Chromosome abnormalities in non-small cell lung cancer pleural effusions: cytogenetic indicators of disease subgroups

A cytogenetic study of pleural effusions (PE) containing metastatic or invasive tumor cells from 11 patients with non-small cell lung cancer (NSCLC) (3 squamous cell carcinomas [SQC] and 8 adenocarcinomas [ADC] including 1 giant cell variant) was performed to identify non-random chromosome abnormalities. Numerical abnormalities seen in > or = 30% of cases included gain of chromosomes 7 and 20, and loss of chromosomes 4, 9, 10, 13, 15, 16, 18, 19, 21, and 22. The most frequent structural abnormality involved rearrangement in 1p with breakpoints clustering at 1p10-p13. Other recurrent breakpoint regions, seen in > or = 30% of cases, occurred in chromosome region 3p10-p21, 3q11-q25, 6p11-p25, 6q13-q23, 7q11-q36, 9q32-q34, 11p11-p13, 11q13-q24, 13p/14p and/or 15p, 17p and 19p, with, in particular, apparent loss of 6q21-q27, 3p21-p26, 7q21-q22, 9p22-p24 (shortest regions of common overlap) and 17p. There was also recurrent gain of 1q23-q44, 8q13-q24, and 11q13-q23. These abnormalities were not restricted to a particular histological subtype, with the exception of +8 and a breakpoint in 9q32-q34, which were seen only in ADC. The 9q32-q34 breakpoint observed in 4 ADC PE (including 1 giant cell variant) represents a new observation in NSCLC. These findings, when compared to those reported for primary NSCLC indicate cytogenetic differences between the two which may be associated with pleural invasion of NSCLC.