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

Abstract

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.

Neoadjuvant chemoradiotherapy followed by surgery in patients with unresectable locally advanced colon cancer: a prospective observational study

“…To our knowledge, 32.0%–33.3% of the patients with locally advanced CC have to undergo an MVR, which is considered to improve local control and OS. 4 , 17 Nevertheless, such an intensive treatment only led to a 5-year OS of 35.1%. 17 Not only that, among those managed with MVR, nearly 13.0% of the cases failed to achieve an R0 resection.…”

“… 17 Not only that, among those managed with MVR, nearly 13.0% of the cases failed to achieve an R0 resection. 4 There was also a considerable number of patients with unresectable disease. It is known that radicality is a very important prognosticator in CC.…”

“…No grade 5 adverse event was observed. Considering that 6.9%–18.8% of the locally advanced CC patients had postsurgical complications in need of re-operation, 4 , 5 NACRT appeared as a tolerable treatment modality for locally advanced CC.…”

“… 3 About 10%–15% of the CC patients are diagnosed with locally advanced disease. 4 To attain a R0 resection, which is defined as a resection with microscopically negative margins, the en-bloc multivisceral resection (MVR) involving a partial or complete removal of the organs adhering to the primary tumor is performed in these patients. 5 This extensive surgical procedure leads to complications with a total incidence rate as high as 20.3%.…”

Interobserver, intraobserver, and interlaboratory variability in reporting pT4a colon cancer

“…A considerable group of colon cancer patients presents with T4 tumors. The T4 category represents the most advanced category with respect to local invasion [1] and is related to a high risk of developing peritoneal metastases [2,3]. Pathological (p)T4 includes two main entities of locally advanced growth, categorized as pT4a (peritoneal penetration) and pT4b (adjacent organ/structure invasion) according to the TNM 8th ed.…”