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.

Computed tomography–assessed presarcopenia and clinical outcomes after laparoscopic surgery for rectal cancer

Purpose@#Previous studies have reported that presarcopenia negatively affects rectal cancer treatment. However, most studies have analyzed patients including majority of open surgery, and the association between presarcopenia and clinical outcomes after laparoscopic rectal cancer surgery remains unclear. This study aimed to evaluate the impact of presarcopenia on the clinical and oncological outcomes after laparoscopic rectal cancer surgery. @*Methods@#Three hundred and one patients undergoing laparoscopic rectal cancer surgery between December 2009 and May 2016 were enrolled. Body composition was assessed using computed tomography by measuring the muscle and fat areas at the third lumbar (L3) vertebra. The L3 skeletal muscle area was used to calculate the skeletal muscle index and evaluate presarcopenia. @*Results@#Presarcopenia was more common in older ( ≥ 70 years, P = 0.008) or female patients (P = 0.045). Patients with presarcopenia had decreased skeletal muscle area (P < 0.001), lower hemoglobin level (P = 0.034), longer time to first flatus (P < 0.001), and more frequent surgical site infection (P = 0.001). However, survival rates were not significantly different between those with and without presarcopenia. @*Conclusion@#Computed tomography-assessed presarcopenia was associated with delayed functional recovery and increased surgical site infection, although it was not revealed as a prognostic factor for oncological outcomes.

Apurinic/apyrimidinic endonuclease 1 is associated with poor prognosis after curative resection followed by adjuvant chemotherapy in patients with stage III colon cancer

Purpose@#Apurinic/apyrimidinic endonuclease 1 (APE1) is a key enzyme involved in the base excision repair pathway. It also has redox activity and maintains various transcription factors in an active reduced state. APE1 may be associated with chemoresistance. In the present study, we first investigated the expression level of APE1 protein and its correlation with oncologic outcomes of oxaliplatin-based chemotherapy in patients with stage III colon cancer. Further, we investigated the effects of human APE1 siRNA on the sensitivity of oxaliplatin in SNU-C2A colon cancer cells. @*Methods@#Tissue specimens from tumor and normal colon of 33 patients with stage III colon cancer were obtained from 2006 to 2009. The patients received at least eight cycles of oxaliplatin-based chemotherapy. APE1 expression was analyzed by immunohistochemistry and Western blotting using a cultured SNU-C2A cell line. Cell viability and apoptosis were determined by Cell Counting Kit-8 and caspase-3 cleavage using Western blotting. @*Results@#All the colon cancer tissues showed APE1 staining in the nucleus, whereas all the normal colon tissues were negative for APE1 staining in the cytoplasm. The group with a higher expression of APE1 demonstrated poorer prognosis than the group with low expression (P=0.026 for overall survival and P=0.021 for disease-free survival). Treatment with oxaliplatin resulted in a dose-dependent increase in APE1 expression in SNU-C2A cells. APE1 siRNA significantly enhanced oxaliplatin-induced growth inhibition, and also increased oxaliplatin-induced apoptosis in SNU-C2A cells. @*Conclusion@#APE1 could be considered a prognostic factor in colon cancer patients treated with oxaliplatin-based chemotherapy.

Omission of neoadjuvant radiotherapy for clinical T2/N1 and T3N0/1 middle and low rectal cancers with safe circumferential resection margins

Purpose@#For moderately advanced rectal cancers with safe circumferential margins, the oncologic benefit of neoadjuvant radiotherapy must be reconsidered because of the possibility of overtreatment, resulting in complications from radiotoxicity. To evaluate the oncologic safety of the omission of neoadjuvant radiotherapy for moderately advanced rectal cancers, we evaluated and compared the prognoses of patients who underwent radical resection with and without neoadjuvant radiotherapy for T2/N1 and T3N0/1 middle and low rectal cancers with safe circumferential resection margins. @*Methods@#We retrospectively enrolled 66 patients who underwent radical resection for clinical (c) T2N1 and T3N0/1 middle and low rectal cancers between 2008 and 2014. Patients with distant metastasis; cT4, cN2, or positive lateral pelvic lymph nodes; positive circumferential resection margin; signet-ring cell carcinoma; cT1/2N0; or those who had received adjuvant radiotherapy were excluded. The clinical and pathological characteristics and 5-year oncologic outcomes of the noradiotherapy (n = 34) and radiotherapy (n = 32) groups were compared. @*Results@#The rates of abdominoperineal resection and ileostomies and the proportion of patients who received adjuvant chemotherapy were significantly higher in the radiotherapy group. There were no significant differences in tumor location, clinical stage, surgery type, pathologic N stage, anastomotic leakage, or long-term oncologic outcomes including 5-year disease-free survival, overall survival, and local recurrence and distant metastasis rates between both groups. @*Conclusion@#The oncologic benefit of neoadjuvant radiotherapy for cT2/N1 and T3N0/1 middle and low rectal cancers with safe circumferential resection margins is considered unclear, and it can be omitted to prevent radiotoxicity and facilitate prompt essential treatment.

