Approximately 10% of colorectal cancer (CRC) cases occur in the context of hereditary cancer-predisposing conditions caused by germline pathogenic variants (PVs) in cancer predisposition genes, with Lynch syndrome and familial adenomatous polyposis at the top of the list. Although the identification of hereditary CRC has traditionally relied on clinical characteristics, including familial accumulation, multiple and early onset of CRC and other related cancers, and the presence of gastrointestinal polyposis, more comprehensive approaches, such as universal tumor screening and universal germline testing, have recently been employed. From a technical standpoint, next-generation sequencing has enabled genome-wide analysis of genetic alterations in germline and somatic settings. Taking advantage of this technology, germline multigene panel testing has been utilized in genetic testing, which leads to the identification of PVs, not only in well-known hereditary CRC genes but also in rare causal genes, moderate-risk genes, and high-risk genes previously not linked to CRC predisposition. In addition, comprehensive genomic profiling and companion diagnostics for solid tumors occasionally yield unexpected hereditary CRC diagnoses. Thus, more hereditary CRCs have been identified not based on clinical phenotypes but rather by comprehensive approaches or as secondary findings of treatment drug testing. In this review, we discuss the impact of recent advances in genomic medicine on the clinical aspects of hereditary CRC, which has promoted an understanding of the entire landscape of genetic predisposition to CRC.

Hemorrhoids manifest with a range of symptoms and severities, prompting the development of various conservative, interventional, and surgical treatments. Selecting the most suitable treatment for each case is challenging, especially with the continuous evolution of new methods. This review aims to advance hemorrhoid treatment and research by exploring recent developments over the last five years. Conservative approaches have focused on isolating active ingredients from traditional herbal remedies to create new products and understand their mechanisms. In office-based treatments, advanced devices such as modified rubber band ligation and polymer clips with stronger binding forces have been introduced. Polidocanol in foam form has shown promise in sclerotherapy, while infrared coagulation is being replaced by alternative energy-based methods. Additionally, endoscopic office treatments and embolization of hemorrhoidal vessels via angiography are increasingly used as safer options for patients with high surgical risks or bleeding issues. Stapled hemorrhoidopexy has shifted to partial resection instead of complete circular resection, and hemorrhoidal artery ligation techniques have been reported to be effective when combined with stapled hemorrhoidopexy or excisional hemorrhoidectomy in severe cases. Evidence is growing that hemorrhoidal artery ligation remains effective even without Doppler guidance. With ongoing research into various methods, there is a need for scientific comparison and evaluation of their advantages and disadvantages, standardization of indicators and treatment protocols, and cost-effectiveness considerations. Surgeons should offer well-informed options and explanations to patients, based on a comprehensive understanding of available treatments.

Objectives: Recently, several simple inflammation-based prognostic scores that can be calculated easily from serum parameters, have been reported to be related to colorectal cancer prognosis. This study aimed to investigate factors influencing the prognosis of patients, including inflammation-based prognostic scores, with stage I-III colorectal cancer following curative resection.

Methods: This single-center study included 608 patients with stage I-III colorectal cancer who underwent curative resection between April 2010 and December 2018. A retrospective analysis was performed to identify the prognosis-associated variables in these patients. As a multi-center study, the Hiroshima Surgical study Group of Clinical Oncology database was used to analyze 1659 patients with stage I-III colorectal cancer who underwent curative resection to confirm the results of our single-center study.

Results: Of the inflammation-based prognostic scores, only preoperative C-reactive protein-albumin-lymphocyte index was revealed to predict a poor prognosis in patients with stage I-III colorectal cancer following curative resection. The low C-reactive protein-albumin-lymphocyte index was associated with poor overall survival and recurrence-free survival, which was similar in patients from multi-center database. The C-reactive protein-albumin-lymphocyte index was found to be associated with patient age, systemic condition, comorbidities, and tumor factors. The time-dependent area under the curve for the postoperative proghosis of the C-reactive protein-albumin-lymphocyte index was superior to those of other inflammation-based prognostic scores in most postoperative observation periods.

Conclusions: The preoperative C-reactive protein-albumin-lymphocyte index was independently associated with long-term prognosis in patients with stage I-III colorectal cancer following curative resection.

Objectives: Predicting the response to chemotherapy can lead to the optimization of neoadjuvant chemotherapy (NAC). The present study aimed to develop a non-invasive prediction model of therapeutic response to NAC for rectal cancer (RC).

