The study aims to determine whether type and density of tumour-infiltrating lymphocytes (TILs) can predict the clinical course in gastric cancer. Gastric carcinomas (n=220) were immunostained for CD3, CD8, CD20, and CD45RO and evaluated for clinicopathologic characteristics. Number of TILs that immunostained positively for each marker were counted using NIH ImageJ software. Tumours were grouped into low- and high-density groups for each marker (CD3, CD8, CD45RO). The densities of CD3⁺, CD8⁺, and CD45RO⁺ TILs were found to be independent predictors of lymph node metastasis by multivariate analysis with odds ratios (95% CI) of 0.425 (0.204–0.885), 0.325 (0.150–0.707), and 0.402 (0.190–0.850), respectively. Kaplan–Meier survival analysis revealed that patients in the high-density groups for CD3, CD8, and C45RO had a significantly longer survival time than the patients in the corresponding low-density groups, respectively. In multivariate survival analysis, the densities of CD3⁺, CD8⁺, and CD45RO⁺ TILs remained independent prognostic factors with hazard ratios (95% CI) of 0.549 (0.317–0.951), 0.574 (0.347–0.949), and 0.507 (0.298–0.862), respectively. In conclusion, density of TILs was found to be independently predictive of regional lymph node metastasis and patient survival in gastric cancer.

Aims:  Epidermal growth factor receptor (EGFR) expression has been observed in a variety of solid tumours with the potential of new targeted therapeutic agents. The aim was to evaluate the EGFR status of gastric carcinoma (GC) using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH).Methods and results:  The EGFR status was evaluated in GC tissues from 511 patients using IHC and FISH. In addition, the clinicopathological characteristics were examined and the results were compared with the EGFR status. One hundred and forty cases (27.4%) showed EGFR overexpression by IHC. EGFR overexpression was associated with older age (P = 0.001), moderately or poorly differentiated histology (P = 0.001) and higher stage disease (P = 0.046). Sixteen cases (3.1%) showed high polysomy and 12 cases (2.3%) had gene amplification by FISH. The correlation between IHC and FISH results was statistically significant (P < 0.001). The patients with GC who had EGFR overexpression had an unfavourable prognosis and multivariate analysis showed that EGFR overexpression was a possible independent unfavourable prognostic factor.Conclusions:  EGFR overexpression was observed in a subset of cases with GC and was associated with an unfavourable prognosis. It will be important to evaluate EGFR status to interpret future clinical trials properly using EGFR targeted agents.

The PTEN/MMAC1/TEP1 gene (phosphatase and tensin homolog deleted on chromosome 10/mutated in multiple advanced cancers/TGF-β regulated and epithelial cell enriched phosphatase 1), which regulates the signaling pathways of Akt, is a novel tumor suppressor gene implicated in multiple cancers. Because a number of tumor suppressor genes are known to be silenced by aberrant promoter methylation, we examined the methylation status of the 5′ CpG islands of PTEN using methylation-specific PCR. The altered expression of PTEN in 310 gastric carcinomas was analyzed by immunohistochemical staining using tissue-array and clinicopathologic profiles related to PTEN expression were characterized. Of 310 consecutive gastric carcinomas, 62 cases (20%) showed expression loss of PTEN. Altered PTEN expression was significantly associated with tumor depth and size, lymphatic invasion, advanced stage, pTNM stage, and patient survival (p < 0.001). The promoter methylation frequency of PTEN was found to be present in 26 (39%) of 66 cases examined, and 19 (73%) of 26 gastric cancer tissues showing promoter methylation exhibited the loss of PTEN expression. Abnormalities in the expression of PTEN significantly correlated with promoter methylation (p < 0.001). In conclusion, silencing of the PTEN gene occurs frequently in gastric carcinoma and aberrant promoter methylation is a major mechanism of silencing of the PTEN gene. The abnormalities of the PTEN gene are associated with tumor progression, metastasis, and survival.

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BACKGROUND Although mucin expressions appear to be correlated with prognoses in patients with various cancers, several studies have reported conflicting and inconclusive results on the prognostic significance of mucin expression in gastric carcinomas. METHODS To clarify the correlations between clinicopathologic profiles and the patients' survival, the expression of MUC1, MUC2, MUC5AC, MUC6 mucins and the p53 protein were evaluated immunohistochemically in 300 consecutive gastric carcinomas using the tissue‐array method. In addition, 59 gastric adenomas and 57 adenoma‐associated carcinomas were investigated. RESULTS MUC1 was expressed in 2 (3.4%) cases of gastric adenoma, and MUC2 in 19 (32.2%) cases of gastric adenoma, out of a total of 59 lesions. In consecutive gastric carcinomas, 24.3% of gastric carcinomas expressed MUC1, 27.3% expressed MUC2, 38.0% expressed MUC5AC and 12.7% expressed MUC6. The rate of MUC1 expression in gastric carcinomas was significantly higher than in associated gastric adenomas (P < 0.01). The patients with MUC1‐positive carcinomas showed significantly poorer survival than those with MUC1‐negative carcinomas. On the other hand, MUC2, MUC5AC and MUC6 expressions were not significantly associated with patient survival. Interestingly, combined evaluation revealed that the group with the MUC1‐negative plus p53‐negative expression pattern showed a better prognosis than the remaining cases. In contrast, the group with the MUC2‐negative plus p53‐positive pattern showed a worse prognosis. CONCLUSIONS Mucin expression is altered in gastric adenoma and carcinoma, and MUC1 mucin expression is significantly associated with poorer outcome in gastric carcinomas. A MUC1‐negative plus p53‐negative pattern or a MUC2‐negative plus p53‐positive pattern may predict outcome in patients with gastric carcinomas. Cancer 2001;92:1427–34. © 2001 American Cancer Society.