Intestinal Perforation as a Paradoxical Reaction to Antitubercular Therapy: A Case Report

Paradoxical reactions to tuberculosis (TB) treatment are characterized by an initial improvement of the clinical symptoms followed by clinical or radiological deterioration of existing tuberculous lesions, or by development of new lesions. Intestinal perforation in gastrointestinal TB can occur as a paradoxical reaction to antitubercular therapy. A 55-year-old man visited the outpatient department with lower abdominal pain and weight loss. He was diagnosed with intestinal TB and started antitubercular therapy. After 3 months of antitubercular therapy, a colonoscopy revealed improvement of the disease. Three days after the colonoscopy, the patient visited the emergency room complaining of abdominal pain. Abdominal computed tomography revealed extraluminal air-filled spaces in the pelvic cavity. We diagnosed a small bowel perforation and performed an emergency laparotomy and a right hemicolectomy with small bowel resection. This report describes the case of intestinal perforation presenting as a paradoxical reaction to antitubercular and provides a brief literature review.

Intestinal Perforation as a Paradoxical Reaction to Antitubercular Therapy: A Case Report

Paradoxical reactions to tuberculosis (TB) treatment are characterized by an initial improvement of the clinical symptoms followed by clinical or radiological deterioration of existing tuberculous lesions, or by development of new lesions. Intestinal perforation in gastrointestinal TB can occur as a paradoxical reaction to antitubercular therapy. A 55-year-old man visited the outpatient department with lower abdominal pain and weight loss. He was diagnosed with intestinal TB and started antitubercular therapy. After 3 months of antitubercular therapy, a colonoscopy revealed improvement of the disease. Three days after the colonoscopy, the patient visited the emergency room complaining of abdominal pain. Abdominal computed tomography revealed extraluminal air-filled spaces in the pelvic cavity. We diagnosed a small bowel perforation and performed an emergency laparotomy and a right hemicolectomy with small bowel resection. This report describes the case of intestinal perforation presenting as a paradoxical reaction to antitubercular and provides a brief literature review.

Prognostic Factor and Survival Benefit of Adjuvant Chemotherapy in Stage IIA Colon Cancer

Purpose@#There is no clear evidence of the benefit of adjuvant chemotherapy (AC) in stage IIA colon cancer. Therefore, we aimed to evaluate the prognostic factors and survival benefit of AC in this disease. @*Methods@#A retrospective data collection for patients who underwent radical surgery for colon cancer between January 2008 and December 2015 was undertaken. The cohort was divided into the no-AC and AC groups. @*Results@#We included 227 patients with stage IIA colon cancer in our study cohort, including 67 and 160 patients in the no-AC and AC groups, respectively. The number of retrieved lymph nodes and the presence of tumor complications as obstruction or perforation were independent risk factors for survival. In the no-AC group, there was a significant difference in survival according to the number of retrieved lymph nodes. In the AC group, there were significant differences in survival according to sidedness and preoperative carcinoembryonic antigen (CEA). There was no significant difference in survival between the no-AC and the AC groups. @*Conclusion@#The number of retrieved lymph nodes and the presence of tumor complications were prognostic factors for stage IIA colon cancer but lymphovascular and perineural invasion were not. Sidedness and preoperative CEA could be used as factors to predict the benefit of adjuvant chemotherapy. Currently, it is believed that there is no benefit of AC for stage IIA colon cancer. Further studies are needed to determine the survival benefit of adjuvant chemotherapy in stage IIA colon cancer.

