High rates of postoperative bowel, sexual, and urinary dysfunction have been a well-known phenomenon in rectal cancer surgery, ranging between 30% and 60% [29]. Bowel dysfunction, otherwise referred to as low anterior resection syndrome (LARS), is present in up to 50–60% of patients after TME; symptoms may include incontinence, frequent bowel movements, bowel emptying difculties, and urge, and may affect quality of life signicantly. Outcomes in urologic and sexual func­tion improved with the advent of sharp dissection and precise technique used in TME, which made the identication and preservation of the autonomic pelvic nerves an integral part of the procedure. In an early study of 42 men undergoing sphincter-preserving operations for treatment of rectal cancer, Enker demonstrated high rates of potency (86.7%) and normal ejaculation (87.9%) with the introduction of nerve-preserving TME [30]. In a comprehensive, retrospective study in both women and men, Havenga reported the sexual and urinary function of 136 patients undergoing nerve-sparing TME for cancer [31], as assessed by survey. The ability to engage in intercourse was maintained by 86% of patients younger than 60years of age and by 67% of patients 60 years and older. Eighty-seven percent of men maintained their ability to achieve orgasm. Type of surgery (APR compared to LAR) and age greater than 60 were signicantly associated with worse male sexual function. Women had similarly good results, with 85% able to experience arousal with vaginal lubrication and 91% able to achieve an orgasm. The majority of patients had few or no complaints related to urinary function. Serious urinary dysfunction such as neurogenic bladder was not encountered in this study. The importance of autonomic nerve identication and preservation during TME was also highlighted in a study by Shirouzu and colleagues, who assessed outcomes of 403 patients undergoing TME with or without nerve-sparing over a 20-year period [32]. In patients who underwent TME with nerve preservation, urinary function was pre­served in over 80% of patients, erection in 79%, and ejaculation in 65%, whereas when TME was performed without nerve preservation, urinary disorders were found in over 90% and sexual dysfunction in virtually all patients, even in those younger than age 60.

To further investigate this treatment approach, the ongoing multicenter Phase II/ III study CALGB PROSPECT (Preoperative Radiation or Selective Preoperative Evaluation of Chemotherapy and TME) is randomizing patients to either the stan­dard treatment arm (chemoradiotherapy, surgery, and adjuvant FOLFOX chemo­therapy) or the selective arm, with 6 cycles of FOLFOX, evaluation of response, followed by TME, with consideration for standard chemoradiotherapy if the reduc­tion of the primary tumor is <20% on endoscopic and radiographic ndings [44]. Eligible patients must have biopsy-proven adenocarcinoma with the primary tumor located 5–12cm from the anal verge and must be candidates for sphincter-sparing surgery. The primary outcomes of the Phase II component are R0 resection rate and time to local recurrence. The primary endpoints of the Phase III component are time to local recurrence and disease-free survival. This study has accrued, and results will provide important insight into the potential for a more individualized treatment approach for rectal cancer through selective use of radiation.