Detection and clinical significance of CEACAM5 methylation in colorectal cancer patients.

Colorectal cancer (CRC) is a globally common cancer, and the serum carcinoembryonic antigen (sCEA) is widely applied as a diagnostic and prognostic tumor marker in CRC. This study aimed to elucidate the mechanism of CEA expression and corresponding clinical features to improve prognostic assessments. In CRC cells, hypomethylation of the CEACAM5 promoter enhanced CEA expression in HCT116 and HT29 cells with 5-aza-2'-deoxycytidine (5-Aza-dC) treatment. Our clinical data indicated that 64.7% (101/156) of CRC patients had an sCEA level above the normal range, and 76.2% (77/101) of those patients showed a lower average CpG methylation level of the CEACAM5 promoter. The methylation analysis showed that both CRC cell lines and patient samples shared the same critical methylation CpG regions at -200 to -500 and -1000 to -1400 bp of the CEACAM5 promoter. Patients with hypermethylation of the CEACAM5 promoter showed features of a BRAF mutation, TGFB2 mutation, microsatellite instability-high, and preference for right-sided colorectal cancer and peritoneal seeding presentation that had a similar clinical character to the consensus molecular subtype 1 (CMS1) of colorectal cancer. Additionally, hypermethylation of the CEACAM5 promoter combined with evaluated sCEA demonstrated the worst survival among the patients. Therefore, the methylation status of the CEACAM5 promoter also served as an effective biomarker for assessing disease prognosis. Results indicated that DNA methylation is a major regulatory mechanism for CEA expression in colorectal cancer. Moreover, our data also highlighted that patients in a subgroup who escaped from inactivation by DNA methylation had distinct clinical and pathological features and the worst survival.

Surgical strategy for colorectal cancer with synchronous liver and extrahepatic metastases: A scoring system and decision tree model.

BACKGROUND: The role of hepatectomy in a specific group of patients with synchronous colorectal cancer with liver metastases (SCRLM) and synchronous extrahepatic disease (SEHD) is still unclear. The aim of this study was to evaluate the efficacy of liver surgery and define the selection criteria for surgical candidates in patients with SCRLM + SEHD. METHODS: Between July 2007 and October 2018, 475 patients with colorectal cancer with liver metastases (CRLM) who underwent liver resection were retrospectively reviewed. Sixty-five patients with SCRLM + SEHD were identified and included in the study. Clinical pathological data of these patients were analyzed to evaluate the influence on survival. Important prognostic factors were identified by univariate and multivariate analyses. The risk score system and decision tree analysis were generated according to the important prognostic factors for better patient selection. RESULTS: The 5-year survival rate of patients with SCRLM + SEHD was 21.9%. The most important prognostic factors were SCRLM number of more than five, site of SEHD other than the lung only, inability to achieve SCRLM + SEHD R0 resection, and BRAF mutation of cancer cells. The proposed risk score system and decision tree model easily discriminated between patients with different survival rates and identified the profile of suitable surgical patients. CONCLUSION: Liver surgery should not be a contraindication for patients with SCRLM + SEHD. Patients with complete SCRLM + SEHD R0 resection, SCRLM number less than or equal to five, SEHD confined to the lung only, and wild-type BRAF could have favorable survival outcomes. The proposed scoring system and decision tree model may be beneficial to patient selection in clinical use.

Modeling the survival of colorectal cancer patients based on colonoscopic features in a feature ensemble vision transformer.

The prognosis of patients with colorectal cancer (CRC) mostly relies on the classic tumor node metastasis (TNM) staging classification. A more accurate and convenient prediction model would provide a better prognosis and assist in treatment. From May 2014 to December 2017, patients who underwent an operation for CRC were enrolled. The proposed feature ensemble vision transformer (FEViT) used ensemble classifiers to benefit the combinations of relevant colonoscopy features from the pretrained vision transformer and clinical features, including sex, age, family history of CRC, and tumor location, to establish the prognostic model. A total of 1729 colonoscopy images were enrolled in the current retrospective study. For the prediction of patient survival, FEViT achieved an accuracy of 94 % with an area under the receiver operating characteristic curve of 0.93, which was better than the TNM staging classification (90 %, 0.83) in the experiment. FEViT reduced the limited receptive field and gradient disappearance in the conventional convolutional neural network and was a relatively effective and efficient procedure. The promising accuracy of FEViT in modeling survival makes the prognosis of CRC patients more predictable and practical.

