Robotic True D3 Lymph Node Dissection With Superior Mesenteric Vein-Taping Technique for Right-Sided Colon Cancer.

BACKGROUND: D3 is unaffected by anatomic factors even when the ileocolic artery runs along the dorsal side of the superior mesenteric vein. Complete "true D3" lymph node dissection in minimally invasive surgery for right-sided colon cancer could be beneficial for certain patients with lymph node metastases. IMPACT OF INNOVATION: The study aimed to determine the safety and feasibility of robotic true D3 lymph node dissection for right-sided colon cancer using a superior mesenteric vein-taping technique. TECHNOLOGY, MATERIALS, AND METHODS: The superior mesenteric vein was slowly and gently separated from the surrounding tissues and taped. Lifting the tape with the robotic third arm and fixing it in place using rock-stable tractions provides a good surgical view, which cannot otherwise be obtained. As a result, the ileocolic artery that branches from the superior mesenteric artery can be accurately exposed. Handling of the taping then enables expansion to a different surgical view. As the lymph nodes are originally concealed on the dorsal side of the superior mesenteric vein, this technique provides a good view for lymph node dissection. The root of the ileocolic artery was clipped and separated, and true D3 was thus completed. PRELIMINARY RESULTS: Fourteen patients underwent robotic true D3 lymph node dissection for right-sided colon cancer. No Clavien-Dindo classification grade II or higher intraoperative or postoperative complications were observed. The 30-day mortality rate was 0%. CONCLUSIONS: Our robotic true D3 lymph node dissection with superior mesenteric vein-taping technique is considered safe and feasible; it might be a promising surgical procedure for treating advanced right-sided colon cancer. FUTURE DIRECTIONS: Even when the ileocolic artery runs along the dorsal aspect of the superior mesenteric vein, the technique seems promising for facilitating robotic D3 lymph node dissection.

[Significance of Colorectal Cancer Resection for the Elderly].

INTRODUCTION: Elderly patients requiring surgical treatment is increasing in Japan, and while surgical treatment is expected to be effective even in the very elderly, there is a lack of evidence for the safety and efficacy of surgical resection due to problems with perioperative management and operative tolerance. We therefore retrospectively examined the short-term and long-term outcomes of colorectal cancer surgery for the very elderly at our hospital. SUBJECTS: The study included 14 cases of colorectal cancer in the very elderly who underwent radical resection at our hospital between January 2010 and March 2020. RESULTS: The mean age was 92 years, PS; 1/2=8/6, ASA-PS; 2/3/4=8/4/2, primary site was C/A/T/S/R= 2/5/2/2/3, pStage; 1/2/3=1/9/4, and only 1 case of decompression with ileus tube due to obstructive symptoms was treated before surgery. All patients underwent radical surgery. Median blood loss was 61 mL, median operation time was 190.5 min, and median postoperative hospital stay was 16 days. 5 patients had CD≥2 complications. All patients did not receive adjuvant chemotherapy, and recurrence in was observed 3 patients. CONCLUSION: Surgical treatment of very elderly patients seems to be acceptable under appropriate patient selection.

[A Case of Pathologically Complete Response after Preoperative Chemotherapy in a Locally Advanced Rectal Cancer].

The case is a 78-year-old male. The chief complaint was melena and weight loss. After careful examination, the patient was diagnosed with advanced rectal cancer, and 3 courses of capecitabine plus oxaliplatin therapy were performed as preoperative chemotherapy. He underwent robot-assisted laparoscopic rectal resection, D3 lymphadenectomy, lateral lymphadenectomy, and temporary colostomy, and was discharged on hospital day 15. Postoperative pathological diagnosis showed only ulcerative lesions in the rectum, and malignant cells could not be confirmed. After postoperative adjuvant chemotherapy, the patient is alive without recurrence on an outpatient basis. There are many reports that it is slightly lower than radiotherapy. Therefore, it is important to select a more appropriate preoperative treatment, and the concentration of future cases is recognized.

Robotic total mesorectal excision for rectal cancer based on the theory of fundamental use of surgical energy.

