Risk factors for tumour present in a circumferential line of resection after excision of rectal cancer

Background: Transected tumour in a circumferential line of resection after excision of rectal cancer carries a high likelihood of local recurrence. The aim of this study was to identify independent risk factors for transected tumour and to examine their temporal variability. Methods: Data were drawn from a comprehensive, prospective hospital registry of all resections for rectal cancer from January 1971 to July 2004. Transected tumour was defined as tumour present histologically in a line of resection and was assessed in all specimens. Results: Transection occurred in 129 of 1613 patients (8.0 (95 per cent confidence interval 6.7 to 9.4) per cent). The following variables were independently associated with transected tumour: tumour perforation, a non-restorative operation, tumour adherence, non-standardized operative technique, preoperative radiotherapy, male sex, histological involvement of an adjacent organ or tissue, high-grade tumour and venous invasion. The mean number of risk factors per patient per year and the annual percentage of patients with transection varied distinctly over the history of the database. Conclusion: The varying prevalence of risk factors, both within and between hospitals and patient series, should be taken into account if the rate of transection is to be regarded as an index of the quality of surgery.