Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment.

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients' values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Diagnostic performance of a deep-learning model using 18F-FDG PET/CT for evaluating recurrence after radiation therapy in patients with lung cancer.

OBJECTIVE: We developed a deep learning model for distinguishing radiation therapy (RT)-related changes and tumour recurrence in patients with lung cancer who underwent RT, and evaluated its performance. METHODS: We retrospectively recruited 308 patients with lung cancer with RT-related changes observed on 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) performed after RT. Patients were labelled as positive or negative for tumour recurrence through histologic diagnosis or clinical follow-up after 18F-FDG PET/CT. A two-dimensional (2D) slice-based convolutional neural network (CNN) model was created with a total of 3329 slices as input, and performance was evaluated with five independent test sets. RESULTS: For the five independent test sets, the area under the curve (AUC) of the receiver operating characteristic curve, sensitivity, and specificity were in the range of 0.98-0.99, 95-98%, and 87-95%, respectively. The region determined by the model was confirmed as an actual recurred tumour through the explainable artificial intelligence (AI) using gradient-weighted class activation mapping (Grad-CAM). CONCLUSION: The 2D slice-based CNN model using 18F-FDG PET imaging was able to distinguish well between RT-related changes and tumour recurrence in patients with lung cancer.

Clinical Progression of Colorectal Resection in Gynecologic Cancer Patients: Does the Risk of Anastomotic Leakage Increase after Surgery?

OBJECTIVES: This research aimed to examine the clinicopathological results of colorectal resection in patients with advanced gynecological cancers. METHODS: We retrospectively reviewed the medical records of 104 patients with gynecological cancer who underwent colorectal resection from December 2008 to August 2020 at a single hospital (PNUYH). Using descriptive statistics, variables for risk factors and surgical complications were compared. We eliminated instances with malignancies originating from organs other than the female genitalia, benign gynecological illnesses, primary stoma formation, and any other bowel procedures outside colon resection. RESULTS: The average age of 104 patients was determined to be 62.0 years. The most prevalent gynecological cancer was ovarian cancer (85 patients, 81.7%), and the most frequent procedure was low anterior resection (80 patients, 76.9%). There were postoperative problems in 61 patients (58.7%), while there was anastomotic leaking in just 3 patients (2.9%). Among the risk factors, only preoperative albumin was statistically significant (p=0.019). CONCLUSION: Our findings imply that colorectal resection can be performed safely and effectively on individuals with advanced gynecological cancer.

Multidisciplinary Treatment Strategy for Early Colon Cancer: A Review-An English Version.

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.

Role of C-Reactive Protein, White Blood Cell Counts, and Serum Glucose Levels as Early Predictors of Infectious Complications After Laparoscopic Colorectal Surgery for Colorectal Cancer.

BACKGROUND: The early detection of infectious complications of colorectal surgery leads to better patient outcomes. This study aimed to assess the role of C-reactive protein (CRP), white blood cell count (WBC), and serum glucose in the early prediction of infectious complications of laparoscopic colorectal surgery. METHODS: Patients who underwent laparoscopic colorectal surgery were included and stratified into two groups: infectious complication (IC) or no infectious complication (non-IC). Serum levels were measured on postoperative days (PODs) 2 and 4. RESULTS: Analysis of 224 patients (IC group: 27, Non-IC group: 197) revealed higher CRP levels in IC group on POD 2 (P = .001). On POD 4, CRP levels and WBC counts were higher in IC group (P<.001, P = .011, respectively). The area under the curve (AUC) of the receiver operating characteristic (ROC) for CRP on PODs 2 and 4 were .743 and .907, respectively, and for WBC on POD 4 was .687. The cut-offs of CRP on PODs 2 and 4 were 156.2 mg/L and 91.3 mg/L, respectively; the cut-off of WBC was 7,220 cells/mm3. Sensitivity of CRP level ≥91.3 mg/L or WBC count ≥7,220 cells/mm3 was 96.3%; (cf. 88.9% for CRP alone), and specificity of CRP level ≥91.3 mg/L and WBC count ≥7,220 cells/mm3 was 93.4% (cf. 82.2% for CRP alone). DISCUSSION: The CRP level on postoperative day (POD) 2 and the combined CRP and WBC on POD 4 were meaningful in predicting infectious complications after laparoscopic colorectal surgery. However, serum glucose levels had a low predictive value for infectious complications.

