The presence of inflammatory cells is a common phenomenon in human colorectal cancer, and the infiltration by various inflammatory cells within the tumor and at the invasive margins tends be regarded as a nonspecific finding. The prognostic effect of tumor-infiltrating lymphocytes (TILs) and tumor-related immune responses has recently become increasingly recognized, and a greater lymphocytic reaction to colorectal cancer has been associated with longer patient survival.^1-5 However, the true nature of this association and the exact mechanisms underlying it remain uncertain, and whether the presence of TILs is a definite prognostic factor remains controversial.^6,7

The metastatic process involves the migration and invasion of cancer cells throughout the body to produce secondary tumors at distant sites. Through of epithelial-mesenchymal transition (EMT), cancer cells employ developmental processes to gain migratory and invasive properties. CD44 is the transmembrane adhesion receptor for Hyaluronan (HA) and plays a central role in the remodeling and degradation of HA that leads to cell migration, as well as to cancer invasion and metastasis. CD44 is highly expressed in primary and metastatic colon cancer but lowly expressed in normal tissues. We evaluated the impact of CD44 on EMT and invasion of colon cancer cells. The functional role of CD44 in EMT was determined by the overexpression or knockdown of CD44. CD44 was overexpressed by transfection with plasmid-RT-PCR product and knockdown of CD44 by small hairpin RNA (shRNA)-mediated depletion of CD44 in SW480 colon cancer cells. Morphological changes were evaluated by confocal laser microscopy in the culture media. The expression of EMT markers (E-cadherin/N-cadherin/vimentin/fibronectin/actin/MMPs) and CD44/EGFR/PI3K-Akt signaling were evaluated using western blotting. The influence of EMT in tumor biology was assessed with proliferation, migration and invasion assays. EMT changes increased in CD44-overexpressing SW480 cells and decreased in CD44 knockdown cells. CD44 activation induced expression of EGFR and activation of phosphatidylinositol 3' kinase (PI3K)/Akt and expression of glycogen synthase kinase-3 β (GSK-3β). In terms of EMT markers, CD44 downregulated E-cadherin expression, upregulated N-cadherin, α-actin, vimentin, fibronectin and MT1-MMP, and inhibited the formation of the membrane-associated E-cadherin-β-catenin complex, which resulted in cell invasion and migration.

Objective: This study aimed to assess the impact of preoperative immunonutrition on the outcomes of colon cancer surgery. Background: Although current guidelines recommend that immunonutrition should be prescribed for malnourished patients before major gastrointestinal surgery, the benefit of preoperative immunonutrition remains debatable. Methods: Between April 2019 and October 2020, 176 patients with primary colon cancer were enrolled and randomly assigned (1:1) to receive preoperative immunonutrition plus a normal diet (n = 88) or a normal diet alone (n = 88). Patients in the immunonutrition group received oral nutritional supplementation (400 mL/d) with arginine and ω-3 fatty acids for 7 days before elective surgery. The primary endpoint was the rate of infectious complications, and the secondary endpoints were the postoperative complication rate, change in body weight, and length of hospital stay. Results: The rates of infectious (17.7% vs 15.9%, P = 0.751) and total (31.6% vs 29.3%, P = 0.743) complications were not different between the two groups. Old age was the only significant predictive factor for the occurrence of infectious complications (odds ratio = 2.990, 95% confidence interval 1.179–7.586, P = 0.021). The length of hospital stay (7.6 ± 2.5 vs 7.4 ± 2.3 days, P = 0.635) and overall change in body weight (P = 0.379) were similar between the two groups. However, only the immunonutrition group showed weight recovery after discharge (+0.4 ± 2.1 vs −0.7 ± 2.3 kg, P = 0.002). Conclusions: Preoperative immunonutrition was not associated with infectious complications in patients undergoing colon cancer surgery. Routine administration of immunonutrition before colon cancer surgery cannot be justified.

The prognostic role of surgical resection of primary tumors is not well established in patients with asymptomatic unresectable stage IV colorectal cancer. The aims of this study were to reveal the prognostic role of surgical resection of primary tumors and to define prognostic factors affecting long-term oncological outcomes in patients with asymptomatic unresectable synchronous metastases. This study was a retrospective analysis of prospectively collected data. Between 2000 and 2008, a total of 416 patients with asymptomatic unresectable stage IV colorectal cancer were analyzed with propensity score matching. Prematching baseline characteristics were compared by bivariate analysis, and 113 pairs were selected after 1:1 matching with propensity scores estimated from logistic regression. The primary end point was overall survival. Among 416 patients, 218 (52.4%) underwent palliative resection of the primary tumor. Before propensity score matching, palliative resection resulted in a better survival rate than nonresection in univariate analysis (p < 0.001), but not in multivariate analysis (p = 0.08). After matching, the 5-year overall survival rate was significantly lower for patients with peritoneal metastasis and clinical M1b stage tumors in univariate analysis (p = 0.004 and p = 0.02). However, neither peritoneal metastasis nor clinical M1b stage showed any prognostic significance in multivariate analysis. The overall 5-year survival rate of the postmatching group was 4.9% and 3.5% in the palliative resection and nonresection groups. Consequently, palliative resection was not associated with a significant increase in survival compared with nonresection (p = 0.27). A subgroup analysis performed according to the site of metastasis also did not show any significant survival benefit of palliative resection after matching. Selection bias and potential confounders were limitations of this study. Resection of the primary tumor in patients with asymptomatic unresectable stage IV colorectal cancer was not associated with an improvement in overall survival after propensity score matching.