Despite a trend showing continued improvement in survival by combing targeted agents in colorectal cancer, the improvement was limited, and clinically meaningful benefits were not achieved in peritoneal metastasis. The role of cytoreductive surgery (CRS) and proportion of the benefit from hyperthermic intraperitoneal chemotherapy (HIPEC) have been questioned. The PRODIGE 7 study aimed to assess the specific contribution of HIPEC to the survival benefit of peritoneal metastasis from colorectal cancer (CRC-PM) by grouping CRS alone versus CRS with oxaliplatin-based HIPEC, but failed to show any survival improvement. Of these criticisms, oxaliplatin resistance was suggested as the main cause of the negative result. In this regard, the relative resistance to oxaliplatin in consensus molecular subtype 4 colorectal cancer (CRC) is of great interest. Recent treatments for metastatic CRC have gradually moved to precision medicine based on individual biological information through high-throughput technology such as next generation sequencing. This review aimed to provide an overview of the current status of studies reporting the molecular knowledge of CRC-PM.

Treatment for early colon cancer has progressed rapidly, with endoscopic resection and minimally invasive surgery. It is important to select patients without risk of lymph node metastasis before deciding on endoscopic resection for early colon cancer treatment. Pathological risk factors include histologic grade of cancer cell differentiation, lymphovascular invasion, perineural invasion, tumor budding, and deep submucosal invasion. These risk factors for predicting lymph node metastasis are crucial for determining the treatment strategy of endoscopic excision and radical resection for early colon cancer. A multidisciplinary approach is emphasized to establish a treatment strategy for early colon cancer to minimize the risk of complications and obtain excellent oncologic outcomes by selecting an appropriate treatment optimized for the patient's stage and condition. Therefore, we aimed to review the optimal multidisciplinary treatment strategies, including endoscopy and surgery, for early colon cancer.

Stage IV colorectal cancer (CRC) has heterogeneous characteristics in tumor extent and biology. The overall survival of patients with metastatic CRC has improved with the development of multimodal treatments and new chemotherapeutic drugs. Resection of metastatic CRC is performed for liver, lung, or peritoneal metastases. Conversion surgeries to resect oligometastatic lesions have been developed with tumor regression using chemotherapeutic agents. Two-stage hepatectomy has extended the surgical indications for patients with metastatic CRC. Synchronous liver and primary tumor resection can be considered in patients with adequate conditions. Local ablation with radiotherapy can be used to treat lung metastasis. In the treatment of patients with CRC with peritoneal metastasis, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy can be considered. Surgical treatments should be performed in patients with symptomatic primary tumors with unresectable metastasis. However, primary tumor resection in patients with asymptomatic CRC with synchronous, unresectable metastases did not show overall survival benefits in recent studies. Therefore, the treatment of metastatic CRC is challenging due to the variable tumor extent and heterogenous characteristics. Tailored surgical treatments and multidisciplinary approaches may improve survival and the quality of life in patients with metastatic CRC.

Robotic surgical systems were created in part to solve several constraints of laparoscopic surgery and offer technical advantages. With a substantial body of evidence that demonstrates its efficacy in the treatment of rectal cancer, robotic surgery will soon become another conventional treatment. However, further investigations and randomized trials focusing on primary endpoints are needed to establish some advantages for robot-assisted colon surgery. Da Vinci Single-Site^® and SP^® platforms were developed to overcome the shortcomings of single-port laparoscopic surgery. Despite the currently insufficient evidence, it appears that the SP platform addresses many of the limitations of single-port transabdominal or transanal surgery. Robotic transanal minimally invasive surgery and total mesorectal excision were developed to overcome some of the limitations of conventional platforms, using wristed instrumentation to enhance dexterity and ergonomics. Studies on the effectiveness and viability of this novel approach are ongoing. The near-infrared fluorescence technique, real-time stereotactic navigation technology, and other surgical data platforms based on artificial intelligence incorporated into the robotic system will play an important role in improving outcomes. Robotic systems for advanced colorectal cancer offer technical advantages for complex and precise surgeries. If the cost of robotic surgery is reduced by expanding its indications and enhancing competition among different robotic platforms, it will provide clinical benefits to more patients and reduce social healthcare costs.

Colorectal cancer (CRC) is the fourth most common malignancy in Korea and has been ranked as the third leading cause of cancer deaths in 2020. Although the incidence and mortality rates of CRC have decreased in recent years in Korea, it is still a significant public health burden. From the early 1990s until the mid-2000s, the 5-year relative survival of patients with CRC in Korea continuously increased. This finding appears to be a consequence of the successful introduction of a government-led screening program; the development of improved surgical techniques, anticancer drugs, and adjuvant treatment; and the advancement of medical resources and infrastructure along with economic growth. However, the improvement in survival has stagnated since the late 2000s. The recent coronavirus disease 2019 outbreak led to a reduction in hospital visits and screenings, which is expected to cause a stage shift to advanced disease stages and a worse prognosis for patients with CRC. Exploring modifiable environmental risk factors and appropriate screening test methods in Korea is necessary to overcome these challenges. Primary prevention through risk factor mediation and secondary prevention using suitable screening programs can help reduce the incidence and mortality rates of CRC.

