ras oncogene is expressed in adenocarcinoma of the endometrium

Activation of c-ras oncogenes has been implicated in human carcinomas of the colorectum, prostate, bladder and breast. The major peptide product of c-ras is a 21 kilodalton peptide (p21), but other larger "ras-related" peptides have been described in urine obtained from patients with several types of cancers. In the present investigation immunohistochemical methods were used to assess c-ras expression in tissues obtained from patients with endometrial adenocarcinoma. Formalin-fixed, paraffin-embedded tissues were processed in routine fashion, then incubated with a monoclonal antibody raised against a v-H-ras synthetic peptide. ras Peptides were not detected in proliferative or secretory endometrium or in benign adenomatous hyperplasia. One of four specimens of atypical adenomatous hyperplasia and two of 11 specimens of grade 1 (international Federation of Gynecology and Obstetrics) adenocarcinoma stained positive for ras peptides. A total of 95% of the grade 2 and 3 adenocarcinoma studied contained detectable ras peptides within neoplastic cells. In contrast to previous immunohistochemical studies that identified ras peptides only in neoplastic cells of bladder, prostate, colon, and breast cancers, we routinely found ras peptides within stromal cells of high-grade endometrial carcinomas. When stained with hematoxylin and eosin, these cells have the appearance of foamy macrophages.