BACKGROUND: Improving oncological curability and preserving urinary function must be established in robotic total mesorectal excision (TME) for rectal cancer. To achieve this, it is important to avoid nerve injury by sharp dissection of the avascular plane by the monopolar device and thermal spread. The aim of this study was to improve the robotic TME quality by focusing on the theory of fundamental use of surgical energy (FUSE) of the monopolar device and investigating the surgical procedure. METHODS: In this single-center retrospective study, 26 consecutive patients who underwent robotic TME for rectal cancer at Tokyo Medical University Hospital between June 2022 and August 2022 were included. All surgeries were performed by FUSE-certified surgeons in accordance with FUSE theory, which was, thermal effect = current density (current/area) squared × tissue resistance × contact time. RESULT: The median age of the patients was 64 years (range 40-79 years), and 17 patients were male. The median operative time was 287 min (range 229-430 min); median bleeding volume, 22 ml (range 5-223 ml); and the median number of harvested lymph nodes, 17 (range 4-40). The conversion rate to open surgery was 0%. A breakdown of Clavien-Dindo classification Grade ≥ II post-operative complications was as follows: surgical site infection, one patient (3.8%); ileus, one patient (3.8%); and urinary dysfunction, one patient (3.8%). No surgery-related or in-hospital deaths occurred. The pathological positive resection margin was not observed. CONCLUSIONS: Robotic TME for rectal cancer based on the theory of FUSE can be safely performed, making it a promising surgical procedure. It is suggested that robotic surgeons acquire surgical operation skills with monopolar devices based on the principles of FUSE, which may lead to an increased quality of robotic TME.

Robotic versus laparoscopic approach for minimally invasive lateral pelvic lymph node dissection of advanced lower rectal cancer: a retrospective study comparing short-term outcomes.

PURPOSE: The importance of lateral pelvic lymph node dissection (LLND) for advanced low rectal cancer is gradually being recognized in Europe and the USA, where some patients were affected by uncontrolled lateral pelvic lymph node (LLNs) metastasis, even after total mesorectal excision (TME) with neoadjuvant chemoradiotherapy (CRT). The purpose of this study was thus to compare robotic LLND (R-LLND) with laparoscopic (L-LLND) to clarify the safety and advantages of R-LLND. METHODS: Sixty patients were included in this single-institution retrospective study between January 2013 and July 2022. We compared the short-term outcomes of 27 patients who underwent R-LLND and 33 patients who underwent L-LLND. RESULTS: En bloc LLND was performed in significantly more patients in the R-LLND than in the L-LLND group (48.1% vs. 15.2%; p = 0.006). The numbers of LLNs on the distal side of the internal iliac region (LN 263D) harvested were significantly higher in the R-LLND than in the L-LLND group (2 [0-9] vs. 1 [0-6]; p = 0.023). The total operative time was significantly longer in the R-LLND than in the L-LLND group (587 [460-876] vs. 544 [398-859]; p = 0.003); however, the LLND time was not significantly different between groups (p = 0.718). Postoperative complications were not significantly different between the two groups. CONCLUSION: The present study clarified the safety and technical feasibility of R-LLND with respect to L-LLND. Our findings suggest that the robotic approach offers a key advantage, allowing significantly more LLNs to be harvested from the distal side of the internal iliac region (LN 263D). Prospective clinical trials examining the oncological superiority of R-LLND are thus necessary in the near future.

Predicting the prognosis of lower rectal cancer using preoperative magnetic resonance imaging with artificial intelligence.

BACKGROUND: There are various preoperative treatments that are useful for controlling local or distant metastases in lower rectal cancer. For planning perioperative management, preoperative stratification of optimal treatment strategies for each case is required. However, a stratification method has not yet been established. Therefore, we attempted to predict the prognosis of lower rectal cancer using preoperative magnetic resonance imaging (MRI) with artificial intelligence (AI). METHODS: This study included 54 patients [male:female ratio was 37:17, median age 70 years (range 49-107 years)] with lower rectal cancer who could be curatively resected without preoperative treatment at Tokyo Medical University Hospital from January 2010 to February 2017. In total, 878 preoperative T2 MRIs were analyzed. The primary endpoint was the presence or absence of recurrence, which was evaluated using the area under the receiver operating characteristic curve. The secondary endpoint was recurrence-free survival (RFS), which was evaluated using the Kaplan-Meier curve of the predicted recurrence (AI stage 1) and predicted recurrence-free (AI stage 0) groups. RESULTS: For recurrence prediction, the area under the curve (AUC) values for learning and test cases were 0.748 and 0.757, respectively. For prediction of recurrence in each case, the AUC values were 0.740 and 0.875, respectively. The 5-year RFS rates, according to the postoperative pathologic stage for all patients, were 100%, 64%, and 50% for stages 1, 2, and 3, respectively (p = 0.107). The 5-year RFS rates for AI stages 0 and 1 were 97% and 10%, respectively (p < 0.001 significant difference). CONCLUSIONS: We developed a prognostic model using AI and preoperative MRI images of patients with lower rectal cancer who had not undergone preoperative treatment, and the model could be useful in comparison with pathological classification.