Anti-VEGF Therapy Possibly Extends Survival in Patients With Colorectal Brain Metastasis by Protecting Patients From Neurologic Disability.

BACKGROUND: Colorectal brain metastases (CBMs) are rare with poor prognosis. There is still no standard systemic treatment for multiple or unresectable CBM. our study aimed to explore the impact of anti-VEGF therapy on overall survival, brain-specific disease control, and neurologic symptom burden in patients with CBM. METHODS: A total of 65 patients with CBM under treatment were retrospectively enrolled and divided into anti-VEGF based systemic therapy or non-anti-VEGF based therapy. A total of 25 patients who received at least 3 cycles of anti-VEGF agent and 40 patients without anti-VEGF therapy were analyzed by endpoints of overall survival (OS), progression-free survival (PFS), intracranial PFS (iPFS) and neurogenic event-free survival (nEFS). Gene expression in paired primary metastatic colorectal cancer (mCRC), liver, lung and brain metastasis from NCBI data was analyzed using top Gene Ontology (GO) and cBioPortal. RESULTS: Patients who treated with anti-VEGF therapy had significantly longer OS (19.5 vs. 5.5 months, P = .009), iPFS (14.6 vs. 4.1 months, P < .001) and nEFS (17.6 vs. 4.4 months, P < .001). Patients who received anti-VEGF therapy beyond any disease progression presented with superior OS (19.7 vs. 9.4 months, P = .039). Top GO and cBioPortal analysis revealed a stronger molecular function of angiogenesis in intracranial metastasis. CONCLUSIONS: Anti-VEGF based systemic therapy showed favorable efficacy that was reflected in longer overall survival, iPFS and NEFS in patients with CBM.

Enhanced prognostic value of combined circulating tumor cells and serum carcinoembryonic antigen in patients with colorectal cancer.

BACKGROUND: Circulating tumor cells (CTCs) have been investigated as a potential biomarker for predicting prognosis and monitoring therapeutic responses in colorectal cancer (CRC). However, the sensitivity of CTCs detection is low, thus limiting the clinical utility of CTCs. We aim to examine the clinicopathological parameters that improve prognosis prediction for CRC using CTCs as a biomarker. METHODS: We enumerated CTCs in 186 CRC patients and associated the number of CTCs with the clinicopathological features and overall survival (OS) using a univariate and multivariate Cox regression model and Kaplan-Meier survival analysis. RESULTS: The presence of CTCs from 186 CRC patients was significantly associated with stage, preoperational carcinoembryonic antigen (CEA), and CA19-9 levels. Using Kaplan-Meier survival and Cox regression analysis, patients with five or more CTCs exhibited significantly worse OS compared to patients with fewer than five CTCs. The combination of CTCs with tumor marker CEA has a better OS prediction than individual CTCs or CEA and serves as a more effective prediction model in patients with CRC. CONCLUSION: We identified that patients with more than five CTCs exhibited significantly worse OS. Additionally, patients with the normal level of CEA, but who also had more than five CTCs trended towards a worse OS.

Protective loop ileostomy or colostomy? a risk evaluation of all common complications.

Purpose: Protective ileostomy and colostomy are performed in patients undergoing low anterior resection with a high leakage risk. We aimed to compare surgical, medical, and daily care complications between these 2 ostomies in order to make individual choice. Methods: Patients who underwent low anterior resection for rectal tumors with protective stomas between January 2011 and September 2018 were enrolled. Stoma-related complications were prospectively recorded by wound, ostomy, and continence nurses. The cancer stage and treatment data were obtained from the Taiwan Cancer Database of our Big Data Center. Other demographic data were collected retrospectively from medical notes. The complications after stoma creation and after the stoma reversal were compared. Results: There were 176 patients with protective colostomy and 234 with protective ileostomy. Protective ileostomy had higher proportions of high output from the stoma for 2 consecutive days than protective colostomy (11.1% vs. 0%, P<0.001). Protective colostomy resulted in more stoma retraction than protective ileostomy (21.6% vs. 9.4%, P=0.001). Female sex, open operation, ileostomy, and carrying stoma more than 4 months were also significantly associated with a higher risk of stoma-related complications during diversion. The incidence of complication after stoma reversal did not differ between colostomy group and ileostomy group (24.3% vs. 20.9%, P=0.542). Conclusion: We suggest avoiding colostomy in patients who are female and potential prolong diversion when stoma retraction is a concern. Otherwise, ileostomy should be avoided for patients with impaired renal function. Wise selection and flexibility are more important than using one type of stoma routinely.

