Heteromorphism of constitutive heterochromatin in carcinoma and dysplasia of the uterine cervix.

Chromosomal heteromorphism in constitutive heterochromatin of chromosomes 1, 9 and 16 was studied in 8 patients with cervix cancer and 15 patients with cervix dysplasia. Tissue cultures (diploid fibroblasts) established from tumor biopsies as well as lymphocyte cultures were used for making C-banded chromosome preparations. The heteromorphism in the appearance of C-bands was expressed as differences in band size or position (inversions). 5 of the cervix cancer patients and 8 of those with dysplasia showed heteromorphism in chromosome 1. In two cancer patients, tissue culture as well as blood cells were available for analysis and both showed the same pattern of heteromorphism, thus suggesting an inherited origin of the variability. Heterochromatin heteromorphism was more common in chromosome 1 than in chromosomes 9 and 16. The heteromorphism in constitutive heterochromatin of chromosome 1 might be among the factors that dispose to cancer.