Predictive modelling for high-risk stage II colon cancer using auto-artificial intelligence.

BACKGROUND: Recently, stratification of high-risk stage II colon cancer (CC) and the need for adjuvant chemotherapy have been the focus of attention. The aim of this retrospective study was to define high-risk factors for recurrent stage II CC using Prediction One auto-artificial intelligence (AI) software and develop a new predictive model for high-risk stage II CC. METHODS: The study included 259 consecutive pathological stage II CC patients undergoing curative resection at our institution between January 2000 and December 2016. Prediction One software with five-fold cross-validation was used to create a predictive model and receiver operating characteristic (ROC) curve. Predictive accuracy of AI was evaluated using the area under the ROC curve (AUC). We also evaluated the importance of variables (IOV) using a method based on permutation feature importance (IOV > 0.01 defined high-risk factors) to evaluate disease-free survival (DFS). RESULTS: The median observation period was 6.1 (range = 0.3-15.8) years. Thirty-seven patients had recurrence (14.3%); the AUC of the AI model was 0.775. Preoperative carcinoembryonic antigen > 5.0 ng/mL (IOV = 0.047), venous invasion (IOV = 0.014), and obstruction (IOV = 0.012) were high-risk factors contributing to cancer recurrence. Patients with 2-3 high-risk factors had lower 5-year DFS than those with 0-1 factor (87.4% vs 62.7%, p < 0.001). CONCLUSIONS: We developed a new predictive model that could predict recurrent high-risk stage II CC with high probability using auto-AI Prediction One software. Patients with ≥ 2 of the aforementioned factors are considered to have high risks for recurrent stage II CC and may benefit from adjuvant chemotherapy.

[A Case of Rectal Cancer with Solitary Lymph Node Metastasis in the Stomach after Hepatectomy for Liver Metastasis].

A 44-year-old woman had undergone a laparoscopic low anterior resection and lymph node dissection for rectal cancer (pT4aN2aH0P0M0, pStage Ⅲc)in 20XX. Six months postoperatively, a CT scan revealed recurrent liver metastasis. She underwent surgery and adjuvant chemotherapy. Three years after the initial surgery, her liver metastasis recurred again, and the patient underwent another cycle of surgical treatment and adjuvant chemotherapy. Five years after the initial surgery, a lesion was found in a gastric lesser curvature lymph node. Gastric kyphosis lymph node dissection was performed under the suspicion of a solitary lymph node metastasis. The resected lymph node was diagnosed as a medium-differentiated adenocarcinoma, with findings consistent with a lymph node metastasis from the initial rectal cancer. Postoperative adjuvant chemotherapy was administered. No recurrence was noted 6 years and 6 months after the initial surgery. Rectal cancer rarely metastasizes to the gastric lymph nodes in a solitary fashion. We describe a case of a solitary gastric regional lymph node metastasis observed after the resolution of previous liver metastases.

[Short-Term and Long-Term Results of Robot-Assisted Rectal Resections Performed in Our Department].

BACKGROUND: We introduced the da Vinci robotic surgical system in 2006 for the first time in Japan, and have been performing robot-assisted rectal cancer surgeries since 2010, after receiving approval from the hospital's Ethics Review Committee in 2009. Here we report the long-term and short-term outcomes of robot-assisted rectal cancer surgeries performed in our department. METHODS: Target patients were those who underwent robot-assisted radical rectal resection for rectal cancer; 165 patients in the short term(2010-2021), and 49 patients in the long term(2010-2016). Data were retrospectively analyzed, and Kaplan-Meier curves were used for the survival analysis. RESULTS: The short-term results are summarized in Table 1. The long-term results were as follows: 5-year overall survival rate, 90.8%; 5-year recurrence-free survival rate, 90.6%; 5-year cumulative local recurrence rate, 7.3%; 5-year cumulative distant metastasis rate, 9.4%. CONCLUSION: In our department, 11 years have passed since we began performing robotic rectal surgeries, and the short- and long-term results have generally been acceptable.