The impact of inflammatory markers on prognosis of stage II colon cancers depends on tumour sidedness.

BACKGROUNDS: Accumulating evidence has reported a high correlation between inflammatory markers and oncological outcomes in colorectal cancer. In the present study, we aimed to assess the prognostic values of five inflammatory markers in stage II colon cancer patients with different tumour locations. METHODS: The consecutive stage II colon adenocarcinoma patients undergoing curative resection were analysed retrospectively. ROC curves and the area under the curve (AUCs) via bootstrap method were used to analyse the prognostic impact of various inflammatory markers, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index (SII) and prognostic nutrition index (PNI). RESULTS: A total of 768 patients were enrolled for analysis. In univariate analysis, right-sided colon cancer (RCC) patients have significantly higher mean levels of all inflammatory markers than left-sided colon cancer (LCC) patients. In multivariate analyses, high NLR in LCC (P = 0.025) and low PNI in both RCC (P = 0.049) and LCC (P = 0.027) were significantly associated with a worse OS while none of the inflammatory markers was found to have a significant impact on DFS or CSS. CONCLUSIONS: The profiles and prognostic impact of inflammatory markers are significantly different between stage II RCC and LCC patients. Researchers should take sidedness into consideration when addressing survival analysis of inflammatory markers.

The clinical experience of the prognosis in opposite CEA and image change after therapy in stage IV colorectal cancer.

Carcinoembryonic antigen (CEA) levels and imaging are used to guide treatment for metastatic colorectal cancer (mCRC). This study evaluated changes in CEA and imaging findings in mCRC patients following systemic therapy and their clinical significance, especially the ones with inconsistent results of CEA and image findings. We enrolled 330 stage IV CRC patients who systemic therapy. Based on the Response Evaluation Criteria in Solid Tumors (RECIST) and a modification for CEA, patients were stratified into consistent and inconsistent response groups. Clinicopathological features and prognoses were compared between each groups. Different CEA/IMG groups showed no significant differences in terms of tumor location, initial CEA level, mucinous component, tumor differentiation and further surgical treatment rate. Inconsistent responses were observed in half of the patients (n = 165, 50%). The prognosis in the inconsistent groups with either CEA-SD or IMG-SD was dependent on the result of the other evaluation method (PR or PD). Cases with conflicting results between CEA and image groups (CEA-RD/IMG-PD, CEA-PD/IMG-PR) had an OS close to that of CEA-SD/IMG-SD (18.2 m, 16.2 m vs. 18.8 m, P = 0.620). The overall survival (OS) in the consistent (PR/PR ro PD/PD) groups were significantly different (P < 0.001). Combining CEA and imaging provides more information about mCRC patients who have undergone systemic therapy. Approximately half the patients have inconsistent responses, which is still valuable in predicting the prognosis.

Clinical outcome of local treatment and radical resection for pT1 rectal cancer.

BACKGROUND: Rectal cancer is mainly cured by radical resection with neoadjuvant chemoradiation or adjuvant chemotherapy. Pathological T1 lesions can be managed by local treatment and radiotherapy thereafter. Lower morbidity is the key benefit of these local treatments. Since nodal metastasis is important for staging, radical resection (RR) is suggested. Rectal cancer has higher surgical morbidity than colon cancer; local treatment has been the preferred choice by patients. METHODS: We retrospectively enrolled data of 244 patients with pT1 rectal adenocarcinoma. A total of 202 patients (82.8%) underwent RR, including low anterior resection (LAR) and abdomino-perineal resection (APR), and 42 patients (17.2%) underwent LT, including transanal excision and colonoscopic polypectomy. RESULTS: In our study, seven patients (16.7%) had loco-regional recurrence and distant metastasis from the LT group while eight patients (4.0%) had distant metastasis without loco-regional recurrence from the RR group. The lymph node metastasis rate in RR group was 8.4%. Forty-seven patients (24.2%) underwent LAR with temporary stoma, and its reversal rate was 100%. In the RR group, postoperative complication rate was 10.4% with a mortality rate of 0.5%. Recurrence-free survival (RFS) was 95.7% for RR and 80.2% for LT (P = 0.001), and overall survival (OS) was 93.7% for RR and 70.0% for LT (P = 0.001). CONCLUSION: This study found that RFS and OS in patients of pT1 rectal adenocarcinoma that had received RR were better than receiving LT. Further adjuvant chemotherapy was possible for some RR patients. A higher recurrence rate after LT must be balanced against the morbidity and mortality associated with RR.

