Chromosome banding analysis was performed on five cases of human malignant melanoma. Results demonstrated a variety of chromosome alterations, including deletion or translocation of chromosome 6q, in four of five cases. A comparison of our results with previously published studies suggests that chromosome 6q may represent a specific site of chromosome aberration in malignant melanoma.

The recognition of recurring sites of chromosome change in human cancers has pinpointed the location in the genome of several important growth-regulatory sequences (e.g., cellular oncogenes). This report details the finding of a recurring translocation site involving the long arm of chromosome 6 (6q) in malignant melanoma. We have observed a translocation (t) between chromosomes 1 and 6 in five different cases of malignant metastatic melanoma. All five melanomas evidencing t(1;6) involved band regions 6q11-13, while two different regions of chromosome 1 (p22, q12-q21) were shown to be translocated to 6q. In reviewing previously published cases of melanoma, an additional two cases of t(1;6) and 13 cases of other translocations to 6q11-13 have been identified. Chromosome 6q contains several biologically important gene sequences including the proto-oncogenes ros, myb, and mas1. However, based on current mapping studies, the breakpoint of this translocation (6q11-13) is not within the region encoding these sequences. By analogy to other systems, molecular analysis of the translocation breakpoints may identify a gene(s) which plays a role in melanoma tumorigenesis.

The value of chromosomal analysis is well established in human hematologic neoplasms. In contrast, the relation between chromosomal abnormalities and clinical outcome in solid tumors in humans has received little study. We undertook this study to determine whether chromosomal abnormalities could provide information on the survival of patients with malignant melanoma. Chromosome-banding analysis was performed on tumor-biopsy samples from 62 patients with metastatic melanoma, and recurring cytogenetic abnormalities were correlated with survival. Patients with structural abnormalities of chromosome 7 or 11 had significantly shorter survival than patients without these abnormalities. We conclude that cytogenetic analysis may provide useful prognostic information about patients with metastatic melanoma.