The relationship between tumor and host factors and survival in patients undergoing adjuvant chemotherapy for colorectal cancer.

Abstract

525 Background: The tumor microenvironment and host inflammatory responses are important determinants of outcome in colorectal cancer (CRC), however their impact on survival in patients receiving adjuvant chemotherapy remains unclear. The aim of the present study was to examine the relationship between these factors, clinicopathological characteristics and survival in patients receiving adjuvant chemotherapy for CRC. Methods: 365 patients who had undergone CRC resection at a single institution between 1997-2008 were included; 88 patients subsequently received chemotherapy. Tumor stroma percentage (TSP) and necrosis were assessed on H and E sections and graded as low or high. Local inflammatory response was assessed using the Klintrup-Mäkinen (K-M), Galon and revised Immunoscore (CD45RO+ /CD8+, and CD3+/CD8+at the invasive margin and tumor center, respectively). Systemic inflammation was assessed using modified Glasgow Prognostic Score (mGPS). Results: Patients receiving adjuvant chemotherapy were younger with a lower ASA (both P<0.05), had advanced T- and N-stage (P<0.05 and P<0.001, respectively), poor tumor differentiation (P<0.05), venous invasion (VI) (P<0.01), margin involvement, infiltrative invasive margin (both P<0.05) and high TSP (P<0.01). In those patients who received adjuvant chemotherapy, on multivariate analysis of clinicopathological factors, VI (HR 3.00, 95%CI 1.22-7.37, P=0.017), TSP (HR 3.00, 95%CI 1.26-7.12, P=0.013), K-M score (HR 5.24, 95%CI 1.21-22.68, P=0.027) and mGPS (HR 3.10 95%CI 1.47-6.55, P=0.003) were independently associated with cancer-specific survival. When the interrelationships between factors independently associated with cancer survival were examined, VI, mGPS, K-M score and TSP were independent of each other (all P>0.05). Conclusions: Compared to standard CRC pathological staging, the present results suggest that assessment of both tumor microenvironment and host inflammatory responses may have superior prognostic value compared with TNM in patients receiving adjuvant chemotherapy.