Desley van Zoggel

Summary, discussion and future perspectives 145 CHAPTER 8 Discussion Introduction As a result of the change in management of primary rectal cancer, locally recurrent rectal cancer (LRRC) has become a relatively rare disease. Better understanding of the anatomy of the pelvis with its well defined fascial layers has led to the universally accepted total mesorectal excision approach (TME), which is based on the removal of the complete rectum and mesorectum enveloped in the mesorectal fascia. In low tumours, where themesorectumhas become thin and extension beyond themuscularis propria easily results in infiltration into the inner layers of the pelvic floor, the extra levator abdominoperineal (ELAPE) has been accepted as a surgical technique, which avoids positive circumferential resection margins and subsequently has also reduced local recurrence rates. In order to facilitate surgery with clear resectionmargins, preoperative therapies have been introduced to downsize and even downstage rectal tumours. One of the most recent randomized studies was the RAPIDO1, which compared preoperative long course chemoradiation with short course radiotherapy followed by consolidation systemic treatment before surgery, and showed that the combination arm was superior with regard to tumour response. Another French randomized study, the PRODIGE 232, also showed that intensification of preoperative treatment by adding systemic treatment resulted in better tumour response. In several ongoing studies even in less advanced tumours the objective to downstage the tumour and possibly obviate surgical resection, without compromising oncological outcome are underway (TESAR, STARTREC)3,4. In the whole spectrum of primary rectal cancer, preoperative downstaging is an accepted treatment principle. Once these heavily pretreated patients are resected and a local recurrence occurs, twomain problems need to be tackled. Firstly, after the central compartment of the rectumwith its covering mesorectal facia or levator muscles have been removed during a TME or ELAPE procedure, the recurrence is likely to involve other pelvic compartments and infiltrate into the structures and organs contained in these compartments. Extended surgical resections without the guidance of fascial layers, which have been breached during primary surgery, will be required. Secondly, most patients have underwent radiotherapy and/or systemic treatment for their primary tumour and therefore, the recurrent tumour may consist of resistant clones, whereas normal tissue tolerance is limited and prevents the administration of efficient tumouricidal doses.