Cell proliferation, apoptosis, oncogene, and tumor suppressor gene status in adenosis with comparison to benign prostatic hyperplasia, prostatic intraepithelial neoplasia, and cancer

There is scant information on the cell proliferation, apoptosis, oncogenes, and tumor suppressor genes status in adenosis. Forty-eight foci of adenosi s were studied with immunohistochemistry for MIB-1; c-erbB-2, c-erbB-3, bcl -2 oncogenes; and p53. To evaluate apoptosis, the TdT dUTP nick end labelin g (TUNEL) method was applied. Results were compared with the same studies o n benign prostatic hyperplasia (BPH) (n = 20), low-grade prostatic intraepi thelial neoplasia (PIN) (n = 10); high-grade PIN (n = 20), Gleason sum 2 to 6 canter (n = 16); and Gleason sum 7 to 10 cancer (n = 92). MIB-1 prolifer ation index was lowest in BPH, followed by adenosis, low-grade prostatic in traepithelial neoplasia (PIN), low-grade cancer, high-grade PIN, and high-g rade cancer. The apoptotic rate was generally low in all groups, although i t was higher in PIN and cancer. In BPH and adenosis, bcl-2 was absent in lu minal cells. In low- and high-grade PIN, both basal and luminal cells expre ssed bcl-2, whereas in cancer, expression was found in only 1 case (3%). C- erbB-2 showed absent or low values for cancer and adenosis, whereas it was commonly expressed in BPH and low- and high-grade PIN. Low expression in ad enosis was also found with c-erbB-3 (6%) compared with all other groups. Ex pression of PS3 was confined to cancer. Despite a significantly higher prol iferation index rate compared with BPH, adenosis showed a markedly lower pr oliferating index when compared with low-grade PIN, high-grade PIN, and can cer. Expression of the oncogenes c-erbB-2 and c-erbB-3 was very low in aden osis, and the staining pattern for bcl-2 was similar to that of BPH. These results provide additional evidence to that of prior studies that adenosis is a histological small acinar proliferation more akin to BPH than high-gra de PIN or adenocarcinoma. HUM PATHOL 30:1077-1086. Copyright (C) 1999 by W. B. Saunders Company.