Fig. 1
From: Primary gross tumor volume is prognostic and suggests treatment in upper esophageal cancer
Optimal cutoff of GTV-p in 568 patients with upper ESCC. The effects of GTV-p on (A) OS and (B) PFS are modeled with a P-spline expansion, with GTV-p as a continuous variable. Estimated logarithm HRs (solid lines) with 95% confidence intervals (shaded area) for the association of GTV-p with OS or PFS according to the degrees of freedom in multivariate additive Cox in smoothHR - Optimal extended Cox - type additive hazard regression unadjusted model