PTK-7 Expression in Gastric Cancer: A Prognostic Determinant

Background: Protein tyrosine kinase-7, a regulatory protein in the Wnt signaling pathway, was highly overexpressed in various cancer types and assumed to be related to prognosis. Aims: The purpose of this study is to assess whether protein tyrosine kinase-7 expression status in curatively resected gastric carcinoma would independently identify patients with a high risk of recurrence and death. Study Design: Retrospective cohort study. Methods: We included patients who were at least 18 years of age and diagnosed with gastric cancer. The exclusion criterion was a metastatic disease at the time of diagnosis or operation. Data on clinicopathological prognostic determinants and clinical courses, including the date of disease relapse and survival status, were collected with the use of medical records. Surgically removed tumor tissue specimens were examined by two independent pathologists at the pathology department of our institution. Protein tyrosine kinase-7 expression status was assessed with immunohistochemical processing and stratified on a scale ranging from 0 to +3 according to the extent of stained tumor cells. It was then further categorized into two groups, one being + (positive), including +1, +2, and +3 scores, another was-(negative), including-and +/− scores. Results: A total of 114 patients were analyzed. Protein tyrosine kinase-7 expression was present in 66.7% of the surgical tumor specimens. There was no statistically significant difference in almost all relevant parameters between the protein tyrosine kinase-7 positive and negative groups. The estimated median survival in the protein tyrosine kinase-7 positive group was significantly better than the protein tyrosine kinase-7 negative group (60 vs 22 months, p<0.001). Disease-free survival was found to be 55 months in the protein tyrosine kinase-7 positive group, whereas it was 21 months in the negative group (p=0.015). In the multivariate analysis, along with negative protein tyrosine kinase-7 expression, poor performance status, and advanced stage were significantly associated with the risk of death (p<0.001 for each). Conclusion: Compared to patients with negative PTK-7 expression, patients with positive PTK-7 expression have better disease-free survival and overall survival rates. Efforts should be made to enhance this finding and translate it into clinical practice.

Prognostic significance of protein kinase B/Akt pathway in patients with non-small cell lung cancer.

PURPOSE: Akt, also known as protein kinase B (PKB), is an intracellular signal transduction protein activated by growth hormones. PKB/Akt is frequently activated in a variety of cancer types, but its role in the development and progression of lung cancer has not been completely elucidated yet. The aim of the present study was to determine the prognostic value of PKB/Akt in non-small cell lung cancer (NSCLC). METHODS: A total of 32 tumor samples from NSCLL patients were examined before treatment. The staining characteristics of the cases were evaluated in terms of age, stage (T and N), response to therapy, histological type, tumor size, and ECOG performance status (PS). RESULTS: No statistical correlation was found between PKB/ Akt expression and gender, ECOG PS and stage (T and N), while significant correlation between cytoplasmic PKB/akt expression and age was detected (p<0.05). In addition, squamous cell carcinoma histology was significantly associated with both nuclear and cytoplasmic staining (p=0.033), and tumor size ( <5 cm) was correlated with nuclear PKB/Akt expression (p=0.03). Both overall survival (OS) and progression- free survival (PFS) were similar in patients with and without both nuclear and cytoplasmic PKB/Akt expression. CONCLUSION: Our results showed that although PKB/Akt was not associated with survival in NSCLC patients, it may be a potential therapeutic target for NSCLC; more studies with higher numbers of patients are needed to verify this hypothesis.