[Preoperative Prognostic Factors in CRS plus HIPEC for Patients with Peritoneal Dissemination of Colorectal Cancer].

Peritoneal dissemination of colorectal cancer has the poorest prognosis among metastatic sites, with an average overall survival of less than 6 months. Various treatment methods have been reported for these patients, and recently there have been several reports showing the usefulness of cytoreductive surgery(CRS)combined with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the studies on this treatment are limited. In this study, we retrospectively reviewed cases of CRS plus HIPEC. Twenty-one patients who underwent CRS plus HIPEC at Tokyo Medical University Hospital and Toda Central General Hospital between August 2014 and December 2017 were included in this study. The long-term and short-term survival groups were analyzed separately, and predictors of preoperative treatment efficacy were examined. The surgical approach was open in 16 cases and laparoscopic in 5 cases. Complete resection was achieved in 10 of these patients. Postoperative complications occurred in 6 patients. There were no deaths within 90 days of surgery. The median overall survival was 17.0 months, and the 1-year survival rate was 65%. Median progression-free survival was 11.0 months. In a multivariate analysis predicting long-term versus short-term survival groups, sex, primary tumor location, and P factor were independent predictors of treatment response. CRS plus HIPEC therapy is considered an effective treatment option. The predictors of preoperative treatment response include sex, primary tumor location, and P factor.

Salivary metabolomics with machine learning for colorectal cancer detection.

As the worldwide prevalence of colorectal cancer (CRC) increases, it is vital to reduce its morbidity and mortality through early detection. Saliva-based tests are an ideal noninvasive tool for CRC detection. Here, we explored and validated salivary biomarkers to distinguish patients with CRC from those with adenoma (AD) and healthy controls (HC). Saliva samples were collected from patients with CRC, AD, and HC. Untargeted salivary hydrophilic metabolite profiling was conducted using capillary electrophoresis-mass spectrometry and liquid chromatography-mass spectrometry. An alternative decision tree (ADTree)-based machine learning (ML) method was used to assess the discrimination abilities of the quantified metabolites. A total of 2602 unstimulated saliva samples were collected from subjects with CRC (n = 235), AD (n = 50), and HC (n = 2317). Data were randomly divided into training (n = 1301) and validation datasets (n = 1301). The clustering analysis showed a clear consistency of aberrant metabolites between the two groups. The ADTree model was optimized through cross-validation (CV) using the training dataset, and the developed model was validated using the validation dataset. The model discriminating CRC + AD from HC showed area under the receiver-operating characteristic curves (AUC) of 0.860 (95% confidence interval [CI]: 0.828-0.891) for CV and 0.870 (95% CI: 0.837-0.903) for the validation dataset. The other model discriminating CRC from AD + HC showed an AUC of 0.879 (95% CI: 0.851-0.907) and 0.870 (95% CI: 0.838-0.902), respectively. Salivary metabolomics combined with ML demonstrated high accuracy and versatility in detecting CRC.

Prognostic value of preoperative high-sensitivity modified Glasgow prognostic score in advanced colon cancer: a retrospective observational study.

BACKGROUND: Several studies have demonstrated that the preoperative Glasgow prognostic score (GPS) and modified GPS (mGPS) reflected the prognosis in patients undergoing curative surgery for colorectal cancer. However, there are no reports on long-term prognosis prediction using high-sensitivity mGPS (HS-GPS) in colorectal cancer. Therefore, this study aimed to calculate the prognostic value of preoperative HS-GPS in patients with colon cancer. METHODS: A cohort of 595 patients with advanced resectable colon cancer managed at our institution was analysed retrospectively. HS-GPS, GPS, and mGPS were evaluated for their ability to predict prognosis based on overall survival (OS) and recurrence-free survival (RFS). RESULTS: In the univariate analysis, HS-GPS was able to predict the prognosis with significant differences in OS but was not superior in assessing RFS. In the multivariate analysis of the HS-GPS model, age, pT, pN, and HS-GPS of 2 compared to HS-GPS of 0 (2 vs 0; hazard ratio [HR], 2.638; 95% confidence interval [CI], 1.046-6.650; P = 0.04) were identified as independent prognostic predictors of OS. In the multivariate analysis of the GPS model, GPS 2 vs 0 (HR, 1.444; 95% CI, 1.018-2.048; P = 0.04) and GPS 2 vs 1 (HR, 2.933; 95% CI, 1.209-7.144; P = 0.017), and in that of the mGPS model, mGPS 2 vs 0 (HR, 1.51; 95% CI, 1.066-2.140; P = 0.02) were independent prognostic predictors of OS. In each classification, GPS outperformed HS-GPS in predicting OS with a significant difference in the area under the receiver operating characteristic curve. In the multivariate analysis of the GPS model, GPS 2 vs 0 (HR, 1.537; 95% CI, 1.190-1.987; P = 0.002), and in that of the mGPS model, pN, CEA were independent prognostic predictors of RFS. CONCLUSION: HS-GPS is useful for predicting the prognosis of resectable advanced colon cancer. However, GPS may be more useful than HS-GPS as a prognostic model for advanced colon cancer.

