Daeyoun David Won

Sarcopenia is negatively associated with long-term outcomes in locally advanced rectal cancer

The association of sarcopenia and visceral obesity to treatment outcome is not clear for locally advanced rectal cancer. This study evaluates the influence of skeletal muscle and visceral fat on short‐term and long‐term outcomes in locally advanced rectal cancer patients treated with neoadjuvant chemoradiation therapy followed by curative resection.

A colorectal cancer prediction model using traditional and genetic risk scores in Koreans

BackgroundGenome-wide association studies have identified numerous single nucleotide polymorphisms (SNPs) as associated with colorectal cancer (CRC) risk in populations of European descent. However, their utility for predicting risk to CRC in Asians remains unknown. A case-cohort study (random sub-cohort N = 1,685) from the Korean Cancer Prevention Study-II (KCPS-II) (N = 145,842) was used. Twenty-three SNPs identified in previous 47 studies were genotyped on the KCPS-II sub-cohort members. A genetic risk score (GRS) was calculated by summing the number of risk alleles over all SNPs. Prediction models with or without GRS were evaluated in terms of the area under the receiver operating characteristic curve (AUROC) and the continuous net reclassification index (NRI).ResultsSeven of 23 SNPs showed significant association with CRC and rectal cancer in Koreans, but not with colon cancer alone. AUROCs (95% CI) for traditional risk score (TRS) alone and TRS plus GRS were 0.73 (0.69–0.78) and 0.74 (0.70–0.78) for CRC, and 0.71 (0.65–0.77) and 0.74 (0.68–0.79) for rectal cancer, respectively. The NRI (95% CI) for a prediction model with GRS compared to the model with TRS alone was 0.17 (-0.05-0.37) for CRC and 0.41 (0.10–0.68) for rectal cancer alone.ConclusionOur results indicate genetic variants may be useful for predicting risk to CRC in the Koreans, especially risk for rectal cancer alone. Moreover, this study suggests effective prediction models for colon and rectal cancer should be developed separately.

Laparoscopic Surgery for Transverse Colon Cancer: Short- and Long-Term Outcomes in Comparison with Conventional Open Surgery

BACKGROUND Published studies on laparoscopic surgery for transverse colon cancer are scarce. More studies are necessary to evaluate the feasibility, safety, and long-term oncologic outcomes of laparoscopic surgery for transverse colon cancer. SUBJECTS AND METHODS From April 1996 to December 2010, 102 consecutive patients with stage II or III disease who had undergone curative resection for transverse colon cancer were enrolled. Seventy-nine patients underwent laparoscopy-assisted colectomy (LAC), whereas 23 patients underwent conventional open colectomy (OC). Short- and long-term outcomes of the two groups were compared. RESULTS The OC group had a larger tumor size (7.6 ± 3.4 cm versus 5.2 ± 2.3 cm, P = .004) and more retrieved lymph nodes (26.4 ± 11.6 versus 17.5 ± 9.4, P = .002), without differences in resection margins. In the LAC group, return to diet was faster (4.5 ± 1.2 days versus 5.4 ± 1.8 days, P = .013), and postoperative hospital stay was shorter (12.1 ± 4.2 days versus 15.9 ± 4.8 days, P = .000). There were no differences in occurrence of intra- or postoperative complications. There were no statistically significant differences in overall survival rate (OS) or disease-free survival rate (DFS) between the two groups (5-year OS, 90.4% versus 90.5%, P = .670; 5-year DFS, 84.2% versus 90.7%, P = .463). CONCLUSIONS Laparoscopic surgery for transverse colon cancer has better short-term outcomes compared with open surgery, with acceptable long-term outcomes. As in colorectal cancer of other sites, laparoscopic surgery can be a feasible alternative to conventional surgery for transverse colon cancer.