Methods: A dataset of the prechemotherapy computed tomography (CT) images of 57 patients from multiple institutions who underwent rectal surgery after three courses of S-1 and oxaliplatin (SOX) NAC for RC was collected. The therapeutic response to NAC was pathologically confirmed. It was then predicted whether they were pathologic responders or non-responders. Cases were divided into training, validation and test datasets. A CT patch-based predictive model was developed using a residual convolutional neural network and the predictive performance was evaluated. Binary logistic regression analysis of prechemotherapy clinical factors showed that none of the independent variables were significantly associated with the non-responders.

Results: Among the 49 patients in the training and validation datasets, there were 21 (42.9%) and 28 (57.1%) responders and non-responders, respectively. A total of 3,857 patches were extracted from the 49 patients. In the validation dataset, the average sensitivity, specificity and accuracy was 97.3, 95.7 and 96.8%, respectively. Furthermore, the area under the receiver operating characteristic curve (AUC) was 0.994 (95% CI, 0.991-0.997; P<0.001). In the test dataset, which included 750 patches from 8 patients, the predictive model demonstrated high specificity (89.9%) and the AUC was 0.846 (95% CI, 0.817-0.875; P<0.001).

Conclusions: The non-invasive deep learning model using prechemotherapy CT images exhibited high predictive performance in predicting the pathological therapeutic response to SOX NAC.

Objectives: Conservative treatment for hemorrhoids may be long-term, but there are only a few studies that have reported on the long-term use of corticosteroid-containing preparations. Therefore, the aim of this study was to conduct a clinical investigation into the long-term use and safety of Killed Escherichia coli suspension-hydrocortisone combination ointment for the treatment of hemorrhoids.

Methods: A review of 578 hemorrhoid patients who experienced an adverse reaction to Killed Escherichia coli suspension-hydrocortisone combination ointment at Coloproctology Center Takano Hospital between June 2019 and December 2019 was conducted.

Results: Of the 578 patients included in the analysis, 430 patients (74.4%) had internal hemorrhoids and the median duration from the date of initial diagnosis was 0.70 months. The median prescription period of patients treated with Killed Escherichia coli suspension-hydrocortisone combination ointment was 20 days, and no adverse reactions were observed. When the prescription period of patients treated with Killed Escherichia coli suspension-hydrocortisone combination ointment was categorized into a within 30-day period (n=332), a 31-90-day period (n=63), and a ≥91-day period (n=23), the median disease duration at initial diagnosis was 0.46 months, 1.00 months, and 8.00 months, respectively. These findings indicate that the prescription period tended to be longer as the disease duration increased.

Conclusions: In this study, the onset of adverse reactions to the use of Killed Escherichia coli suspension-hydrocortisone combination ointment in the treatment of hemorrhoids could not be confirmed. Further studies to investigate the safety of the long-term use of this treatment needs to be conducted.

Objectives: Cholinesterase is recognized as a marker for nutritional status and associated with inflammatory conditions. The present study aims to evaluate the association between cholinesterase and postoperative complications in patients with lower gastrointestinal perforation.

Methods: The study included 71 patients who had undergone emergency surgery for lower gastrointestinal perforation. We retrospectively investigated the relationship between preoperative serum cholinesterase levels and postoperative complications. Complications were defined as Clavien-Dindo (C-D) grade II or higher, with severe complications classified as C-D grade III-V. We performed univariate and multivariate analyses to evaluate independent risk factors for postoperative complications.

Results: Among of all, 43 patients (61%) developed postoperative all complications (C-D ≥ II), and 17 patients (24%) developed severe complications (C-D ≥ III-V). In multivariate analysis, cholinesterase (p=0.006), C-reactive protein (p=0.028), and blood loss (p=0.028) were independent risk factors for postoperative all complications (C-D ≥ II). Also, cholinesterase (p=0.006) was an independent risk factors for postoperative severe complication (C-D ≥ III- V). Patients in the cholinesterase-low group had significantly lower preoperative hemoglobin (p=0.001), albumin (p<0.001), and prognostic nutritional index (p<0.001), as well as higher C-reactive protein (p=0.010), neutrophil-lymphocyte ratio (p=0.038), proportion of wound infection (30% vs. 4.8%, p=0.026) and abdominal abscess (30% vs. 0.0%, p=0.003) compared to those in the cholinesterase-high group.

Conclusions: Preoperative serum cholinesterase levels may be associated with postoperative severe course in patients with lower gastrointestinal perforation. This association underscores the potential role of cholinesterase as an indicator of nutritional and inflammatory status.

