Abnormalities in p53 gene expression have been implicated in many inherited and sporadic forms of malignancies in humans. Immunohistochemical staining using monoclonal antibody D0-7 for the p53 protein expression was performed in 81 cases of pure DCIS, 14 benign breast lesions and 2 cases with normal breast tissue. Expression of p53 protein was detected in 15 (18.5%) cases of pure DCIS. Thirteen (25%) of the 52 comedo type DCIS showed p53 protein expression compared with 2 (6.9%) of the 29 non-comedo types (P < 0.02). p53 protein expression was also associated with high nuclear grade (P < 0.001) and high mitotic index (P < 0.05). The pattern of p53 protein staining was diffuse in one comedo type DCIS, regional in 6 comedo types, and focal in the remaining 8 cases (6 comedo type and 2 micropapillary type DCIS). The patient with comedo type DCIS showing diffuse staining has a family history of breast cancer in the first and second degree relatives (sister and maternal aunt). Clinical follow-up data was available in 52 cases. Follow-up period ranged from 9 to 55 months. Three patients, who were primarily treated by local excision, have had a documented local recurrence in the form of residual tumor within a short interval of 5 to 11 months. In all these three patients both the original and the recurrent tumors are negative for p53 protein expression. The difference in the local recurrence rate between p53 positive (0/15) and p53 negative (3/37) cased does not reach statistical significance (p > 0.05). We interpret that the local tumor recurrence in these three cases within a short period after primary excision is due to the presence of residual tumor at the excision site and is independent of the p53 gene alteration. It is concluded that p53 protein expression in DCIS is associated with comedo subtype, high nuclear grade, and high mitotic index, and is a promising new parameter to evaluate the cellular biology and prognosis of DCIS.
Summary Increased expression of oestrogen (ER) and progesterone (PR) receptors have been reported in gastric adenocarcinoma, although results have been variable. Immunohistochemical staining methodologies, in particular in the detection of ER, have been inconsistent with many tumours being classified ER-negative. In this study we have used flow cytometry to quantify expression of ER and PR in gastric adenocarcinoma and examine their relationships with established prognostic indicators. Cytokeratin-positive cells obtained from tumour biopsies of 50 patients with gastric cancer and ten control patients were labelled with biotinylated ER or PR antibodies followed by streptavidin PE. Flow cytometry was seen to increase the detection of ER levels in gastric cancer with more receptor-positive patients in this study than in results 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 detected using cytokeratin gating. On analysis, the data showed no significant correlations with tumour stage and grade, and no differences were seen between normal mucosa and gastric cancer samples.
Summary Increased expression of oestrogen (ER) and progesterone (PR) receptors have been reported in gastric adenocarcinoma, although results have been variable. Immunohistochemical staining methodologies, in particular in the detection of ER, have been inconsistent with many tumours being classified ER-negative. In this study we have used flow cytometry to quantify expression of ER and PR in gastric adenocarcinoma and examine their relationships with established prognostic indicators. Cytokeratin-positive cells obtained from tumour biopsies of 50 patients with gastric cancer and ten control patients were labelled with biotinylated ER or PR antibodies followed by streptavidin PE. Flow cytometry was seen to increase the detection of ER levels in gastric cancer with more receptor-positive patients in this study than in results 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 detected using cytokeratin gating. On analysis, the data showed no significant correlations with tumour stage and grade, and no differences were seen between normal mucosa and gastric cancer samples.
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