Differences in Factors Predicting Lymph Node Metastasis Between pT1 Rectal Cancer and pT1 Colon Cancer: A Retrospective Study.

BACKGROUND: Studies have demonstrated conflicting results regarding factors that predict lymph node metastasis (LNM) in pT1 colorectal cancers. We hypothesized that these discrepancies could be related to different factors predicting LNM between rectal and colon cancer. This study aimed to compare predicting factors for LNM between pT1 rectal and colon cancer. METHODS: This retrospective study evaluated a prospectively maintained database that included 380 patients with pT1 colorectal cancer from January 2010 to December 2020. Patients were grouped according to whether they had rectal or colon cancer, with or without LNM, and factors predicting LNM were analyzed. RESULTS: In pT1 rectal cancer, LNM was associated with deeper submucosal (SM) invasion (P = .024) and a higher proportion of poorly differentiated tumors (P = .006). In pT1 colon cancer, LNM was associated with a higher proportion of moderately/poorly differentiated tumors (P = .002) and lymphatic invasion (P = .004). In the multivariate analysis for rectal cancer, depth of SM invasion (≥3000 µm) was an independent predictive factor for LNM (95% confidence interval [CI], 1.48-27.94; P = .013), whereas for colon cancer, moderately/poorly differentiated tumors (95% CI, 1.38-8.13; P = .008) and lymphatic invasion (95% CI, 1.44-11.78; P = .008) were independent predictive factors for LNM. DISCUSSION: There were distinct differences in the factors predicting LNM between pT1 rectal cancer and colon cancer. These results suggest the necessity in differentiating between rectal and colon cancer when performing studies on LNM in pT1 colorectal cancer.

Histomorphometric analysis of the sinus lateral wall and Schneiderian membrane: A cadaveric study.

OBJECTIVES: Sinus augmentation is frequently used to maintain implant stability when there is severe alveolar bone loss. The aim of this study was to determine the thicknesses and histologic features of the sinus lateral wall and Schneiderian membrane in embalmed cadavers. DESIGN: This study included 35 hemimaxillae from 25 cadavers (19 males and 6 females with a mean age at death of 59 years). Specimens obtained from the first premolar to the second molar were embedded in paraffin, stained with hematoxylin-eosin, and observed under a light microscope. The thicknesses of the lateral wall and Schneiderian membrane were measured according to tooth site and measurement level, and their histologic features were evaluated. RESULTS: The mean thicknesses of the lateral wall were 2.22, 2.17, 2.64, and 2.64 mm at the first premolar, second premolar, first molar, and second molar, respectively, and 2.79, 2.24, and 2.12 mm at 0, 2, and 8 mm from the sinus floor. The mean thickness of the Schneiderian membrane did not differ significantly between at the sinus floor (0.41 mm) and 2 mm above the floor (0.38 mm). The lateral wall consisted of the outer cortical plate, trabecular bone in the center, and the inner cortical plate near the Schneiderian membrane, being the inner cortical plate the more porous. CONCLUSIONS: These histomorphometric results for the sinus lateral wall and Schneiderian membrane are expected to provide relevant information for use in sinus augmentation procedures.

Reducing Supply Cost by Standardization of Surgical Equipment in Laparoscopic Appendectomy.

