Total mesorectal excision, lateral lymphadenectomy and autonomic nerve preservation for lower rectal cancer: significance in the long-term follow-up study

We clarify the significance of total mesorectal excision (TME), lateral lymphadenectomy (LLA), and of autonomic nerve preservation (ANP) compared to conventional surgery (CVS), for lower rectal cancer. All 458 patients curatively resected between 1962 and 1997 were retrospectively investigated. In Period I from 1962-1974, when CVS only was performed, in Period II from 1975-1984, TME or TME + LLA was performed, and in Period III from 1985-1997, TME + ANP, TME + ANP + LLA, or TME + LLA was performed. In Dukes A + B disease, there was no significant difference among the three periods, regardless of operation methods. In Dukes C disease, in Period I, CVS (42 patients: pts) had a local recurrence (LR) rate of 45.2% and 5-year disease-free survival (5YDFS) rate of 33.3%. In Period II, TME + LLA (82 pts) had a lower LR rate of 26.8% (p = 0.0628) and higher 5YDFS 51.0% (p < 0.05) vs CVS. In Period III, TME + ANP (12 pts) had LR 25.0% and 5YDFS 55.6%, TME + ANP + LLA (45 pts) had LR 13.3% (p < 0.005, vs CVS) and 5YDFS 56.1% (p < 0.01, vs CVS), and TME + LLA (18 pts) had LR 16.7% (p < 0.05, vs CVS) and 5YDFS 20.8%. Also, CVS had the lowest curability rate 64.8% and the highest mortality rate 7.2%. TME and/or LLA was significant for reducing LR and improving survival in patients with Dukes C lower rectal cancer, compared to CVS. ANP was beneficial with LLA. TME + ANP was suitable for Dukes A or B disease.