Nuclear morphometric measurements in rectal adenocarcinoma cells of patients of different races.

The reasons for the different long-term prognoses of black and white patients following curative resection of a rectal adenocarcinoma are unknown. In order to investigate whether rectal adenocarcinomas in blacks have clinical or pathologic characteristics that are different from rectal adenocarcinomas in whites, 149 patients with potentially curable rectal cancers resected at the University of Chicago Medical Center between 1965 and 1981 were retrospectively analyzed. Clinical records, pathology reports and pertinent slides were reviewed in each case. In 142 cases, enough histologic material was available to perform nuclear photometric measurements and determinations of DNA content by the slide-cytophotometric method. There was no difference between black and white patients in the stage, differentiation degree, morphology and ploidy of the tumors, or in the presence of microinvasion, metastases and mucin production. However, adenocarcinoma cells of black patients had smaller nuclei than did the corresponding nuclei of white patients (54.7 +/- 2.34 sq microns versus 58.9 +/- 1.84 sq microns; P less than .05), and the neoplastic nuclei of black patients were significantly rounder and more regular than the nuclei of white patients (mean roundness factors of 1.1 +/- 0.003 vs. 1.11 +/- 0.005; P less than .05). Although these findings will require confirmation from other large clinical series, they suggest that the different prognoses of black and white patients after curative resection of a rectal adenocarcinoma may be explained by a different tumor behavior intrinsically related to different karyotypic characteristics of the neoplastic cells.