Observations on rectal cancer practice in Japan (report of the Ronald Raven Travelling Fellowship 2002)

Abstract

In Japan, the surgical approach to colorectal cancer is more reliant on radical resection for the primary disease and for recurrent and metastatic disease. In Europe, trends in primary colorectal cancer therapy are away from radical lymph node surgery and towards total mesorectal excision combined with adjuvant treatment. The aim of radical lymph node dissection for primary disease is to achieve potential cure with surgery alone. Due to increased post-operative morbidity associated with radical pelvic lymph node dissection, such as urinary and sexual dysfunction, pelvic autonomic nerve sparing techniques are commonly used in combination with the radical surgery as this seems to reduce the occurrence of these complications.1,2 Moriya (1995) has shown that the rate of local recurrence in nerve sparing surgery is no higher than so called extended surgery. Such techniques result in a local recurrence of 5% and an overall disease free 5-year survival approaching 80%.3,4 The extent of lymph node dissection, both proximal and lateral for rectal cancer, and the type of nerve sparing technique is specific to each patient and is based on the preoperative staging, and intra-operative assessment of lymph node spread. Other factors such as the site and extent of tumour, histology, age, sex and co-morbidity are also taken into account. Recently published data from the National Cancer Center5 suggest that pre-operative assessment of pattern of lymphatic spread in rectal cancer based on tumour morphology is more reliable than intra-operative assessment of lymph node status by the operating surgeon. More distal rectal tumours have increased tendency to lymph node spread especially lateral lymph node metastases. Tumours>3 cm with increasing depth of bowel wall invasion are strongly related to the presence of lymph node metastases, while peritoneal reflection has no discriminating role in the mode of spread.5