Novel and Simple Nomograms Using Inflammation and Nutritional Biomarkers for Stage II-III Colon Cancer, Taking "Time after Curative Surgery" into Consideration.

PURPOSE: Recurrence of colon cancer is associated with time after curative surgery. This study aimed to construct novel nomograms to predict relapse-free survival (RFS) in stage II-III colon cancer, considering "time after surgery" and using various inflammatory and nutritional biomarkers. METHODS: All 542 patients who underwent radical surgery for stage II-III colon cancer between January 2000 and August 2015 at our institute were retrospectively analyzed. Time-dependent receiver operating characteristic curves and cutoff values were obtained for neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio, platelet-lymphocyte ratio, Japanese modified Glasgow prognostic score (mGPS), C-reactive protein-albumin ratio (CAR), prognostic nutritional index, and controlling nutritional status (CONUT) for each postoperative period (1 - 5 years). We used Cox proportional hazard analyses to evaluate independent risk factors and to construct nomograms in each period. RESULTS: We obtained a good accuracy in NLR, CAR, mGPS, and CONUT (area under the curve > 0.5). NLR was the only preoperative independent risk factor, except age, in multivariate analysis. We constructed the nomograms and obtained a good discrimination value of the concordance index in each period (>0.75). CONCLUSION: Using inflammatory and nutritional biomarkers, we established and calibrated novel nomograms for predicting time-dependent RFS for stage II-III colon cancer patients.

A new technique for robotic lateral pelvic lymph node dissection for advanced low rectal cancer with emphasis on en bloc resection and inferior vesical vessel preservation.

BACKGROUND: Lateral pelvic lymph node (LPLN) dissection is becoming increasingly important in the treatment of advanced low rectal cancer patients. However, the surgery has several disadvantages, including its technical complexity and high risk of urinary dysfunction. Herein, we report a new technique for robotic lateral pelvic lymph node dissection for advanced low rectal cancer with emphasis on en bloc resection and inferior vesical vessel preservation. METHODS: Robotic LPLN dissection was performed in 12 consecutive patients between April 2020 and December 2021. Six surgical ports were placed in the abdomen under general anesthesia. Fascia-oriented LPLN dissection of the internal iliac region and obturator region was performed using the ureterohypogastric nerve fascia, vesicohypogastric fascia, and internal obturator muscles as anatomical landmarks. Lymph nodes were resected en bloc via the caudal side of the inferior vesical vessels. The inferior vesical vessels were spared to prevent urinary dysfunction. RESULTS: The median patient age was 62 years (range, 43-82 years), and eight patients were male. The median operative time was 498 min (range, 424-661 min), the median bleeding volume was 56 ml (range, 13-467 ml), and the median number of harvested LPLN was 16 (range, 1-70). The conversion rate to open surgery was 0%. Clavien-Dindo Grade ≥ II urinary dysfunction rated was not observed. CONCLUSION: A new technique for robotic LPLN dissection for advanced low rectal cancer with emphasis on en bloc resection and inferior vesical vessel preservation can be safely performed, making it a promising surgical procedure.

Artificial intelligence predicts lymph node metastasis or risk of lymph node metastasis in T1 colorectal cancer.

