Prognostic impact of SOX9 in stage II colon cancer: Results from a large nationwide cohort

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Background: Up-regulation of the transcription factor SOX9 has been described in colon cancer, and it has been argued that differences in the expression levels dictates cell proliferation. The aim of the present study was to analyze the prognostic impact of SOX9 in patients with stage II colon cancer. Methods: Individual patient data and formalin fixed paraffin embedded tumor tissue were collected from a large unbiased, population-based cohort, representing all patients operated for stage II colon cancer in Denmark in 2002 and 2003. The SOX9 expression was evaluated by immunohistochemistry on whole tumor sections. Patients were classified into three groups dependent on the SOX9 expression gradient in the tumor: luminal, peripheral, and uniform for comparison with the clinical data. The endpoint was disease free survival (DFS). Results: A total of 1,153 patients were included. We detected an expression-dependent relationship between SOX9 and prognosis. Patients with tumors exhibiting a luminal expression pattern (N = 267, increasing SOX9 expression towards the luminal compartment of the tumor) were characterized by a significantly better DFS compared to the uniform (N = 846) and peripheral (N = 40) patterns, p = 0.0070. The five-year DFS rates were 74%, 67%, and 56%, respectively. Multiple Cox regression analysis, confirmed an independent prognostic advantage of the luminal SOX9 expression pattern, as compared to the uniform pattern, hazard ratio (HR) 0.7211 (95% confidence interval (CI) 0.5561-0.9351), p = 0.0137, whereas the possible disadvantage of the periphery pattern could not be verified, p = 0.1405. Conclusions: The present results support a prognostic impact of SOX9 in stage II colon cancer. The consequence of an altered SOX9 expression seems to differ between intra-tumoral compartments, and we propose that a gradient-dependent evaluation should be applied to provide the most clinically relevant information about this transcription factor.

Prognostic impact of SOX9 in stage II colon cancer: Results from a large nationwide cohort

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Background: Up-regulation of the transcription factor SOX9 has been described in colon cancer, and it has been argued that differences in the expression levels dictates cell proliferation. The aim of the present study was to analyze the prognostic impact of SOX9 in stage II colon cancer. Methods: Individual patient data and formalin fixed paraffin embedded tumor tissue were collected from a large unbiased, population-based cohort, representing all patients operated for stage II colon cancer in Denmark in 2002 and 2003. The SOX9 expression was evaluated by immunohistochemistry on whole tumor sections. Patients were classified into three groups dependent on the SOX9 expression gradient in the tumor: luminal, peripheral, and uniform for comparison with the clinical data. The endpoint was disease free survival (DFS). Results: A total of 1,153 patients were included. We detected an expression-dependent relationship between SOX9 and prognoses. Patients with tumors exhibiting a luminal expression pattern (N = 267, increasing SOX9 expression towards the luminal compartment of the tumor) were characterized by a significantly better DFS compared to the uniform (N = 846) and peripheral (N = 40) patterns, p = 0.0070. The five-year DFS rates were 74%, 67%, and 56%, respectively. Multiple Cox regression analysis, adjusted for all standard high risk factors, confirmed an independent prognostic advantage of the luminal SOX9 expression pattern, as compared to the uniform pattern, hazard ratio (HR) 0.7211 (95% confidence interval (CI) 0.5561-0.9351), p = 0.0137, whereas the possible disadvantage of the periphery pattern could not be verified, HR 1.4393 (95% CI 0.8869-2.3660), p = 0.1405. Conclusions: The present results support a prognostic impact of SOX9 in stage II colon cancer. The consequence of an altered SOX9 expression seems to differ between intra-tumoral compartments, and we propose that a gradient-dependent evaluation should be applied to provide the most clinically relevant information about this transcription factor.

The prognostic value of tumour stroma ratio and tumour budding in stage II colon cancer. A nationwide population-based study

PURPOSE

High-risk patients with stage II colon cancer (CC) may benefit from adjuvant chemotherapy, but additional prognostic markers are needed for better stratification. We investigated the prognostic value of tumour stroma ratio (TSR) and tumour budding (TB).

METHODS

A nationwide population-based cohort of 573 patients with stage II CC was included. TSR was scored on hematoxylin and eosin sections as low TSR (> 50% stroma) and high TSR (≤ 50% stroma). TB was evaluated in hotspots on pan-cytokeratin stained sections in 10 high power fields (HPF) at the invasive front and classified by the mean number of buds per HPF as high grade budding (≥ 10 buds) or low-grade budding (< 10 buds). The prognostic value was investigated in Cox proportional hazard models for recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Low TSR was associated with worse RFS (HR = 1.342 (95% CI 1.006-1.791), p = 0.045) and OS (HR = 1.376 (95% CI 1.016-1.862), p = 0.039). Furthermore, an association was found between low TSR and microsatellite stabile tumours (p < 0.001). The mean number of buds per HPF was associated to TSR with increasing number of buds related to a lower TSR (p = 0.026). No statistically significant prognostic impact of TB regarding OS or RFS was detected.

CONCLUSIONS

TSR provided valuable prognostic information, and adding TSR to the current risk stratification may contribute to better patient selection. The estimates of TSR and TB were found to be associated, but no prognostic value of TB was documented.