BACKGROUND AND OBJECTIVES: Compensation for increased medical services from reimbursement systems are sometimes insufficient. Generally, appendectomies are performed by individual surgeons with their preferred instrument. Surgical equipment standardization is known to reduce medical cost without compromising patient safety. Hence, we investigated the effectiveness of surgical equipment standardization to reduce the required operative cost for laparoscopic appendectomy at our tertiary hospital. METHODS: Nine surgeons at our tertiary hospital agreed to use standardized equipment for laparoscopic appendectomy. We compared outcomes among patients who underwent laparoscopic appendectomy between December 2012 and June 2013 before standardization (control group) and between August 2015 and February 2016 after standardization. Participating provider and staff convenience was also surveyed using a questionnaire. RESULTS: The implementation of standardized equipment for laparoscopic appendectomy decreased intraoperative supply cost from US $552.92 to $450.17. Operative times also decreased from 73.8 to 53.3 minutes. However, hospital days and complication rates remained unchanged. Participants responded that surgical equipment standardization improved efficiency in the operating room and reduced the cost. CONCLUSION: Surgical equipment standardization in laparoscopic appendectomy is effective in reducing intraoperative supply cost without compromising patient safety.

Absent or impaired rectoanal inhibitory reflex as a diagnostic factor for high-grade (grade III-V) rectal prolapse: a retrospective study.

BACKGROUND: Clinically diagnosing high-grade (III-V) rectal prolapse might be difficult, and the prolapse can often be overlooked. Even though defecography is the significant diagnostic tool for rectal prolapse, it is noticed that rectoanal inhibitory reflex (RAIR) can be associated with rectal prolapse. This study investigated whether RAIR can be used as a diagnostic factor for rectal prolapse. METHODS: In this retrospective study, we evaluated 107 patients who underwent both anorectal manometry and defecography between July 2012 and December 2019. Rectal prolapse was classified in accordance with the Oxford Rectal Prolapse Grading System. Patients in the high-grade (III-V) rectal prolapse (high-grade group, n = 30), and patients with no rectal prolapse or low-grade (I, II) rectal prolapse (low-grade group, n = 77) were analyzed. Clinical variables, including symptoms such as fecal incontinence, feeling of prolapse, and history were collected. Symptoms were assessed using yes/no surveys answered by the patients. The manometric results were also evaluated. RESULTS: Frequencies of fecal incontinence (p = 0.002) and feeling of prolapse (p < 0.001) were significantly higher in the high-grade group. The maximum resting (77.5 vs. 96 mmHg, p = 0.011) and squeezing (128.7 vs. 165 mmHg, p = 0.010) anal pressures were significantly lower in the high-grade group. The frequency of absent or impaired RAIR was significantly higher in the high-grade group (19 cases, 63% vs. 20 cases, 26%, p < 0.001). In a multivariate analysis, the feeling of prolapse (odds ratio [OR], 23.88; 95% confidence interval [CI], 4.43-128.78; p < 0.001) and absent or impaired RAIR (OR, 5.36; 95% CI, 1.91-15.04, p = 0.001) were independent factors of high-grade (III-V) rectal prolapse. In addition, the percentage of the absent or impaired RAIR significantly increased with grading increase of rectal prolapse (p < 0.001). The sensitivity of absent or impaired RAIR as a predictor of high-grade prolapse was 63.3% and specificity 74.0%. CONCLUSIONS: Absent or impaired RAIR was a meaningful diagnostic factor of high-grade (III-V) rectal prolapse. Furthermore, the absent or impaired reflex had a positive linear trend according to the increase of rectal prolapse grading.

Safety and feasibility of 3-month interval access and flushing for maintenance of totally implantable central venous port system in colorectal cancer patients after completion of curative intended treatments.

