ABSTRACT
Tumor necrosis has been reported to represent an independent prognostic factor in colorectal cancer, but its evaluation methods have not been described in sufficient detail to introduce tumor necrosis evaluation into clinical use. To study the potential of tumor necrosis as a prognostic indicator in colorectal cancer, criteria for 3 methods for its evaluation were defined: the average percentage method (tumor necrosis percentage of the whole tumor), the hotspot method (tumor necrosis percentage in a single hotspot), and the linear method (the diameter of the single largest necrotic focus). Cox regression models were used to calculate cancer-specific mortality hazard ratios (HRs) for tumor necrosis categories in 2 colorectal cancer cohorts with more than 1800 cases. For reproducibility assessment, 30 cases were evaluated by 9 investigators, and Spearman's rank correlation coefficients and Cohen's kappa coefficients were calculated. We found that all 3 methods predicted colorectal cancer-specific survival independent of other prognostic parameters, including disease stage, lymphovascular invasion, and tumor budding. The greatest multivariable HRs were observed for the average percentage method (cohort 1: HR for ≥ 40% vs. <3% 3.03, 95% CI, 1.93-4.78; cohort 2: HR for ≥ 40% vs. < 3% 2.97; 95% CI, 1.63-5.40). All 3 methods had high reproducibility, with the linear method showing the highest mean Spearman's correlation coefficient (0.91) and Cohen's kappa (0.70). In conclusion, detailed criteria for tumor necrosis evaluation were established. All 3 methods showed good reproducibility and predictive ability. The findings pave the way for the use of tumor necrosis as a prognostic factor in colorectal cancer.
ABSTRACT
PURPOSE: The purpose of this study was to compare a B cell/plasma cell-based scoring system to T cell score and evaluate their prognostic value in colorectal cancer. METHODS: We used immunohistochemistry to analyze the expression of CD20, CD138, CD3, and CD8 in 221 colorectal cancer patients. CD20+ B cell and CD138+ plasma cell densities in the tumor center and invasive margin were calculated and converted into a B cell/plasma cell score. T cell score was defined similarly, using CD3+ and CD8+ T cell densities. Their associations with tumor and patient characteristics and survival were analyzed. RESULTS: Kaplan-Meier analysis showed a high B cell/plasma cell score was associated with a tendency towards longer survival (p = 0.089), but no statistically significant association was found. High T cell score associated with longer cancer-specific survival in Kaplan-Meier analysis and multivariable Cox regression analysis (p < 0.001). Additionally, high T cell score associated with lower disease stage (p < 0.001) and lesser lymphovascular invasion (p = 0.020). CONCLUSIONS: High T cell score is associated with longer survival and clinicopathological factors typical to less aggressive tumors. This study did not support the additional prognostic value of B cell/plasma cell quantification.