Objectives: Few studies have compared the tumor-site-based postoperative short-term outcomes of a bridge to surgery using self-expandable metallic stents. This study compared the perioperative outcomes following stent placement between right- and left-sided obstructive colorectal cancers, focusing on patients undergoing laparoscopic surgery.

Methods: This study included 127 patients with stage I-IV obstructive colorectal cancer (right-sided, n = 25 [19.7%]; left-sided, n = 102 [80.3%]) who underwent laparoscopic-assisted surgery following stent placement between May 2012 and September 2021. We compared the postoperative complication rates and the success rates of stent placement.

Results: The clinical success rate was not significantly different (92% vs. 97.1%, P = 0.254). The rates of all-grade complications (36% vs. 16.7%, P = 0.05) and postoperative ileus or small-bowel obstruction (20% vs. 2%, P = 0.003) were significantly higher in the right-sided group. The rates of the Clavien-Dindo classification ≥ III complications (8% vs. 6.9%, P = 1) and the median durations of postoperative hospital stay (8 days vs. 8 days, P = 1) were not significantly different. On multivariate analysis, right-sided colon cancer was an independent risk factor for postoperative ileus or small-bowel obstruction (odds ratio [OR]: 16.5, 95% confidence interval [CI]: 2.42-112, P = 0.004) but not for all grades of complications (OR: 2.63, 95% CI: 0.976-7.09, P = 0.056).

Conclusions: Although the rates of clinical success, postoperative Clavien-Dindo classification ≥ III severe complications, and postoperative hospital stay were comparable, the bridge to surgery following stent placement for right-sided obstructive colon cancer raises concerns about ileus or small-bowel obstruction.

Objectives: Adjuvant chemotherapy for stage II colorectal cancer patients with high-risk factors for recurrence can be useful; however, its advantage in prognosis remains to be controversial. Thus, in this study, we aimed to assess whether a combination of preoperative serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels can predict the prognosis and advantage of adjuvant chemotherapy.

Methods: Using a Japanese nationwide database, in total, 3,688 patients with curative resected stage II colorectal cancer were registered retrospectively between 2008 and 2012 in 24 referral institutions. Patients were classified into three groups as follows: Group A (both non-high levels of CEA and CA19-9), Group B (either high levels of CEA or CA19-9), and Group C (both high levels of CEA and CA19-9).

Results: Multivariable Cox regression analysis, adjusting the depth of tumor invasion, number of dissected lymph nodes, tumor differentiation, lymphatic and venous invasion, and other covariates, showed that the 5-year disease-free survival and overall survival were shorter in Group C than in Groups A and B. Furthermore, in Group C, the 5-year disease-free survival rate was improved in the surgery-plus-AC group compared to the surgery-alone group.

Conclusions: As with existing high-risk factors for recurrence, the combination assessment of preoperative serum CEA and CA19-9 can predict the prognosis for colorectal cancer. Adjuvant chemotherapy may provide a prolonged disease-free survival advantage in stage II colorectal cancer patients with high levels of both tumor markers.

Objectives: Acute appendicitis is a common disease that often requires emergency surgery. However, recently, not all cases are treated as an urgent operation, but surgery may be delayed to when medical resources are abundant to perform the operation safely. In such cases, preoperative antibiotics are administered during the waiting period. Though the choice is empiric, an appropriate choice is needed to avoid emergency surgery. Guidelines for the choice of antibiotics recognized as international standards cannot be applied in Asia due to the high rate of extended-spectrum β-lactamase (ESBL) producers or fluoroquinolone-resistant Escherichia coli. The purpose of this study was to determine the optimal antibiotic during the in-hospital waiting period for patients with appendicitis scheduled for surgery.

Methods: Bacterial culture results and antibiotic susceptibility were retrospectively examined in 106 cases who underwent surgery for appendicitis.

Results: Bacterial cultures were positive in 53 cases (50%). Twenty-six strains of E. coli were identified. Of these, four (15%) were ESBL producers, and seven (27%) were fluoroquinolone resistant. Twenty-two strains of anaerobic bacteria were identified. Carbapenems and tazobactam/piperacillin were effective for all. The rates of susceptibility to clindamycin (CLDM) and cefmetazole (CMZ) were 59% and 82%, respectively.

