Autonomic nerve plexus involvement and prognosis in patients with rectal cancer

Abstract

Background: A detailed knowledge of the fundamental basis for cancer involvement of the autonomic nerve plexus and the outcome of patients with such cancer foci is important when considering nerve-preserving surgery for rectal cancer. Methods: Extrarectal autonomic nerve plexuses were obtained from 61 patients with advanced rectal cancer who were undergoing extended resection of the rectum with the associated nervous system. The specimens were sectioned totally so that any indirect cancer involvement of the extrarectal autonomic nerves and/or the surrounding tissue could be detected. Results: Autonomic nerve plexus involvement was observed in nine patients: none of 25 with Dukes A/B, six of 28 with Dukes C and three of eight with Dukes 'D' lesions. Five of 25 patients with nodal involvement in the pararectal area had such foci, and four of eight patients with nodal involvement further from the primary tumour. Furthermore, of the nine patients with nerve plexus involvement, seven had extranodal cancer deposits in the mesorectum. The 3-year survival rate of patients with nerve plexus involvement was 33 per cent, while it was 83 per cent in those without such disease. Conclusion: Nerve plexus involvement was observed in direct proportion to the extent of cancer spread to the mesorectum, and the prognosis of patients with such disease was unfavourable. Further investigation is needed to better identify those patients who would clearly benefit from an en bloc resection of the autonomic nerves.