Comparative study between transanal tube and loop ileostomy in low anterior resection for mid rectal cancer: a retrospective single center trial

Purpose To investigate the efficacy and safety of the transanal tube (TAT) in preventing anastomotic leak (AL) in rectal cancer surgery. Methods Clinical data of the patients who underwent curative surgery for mid rectal cancer from February 2010 to February 2014 were reviewed retrospectively. Rectal cancers arising 5 to 10 cm above the anal verge were selected. Patients were divided into the ileostomy, TAT, or no-protection groups. Postoperative complications including AL and postoperative course were compared. Results We included 137 patients: 67, 35, and 35 patients were included in the ileostomy, TAT, and no-protection groups, respectively. Operation time was longer in the ileostomy group (P = 0.029), and more estimated blood loss was observed (P = 0.018). AL occurred in 5 patients (7.5%) in the ileostomy group, 1 patients (2.9%) in the TAT group, and 6 patients (17.1%) in the no-protection group (P = 0.125). Patients in the ileostomy group resumed diet more than 1 day earlier than those in the other groups (P = 0.000). Patients in the no-protection group had about 1 or 2 days longer postoperative hospital stay (P = 0.048). The ileostomy group showed higher late complication rates than the other groups as complications associated with the stoma itself or repair operation developed (P = 0.019). Conclusion For mid rectal cancer surgery, the TAT supports anastomotic site protection and diverts ileostomy-related complications. Further large scale randomized controlled studies are needed to gain more evidence and expand the range of TAT usage.

Effect of Adjuvant Chemotherapy on Stage II Colon Cancer: Analysis of Korean National Data

Purpose Debates exist regarding the effectiveness of adjuvant chemotherapy for stage II colon cancer. This study aimed to investigate the current status of adjuvant chemotherapy and its impact on survival for Korean stage II colon cancer patients by analyzing the National Quality Assessment data. Materials and Methods A total of 7,880 patientswho underwent curative resection for stage II colon adenocarcinoma between January 2011 andDecember 2014 in Koreawere selected randomly as evaluation subjects for the quality assessment. The factors that influenced overall survival were identified. The high-risk group was defined as having at least one of the following: perforation/obstruction, lymph node harvest less than 12, lymphovascular/perineural invasion, positive resection margin, poor differentiation, or pathologic T4 stage. Results The median follow-up period was 38 months (range, 1 to 63 months). Chemotherapy was a favorable prognostic factor for either the high- (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.38 to 0.59; p < 0.001) or low-risk group (HR, 0.74; 95% CI, 0.61 to 0.89; p=0.002) in multivariate analysis. This was also the case in patients over 70 years of age. The hazard ratio was significantly increased as the number of involved risk factors was increased in patients who didn’t receive chemotherapy. Adding oxaliplatin showed no difference in survival (HR, 1.36; 95% CI, 0.91 to 2.03; p=0.132). Conclusion Adjuvant chemotherapy can be recommended for stage II colon cancer patients, but the addition of oxaliplatin to the regimen must be selective.

Novel predictors for lymph node metastasis in submucosal invasive colorectal carcinoma

AIM To evaluate a novel grading system to predict lymph node metastasis (LNM) in patients with submucosal invasive colorectal carcinoma (SICRC). METHODS We analyzed the associations between LNM and various clinicopathological features in 252 patients with SICRC who had undergone radical surgery at the Seoul Saint Mary’s hospital between 2000 and 2015. RESULTS LNM was observed in 31 patients (12.3%). The depth and width of the submucosal invasion, lymphatic invasion, tumor budding, and the presence of poorly differentiated clusters (PDCs) were significantly associated with the incidence of LNM. Using multivariate analysis, the receiver operating characteristic curvewas calculated and the area under curve (AUC) was used to compare the ability of the different parameters to identify the risk of LNM. The most powerful clinicopathological parameter for predicting LNM was lymphatic invasion (difference AUC = 0.204), followed by the presence or absence of tumor budding (difference AUC = 0.190), presence of PDCs (difference AUC = 0.172) and tumor budding graded by the Ueno method (difference AUC = 0.128). CONCLUSION Our results indicate that the tumor budding and the depth multiplied by the width measurements of submucosal invasion can provide important information for patients with SICRC.