Background: Tumour stroma percentage (TSP) has previously been reported to predict survival in patients with colorectal cancer (CRC); however, whether this is independent of other aspects of the tumour microenvironment is unknown. In the present study, the relationship between TSP, the tumour microenvironment and survival was examined in patients undergoing elective, curative CRC resection.
Patients and methods: Patients undergoing resection at a single centre (1997-2008) were identified from a prospective database. TSP was measured at the invasive margin and its association with cancer-specific survival (CSS) and clinicopathological characteristics examined.
Results: Three hundred and thirty-one patients were included in the analysis. TSP was associated with CSS in patients with stage I-III disease [hazard ratio (HR) 1.84, 95% confidence interval (CI) 1.17-2.92, P = 0.009], independent of age, systemic inflammation, N stage, venous invasion and Klintrup-Mäkinen score. Furthermore, TSP was associated with reduced CSS in patients with node-negative disease (HR 2.14, 95% CI 1.01-4.54, P = 0.048) and those who received adjuvant chemotherapy (HR 2.83, 95% CI 1.23-6.53, P = 0.015), independent of venous invasion and host inflammatory responses. TSP was associated with several adverse pathological characteristics, including advanced T and N stage. Furthermore, TSP was associated with an infiltrative invasive margin and inversely associated with necrosis.
Conclusions: The TSP was a significant predictor of survival in patients undergoing elective, curative CRC resection, independent of adverse pathological characteristics and host inflammatory responses. In addition, TSP was strongly associated with local tumour growth and invasion.
Keywords: colorectal cancer; survival; tumour microenvironment; tumour stroma.