Table 2.

Colorectal cancer recurrence and overall survival according to tumour risk strata and CD8⁺ cell density in pooled VICTOR and QUASAR2 trial population

	No.	No. events	Predicted proportion event free at 3 years		Univariable analysis			Multivariable analysis
			25th centile CD8+ cell density (95% CI)	75th centile CD8+ cell density (95% CI)	HR (95% CI)	P	P INTERACTION	HR (95% CI)	P	P INTERACTION
Time to recurrence
Low risk (pT3, N0)	453	60	0.90 (0.88 –0.93)	0.90 (0.88–0.93)	1.02 (0.86–1.20)	0.85	0.072	1.03 (0.87–1.21)	0.75	0.090
Intermediate risk (pT4, N0 or pT1-3, N1/2)	1035	242	0.79 (0.76–0.82)	0.82 (0.80–0.85)	0.91 (0.85–0.98)	0.016		0.92 (0.86–1.0)	0.046
High risk (pT4, N1/2)	303	132	0.58 (0.53–0.64)	0.69 (0.63–0.75)	0.86 (0.78–0.96)	4.7 × 10−3		0.87 (0.79–0.97)	9.4 × 10−3
Overall survival
Low risk (pT3, N0)	453	52	0.95 (0.94–0.97)	0.95 (0.93–0.96)	1.03 (0.87–1.23)	0.72	0.051	1.04 (0.87–1.24)	0.69	0.056
Intermediate risk (pT4, N0 or pT1-3, N1/2)	1035	177	0.89 (0.87–0.91)	0.90 (0.88–0.92)	0.94 (0.86–1.03)	0.20		0.94 (0.86–1.03)	0.22
High risk (pT4, N1/2)	303	120	0.75 (0.71–0.80)	0.82 (0.78–0.86)	0.88 (0.79–0.97)	0.017		0.88 (0.79–0.98)	0.022

Point estimates of probability of colorectal cancer recurrence and overall survival are derived from univariable Cox regression of CD8⁺ cell density as a continuous variable (corresponding estimates by the Kaplan–Meier estimator for cases dichotomised at the median CD8⁺ cell density are shown in Table S6). Both point estimates and univariable hazard ratios are derived from complete case analyses. Multivariable-adjusted hazard ratios are adjusted for age, sex, tumour location, BRAF mutation, MMR-D/POLE mutation, CIN and adjuvant bevacizumab. Tests for interaction are from the cross product term of tumour risk stratum and log2 CD8⁺ cell density in bi-variable and multivariable models

HR hazard ratio, 95% CI 95% confidence interval, pT pathological tumour (T) stage