Deletions of the long arm of chromosome 7, with breakpoints varying fr
om q11 to q34, are described in 13 malignant tumors, including three c
arcinomas of the prostate, three colorectal carcinomas, and four testi
cular germ cell tumors. In two of the tumors, the chromosome also had
a deletion of 7p. Review of the literature shows that 7q- chromosomes
have been detected in various tumor types and are particularly common
in benign and malignant mesothelial tumors, secondary leukemias, testi
cular cancers, and carcinomas of the ovary and prostate. Their signifi
cance may lie in loss of an unknown tumor-suppressor gene situated dis
tally on 7q.