Overexpression of podocalyxin-like protein is an independent factor of poor prognosis in colorectal cancer

Background:Podocalyxin-like 1 (PODXL) is a cell-adhesion glycoprotein and stem cell marker that has been associated with an aggressive tumour phenotype and poor prognosis in several forms of cancer. In this study, we investigated the prognostic impact of PODXL expression in colorectal cancer (CRC).Methods:Using tissue microarrays and immunohistochemistry, PODXL expression was evaluated in 536 incident CRC cases from a prospective, population-based cohort study. Kaplan-Meier analysis and Cox proportional hazards modelling were used to assess the impact of PODXL expression on cancer-specific survival (CSS) and overall survival (OS).Results:High PODXL expression was significantly associated with unfavourable clinicopathological characteristics, a shorter CSS (hazard ratio (HR)=1.98; 95% confidence interval (CI) 1.38-2.84, P<0.001) and 5-year OS (HR=1.85; 95% CI 1.29-2.64, P=0.001); the latter remaining significant in multivariate analysis (HR=1.52; 95% CI 1.03-2.25, P=0.036). In addition, in curatively resected stage III (T1-4, N1-2, M0) patients (n=122) with tumours with high PODXL expression, a significant benefit from adjuvant chemotherapy was demonstrated (p(interaction) =0.004 for CSS and 0.015 for 5-year OS in multivariate analysis).Conclusion:Podocalyxin-like 1 expression is an independent factor of poor prognosis in CRC. Our results also suggest that PODXL may be a useful marker to stratify patients for adjuvant chemotherapy

A cohort study of the prognostic and treatment predictive value of SATB2 expression in colorectal cancer

BACKGROUND: Special AT-rich sequence-binding protein 2 (SATB2) is a novel diagnostic marker of colorectal cancer (CRC), and loss of SATB2 has been linked to poor survival from the disease. In this study, we validated the prognostic ability of SATB2 expression in a large, prospective CRC cohort. METHODS: Immunohistochemical SATB2 expression was assessed in 527 incident CRC cases from the Malmö Diet and Cancer Study. Kaplan–Meier analysis and Cox proportional hazards modelling were used to explore the impact of SATB2 expression on cancer-specific survival (CSS) and overall survival (OS). RESULTS: High SATB2 expression was associated with a prolonged CSS in the full cohort (hazard ratio (HR)=0.61; 95% CI 0.41–0.92) and in colon cancer (HR=0.39; 95% CI 0.20–0.75), remaining significant in multivariable analysis of colon cancer (HR=0.49; 95% CI 0.25–0.96), with similar findings for OS. In curatively resected stage III-IV patients, a significant benefit from adjuvant and/or neoadjuvant therapy was observed for SATB2 high tumours (P(interaction)=0.037 for OS) and high SATB2 expression in rectal cancer correlated with an enhanced effect of neoadjuvant therapy (P(interaction)=0.033 for OS). CONCLUSION: High SATB2 expression is an independent marker of good prognosis in colon cancer and may modulate sensitivity to chemotherapy and radiation

Heterogenous mismatch-repair status in colorectal cancer

Background: Immunohistochemical staining for mismatch repair proteins is efficient and widely used to identify mismatch repair defective tumors. The tumors typically show uniform and widespread loss of MMR protein staining. We identified and characterized colorectal cancers with alternative, heterogenous mismatch repair protein staining in order to delineate expression patterns and underlying mechanisms. Methods: Heterogenous staining patterns that affected at least one of the mismatch repair proteins MLH1, PMS2, MSH2 and MSH6 were identified in 14 colorectal cancers. Based on alternative expression patterns macro-dissected and micro-dissected tumor areas were separately analyzed for microsatellite instability and MLH1 promoter methylation. Results: Heterogenous retained/lost mismatch repair protein expression could be classified as intraglandular (within or in-between glandular formations), clonal (in whole glands or groups of glands) and compartmental (in larger tumor areas/compartments or in between different tumor blocks). These patterns coexisted in 9/14 tumors and in the majority of the tumors correlated with differences in microsatellite instability/MLH1 methylation status. Conclusions: Heterogenous mismatch repair status can be demonstrated in colorectal cancer. Though rare, attention to this phenomenon is recommended since it corresponds to differences in mismatch repair status that are relevant for correct classification. Virtual Slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/177194032312678