Expression of oestrogen and progesterone receptors in gastric cancer: a flow cytometric study

increased expression of oestrogen (ER) and progesterone (PR) receptors have been reported in gastric adenocarcinoma, although results have been variab le. Immunohistochemical staining methodologies, in particular in the detect ion of ER, have been inconsistent with many tumours being classified ER-neg ative. In this study we have used flow cytometry to quantify expression of ER and PR in gastric adenocarcinoma and examine their relationships with es tablished prognostic indicators. Cytokeratin-positive cells obtained from t umour biopsies of 50 patients with gastric cancer and ten control patients were labelled with biotinylated ER or PR antibodies followed by streptavidi n PE. Flow cytometry was seen to increase the detection of ER levels in gas tric cancer with more receptor-positive patients in this study than in resu lts published to date. We believe this is related to the sensitivity of the flow cytometric assay with the detection of small shifts in ER level detec ted using cytokeratin gating. On analysis, the data showed no significant c orrelations with tumour stage and grade, and no differences were seen betwe en normal mucosa and gastric cancer samples.