Locally Advanced Colon Cancer: Evaluation of Current Clinical Practice and Treatment Outcomes at the Population Level.

The goal of this study was to evaluate current clinical practice and treatment outcomes regarding locally advanced colon cancer (LACC) at the population level. Data were used from the Dutch Surgical Colorectal Audit from 2009 to 2014. A total of 34,527 patients underwent resection for non-LACC and 6,918 for LACC, which was defined as cT4 and/or pT4 stage. LACC was divided into those with multivisceral resection (LACC-MV; n=3,385) and without (LACC-noMV; n=1,595). Guideline adherence, treatment strategy, and short-term outcomes were evaluated. Guideline adherence was >90% regarding preoperative imaging and ≥80% regarding preoperative multidisciplinary team (MDT) discussion. In the elective setting, neoadjuvant chemoradiotherapy (chemoRT) was applied in 6.2% of the cT4 cases, and neoadjuvant chemotherapy in 4.0%. R0 resection rates were 99%, 91%, and 87% in patients with non-LACC, LACC-noMV, and LACC-MV, respectively (<.001). A postoperative complicated course occurred in 17%, 25%, and 29% of patients (<.001), and the 30-day/in-hospital mortality rate was 3.6%, 6.0%, and 5.4% (<.001) in the non-LACC, LACC-noMV, and LACC-MV groups, respectively. This population-based study suggests that there is room for improvement in the treatment of LACC, with regard to short-term surgical outcomes and oncologic outcomes (ie, radicality of resection). Improvement might be expected from optimized preoperative imaging, routine MDT discussions, and further specialization and centralization of care. Optimized use of neoadjuvant treatment strategies based on already available and upcoming evidence is likely to result in a better margin status and thereby a better long-term prognosis. Furthermore, lower R0 resection rates in an emergency setting suggest a potential role for bridging strategies in order to enable optimal staging, neoadjuvant treatment, and elective surgery by a surgical team most optimally qualified for the procedure.