Factors influencing histopathology-assessed TME quality after low anterior rectal resection: Results of a prospective multicenter observational trial.

Abstract

3547 Background: Total mesorectal excision (TME) has become standard of care in rectal cancer surgery, leading to a massive reduction in local recurrence rate. However, incomplete TME is associated with an increase in local recurrences. To date, there are no reliable data on clinical factors predicting incomplete TME in patients undergoing rectal cancer surgery. We used the data set of the German Quality Assurance in Rectal Cancer Surgery prospective multicenter observational trial to investigate this issue under routine clinical care conditions. Methods: This is a retrospective analysis of a prospectively gathered data set involving >300 German hospitals of all levels of care. Patients undergoing low anterior rectal resection for rectal cancer between 01/01/05 and 12/31/09 were included. Multivariate analysis using a stepwise logistic regression model was performed in order to identify factors predicting suboptimal TME as determined at postoperative histopathology. Risk factors analyzed included age, BMI, tumor distance from the anal verge, neoadjuvant therapy, duration of surgery, surgeon experience, laparoscopic vs. open approach, dissection technique, intraoperative complications, and pT stage. Results: A total of 6,179 patients were included. Due to missing data for one or more parameters 1,573 patients had to be removed from the data set, leaving 4,606 patients for analysis. pT stage >2 (OR 1.22), tumor distance from the anal verge <8 cm (OR 1.27), advanced age (>65 years, OR 1.24; >80 years, OR 1.59), presence of intraoperative complications (OR 2.06), monopolar dissection technique (OR 1.44), and low experience of the operating surgeon (OR 1.20) were identified as being independently associated with moderate or poor TME quality. Conclusions: This is the largest analysis of factors predicting incomplete TME to date. Since good TME quality is a prerequisite for a low recurrence rate, rectal cancer surgery should be performed or supervised by experienced colorectal surgeons. Monopolar pelvic dissection technique should be avoided. On the other hand, laparoscopic approach and use of neoadjuvant therapy do not seem to increase the risk for incomplete TME.