ABSTRACT: Patients with colorectal cancer (CRC) treated with curative intent surgery undergo continuous fluorouracil (5-FU) infusion-based chemotherapy using totally implantable central venous port system (TICVPS) in cases with high risk of recurrence. Approximately 30% of patients relapse after therapy completion, especially within 2 years. Hence, many patients with high risk CRC keep the TICVPS for 6 to 24 months after treatment with regular intervals of TICVPS flushing. However, little is known about the proper interval duration of the port. The aim of this study is to investigate whether a 3 months extended interval is safe and if port maintenance is feasible.A retrospective cohort was compiled of patients with CRC who underwent curative intent surgery and perioperative chemotherapy using TICVPS between 2010 and 2017. The primary end point was TICVPS maintenance rate, including maintenance of TICVPS for at least 6 months, planned TICVPS removal after 6 months, and regaining the use of TICVPS at the time of recurrence.A total of 214 patients with CRC underwent curative intent treatments during the study period. Among them, 60 patients were excluded, including 6 patients for early recurrence within 3 months and 54 patients with violation of flushing interval. Finally, 154 patients were analyzed. Mean flushing interval was 98.4 days (95% confidence interval [CI], 96.2-100.6; range, 60-120). In December 2018, 35 patients kept the TICVPS, 92 patients had planned removal, 25 patients reused the TICVPS, and 2 patients had to unexpectedly remove the TICVPS due to site infection and pain. Thus, the functional TICVPS maintenance rate was 98.8% (152/154). Thirty-eight patients relapsed, and 30 patients were treated with intravenous chemotherapy. Among them, 25 patients (83.3%) reused the maintained TICVPS without a reinsertion procedures.Our study demonstrated that 3-month interval access and flushing is safe and feasible for maintaining TICVPS during surveillance of patients with CRC. An extended interval up to 3 months can be considered because it is compatible with CRC surveillance visit schedules.

Tumor grade 2 as the independent predictor for lymph node metastasis in 10-20 mm sized rectal neuroendocrine tumor.

Purpose: Rectal neuroendocrine tumors (NETs) <10 mm are endoscopically resected, while those ≥20 mm are treated with radical surgical resection. The choice of treatment for 10-20 mm sized rectal NETs remains controversial. This study aimed to verify factors predicting lymph node metastasis (LNM) of 10-20 mm sized rectal NET and utilize them to decide upon the treatment strategy. Methods: Twenty-eight patients with 10-20 mm sized rectal NETs treated at Pusan National University Yangsan Hospital from January 2009 to September 2020 were divided into LNM (+) and LNM (-) groups, and their respective data were analyzed. Results: Seven patients (25%) had LNM while 21 patients (75%) did not. Endorectal ultrasound findings showed tumor size was significantly larger in the LNM (+) than in the LNM (-) group (15 mm vs. 10 mm, P=0.018); however, pathologically, there was no significant difference in tumor size (13 mm vs. 11 mm, P=0.109). The mitotic count (P=0.011), Ki-67 index (P=0.008), and proportion of tumor grade 2 patients (5 cases, 71% vs. 1 case, 5%; P=0.001) were significantly higher in the LNM (+) group. In multivariate analysis, tumor grade 2 was the independent factor predicting LNM (odds ratio, 61.32; 95% confidence interval, 3.17-1,188.64; P=0.010). Conclusion: Tumor grade 2 was the independent factor predicting LNM in 10-20 mm sized rectal NETs. Therefore, it could be considered as the meaningful factor in determining whether radical resection is necessary.

Synchronous Quadruple Colon Cancer With Two Lesions Previously Obscured by Ischemic Colitis, Plus Bladder Cancer and Thymoma: A Case Report.

Synchronous quadruple colorectal cancer (CRC) is extremely rare without genetic alterations. We present a case of synchronous quadruple CRC with 2 lesions previously obscured by ischemic colitis. A 73-year-old woman was admitted to our emergency department. An abdominal computed tomography revealed ischemic colitis and irregular wall thickening of the sigmoid colon and sigmoid-descending junction, suspicious of 2 colon cancers. A colonoscopy examination revealed a fungating mass 20 cm from the anal verge, as well as ischemic colitis spanning the mucosa from the sigmoid colon to the transverse colon. The patient underwent laparoscopic Hartmann procedure. Pathologic examination confirmed both lesions as adenocarcinomas with microsatellite stable. Seven months postoperatively, instead of a laparoscopic Hartmann reversal, a laparoscopic total colectomy was performed due to the continued presence of severe ischemic colitis. The pathologic report suggested the presence of 2 distinct invasive adenocarcinomas in the descending colon without genetic alterations such as microsatellite instability.

