MET Is highly expressed in advanced stages of colorectal cancer and indicates worse prognosis and mortality

The aim of the present study was to evaluate by immunohistochemistry the prognostic meaning of the tumor marker MET (hepatocyte growth factor) in patients submitted to surgical resection due to primary colorectal adenocarcinoma. PATIENTS AND METHODS: A retrospective study was carried out that included 286 consecutive patients with colorectal adenocarcinoma, submitted to surgical resection at Barretos Cancer Hospital, from 1993 to 2002. The histopathological expression of the MET tumor marker was evaluated using an anti-protein monoclonal antibody against MET by the streptavidin-biotin-peroxidase technique. The expression of the tumor marker was semi-quantitative, and the slide samples were independently analyzed by three pathologists unaware of patient clinical and histopathological data. RESULTS: The tumor marker expression was positive in 236 (79%) out of a total of 286 patients. This expression was statistically significantly different between stages I and IV (p=0.004), for overall survival (p=0.009), and for cancer-related mortality rates (p=0.022). However, no association between the tumor marker and recurrence (p=0.89) or disease-free interval (p=0.91) was observed. CONCLUSION: MET has shown significant expression at advanced stages of the disease, as well as for overall survival and cancer-related mortality rates demonstrating to be a valuable marker for poor prognosis in colorectal cancer patients

Lack of microsatellite instability in gastrointestinal stromal tumors

The microsatellite instability (MSI) phenotype may constitute an important biomarker for patient response to immunotherapy, particularly to anti-programmed death-1 inhibitors. MSI is a type of genomic instability caused by a defect in DNA mismatch repair (MMR) proteins, which is present mainly in colorectal cancer and its hereditary form, hereditary nonpolyposis colorectal cancer. Gastrointestinal stromal tumor (GIST) development is associated with activating mutations of KIT proto-oncogene receptor tyrosine kinase (KIT) or platelet-derived growth factor receptor alpha (PDGFRA), which are oncogenes that predict the response to imatinib mesylate. In addition to KIT/PDGFRA mutations, other molecular alterations are important in GIST development. In GISTs, the characterization of the MSI phenotype is scarce and the results are not consensual. The present study aimed to assess MSI in a series of 79 GISTs. The evaluation of MSI was performed by pentaplex polymerase chain reaction comprising five markers, followed by capillary electrophoresis. The expression of MMR proteins was evaluated by immunohistochemistry. Regarding the KIT/PDGFRA/B-Raf proto-oncogene, serine/threonine kinase molecular profile of the 79 GISTs, 83.6% of the tumors possessed KIT mutations, 10.1% had PDGFRA mutations and 6.3% were triple wild-type. The mutated-PDGFRA cases were associated with gastric location and a lower mitotic index compared with KIT-mutated and wild-types, and these patients were more likely to be alive and without cancer. MSI analysis identified 4 cases with instability in one marker, however, additional evaluation of normal tissue and immunohistochemical staining of MMR proteins confirmed their microsatellite-stable nature. The results of the present study indicated that MSI is not involved in GIST tumorigenesis and, therefore, cannot serve as a biomarker to immunotherapy response in GIST.The present study was supported by The Brazilian National Council for Scientific and Technological Development (grant no. 476192/2013-7) and the São Paulo Research Foundation Doctoral Fellowship (grant no. 2013/25787-3).info:eu-repo/semantics/publishedVersio

Prognostic and Risk Factors in Patients with Locally Advanced Cutaneous Squamous Cell Carcinoma of the Trunk and Extremities

55 patients with advanced cutaneous squamous cell carcinoma (CSCC) of the trunk and extremities were studied. A Tissue Microarray was constructed using immunohistochemistry to quantify expression of the HER family, E-cadherins, and podoplanin. Clinical and histopathological factors related to lymph node metastasis and prognosis were also established. Primary tumor positivity was 25.5% for EGFR, 87.3% for HER-3, and 48.1% for HER-4. Metastases were positive for EGFR in 41.7%, for HER-3 in 83.3%, and HER-4 in 43.5%. HER-2 was negative in all samples. Membrane E-cadherin and cytoplasmic E-cadherin were positive in 47.3% and 30.2% of primary tumors and 45.5% and 27.3% of metastases, respectively. Podoplanin was positive in 41.8% of primary tumors and 41.7% of metastases. Intratumoral lymphocytic infiltrate was associated with lymph node metastasis. Patients with T3 tumors had better cancer-specific survival (CSS) than those with T4 tumors; patients with no lymph node involvement had better CSS than patients with N1 tumors. Undifferentiated tumors and hyperexpression of podoplanin were negative prognostic indicators on multivariate analysis

PIK3CA mutations are frequent in esophageal squamous cell carcinoma associated with chagasic megaesophagus and are associated with a worse patient outcome

