Prognostic Significance of Heat Shock Protein 70 Expression in Early Gastric Carcinoma

BACKGROUND: Overexpression of heat shock protein 70 (HSP70) has been observed in many types of cancer including gastric adenocarcinomas, although the exact role of HSP70 in carcinogenesis remains unclear. METHODS: The study analyzed a total of 458 radical gastrectomy specimens which were immunohistochemically stained with HSP70, p53, and Ki-67 antibodies. RESULTS: The study determined that the expression of HSP70 was significantly increased in early gastric cancer (EGC) compared to advanced gastric cancer (p<0.001). The HSP70 expression was correlated with well-differentiated tumor type, intestinal type of Lauren classification and the lower pT and pN stage. Negative expression of Ki-67 and p53 expression was associated with poor prognosis. The study did not find any correlation between HSP70 and p53 expression. The study determined that HSP70 expression in the EGC subgroup was associated with a poor prognosis (p=0.009), as well as negative Ki-67 expression (p=0.006), but was not associated with p53. Based on multivariate analysis, HSP70 expression (p=0.024), negative expression of Ki-67, invasion depth and lymph node metastasis were determined to be independent prognostic markers. CONCLUSIONS: HSP70 is expressed in the early stages of gastric adenocarcinoma. In EGC, HSP70 is a poor independent prognostic marker and is correlated with a low proliferation index.

Plexiform Angiomyxoid Myofibroblastic Tumor of the Stomach: Report of Two Cases and Review of the Literature

Plexiform angiomyxoid myofibroblastic tumor (PAMT) of the stomach is a recently recognized entity. Because of its rarity, only 22 cases have been reported in the English-language literature and most of these are single case reports. We report two cases of gastric PAMT. The tumor cells were bland and plexiform arranged in a myxoid stroma, which was positive for alcian blue. Immunohistochemically, the tumor cells were positive for smooth muscle actin, but negative for c-kit, CD34, desmin, S-100 protein, epithelial membrane antigen, neurofilament, and protein kinase C-theta. Mutation analyses for exon 9, 11, 13, and 17 of KIT genes and 12, 14, and 18 of the platelet-derived growth factor receptor alpha (PDGFRA) genes were performed and the tumors were wild-type for mutation.

Plexiform Angiomyxoid Myofibroblastic Tumor of the Stomach: Report of Two Cases and Review of the Literature

Plexiform angiomyxoid myofibroblastic tumor (PAMT) of the stomach is a recently recognized entity. Because of its rarity, only 22 cases have been reported in the English-language literature and most of these are single case reports. We report two cases of gastric PAMT. The tumor cells were bland and plexiform arranged in a myxoid stroma, which was positive for alcian blue. Immunohistochemically, the tumor cells were positive for smooth muscle actin, but negative for c-kit, CD34, desmin, S-100 protein, epithelial membrane antigen, neurofilament, and protein kinase C-theta. Mutation analyses for exon 9, 11, 13, and 17 of KIT genes and 12, 14, and 18 of the platelet-derived growth factor receptor alpha (PDGFRA) genes were performed and the tumors were wild-type for mutation.

Expression of SIRT1 and DBC1 in Gastric Adenocarcinoma

BACKGROUND: Sirtuin 1 (SIRT1) and deleted in breast cancer 1 (DBC1) are known as tumor suppressor or promoter genes. This may be due to their diverse functions and interaction with other proteins. Gastric adenocarcinoma is one of the most common malignancies, but little is known about its carcinogenesis. Therefore, we investigated the association of immunohistochemical expression of SIRT1, DBC1, p53, and beta-catenin and their variable clinicopathological characteristics. METHODS: We obtained samples from 452 patients who underwent gastrectomy. Tissue microarray blocks were constructed and immonohistochemical staining was performed. RESULTS: Expression of DBC1 and SIRT1 was associated with lower histologic grade, intestinal type of Lauren classification, and lower pT (p<0.001) and pN stage (DBC1, p=0.002; SIRT1, p<0.001). Association between absence of lymphatic invasion, and SIRT1 (p=0.001) and DBC1 (p=0.004) was observed. Cytoplasmic beta-catenin expression was associated with lower histologic grade, pT, pN, tumor-node-metastasis (TNM) stage, DBC1 (p<0.001), and SIRT1 (p=0.001). Expression of SIRT1 and DBC1 was not associated with p53 (p=0.063 and p=0.060). DBC1 was an independent good prognostic factor in multivariate analysis (p=0.012). CONCLUSIONS: SIRC1 and DBC1 can be considered to be good prognostic factors in gastric adenocarcinoma.

Pigmented Perivascular Epithelioid Cell Tumor (PEComa) of the Kidney: A Case Report and Review of the Literature

Heavily pigmented perivascular epithelioid cell tumors (PEComa) are rare, only eight cases of which have been reported. Unlike typical epithelioid angiomyolipoma, most of these tumors have been encountered in female patients without tuberous sclerosis. The long-term prognosis thereof is undetermined. Cytological similarity and heavy melanin pigment make it difficult for pigmented PEComa to be differentiated from pigmented clear cell renal cell carcinoma or malignant melanoma. The immunoprofile of tumor cells, such as human melanoma black-45 expression, as well as the absence or presence of other melanocytic or epithelial markers, are helpful in determining a differential diagnosis. Here we report a case of heavily pigmented PEComa of the right kidney and review the literature describing this tumor. In this case, the immunoprofile and clinical features corresponded well to those described in the literature. Since the prognosis of such disease has not yet been established, close follow-up of this patient was recommended.