CD8+ lymphocytes/ tumour-budding index: An independent prognostic factor representing a pro-/anti-tumour approach to tumour host interaction in colorectal cancer

Abstract

Background:The tumour-host interaction at the invasive front of colorectal cancer, including the epithelial-mesenchymal transition and its hallmark tumour budding, is an important area of investigation in terms of prognosis. The aim of this study was to determine the prognostic impact of a pro-/anti-tumour approach defined by an established pro-tumour (tumour budding) and host-related anti-tumour factor of the adaptive immunological microenvironment (CD8 lymphocytes).Methods:Double immunostaining for CK22/CD8 on whole tissue sections (n279; Cohort 1) and immunohistochemistry for CD8 using tissue microarrays (n191; Cohort 2) was carried out. Tumour buds, CD8 and CD8 T-lymphocytes: tumour buds indices were evaluated per high-power field.Results:In Cohort 1, a low-CD8/ buds index was associated with lymph node metastasis (P0.001), vascular invasion (P0.009), worse survival in univariate (P0.001) and multivariable (P0.001) analysis, and furthermore in lymph node-negative patients (P0.002). In Cohort 2, the CD8/ buds index was associated with T stage (P0.001), N stage (P0.041), vascular invasion (P0.005) and survival in patients with TNM stage II (P0.019), stage III (P0.004), and adjuvantly untreated (P0.009) and treated patients (P0.001).Conclusion:The CD8 lymphocyte: tumour-budding index is an independent prognostic factor in colorectal cancer and a promising approach for a future prognostic score for patients with this disease. © 2009 Cancer Research UK All rights reserved.