Chromosome 1 heterochromatin variants and cancer: a reassessment

Evidence for a relationship between chromosome #1 heterochromatin polymorphisms and cancer has been reviewed. Eighty-four of 135 (62%) patients with epithelial malignancies were heteromorphic for C-band size compared with 38 of 107 (36%) controls (significant at the 0.1% level). However, only 33 of 67 (49%) patients with nonepithelial malignancies were heteromorphic (not significantly different from controls). Similarly, the incidence of partial inversions of the C-band region in one or both homologs was significantly greater than controls [28 of 107 (26%)] for patients with epithelial [66 of 135 (49%)] but not nonepithelial [25 of 67 (37%)] malignancies. However, when the presence of either or both size heteromorphism and inversions were assessed, the incidence was significantly higher in patients with nonepithelial [46 of 67 (69%), including 11 of 11 patients with leukemia or myeloproliferative disorders] as well as epithelial [112 of 135 (83%)] malignancies compared with controls [52 of 107 (49%)]. Forty-seven of the patients did not differ significantly from controls with respect to the incidence of chromosome #1 heteromorphism as revealed by the Giemsa-11 technique. However, 26 patients assessed for their chromosome #1 lateral asymmetry pattern differed significantly from controls, having a higher incidence of compound asymmetry with a large proximal and small distal block and a lower incidence of simple asymmetry.