Tumor-stroma ratio predicts recurrence in patients with colon cancer treated with neoadjuvant chemotherapy

Background: Neoadjuvant chemotherapy represents a new treatment approach to locally advanced colon cancer. The aim of this study was to analyze the ability of tumor-stroma ratio (TSR) to predict disease recurrence in patients with locally advanced colon cancer treated with neoadjuvant chemotherapy.Material and methods: This study included 65 patients with colon cancer treated with neoadjuvant chemotherapy in a phase II trial. All patients were planned for three cycles of capecitabine and oxaliplatin before surgery. Hematoxylin and eosin stained tissue sections from surgically resected primary tumors were sampled and analyzed by conventional microscopy. Patients were divided into stroma-high (>50%, i.e. TSR low) and stroma-low (50%, i.e. TSR high) for the comparison with clinical data.Results: A low TSR was found in 47% of the surgically resected primary tumors and correlated to a significantly higher T- and N-category compared, to tumors with a high TSR (p<.01). A low TSR was also significantly associated with disease recurrence (p=.008), translating into significant differences in disease free survival (DFS) and overall survival, p<.002. The 5-year DFS rate for patients with a low TSR was 55%, compared to 94% in the group of patients with a high TSR.Conclusions: TSR assessed in the surgically resected primary tumor from patients with locally advanced colon cancer treated with neoadjuvant chemotherapy provides prognostic value and may serve as a relevant parameter in selecting patients for post-operative treatment.