Distal clearance margin of 1 cm or less: a safe distance in lower rectum cancer surgery

The purpose of this study was to investigate the prognostic role of distal clearance margin (DCM) in lower rectum cancer surgery. Two-hundred-three cancer patients underwent total rectal resection, possibly followed by adjuvant chemoradiotherapy. DCM was classified as positive or negative (< 1, a parts per thousand yen1 cm) and investigated with multivariable proportional hazard models. A total of 52 deaths, 19 local relapses, 40 distant metastases, and three second primaries were observed as first events. Five-year survival with positive, negative < 1, or negative a parts per thousand yen1 cm DCM was 51%, 81%, and 69%, respectively (p = 0.018). The difference was significant between positive and negative DCM (p = 0.031), not between negative < 1 and a parts per thousand yen1 cm (p = 0.106). Local and distant 5-year incidences according to DCM were 30%, 8%, and 8% (p = 0.006) and 38%, 26%, and 19% (p = 0.857), respectively. DCM, but not tumor size, is a prognostic factor after sphincter-saving surgery, which is safe whenever a negative margin is achieved.