BACKGROUND: The treatment strategies for colorectal cancer (CRC) must ensure a radical cure of cancer and prevent over/under treatment. Biopsy specimens used for the definitive diagnosis of T1 CRC were analyzed using artificial intelligence (AI) to construct a risk index for lymph node metastasis. METHODS: A total of 146 T1 CRC cases were analyzed. The specimens for analysis were mainly biopsy specimens, and in the absence of biopsy specimens, the mucosal layer of the surgical specimens was analyzed. The pathology slides for each case were digitally imaged, and the morphological features of cancer cell nuclei were extracted from the tissue images. First, statistical methods were used to analyze how well these features could predict lymph node metastasis risk. A lymph node metastasis risk model using AI was created based on these morphological features, and accuracy in test cases was verified. RESULTS: Each developed model could predict lymph node metastasis risk with a > 90% accuracy in each region of interest of the training cases. Lymph node metastasis risk was predicted with 81.8-86.3% accuracy for randomly validated cases, using a learning model with biopsy data. Moreover, no case with lymph node metastasis or lymph node risk was judged to have no risk using the same model. CONCLUSIONS: AI models suggest an association between biopsy specimens and lymph node metastases in T1 CRC and may contribute to increased accuracy of preoperative diagnosis.

Laparoscopic middle colic artery-preserved right hemicolectomy with true D3 lymph node dissection for right-sided colon cancer: modified complete mesocolic excision.

BACKGROUND: Complete mesocolic excision (CME) has been demonstrated to be a useful surgical procedure for advanced colon cancer. We previously reported on laparoscopic (Lap) CME with true central vascular ligation (CVL) for advanced right-sided colon cancer. Lap CME with true CVL is highly plausible from the perspective of surgical oncology. However, true CVL of the middle colic artery (MCA) may require extensive resection of the transverse colon. The Japanese Classification of Colorectal Cancer defines D3 as main lymph node dissection around the superior mesenteric artery (SMA), and true CVL is not listed as a required condition. Our institution has been performing a Lap procedure (Lap D3/modified CME) that consists of the dissection of main lymph nodes around the root of the MCA (#223LNs) while preserving the left branch of the MCA. Two videos of a Lap D3/modified CME are presented, and the short-term outcome is reported. METHODS: Lap D3/modified CME was defined as Lap ligation surgery at the root of the right branch of the MCA that preserves the MCA with #223LNs on the resection side. The present study retrospectively examined 11 cases of Lap D3/modified CME performed at the Tokyo Medical University Hospital between 2015 and 2020. When the SMA is difficult to visualize in Type V/A cases, the SMV is pulled using some silicone string, and the surrounding lymph nodes are dissected while visualizing the SMA. RESULTS: The median operating time was 289 min, and the median blood loss was 57 ml. The median total number of dissected lymph nodes was 38, and the median number of dissected #223LNs was three. No metastasis was found in the dissected #223LNs. CONCLUSION: Although this surgery can be performed safely, we believe that this surgery needs to be performed for suitable cases by a highly experienced and skilled surgical team.

[Examination of Prognostic Factors for Elderly Colon Cancer].

Elderly people tend to be in poor general condition and have many comorbidities. It has been reported that these things may be associated with postoperative recurrence and the increase in mortality rate. In order to evaluate their distinctive comorbidity and immunocompetence, we analyzed the covariates including Charlson comorbidity index(CCI), performance status(PS), and immune-nutrient factors. We retrospectively examined 175 cases of radical resection of colon cancer aged 75 years or older performed in our department from January 2000 to December 2014. There were 133/29/11/2 patients for PS 0/1/2/3, respectively. The median CCI was 4.0(range: 1-11). In the multivariate analysis for overall survival(OS), there was a significant difference in PS, BMI, N-factor, venous invasion, pathological stage, neutrophil-to-lymphocyte rate (NLR), lymphocyte-to-monocyte rate(LMR), and modified Glasgow prognostic scale(mGPS). In the multivariate analysis for relapse-free survival(RFS), there was a significant difference in gender, T-factor, N-factor, pathological stage, collected lymph nodes, NLR, LMR, and mGPS. It was suggested that their preoperative general and nutritional conditions can lead to the good oncologic outcomes for the elderly patients in colon cancer.

[A Case of Gastrointestinal Stromal Tumor(GIST)of the Sigmoid Colon with Early Colon Cancer].

