Classification According to Condition After Surgery

Absence or presence of residual tumor after treatment:R0 = Resection margin is free of tumor (tumor completely removed (with a safety margin) in healthy),R1 = Tumor extends to the resection margin (tumor probably not completely removed in healthy) (histologically detectable residual tumor) or extends straight to the margin (without a safety margin),R2 = Macroscopically detectable residual tumor,Rx = no data.