Extent and technique of surgical resection for colon cancer

Surgery is still the therapy of choice for colon cancer. The central element of a curative therapy for all types of colon cancer-with the exception of pT1 tumors in the low-risk situation-is the en bloc resection of the tumor-bearing colon segment with a systematic lymphadenectomy and the central ligature of the corresponding main vessels. Minimally invasive surgical techniques have improved postoperative, short-term outcomes. In analogy to total mesorectal excision (TME) in rectal cancer, the concept of complete mesocolic excision (CME) aims to achieve a maximum reduction in the local recurrence rate. On the one hand, it includes preserving the integrity of the mesocolon through precise dissection along the embryonic layers and thus protecting the two mesocolic fascia layers in order to avoid possible tumor cell dissemination. On the other hand, the number of resected lymph nodes is increased by the central ligature of the segmental vessels with extended dissection of the D3 lymph node stations. Although adequate CME is associated with a lower local recurrence rate, the evidence regarding long-term oncological outcomes is still unclear. In addition, it is not certain whether all tumor stages benefit from CME. A risk-benefit analysis of CME should be discussed under the aspect of a possibly increased perioperative morbidity with this demanding concept.