Potential Values of Circulating microRNA-21 to Predict Early Recurrence in Patients with Colorectal Cancer after Treatments.

Insufficient prognosis of local recurrence contributes to the poor progression-free survival rate and death in colorectal cancer (CRC) patients. Various biomarkers have been explored in predicting CRC recurrence. This study investigated the expressions of plasma/exosomal microRNA-21 (miR-21) in 113 CRC patients by qPCR, their values of predicting CRC recurrence, and the possibility to improve the prognostic efficacy in early CRC recurrence in stratified patients by combined biomarkers including circulating miR-21s, circulating tumour cells/microemboli (CTCs/CTM), and serum carcinoembryonic antigen (CEA)/carbohydrate antigen 19-9 (CA19-9). Expressions of plasma and exosomal miR-21s were significantly correlated (p < 0.0001) in all and late-stage patients, presenting similar correlations with other biomarkers. However, stage IV patients stratified by a high level of exosomal miR-21 and stage I to III patients stratified by a high level of plasma miR-21 displayed significantly worse survival outcomes in predicting CRC recurrence, suggesting their different values to predict CRC recurrence in stratified patients. Comparable and even better performances in predicting CRC recurrence in late-stage patients were found by CTCs/CTM from our blood samples as sensitive biomarkers. Improved prognosing efficacy in CRC recurrence and better outcomes to significantly differentiate recurrence in stratified patients could be obtained by analysing combined biomarkers.

Prognostic value of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio on low-grade appendiceal mucinous neoplasm: A single tertiary hospital experience.

BACKGROUND: Low-grade appendiceal mucinous neoplasm (LAMN) is a rare disease, which prognostic factors were difficult to evaluate. Inflammation markers, like neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), were used as prognosticators for various cancers. This study aimed to investigate the prognostic value of pretreatment NLR and PLR on LAMN. METHODS: From January 2000 to September 2018, there were 57 patients diagnosed with LAMN in Taipei Veterans General Hospital. Patients diagnosed with mucinous cystadenoma, mucinous tumor with uncertain malignant potential before 2010 were also included based on previous classification. Clinical and pathological data were collected. Patients were separated into high-NLR (NLR-H) and low-NLR (NLR-L) groups according to cutoff value of 3. Similarly, they were separated into high-PLR (PLR-H), and low-PLR (PLR-L) groups with cutoff value of 300. Overall survival (OS) and recurrence-free survival (RFS) were analyzed. RESULTS: Among all patients, the median follow-up time was 42 months. Age, gender, clinical manifestations, type of surgery, and T stage were similar in different NLR and PLR groups. Both NLR-H and PLR-H groups had higher rate of M1 stage of diseases (22.7% vs 9.4%, p = 0.04; 57.1% vs 8.8%, p < 0.01, respectively). PLR-H group had more presence of pseudomyxoma peritonei (PMP) (57.1% vs 15.2%, p = 0.03). In univariate analysis, factors such as age, gender, tumor perforation, and operation did not have impact on OS nor RFS. On the other hand, M1b stage is the only significantly poor prognostic factor on RFS (hazard ratio, 57.96, 95% CI, 5.16-651.23, p < 0.01). CONCLUSION: Both NLR-H and PLR-H had more M1 stage of diseases, but they were not correlated to OS nor RFS. PLR-H group had higher rate of presence PMP. Nevertheless, patients with LAMN and cellular PMP (M1b stage) had a higher rate of recurrence, and other factors showed no statistical difference in OS nor RFS.

A Long-Term and Large-Scale Real-World Study in Taiwan: Efficacy of Target Therapy in Stage IV Colorectal Cancer.