Perianal extragastrointestinal stromal tumor.

An extragastrointestinal stromal tumor (EGIST) is a gastrointestinal stromal tumor that arises outside of the gastrointestinal tract. Most EGISTs are located in the omentum, mesentery, and retroperitoneum. The occurrence of an EGIST at the perianal region is very rare. Herein, we report our experience with EGISTs in the perianal area and review the literature. A 70-year-old man presented to our hospital with a 2-year history of anal discomfort. A pelvic magnetic resonance imaging scan showed a homogenous, well-defined, soft tissue density mass. The patient underwent mass excision, and the pathological examination confirmed that the mass was an EGIST. The size of the tumor was 4.3×3.2 cm, and the mitotic count was 1 per 50 high-power fields. The tumor cells were immunohistochemically positive for KIT and CD34 but were negative for S-100 and alpha-smooth muscle actin. There were no other abnormal findings in the gastrointestinal tract; upon pathological review, this case was confirmed as perianal EGIST. Therefore, EGIST should be considered as a differential diagnosis of perianal masses.

Colonic hypoperfusion following ligation of the inferior mesenteric artery in rectosigmoid colon cancer patients.

PURPOSE: Colon perfusion status is one of the most important factors for the determination of postoperative anastomotic complications. Colonic hypoperfusion can be induced by inferior mesenteric artery (IMA) ligation in some patients. This study aimed to evaluate atherosclerotic risk assessment and vascular parameters of CT angiography as predictors of colonic hypoperfusion. METHODS: This prospective study was conducted at a tertiary referral hospital and included 46 rectosigmoid colon cancer patients undergoing laparoscopic anterior resection between August 2013 to July 2014. Atherosclerotic risk scores were assessed using the Framingham cardiovascular risk score system. The IMA length, branching pattern, atherosclerotic calcification, and intermesenteric artery and mesenteric vascular diameters were evaluated using CT angiography. Mesenteric marginal artery pressures were measured before and after IMA clamping. The mean arterial pressure (MAP) index was calculated by dividing the mesenteric marginal MAP into the systemic MAP to determine the mesenteric hypoperfusion status after IMA clamping. A critically low MAP index was defined as <0.4. RESULTS: Critically low MAP index (<0.4) was observed in 6 cases (13.0%) after IMA clamping. Atherosclerotic calcification of the IMA and superior mesenteric artery occurred in 11 (23.9%) and 5 patients (10.9%), respectively. Low MAP index was associated with high atherosclerotic risk score and short IMA length, rather than atherosclerotic calcification and other vascular parameters of the major mesenteric arteries. Multivariate analysis indicated that high atherosclerotic risk and short IMA length were independent predictors of critically low MAP index. CONCLUSION: Atherosclerotic risk assessment and IMA length were useful predictors of the mesenteric hypoperfusion status following IMA ligation during laparoscopic rectosigmoid colon surgery.

Efficacy of preoperative colonoscopic tattooing with indocyanine green on lymph node harvest and factors associated with inadequate lymph node harvest in colorectal cancer.

Objective: Adequate lymph node harvest (LNH) in colorectal cancer is closely related to survival. This study aimed to evaluate the effect of preoperative colonoscopic tattooing (PCT) with indocyanine green (ICG) on adequate LNH in colorectal cancer. Materials and methods: A total of 1079 patients who underwent surgical resection for colorectal cancer were divided into two groups: a tattooing group and a non-tattooing group. The patients were retrospectively analyzed for the number and adequacy of LNH according to tumor locations and stages. Univariate and multivariate analysis for factors associated with adequate LNH were done. Results: There was no significant difference between the two groups in the number and adequacy of LNH according to tumor locations. However, T1 colorectal cancer in the tattooing group had significantly higher adequate LNH (91.6% vs 82.1%, OR 2.370, p = .048) and T1 and N0 rectal cancer in the tattooing group also had higher adequate LNH although there was no statistical significance (100% vs 82.4%, OR 12.088, p = .095; 96.9% vs 84.8%, OR 5.570, p = .099) when compared to the non-tattooing group. Male sex and T1 stage were significantly associated with inadequate LNH in multivariate analysis (OR 0.556 (95% CI 0.340-0.909), p = .019; OR 0.555 (95% CI 0.339-0.910), p = .019, respectively). Conclusion: PCT with ICG did not improve adequate LNH in colorectal cancer but effectively improved adequate LNH in early colorectal cancer. Male sex and early cancer were risk factors for inadequate LNH in colorectal cancer, so PCT is needed for adequate LNH in these patients.