Conclusions: In Japan, from the point of view of reducing carbapenem use, CMZ must be considered a first-choice drug during the in-hospital waiting period for appendectomy.

Objectives: We evaluated the prognostic impact of a novel C-reactive protein (CRP) cut-off value (0.6 mg/dl) and carcinoembryonic antigen (CEA) /carbohydrate antigen 19-9 (CA19-9) in stage II/III colorectal cancer.

Methods: Four hundred ninety-eight patients with stage II (n = 275) or stage III (n = 223) colorectal cancer, surgically treated between January 2010 and December 2016, were analyzed. The optimal CRP cut-off value was fixed at 0.6 mg/dl to predict recurrence based on the receiver operating characteristic curve. Prognostic factors, including CRP/CEA/CA19-9 status, for relapse-free survival (RFS) were evaluated by multivariate analysis.

Results: Recurrent rates were 15% and 32% in stages II and III, respectively. In stage II, CRP, CEA, and CA19-9 were not significant prognostic factors for RFS. In stage III, the RFS of the low CRP group was significantly better than that of the high CRP group (p = 0.002). In stage III, the RFS of CRP (−) /CEA (−) or CRP (−) /CA19-9 (−) was significantly better than the other group, as opposed to the RFS of the CEA (−) /CA19-9 (−) group that was not. The CRP (−) /CEA (−) /CA19-9 (−) group recurrence rate in stage III was significantly better than the CRP (+) /CEA (−) /CA19-9 (−) group (20% vs. 50%, p = 0.006). Multivariate analysis revealed that CRP (−) /CEA (−) /CA19-9 (−) (p = 0.04) and non-T4 (p < 0.001) were good independent prognostic factors in stage III. The CRP (−) /CEA (−) /CA19-9 (−) /non-T4 group recurrence rate in stage III was 11% (8 out of 73).

Conclusions: In stage III, the CRP (−) /CEA (−) /CA19-9 (−) /non-T4 group is favorable risk for recurrence.

Objectives: Although community studies have shown no difference between the sexes in the prevalence of fecal incontinence (FI), few direct comparisons of disease characteristics between male and female patients have been reported. The aim of this study was to determine whether characteristics of FI differ between male and female patients in Japan.

Methods: Included in the study were 408 (149 men, 259 women) patients with FI who visited the Matsushima Hospital Coloproctology Center between October 2016 and September 2017. We retrospectively evaluated data on age, number of bowel movements, Bristol stool form scale, number of FI, incontinence scores, anorectal manometry, comorbidities, and history of anal surgery.

Results: Maximum resting pressure and maximum squeeze pressure were found to be within normal range in significantly more male than female patients (34.9% vs. 12.4%, respectively; p < 0.0001). Irritable bowel syndrome (IBS, 20.1% vs. 9.3%; p = 0.003) and a history of anal surgery (29.5% vs. 17.5%; p = 0.02) were more prevalent among male patients than among female patients. Use of mepenzolate as treatment was significantly more common among male patients than among female patients (16.8% vs. 6.6%, respectively; p = 0.005). Responses to the various treatments were good, regardless of sex.

Conclusions: FI appears to be more commonly accompanied by normal anal sphincter pressures in male patients than in female patients, and IBS and previous anal surgery appear to be more common among male patients than among female patients. FI appears to be controllable in most patients, regardless of sex.

Objectives: Recently, a newly designed short-type single-balloon enteroscope (SBE), SIF-H290S, has been developed with a smaller outer diameter and a longer working length than conventional colonoscopes. It has passive bending and high-force transmission, making insertion easier. However, it is difficult to perform rescue colonoscopy with an SBE after incomplete colonoscopy in the same session. Therefore, this study evaluated the feasibility of consecutive rescue colonoscopy using SIF-H290S without overtube after incomplete colonoscopy.

Methods: This was a single-center retrospective study. We included 19 rescue colonoscopies (19 patients) with SIF-H290S without overtube performed by 11 endoscopists in the SIF group and 38 rescue colonoscopies (38 patients) using a small-caliber colonoscope (PCF-PQ260L) were randomly selected for the control group from procedures performed by the same 11 endoscopists. We compared the cecal intubation rate and other outcomes, such as insertion time, between the two groups.

Results: The median age of the patients was 72 and 69 years, with 8 and 26 males in the SIF and control groups, respectively. The median body mass index was 21.6 and 22.7 kg/m² in the SIF and control groups, respectively. There were no significant differences in the patient backgrounds between the groups, except for the reason for incomplete colonoscopy (p = 0.048). The cecal intubation rate was 78.9% (15/19 procedures) and 92.1% (35/38 procedures) in the SIF and control groups, respectively.

Conclusions: This study revealed the real-world experience and feasibility of rescue colonoscopy using SIF-H290S, which could be a potential rescue device option after incomplete colonoscopy.