Table 3.

Cox regression with R² value and gradient in stage III rectal cancer

	Disease-free survival			Overall survival
	HR	95% Cl	P value	HR	95% CI	P value
R2 value	0.178	0.044–0.722	0.016	0.154	0.043–0.555	0.004
R2(triple)
0.9–1.0 (group 1)	3.121	1.140–8.542	0.027	3.812	1.555–9.347	0.003
0.5–1.0 (group 2)	1.454	0.567–3.728	0.436	1.355	0.532–3.451	0.141
0.3–0.5 (group 3)	1			1
R2 (cutoff)
0.9–1.0 (group I)	1.720	0.795–3.719	0.168	2.111	1.021–4.366	0.044
0.3–0.9 (group II)	1			1
Gradient (value “q”)	0.527	0.156–1.778	0.302	0.551	0.175–1.736	0.309

HR hazards ratio; CI confidence interval

R² value and gradient (value “q”) were calculated through trend line illustrating exponential decrease (Y = px^−q). Group I is the exponential decrease group, and group II is the nonexponential decrease group. Group 1 is the exponential decrease group, group 2 is the nearly exponential decrease group, and group 3 is the randomized clearance group. The gradient (value “q”) is illustrative of the velocity of clearance