Cancer-Associated Fibroblasts and Desmoplastic Reactions Related to Cancer Invasiveness in Patients With Colorectal Cancer.

PURPOSE: We evaluated the relationship of cancer-associated fibroblasts (CAFs) and desmoplastic reactions with cancer invasiveness and long-term outcomes in patients with colorectal cancer (CRC). METHODS: Histologic evaluation of mature CAFs and desmoplasia was performed by observing the collagen fiber structure and fibroblast cytomorphology in the intratumoral stroma and invasive front of CRC tissues. Cancer-cell invasiveness was evaluated using lymphatic invasion, vascular invasion, perineural invasion, tumor budding, and tumor growth patterns. Overall survival and systemic recurrence were analyzed. A network analysis was performed between CAF maturation, desmoplastic reaction, and cancer invasiveness. RESULTS: The proportions of mature CAFs in the intratumoral stroma and the invasive front were 57.6% and 60.3%, respectively. Epidermal growth factor receptor (EGFR) overexpression was significantly higher in the mature CAFs in the invasive front as compared to immature CAFs. Lymphatic invasion increased as the number of mature fibroblasts in the intratumoral stroma increased. Tumor budding was observed in almost half of both mature and immature stroma samples and occurred more frequently in infiltrating tumors. On network analysis, well-connected islands were identified that was associated with EGFR overexpression, CAF maturation, and infiltrating tumor growth patterns leading to tumor budding. CONCLUSION: The maturity of CAFs and desmoplastic reactions were associated with cancer invasion. However, the cytomorphologic characteristics of CAFs were insufficient as an independent prognostic factor for patients with CRC.

Association between carotid artery stenosis and peripheral artery disease: Evaluation by screening carotid ultrasonography (cross-sectional study).

We aimed to investigate the association between carotid artery stenosis and peripheral artery disease (PAD) by screening carotid ultrasonography (CUS).From January 2012 to December 2015, 231 consecutive patients who had undergone preoperative CUS for PAD were included in this study. A radiologist assessed the degree of internal carotid artery (ICA) stenosis by using the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Severe (>70%) ICA stenosis was evaluated based on the type of vascular surgery, PAD lesion, and ankle-brachial index (ABI). Data were analyzed using multiple logistic regression analysis and the χ test.Among 231 PAD patients, multilevel lesions revealed significantly higher incidence of severe ICA stenosis than iliac and infrainguinal lesion (22.5% vs 9.4% vs 8%: P = .016). Age (odds ratio [OR]: 1.05, 95% confidence interval [CI]: 1.00-1.12: P = .035), chronic kidney disease (CKD, OR: 6.19, 95% CI: 2.04-45.04: P = .013), and cerebral vascular disease (CVD, OR: 4.08, 95% CI: 1.13-16.46: P = .037) were significant risk factors of severe ICA stenosis in multivariate analysis. Prevalence of severe ICA stenosis according to ABI in PAD was not significant.Preoperative screening by CUS provides valuable information onasymptomatic carotid artery stenosis (ACAS) that can identify severe ACAS patients who are at high risk of stroke and to consider more intensive management of carotid disease in PAD patients. CUS can be a useful noninvasive preoperative screening imaging tool for PAD patients with multilevel lesions, aged > 65 years old, with CKD and CVD.