Objectives: Complete resection of advanced rectal cancer is challenging, with local recurrence rates ranging from 4% to 12%. Local recurrence is often categorized as central, anastomotic, or lateral, with lateral lymph node (LLN) metastasis being the primary driver of lateral recurrence. Although preoperative radiotherapy effectively manages nonlateral recurrences, it is less effective for lateral recurrences, and LLN dissection significantly reduces lateral recurrence rates. This study aimed to clarify the clinicopathological characteristics associated with lateral and nonlateral recurrences.

Methods: We retrospectively analyzed 232 patients (156 males and 76 females; median age, 64 years) who underwent preoperative radiotherapy followed by curative-intent surgery for clinical T3/4 rectal adenocarcinoma located below the peritoneal reflection between April 2010 and December 2017. In total, 40% of the patients underwent LLN dissection. Univariate and multivariate analyses of clinicopathological data were performed to identify the independent risk factors for lateral and nonlateral recurrences.

Results: Local recurrence occurred in 19 (8%) patients: 7 had lateral recurrence, 13 had nonlateral recurrence, and 1 had both. Multivariate analysis identified mesorectal lymph node metastasis as a significant risk factor for lateral recurrence, whereas positive circumferential resection margin was a significant risk factor for nonlateral recurrence.

Conclusions: The identification of different risk factors for lateral and nonlateral recurrence suggests that lateral recurrence is more strongly associated with lymphatic permeation than nonlateral recurrence. These findings highlight the importance of LLN dissection in minimizing the risk of lateral recurrence.

Objectives: This retrospective study was conducted to elucidate the impact of intraoperative redosing of antibiotics (IRA) on the incidence of surgical site infection (SSI) in elective colorectal surgery.

Methods: The study involved 61 patient pairs matched 1:1 from among 200 patients who, between April 2019 and December 2020, underwent elective surgery of 180 minutes or longer for colorectal cancer either with or without IRA at our hospital. The incidence of SSI, length of stay after surgery, readmission rate, and reoperation rate were compared between the two groups.

Results: No significant between-group difference was found in patient or tumor characteristics or in operative factors. Further, no significant between-group difference was found in the incidence of SSI (with IRA vs. without IRA: 4.9% vs. 4.9%, p=1.000), length of stay after surgery (median 15 [IQR 11-21] days vs. 13 [10-23] days; p=0.302), or reoperation rate (3.3% vs. 0%, p=0.154). No patients in either group were readmitted.

Conclusions: The incidence of SSI, length of stay after surgery, and reoperation rate of the without IRA group were comparable to those of the with IRA group in elective surgery of 180 minutes or longer for colorectal cancer.

Objectives: The Sumikoshi classification for anal fistulas is widely used in Japan; however, it does not include a category for transsphincteric fistulas. Therefore, low transsphincteric fistulas were included in type IIL (low intersphincteric) for convenience; however, high transsphincteric fistulas have not been properly classified. We defined high transsphincteric fistulas as type IIT and investigated their prevalence and clinical characteristics.

Methods: Consecutive patients who underwent fistula surgery at our hospital were included. The operative and endoanal ultrasonography records were retrospectively reviewed, and the following cases were reclassified as type IIT: cases documented as transsphincteric fistulas or cases with written records and/or illustrations indicating that the fistula tract penetrated the upper two-thirds of the external anal sphincter.

Results: Of the 1,069 eligible patients, 895 (83.7%) had type II (intersphincteric) fistulas. Among the type II subtypes, type IIL was the most common with 771 (86.1%) patients, whereas type IIT accounted for 54 (6.0%) patients. The direction of the primary opening was more posterior (62.2%) in patients with type II fistulas other than type IIT, but it was more anterolateral (55.6%) in patients with type IIT fistulas. Patients with type IIT fistulas were more likely to undergo sphincter-sparing surgery than patients with other type II fistulas (37.0 vs. 3.7%, p<0.001).

Conclusions: Type IIT is not rare (6.0%) and should be treated as a complex fistula because of the greater involvement of the external anal sphincter. Surgeons may benefit by including type IIT as a new type II subclass in the Sumikoshi classification system.

Objectives: Several procedures are available for treating rectal prolapse (RP). This study aimed to determine the effectiveness of the Gant-Miwa-Thiersch (GMT) procedure using the Leeds-Keio mesh (LKM) as a treatment for RP.

Methods: This retrospective observational study included all patients with RP who underwent the GMT procedure using the LKM at our hospital between January 2012 and December 2023. The surgery was performed under local or lumbar spinal anesthesia in the jackknife position. The outcome measures included perioperative complications, recurrence rate, and improvement in anal function.

