Nonrandom pattern of cytogenetic abnormalities in squamous cell carcinoma of the larynx

Cytogenetic analysis of short-term cultures from 105 squamous cell carcinomas of the larynx (LSCC) revealed clonal chromosome aberrations in 56 tumors. Simple karyotypic changes (less than four aberrations per clone) were found in 24 cases, and the remaining 32 tumors had complex karyotypes with multiple numerical as well as unbalanced structural rearrangements. Extensive intratumor heterogeneity, in the form of multiple related subclones or unrelated clones, was observed in a large fraction of the tumors. The structural changes most often affected chromosomes 3, 1, 11, 7, 2, 15, 5, 4, 8, and 12, with rearrangements in the centromeric regions, i.e., the centromeric bands p10 and q10 and the juxtacentromeric bands p11 and q11, accounting for 43% of the total breakpoints. The most common imbalances brought about by numerical and unbalanced structural rearrangements were loss of chromosomal region 3p21-pter, chromosome arms 4p, 6q, 8p, 10p, 13p, 14p, 15p, and 17p, and gain of chromosomal regions 3q21-qter, 7q31-pter, and 8q. Among 17 recurrent aberrations identified, the most common were i(8q), hsr(11)(q13), i(3q), i(5p), and del(3)(p11). No statistically significant association was found between major karyotypic features and histological differentiation or TNM stage. The karyotypic features of the LSCC were also compared with previously published oral SCC, a subgroup of SCC that has been more extensively characterized cytogenetically. No clear-cut karyotypic differences were found between LSCC and oral SCC, with the exception that i(8q) was significantly more frequent among the latter.