Evaluating developments in rectal cancer care in routine clinical practice

The aim of this thesis was to evaluate developments in the multidisciplinary treatment of primary rectal cancer on a national level.
Part I focused on the new consensus definition of rectal cancer in the multidisciplinary team meetings, based on the sigmoid take-off landmark. Online training has the potential to improve implementation and unambiguous assessment. By using the sigmoid take-off, 11% of the prior diagnosis of rectal cancer were redefined as sigmoid cancer, with substantial inter-hospital variation and potential implications for multimodality and prognostic value.
In part II new developments in the treatment of rectal cancer were evaluated. When comparing two national cohorts with patients with a resection for rectal cancer in 2011 and 2016, an absolute 50% reduction in radiotherapy use for non-locally advanced rectal cancer was observed. This change in neoadjuvant therapy did not compromise cancer-related outcomes and even an improvement in overall survival from 79.6% to 86.4% was observed. Permanent stoma rate and stoma-related complications were evaluated in the two national cohorts. Remarkable hospital variability in permanent stoma rate was observed. Stoma complications were most often observed after a Hartmann’s Procedure (23%), still requiring a significant number of reinterventions even after one year. No beneficial influence of transanal or robot-assisted laparoscopy was found on the permanent stoma rate.
Part III addresses the prognostic implications of lateral lymph nodes. Results of an online survey showed vast variation in the awareness, definition of suspicious lateral lymph nodes in rectal cancer and different treatment approaches.