Based on the neurophysiology, it is well known that sympathetic nerves control the ejaculatory function and bladder neck closure. In contrast, the parasympathetic nerves control penile erection and bladder wall contraction. Because of the difference in cultural background of the patients and training background of the physicians between Western and Oriental Countries, the Western people did not believe in the efficacy of wide pelvic lymphadenectomy. In the Oriental countries, due to the shortage of standardized facilities, treatment protocol, and manpower, the concurrent preoperative chemoradiation therapy (CCRT) of American style is currently not widely accepted. Therefore, the advantage and disadvantage of these two treatment modalities for advanced rectal cancers need be further clarified. In this project, we plan to randomly assign the patients into two groups:

(1) concurrent preoperative chemoradiation therapy (CCRT) + conventional surgery group; (2) wide pelvic lymphadenectomy group. Thereafter, we plan to evaluate: (1) the anorectal function by anorectal manometry and colonic transit time using radioopaque markers; (2) the micturition function using urodynamic study; (3) the penile erection by RigiScan; and (4) the ejaculatory function by clinical interview of the patients. Moreover, the various clinicopathologic factors, including the depth of tumor invasion and the status of lymph node invasion, were recorded in detail according to the guidelines recommended by the Japanese Society of Coloproctology. Furthermore, we will evaluate the oncological results for these patients.