Results: During the study period, 107 patients with RP underwent the GMT procedure. The median patient age was 81 years, the median length of prolapse was 7 cm, and the median duration of the surgery was 39 minutes. Postoperative complications were observed in 26 (24.3%) patients, including constipation in 21, mesh early exposure in three, mesh infection in one, and bleeding in one patient(s). The median observation period was 29 months, and recurrence of RP was observed in nine (10%) out of 90 patients evaluated for recurrence, with a cumulative 5-year recurrence rate of 10.9%. Of the 65 patients with preoperative fecal incontinence, 33 (50.8%) demonstrated improvement postoperatively.

Conclusions: The GMT procedure using the LKM has a low recurrence rate. The LKM is suitable as a prosthetic material for the Thiersch procedure due to its high elasticity, which can enhance the therapeutic efficacy of the GMT procedure.

Objectives: In surgery for lower rectal cancer, temporary ileostomy can be created to avoid complications, such as anastomotic leakage. However, various complications may occur with the stoma, including stoma outlet obstruction (SOO). The occurrence of SOO can prolong the length of hospital stay and delay the introduction of adjuvant chemotherapy, which can negatively affect the prognosis. We retrospectively reviewed cases of temporary ileostomy at our hospital and evaluated the risk factors for SOO.

Methods: We extracted data pertaining to patients with temporary ileostomy created during surgery for rectal cancer from 2013 to 2023, and compared clinicopathologic factors or short-term outcomes, with or without SOO complications. We scored the independent factors obtained and created predictive scoring model for SOO.

Results: Total of 107 patients were included. SOO was observed in 21 patients (19.6%), all of whom were male. SOO was most frequently diagnosed on sixth postoperative day. In most cases, feeding resumed 4 days after the diagnosis of SOO. Age (≥67 years; p = 0.002), rectus abdominis muscle thickness (≥13.5 mm; p < 0.001) and the amount of stoma output greater than 1,500 ml/day within 3 days of surgery (p < 0.001) were independent risk factors for SOO. The preoperative and early postoperative predictive scoring model, created by adding one point to each risk factor, predicted SOO with sensitivity of 76.2%, specificity of 89.5%.

Conclusions: Age, gender, rectus abdominis muscle thickness, and high early postoperative output are risk factors for SOO. A scoring model may be useful for predicting SOO.

The etiology of eosinophilic myenteric ganglionitis (EMG) remains unclear. We present the case of a 62-year-old man who underwent right hemicolectomy with ileostomy and transverse colon mucous fistula due to ascending colon perforation. Pathological examination revealed severe eosinophilic infiltration in Auerbach's plexus and fibrosis extending from the external longitudinal muscle layer to the subserosal layer, suggesting that the perforation resulted from pseudo-obstruction and EMG-related increased intestinal pressure. Eosinophilic infiltration was observed not only near the perforation site but throughout the entire length of the resected intestine. Four months postoperatively, the patient underwent ileostomy closure, during which the ileal and colonic tracts left external to the wound were resected. Notably, no eosinophilic infiltration in Auerbach's plexus was found in the new specimen, unlike that in the previous surgical specimen, despite the patient receiving no postoperative medication. The patient has remained symptom-free for over 2 years. This is the first report to document histological time-course changes in eosinophil infiltration in Auerbach's plexus and demonstrate the efficacy of surgical treatment in a patient with EMG.

We report a rare case of an ano-Bartholin's gland fistula caused by an anal fistula in a patient without Crohn's disease (CD). A 34-year-old woman was admitted to our hospital due to purulent anal discharge and left vulvar pain. She had experienced several Bartholinitis in the past 2 years. She had no history of inflammatory bowel disease or other relevant conditions. A transanal ultrasound scan and pelvic magnetic resonance imaging showed a transsphincteric anal fistula connecting to an ano-Bartholin's gland abscess in the left vulva. Surgical findings showed that the primary opening of the anal fistula was located between the dentate line and anal verge. The fistula was treated with a sphincter-preserving subcutaneous incision of the fistula tract and internal sphincterotomy, and the Bartholin's gland abscess was effectively managed with drainage alone without excision. The postoperative recovery was successful, with no disturbance in defecation or sexual function. Although complex anal fistulas involving the female genital organs sometimes occur in patients with CD, they are exceedingly rare in patients without CD. This case shows that such fistulas can be managed with targeted anal fistula procedures with minimal invasion of the perineal area.