BIOLOGIC CHARACTERIZATION OF HEREDITARY NONPOLYPOSIS COLORECTAL-CANCER - NUCLEAR PLOIDY, AGNOR COUNT, MICROVESSEL DISTRIBUTION, ONCOGENE EXPRESSION, ANAL GRADE-RELATED PARAMETERS

The identification of hereditary non-polyposis colorectal cancer (HNPC C) is important not only for the patient, but also for family members who are at increased risk of developing cancer. To determine if measur ing various pathobiologic features of the colon carcinomas is useful i n separating sporadic from HNPCC tumors, the authors studied tumor tis sues from 46 patients with HNPCC and compared them to 70 with sporadic colorectal carcinoma. Parameters investigated included DNA ploidy (fl ow cytometry), AgNOR count (by silver staining), microvessel density ( immunohistochemistry), p53 and K-vas expression, and grade-related par ameters. Diploid tumors were more frequent in patients with HNPCC (65% vs 40%, P <.02), thus confirming previous observations concerning suc h an association. Higher AgNOR counts and greater AgNOR areas were obs erved in sporadic tumors than in HNPCC (5.2 +/- 1.5 vs 4.5 +/- 1.8, P <.01). Hereditary tumors tended to be less vascularized, whereas oncog ene expression and grade-related parameters did not show appreciable d ifferences between the two types of tumors. In conclusion, some of the investigated parameters may contribute to defining the biologic profi le of HNPCC. In addition, these findings support the clinical impressi on of a more favorable outcome that is frequently seen in HNPCC patien ts.