This study expands the understanding of the role of target therapy in improving survival of patients with mCRC based on real-world study results. These data represent potential survival outcomes of Taiwanese patients with mCRC in clinical practice. CRC is the most commonly diagnosed cancer and the third leading cause of cancer-related death in Taiwan. The aim of this study was to evaluate the efficacy of target therapy in combination with chemotherapy for mCRC in Taiwan. This was a real-world, retrospective, observational study in patients diagnosed with mCRC (N=1583). A total of 792 patients received chemotherapy plus target therapy (anti-EGFR therapy, n=180; anti-VEGF therapy, n=612) and 791 patients who received chemotherapy alone. Overall survival (OS) and progression-free survival (PFS) were examined. For RAS wild-type patients, the median OS (mOS) was 34.3 months in the EGFR L (left-sided colon) group, 27.3 months in the VEGF L group, 18.4 months in VEGF R (right-sided colon) group, and 13.8 months in EGFR R group (P<0.001). Median PFS (mPFS) was 9.8 months in the EGFR L group, 8.9 months in the VEGF L group, 6.8 months in VEGF R group, and 5.8 months in EGFR R group. In patients with a RAS mutation, mOS was 25.4 months in the VEGF L group and 19.4 months in the VEGF R group (P=0.167). Judicious treatment allocation in Taiwanese patients with mCRC can result in an mOS of 34.3 months using cetuximab plus chemotherapy for left-sided tumors. An mOS of 48.5 months can be achieved using cetuximab plus chemotherapy in the neoadjuvant setting in mCRC patients with left-sided tumors. This study expands our understanding of the role of target therapy in improving survival of mCRC patients based on real-world study results.

Comparison of two-stage and three-stage surgery for obstructing left-sided colon cancer.

BACKGROUND: Whether the timing of stoma reversal after emergency diversion for obstructive left-sided colon cancer affects patient outcomes is unknown. Our study compared the short- and long-term outcomes of two- and three-stage operations for obstructive left-sided colon cancer. METHODS: Patients with obstructive left-sided colon cancer who underwent staged resection at a referral hospital between January 2002 and December 2015 were retrospectively identified. Patient demographics and outcomes were analysed and compared between the two groups. Statistical significance was set as p < 0.05. RESULTS: A total of 191 patients were reviewed. The overall complication rate was higher for two-stage surgery than for three-stage surgery (57.1% versus 36.0%, p < 0.01). Surgical site infection and/or wound dehiscence were the most common complications. Other complications, including anastomotic leakage, ileus, and bowel obstruction, were not significantly different between the two groups. The five-year overall survival and disease-free survival in stage II and III patients were comparable. CONCLUSION: Among patients with obstructive left-sided colon cancer who underwent staged resection, two-stage surgery was associated with a higher complication rate, especially for surgical site infection and/or wound dehiscence, which could be managed by local treatment. The timing of stoma reversal was not associated with survival differences in patients with stage II and III disease. However, issues such as the location of the tumour and diverting stoma, along with the need to resect other upper abdominal organs, should all be considered when deciding between two- and three-stage surgeries.

Three-dimensional versus conventional two-dimensional laparoscopic colectomy for colon cancer: A 3-year follow-up study.

Background: Three-dimensional (3D) laparoscopy was developed to overcome the drawbacks of two-dimensional (2D) laparoscopy, namely lack of depth perception. However, the benefit of 3D laparoscopy in colorectal surgery is inconclusive. Here, we compare the 3-year follow-up outcomes of 3D and 2D laparoscopic colectomy. Patients and Methods: A total of 91 consecutive patients who underwent either 3D or 2D laparoscopy colectomy from October 2015 to November 2017 by a single surgical team for colon cancer were enrolled. Data were collected from a prospectively constructed database, including clinico-pathological features and operative parameters. The pathological results, recurrence, survival and systemic treatment were collected from the Taiwan Cancer Database. Results: There were 47 patients in the 3D group and 44 in the 2D group. There were no significant differences in characteristics of patients, operation data, pathological results, complications, operative time, blood loss or the number of lymph node harvested between the two groups. In addition, disease-free survival and overall survival were equal between the two groups. Conclusions: This is the first long-term result of a 3D laparoscopic colectomy. In our 3-year follow-up, there was no difference in long-term outcomes between 2D and 3D laparoscopy for colorectal surgery in an experienced centre.

