Tumor-associated CD66b+ neutrophil and CD8+ lymphocyte densities as independent prognostic factors for recurrence in localized cervical cancer: Automated digital image analysis and observer-assisted stereological assessments.

Abstract

5532 Background: The prognostic impact of tumor-associated immune cells in cervical cancer is unclear. Methods: Automated digital image analysis (DIA) software and observer-assisted stereological (OAS) assessments were used to obtain densities of immunostains for CD66b+ neutrophils, CD163+ macrophages, and CD8+lymphocytes in scanned whole slide images of tumor sections from 101 patients with FIGO stage IB and IIA cervical cancer. Primary end-point was recurrence-free survival (RFS). Results: The highest densities of CD66b+ neutrophils and CD163+ macrophages were observed by OAS in the peritumoral compartment (median 53.1 cells/mm2 and 1.3% area fraction, respectively). DIA required far less human resources than OAS assessments. We observed high correlations between DIA and OAS variables of corresponding parameters; spearman ρ was 0.79 for CD8+ lymphocytes , 0.85 for CD66b+ neutrophils, and 0.92 for CD163+ macrophages (all p <0.0001). Hazard rates for DIA assessments in the global tumor area were comparable with the prognostically strongest OAS assessments in the peritumoral compartment. In multivariate analysis, high density of CD66b+ neutrophils (HR 2.6; 95% CI 1.2–5.7; p = 0.02), low density of CD8+ lymphocytes (HR 2.3; 95% CI 1.1–4.9; p = 0.03), and presence of lymph node metastases (HR 2.6; 95% CI 1.2–5.5; p = 0.02) were independent predictors of poor RFS, whereas FIGO stage and CD163+macrophage density were not. The CD66b/CD8 immunostain index obtained by DIA had excellent discriminatory power for each quartile with 5-year RFS of 92%, 80%, 65%, and 48% for quartile I (<0.019), II (0.02-0.05), III (0.06-0.24), and IV (>0.25), respectively (p = 0.001). Conclusions: High tumor-associated CD66b+ neutrophil and low CD8+ lymphocyte densities are independent prognostic factors for short recurrence-free survival in cervical cancer assessed by DIA and OAS. Combined CD66b+ neutrophil/CD8+ lymphocyte immunostain index obtained by DIA is a strong and cost-efficient prognostic variable with potential for routine application.