. We analyzed 13 LCNEC and 5 mixed SCLC/ LCNEC tumors by comparative genomic hybridization and subsequently compared our results with previously published data on 32 SCLCs. Comparison with SC LC showed several shared chromosomal aberrations, specifically losses of 3p , 4q, 5q, and 13q and gains of 5p. However, these aberrations are no specia l feature of neuroendocrine lung tumors but can also be found in other high -grade lung carcinomas. From this point of view, genetic similarities of LC NEC and SCLC are less important than the nonrandom changes that differ betw een these 2 tumor types. A gain of 3q observed in 66% of all SCLCs was dete cted only once in the LCNEC group. In contrast to the pure LCNEC, all mixed types with a SCLC component had a gain of 3q. Gains of 6p occurred more fr equently in LCNEC. Deletions of l0q, 16q, and 17p were less frequent in LCN EC than in SCLC. Hum PATHOL 32:1059-1063. Copyright (C) 2001 by W.B. Saunde rs Company.