Preference criteria for regorafenib in treating refractory metastatic colorectal cancer are the small tumor burden, slow growth and poor/scanty spread.

Given the unclear preference criteria for regorafenib in treating refractory metastatic colorectal cancer (mCRC), this study aimed to construct an algorithm in selecting right patients for regorafenib. This was a multicenter retrospective cohort study. Patients with pathology confirmed mCRC and administered with regorafenib for > 3 weeks were enrolled. Patients with good response were defined to have progression-free survival (PFS) of ≥ 4 months. The Kaplan-Meier plot was used to analyze survival. A Cox proportional hazards model was used to analyze univariate and multivariate prognostic factors and was visualized using forest plot. A clustering heatmap was used to classify patients according to responses. The decision tree and nomogram were used to construct the approaching algorithm. A total of 613 patients was analyzed. The median PFS and overall survival (OS) were 2.7 and 10.6 months, respectively. The partial response and stable disease rate are 2.4% and 36.4%. The interval between metastasis (M1) and regorafenib, metastatic status (number, liver, and brain), and CEA level were independent prognostics factors of PFS that classifies patients into three groups: good, bad and modest-1/modest-2 group with PFS > = 4 months rates of 51%, 20%, 39% and 30%, respectively. Results were used to develop the decision tree and nomogram for approaching patients indicated with regorafenib. The preference criteria for regorafenib in treating patients with refractory mCRC are small tumor burden (CEA), slow growth (interval between metastasis and regorafenib) and poor/scanty spread (metastatic status: number and sites of metastasis): The 3S rules.TRIAL registration ClinicalTrials.gov Identifier: NCT03829852; Date of first registration (February 11, 2019).

The efficacy of anti-EGFR therapy in treating metastatic colorectal cancer differs between the middle/low rectum and the left-sided colon.

BACKGROUND: Clinically, metastatic rectal cancer has been considered a subset of left-sided colon cancer. However, heterogeneity has been proposed to exist between high and middle/low rectal cancers. We aimed to examine the efficacy of anti-epidermal growth factor receptor (EGFR) treatment for middle/low rectal and left-sided colon cancers. METHODS: This study enrolled 609 patients with metastatic colorectal cancer who were treated with anti-EGFR therapy. They were divided into groups based on primary tumour locations: the right-sided colon, the left-sided colon or the middle/low rectum. The efficacy of first-line and non-first-line anti-EGFR treatment was analysed. Genomic differences in colorectal cancer data from The Cancer Genome Atlas (TCGA) were investigated and visualised with OncoPrint and a clustered heatmap. RESULTS: On first-line anti-EGFR treatment, patients with middle/low rectal tumours had significantly lower progression-free survival, overall survival, and overall response rates (6.8 months, 27.8 months and 43%, respectively) than those with left-sided colon cancer (10.1 months, 38.3 months and 66%, respectively). Similar outcomes were also identified on non-first-line anti-EGFR treatment. In TCGA analysis, rectal tumours displayed genetic heterogeneity and shared features with both left- and right-sided colon cancer. CONCLUSIONS: Anti-EGFR treatment has lower efficacy in metastatic middle/low rectal cancer than in left-sided colon cancer.

Clinicopathological and Molecular Features of Patients with Early and Late Recurrence after Curative Surgery for Colorectal Cancer.

BACKGROUND: Few reports have investigated genetic alterations between patients with early and late recurrence following curative surgery for colorectal cancer (CRC). METHODS: A total of 1227 stage I-III CRC patients who underwent curative resection were included retrospectively. Among them, 236 patients had tumor recurrence: 139 had early (<2 years after surgery) and 97 had late (≥2 years after surgery) recurrence. Clinicopathological features and genetic alterations were compared between the two groups. RESULTS: Compared to those with late recurrence, patients with early recurrence were more likely to have advanced pathological node (N) categories; tumor, node, metastasis (TNM) stages; adjuvant chemotherapy treatment; liver metastases; APC mutations; and worse five-year overall survival rates. Patients with right-sided colon cancer were more likely to develop early recurrence than were those with left-sided colon cancer or rectal cancer. Regarding rectal cancer, patients with early recurrence were more likely to be at advanced pathological N categories and TNM stages than those with late recurrence. Multivariate analysis revealed old age, early recurrence, multiple-site recurrence, and BRAF and NRAS mutations to be independent prognostic factors. CONCLUSION: CRC patients with early recurrence have a worse OS rate and more APC mutations than those with late recurrence.

