Intertwined leukocyte balances in tumours and peripheral blood as robust predictors of right and left colorectal cancer survival

Figure 1 Survival rates of colorectal cancer patients. A, B: Kaplan-Meier curves for 4-year overall survival (A) and 4-year recurrence-free survival (B) observed in the cohort for both right-sided colorectal cancer (CRC) (orange) and left-sided CRC (green) patients. Survival proportions at 26 mo after surgery (median follow-up) of right-sided CRC and left-sided CRC patients are shown (^bP < 0.01, log-rank test). Number of cases at risk are tabled for both overall survival and recurrence-free survival. RCRC: Right-sided colorectal cancer; LCRC: Left-sided colorectal cancer.

Figure 2 Leukocyte ratios in peripheral blood and tissues from colorectal cancer patients. A-C: Blood circulating leukocytes in right-sided colorectal cancer (CRC) patients (orange, n = 43) and left-sided CRC patients (green, n = 22) represented as lymphocyte-to-monocyte ratio (LMR)_{blood (b)} (A), neutrophil-to-lymphocyte ratio (B), and platelet-to-lymphocyte ratio (C) (^aP < 0.05, unpaired t test, data are mean ± standard deviation); D-F: Tissue-infiltrated leukocytes in right-sided CRC tumours (tumour [t], orange, n = 34) and peritumours (peritumour [pt], light red, n = 34) and left-sided CRC tumours (t, green, n = 20) and peritumours (pt, light green, n = 20), represented as LMR_t/pt (D), CD4⁺-lymphocyte-to-monocyte ratio (CD4MR)_t/pt (E), and CD8⁺-lymphocyte-to-monocyte ratio (CD8MR)_t/pt (F) (^aP < 0.05, ^bP < 0.01, unpaired Mann-Whitney U test, data are mean ± standard deviation); G-I: Blood-to-tissue leukocyte ratios for right-sided CRC tumours (t, orange, n = 34) and peritumours (pt, light red, n = 34) and left-sided CRC tumours (t, green, n = 20) and peritumours (pt, light green, n = 20) represented as LMR_b/LMR_t/pt (G), LMR_b/CD4MR_t/pt (H), and LMR_b/CD8MR_t/pt (I) (^aP < 0.05, ^bP < 0.01, unpaired Mann-Whitney U test, data are mean ± standard deviation). PLR: Platelet-to-lymphocyte ratio.

Figure 3 Leukocyte infiltration in tissues from right-sided colorectal cancer and left-sided colorectal cancer patients. Representative immunohistochemical images (× 100, scale bar = 200 μm) of CD4⁺ lymphocytes, CD8⁺ lymphocytes and CD14⁺ monocytes in tumour and peritumour samples, from one left-sided colorectal cancer (LCRC) patient (left panel) and one right-sided colorectal cancer (RCRC) patient (right panel). Arrows show rich-marker zones in each sample.

Figure 4 Receiver operating curve analyses for overall survival and Kaplan-Meier curves for optimal cutoff values in right-sided colorectal cancer patients for significant predictors. A-B: CD8⁺-lymphocyte (CD8)_{peritumour (pt)}, worse below 8.25; C-D: CD4⁺ plus CD8⁺-lymphocyte (CD4CD8)_pt worse below 10.16; E-F: Lymphocyte-to-monocyte ratio (LMR)_pt worse below 3.185; G-H: CD8⁺-lymphocyte-to-monocyte ratio (CD8MR)_pt worse below 1.65; I-J: LMR_b/LMR_pt worse above 0.985; K-L: LMR_{blood (b)}/ CD8⁺-lymphocyte-to-monocyte ratio_pt worse above 1.485; survival proportions at 26 mo after surgery (median follow-up) are shown (^aP < 0.05, ^bP < 0.01, log-rank test).

Figure 5 Receiver operating curve analysis for overall survival (A) and Kaplan-Meier curve (B) for optimal cutoff value in left-sided colorectal cancer patients for the significant predictor blood lymphocyte-to-monocyte ratio/peritumour CD4⁺-lymphocyte-to-monocyte ratio. Worse above 10.57; survival proportions at 26 mo after surgery (median follow-up) are shown (^aP < 0.05, log-rank test). b: Blood; CD4MR: CD4⁺-lymphocyte-to-monocyte ratio; LMR: Lymphocyte-to-monocyte ratio; pt: Peritumour.

Figure 6 Receiver operating curve analyses for recurrence-free survival and Kaplan-Meier curves for optimal cutoff values in right-sided colorectal cancer patients for significant predictors. A-B: Peritumour lymphocyte-to-monocyte ratio (LMR) worse below 3.185; C-D: Blood (b) LMR/peritumour (pt) LMR worse above 0.985; E-F: Blood LMR/peritumour CD8⁺-lymphocyte-to-monocyte ratio (CD8MR) worse above 1.485; survival proportions at 26 mo after surgery (median follow-up) are shown (^aP < 0.05, ^bP < 0.01, log-rank test).

Figure 7 Nomograms for predicting overall survival and recurrence-free survival after surgical intervention of right-sided colorectal cancer patients. A: The 4-year probability of overall survival was estimated by summing the scores of peritumour (pt) lymphocyte-to-monocyte ratio (LMR), CD8⁺-lymphocyte (CD8)⁺-lymphocyte-to-monocyte ratio (CD8MR)_pt, CD4⁺ plus CD8⁺-lymphocyte (CD4CD8)_pt, blood (b) LMR/LMR_pt, LMR_b/CD8MR _pt, and CD8_pt; B: The 4-year probability of recurrence-free survival was estimated by summing the scores of LMR_pt, LMR_b/LMR_pt, and LMR_b/CD8⁺-lymphocyte-to-monocyte ratio_pt. For each graph, locate the patient’s values for each variable at one of the extremes of its corresponding axis, taking into account the correct position with respect to the optimal cutoff that is indicated; values higher than the cutoff go to the upper end and values lower than the cutoff go to the lower end. Then, draw a line straight upwards to the “Points” axis to determine the score associated to each variable. Add up all the scores, locate this sum in the “Total points” axis and draw a line straight down to the lowest axes of “4-year overall survival” or “4-year recurrence-free survival” to find the predictive probability of the patient for overall survival or recurrence-free survival outcome, respectively.