A 67-year-old male patient was referred to our department for fecal occult blood in March 2019. In April, lower intestinal endoscopic examination revealed a 25-mm pedunculated polyp in the sigmoid colon. Endoscopic mucosal resection was then performed. The pathological diagnosis was tub1-tub2 with an invasion depth of pT1b 3,000 µm, and ly0 and v1 vascular invasion. The tumor marker levels were normal, with CEA of 1.1 ng/mL and CA19-9 of 13.9 U/mL. An additional laparoscopic low anterior resection and D2 dissection were performed in June. After the endoscopic mucosal resection, pathologic examination revealed densely hyperplastic spindle cells arranged in bundles at the proper muscular layer of the scar site. There was no lymph node metastasis. On immunostaining, the lesion tested positive for c-kit, CD34, and DOG1, but negative for desmin, SMA, and S-100, with a MIB-1 index of 2%. The patient was diagnosed with very low risk gastrointestinal stromal tumor(GIST). We encountered a rare case of early sigmoid colon cancer, complicated by sigmoid colon GIST.

Neutrophil-to-lymphocyte ratio is a prognostic factor for colon cancer: a propensity score analysis.

BACKGROUND: A large number of patients suffer recurrence after curative resection, and mortality from colon cancer remains high. The role of systemic inflammatory response, as reflected by neutrophil-to-lymphocyte ratio (NLR), in cancer recurrence and death has been increasingly recognized. This study aimed to analyze long-term oncologic outcomes of Stage II-III colon cancer to examine the prognostic value of NLR using a propensity score analysis. METHODS: A total of 375 patients with colon cancer underwent radical surgery between 2000 and 2014 at Tokyo Medical University Hospital. Long-term oncologic outcomes of these patients were evaluated according to NLR values. A cut-off NLR of 3.0 was used based on receiver operating characteristic curve analysis. Primary outcomes were overall survival (OS) and relapse-free survival (RFS). An analysis of outcomes according to tumor sidedness was also performed. RESULTS: Patients with lower NLR values ("lower NLR group") were more likely to have lymph node metastasis compared to those with higher NLR values ("higher NLR group") before case matching. After case matching, clinical outcomes were similar between the two groups. There were no significant differences in 5-year OS and 5-year RFS rates between the two groups before case matching based on propensity scores. After case matching, 5-year OS rates were 94.5% in the lower NLR group (n = 135) and 87.0% in the higher NLR group (n = 135), showing a significant difference (p = 0.042). Five-year RFS rates were 87.8% in the lower NLR group and 77.9% in the higher NLR group, also showing a significant difference (p = 0.032). Among patients with left-sided colon cancer in the matched cohort, 5-year OS and 5-year RFS rates were 95.2 and 87.3% in the lower NLR group (n = 88), respectively, and 86.4 and 79.2% in the higher NLR group (n = 71), respectively, showing significant differences (p = 0.014 and p = 0.047, respectively). CONCLUSIONS: The NLR is an important prognostic factor for advanced colon cancer, especially for left-sided colon cancer.

Laparoscopic complete mesocolic excision with true central vascular ligation for right-sided colon cancer.

BACKGROUND: Complete mesocolic excision (CME) is known to be effective for colon cancer. However, in right-sided colon cancer, central vascular ligation (CVL) is not easy to perform. In particular, in patients in whom the superior mesenteric vein (SMV) runs on the ventral side of the superior mesenteric artery (SMA) (Type V/A), laparoscopic ligation of the artery at its root is extremely difficult compared with this procedure in patients in whom the SMA runs on the ventral side of the SMV (Type A/V). METHODS: We started performing laparoscopic CME with true CVL for right-sided colon cancer using the SMA as a landmark in 2015, and by 2019, we had completed it for 60 patients. To start, the mesocolon is opened well to the caudal side of the ileocolic vessels. The mesentery is then fully detached from the retroperitoneal tissue, after which the ileocolic vessels are ligated at their roots. D3 lymph node dissection of the lymph nodes around the SMA and SMV on the resection side is also performed using the SMA as a landmark, and depending on the location of the tumor, the roots of the right and middle colic vessels are ligated and divided. This study was conducted with the approval of the Tokyo Medical University Ethics Committee. All patients provided informed consent. RESULTS: The tumor was located in the cecum in 21 cases, the ascending colon in 33, and the transverse colon in 6. The mean operating time was 229 min and the mean volume of hemorrhage was 67 ml. There was one Clavien-Dindo Grade 3 or worse postoperative complication (ileus). There were no surgery-related or in-hospital deaths. CONCLUSION: This procedure can be performed comparatively safely. However, since it requires some skill, we consider that it should only be performed in suitable cases by teams with sufficient experience.