Chronic diseases such as chagasic megaesophagus (secondary to Chagas' disease) have been suggested as etiological factors for esophageal squamous cell carcinoma; however, the molecular mechanisms involved are poorly understood.Background Chronic diseases such as chagasic megaesophagus (secondary to Chagas’ disease) have been suggested as etiological factors for esophageal squamous cell carcinoma; however, the molecular mechanisms involved are poorly understood. Objective We analyzed hotspot PIK3CA gene mutations in a series of esophageal squamous cell carcinomas associated or not with chagasic megaesophagus, as well as, in chagasic megaesophagus biopsies. We also checked for correlations between the presence of PIK3CA mutations with patients’ clinical and pathological features. Methods The study included three different groups of patients: i) 23 patients with chagasic megaesophagus associated with esophageal squamous cell carcinoma (CM/ESCC); ii) 38 patients with esophageal squamous cell carcinoma not associated with chagasic megaesophagus (ESCC); and iii) 28 patients with chagasic megaesophagus without esophageal squamous cell carcinoma (CM). PIK3CA hotspot mutations in exons 9 and 20 were evaluated by PCR followed by direct sequencing technique. Results PIK3CA mutations were identified in 21.7% (5 out of 23) of CM/ESCC cases, in 10.5% (4 out of 38) of ESCC and in only 3.6% (1 case out of 28) of CM cases. In the CM/ESCC group, PIK3CA mutations were significantly associated with lower survival (mean 5 months), when compared to wild-type patients (mean 2.0 years). No other significant associations were observed between PIK3CA mutations and patients’ clinical features or TP53 mutation profile. Conclusion This is the first report on the presence of PIK3CA mutations in esophageal cancer associated with chagasic megaesophagus. The detection of PIK3CA mutations in benign chagasic megaesophagus lesions suggests their putative role in esophageal squamous cell carcinoma development and opens new opportunities for targeted-therapies for these diseases.CAPES and FAPESP - Fundação de Amparo à Pesquisa do Estado de São Paulo [Grant number 2015/20077–3 to FFM] and Barretos Cancer Hospital internal research funds (PAIP)info:eu-repo/semantics/publishedVersio

Is the gastrointestinal stromal tumor arising in the rectovaginal septum an extragastrointestinal entity? A time for reflection

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MET Is highly expressed in advanced stages of colorectal cancer and indicates worse prognosis and mortality

The aim of the present study was to evaluate by immunohistochemistry the prognostic meaning of the tumor marker MET (hepatocyte growth factor) in patients submitted to surgical resection due to primary colorectal adenocarcinoma. The aim of the present study was to evaluate by immunohistochemistry the prognostic meaning of the tumor marker MET (hepatocyte growth factor) in patients submitted to surgical resection due to primary colorectal adenocarcinoma. Patients and Methods: A retrospective study was carried out that included 286 consecutive patients with colorectal adenocarcinoma, submitted to surgical resection at Barretos Cancer Hospital, from 1993 to 2002. The histopathological expression of the MET tumor marker was evaluated using an anti-protein monoclonal antibody against MET by the streptavidin-biotin-peroxidase technique. The expression of the tumor marker was semi-quantitative, and the slide samples were independently analyzed by three pathologists unaware of patient clinical and histopathological data. Results: The tumor marker expression was positive in 236 (79%) out of a total of 286 patients. This expression was statistically significantly different between stages I and IV (p=0.004), for overall survival (p=0.009), and for cancer-related mortality rates (p=0.022). However, no association between the tumor marker and recurrence (p=0.89) or disease-free interval (p=0.91) was observed. Conclusion: MET has shown significant expression at advanced stages of the disease, as well as for overall survival and cancer-related mortality rates demonstrating to be a valuable marker for poor prognosis in colorectal cancer patients

Lymphangiogenic VEGF-C and VEGFR-3 expression in genetically characterised gastrointestinal stromal tumours

This study aimed to assess the distribution of VEGF-C and VEGFR-3 expression in gastrointestinal stromal tumours (GISTs), and to analyse the value of lymphatic vessel density (LVD) in a tumour that is believed to preferentially metastasize through blood vessel conduits. A panel of immunohistochemical antibodies was used to evaluate 51 cases of genetically characterised GISTs: VEGF-C, VEGFR-3, D2-40 (for LVD assessment) and CD31 (for blood vessel density – BDV – assessment). The results were correlated with the clinical-pathological data. The large majority of cases (86.2%; 44/51) showed a mutation of the KIT gene, most of them (72.5%; 37/51) revealing mutations in exon 11. VEGFR-3 was predominantly expressed in KIT mutated GISTs (p=0.019). High LVD was correlated with the absence of metastasis (p=0.010) and high BVD showed a positive correlation with the occurrence of metastasis (p=0.049). The strong expression of VEGF-C and VEGFR-3 in GIST’s cells was not correlated with the clinical parameters of aggressiveness, nor with high LVD