Effect of Primary Tumor Location on Postmetastasectomy Survival in Patients with Colorectal Cancer Liver Metastasis.

BACKGROUND: The effects of primary tumor location on colorectal liver metastasis (CRLM) and post-hepatic-metastasectomy overall survival (OS) are controversial. This study evaluated the difference in post-hepatic-metastasectomy OS among right-sided colon, left-sided colon, and rectal cancer groups. METHODS: In total, 381 patients who underwent curative-intent CRLM resection were enrolled. Patients were grouped based on the primary tumor location (right-sided, left-sided, and rectum). The Kaplan-Meier analysis and log-rank test were performed for survival analysis. The univariate and multivariate analyses of clinical and pathological factors were performed using the Cox proportional hazards model. RESULTS: Significant OS difference was noted among the three groups (log-rank, p = 0.014). The multivariate analysis revealed a 32% lower death risk in left-sided colon cancer compared with right-sided colon cancer (hazard ratio [HR] 0.68, p = 0.042), whereas no OS difference was noted between the rectal cancer and right-sided colon cancer groups. The left- versus right-sided OS advantage was noted only in the KRAS wild-type subgroup (HR 0.46, p = 0.002), and a rectal versus right-sided OS disadvantage was noted in the KRAS mutant subgroup (HR 1.78, p = 0.03). CONCLUSIONS: The CRLM post-hepatic-metastasectomy OS was superior in left-sided colon cancer than in right-sided colon cancer and was similar in rectal and right-sided colon cancer. The OS difference in different primary tumor locations is dependent on KRAS mutation status, with a decreased left- versus right-sided death risk noted only in KRAS wild-type colon cancer and an increased rectal versus right-sided death risk noted only in KRAS mutant colon cancer.

An early experience with the Senhance surgical robotic system in colorectal surgery: a single-institute study.

BACKGROUND: We present our initial single-centre experience with Senhance surgical robot-assisted colorectal surgery and examine its safety and feasibility. METHODS: From June 2019 to December 2019, patients who underwent Senhance surgical robot-assisted colorectal surgery in our hospital were retrospectively analysed. We focused on the short-term outcomes. RESULTS: In total, 46 patients were enrolled in the study. Colorectal cancer was the most common indication for surgery (39 patients). The median total operation time was 283 min, and the median blood loss was 50 cc. Meanwhile, the median number of harvested lymph nodes was 20. Elderly age, advanced American Society of Anaesthesiologists stage, and right-sided colon surgery were associated with the occurrence of complications greater than grade III. CONCLUSION: Our findings demonstrate the feasibility and safety of the Senhance surgical robotic system in colorectal surgery. Care should be taken regarding the indications and patient selection.

Planned Short-Course Radiation (scRT) is Superior to Upfront Concurrent Chemoradiation (CCRT) in Treating Metastatic Rectal Cancer.

BACKGROUND OR PURPOSE: To compare the cost-performance between planned short-course radiation and upfront concurrent chemoradiation on metastatic rectal cancer. METHODS: A total of 75 patients with metastatic rectal cancer who underwent planned short-course radiation or upfront concurrent chemoradiation were enrolled. The Kaplan-Meier method was used to compute the survival rates. The χ2 test was used to compare baseline characteristics. The Cox proportional hazards model was applied to determine the prognostic influence of clinicopathological factors. RESULTS: The planned short-course radiation is superior to upfront concurrent chemoradiation in overall survival for the patients with metastatic rectal cancer (34.8 vs. 20.2 months, P = 0.010). The planned short-course radiation was an independent prognostic factor (P = 0.009, HR (95% CI) = 0.319(0.135-0.752)). The efficacy of radiation on downstaging was similar between planned short-course radiation and upfront concurrent chemoradiation. The total cost of concurrent chemoradiation is 4.52-fold more expensive than that of short-course radiation (340,142 vs. 75,106 NT dollars, respectively). CONCLUSIONS: Based on the impressive cost-performance of planned short-course radiation compared with upfront concurrent chemoradiation (better OS, modest downstaging and lower cost), planned short-course radiation should be the preferred radiation approach for managing metastatic rectal cancer.