[Sister chromatid exchange and cellular kinetics in lymphocytes of patients with adenoma and colonic cancer].

In this paper we describe the sister chromatid exchange (SCE) frequency and the cell-cycle kinetics in lymphocytes of peripheral blood from 51 untreated patients with colonic tumors: 30 with adenomas (A) (17 tubular, 6 tubulovillous and 7 villous) and 21 with carcinomas (C) (4 in situ and 17 invasive). SCE frequencies expressed as M +/- SD were 7.1 +/- 0.2 in A, 6.9 +/- 0.3 in C and 8.7 +/- 0.2 in controls. No differences were seen between the A and C frequencies and both values were significantly less than the control SCE frequencies (p less than 0.01). A lower SCE was observed in these patients especially in chromosomes 1 and 2 and groups B and D with respect to controls (p less than 0.01). The cell cycle kinetics of adenomas and carcinomas presented an elongation of the cell cycle time with reference to the controls (p less than 0.01). Replication indexes (RI) showed the following values: 1.8 +/- 0.06 in A, 1.8 +/- 0.08 in C and 2.1 +/- 0.05 in controls. The patients' values were significantly different from the controls (p less than 0.01). From the cytogenetic viewpoint, the similar behavior in SCE frequencies and cytokinetics found in adenoma and colon carcinoma suggest that adenoma is a preneoplastic lesion.