Clinical impact of sarcopenia in patients with colon cancer undergoing laparoscopic surgery

Purpose@#Previous studies have reported that progressive muscle loss, known as sarcopenia, has a negative impact on colon cancer treatment. However, the majority of studies have analyzed on patients undergoing open resection, and the association of sarcopenia with clinical outcomes is not clear for patients with colon cancer undergoing laparoscopic surgery. Thus, the aim of this study was to evaluate the impact of sarcopenia on clinical outcomes after laparoscopic surgery for colon cancer. @*Methods@#A total of 423 patients who underwent laparoscopic surgery for colon cancer between November 2010 and October 2014 were included. Body composition was assessed by measuring muscle and fat areas at the third lumbar vertebra (L3) on preoperative computed tomography. The L3 skeletal muscle area was used to calculate the skeletal muscle index and to assess for sarcopenia. @*Results@#Sarcopenia was identified in 54 patients (12.8%). The median time to first flatus (3 days), median time to tolerable soft diet (4 days), and median length of hospital stay (7 days) were not significantly different between patients with and without sarcopenia. However, sarcopenia was an independent risk factor for postoperative complications in the logistic regression multivariate analysis (p = 0.015). Sarcopenia was not associated with overall or disease-free survival. @*Conclusion@#Sarcopenia was not negatively associated with functional recovery, hospital stay, and oncologic outcomes in patients with colon cancer who underwent laparoscopic surgery. However, sarcopenia was associated with postoperative complications after laparoscopic surgery for colon cancer.

Prospective study on the safety and feasibility of early ileostomy closure 2 weeks after lower anterior resection for rectal cancer

PURPOSE: Transient loop ileostomies in rectal cancer surgery are generally closed after 2 or more months to allow adequate time for anastomotic healing. Maintaining the ileostomy may cause medical, surgical, or psychological complications; it also reduces the quality of life, and increase treatment costs. We performed this study to evaluate the safety and feasibility of early ileostomy closure 2 weeks postoperatively. METHODS: If a patient who underwent total mesorectal excision had 2 or more risk factors for anastomotic leakage, a loop ileostomy was created. After confirmation of intact anastomosis via sigmoidoscopy and proctography 1 week postoperatively, the patient was enrolled and ileostomy was closed 2 weeks postoperatively. The primary endpoint was the frequency of complication after ileostomy repair. RESULTS: Thirty patients were enrolled in the study and 6 were excluded due to anastomotic leakage. Except for 1 case of wound infection (4.2%), no patient experienced any complication including newly developed leakage after the ileostomy closure. The mean duration to repair was 13.1 days (range, 8–16 days) and mean duration to the start of adjuvant treatment after radical surgery was 5.37 weeks (range, 3.0–8.1 weeks). CONCLUSION: Transient loop ileostomy, which is confirmed to be intact endoscopically and radiologically, can be safely closed 2 weeks postoperatively without requiring a significant delay in adjuvant chemotherapy.

Combination Assessment of Clinical Complete Response of Patients With Rectal Cancer Following Chemoradiotherapy With Endoscopy and Magnetic Resonance Imaging

PURPOSE: The response to neoadjuvant chemoradiotherapy (CRT) for rectal cancer can be assessed using digital rectal examination, endoscopy and magnetic resonance imaging (MRI). Precise assessment of clinical complete response (CR) after CRT is essential when deciding between optimizing surgery or organ-preserving treatment. The objectives of this study were to correlate the CR finding in endoscopy and MRI with pathologic CR and to determine the appropriate approach for combining endoscopy and MRI to predict the pathologic CR in patients with rectal cancer after neoadjuvant CRT. METHODS: This retrospective cohort study included 102 patients with rectal cancer who underwent endoscopy and MRI at 2–4 weeks after CRT. We assigned a confidence level (1–4) for the endoscopic and MRI assessments. Accuracy, sensitivity, and specificity were analyzed based on the endoscopy, MRI, and combination method findings. Diagnostic modalities were compared using the likelihood ratios. RESULTS: Of 102 patients, 17 (16.7%) had a CR. The accuracy, sensitivity, and specificity for the prediction CR of endoscopy with biopsy were 85.3%, 52.9%, and 91.8%, while those of MRI were 91.2%, 70.6%, and 95.3%, and those of combined endoscopy and MRI were 89.2%, 52.9%, and 96.5%, respectively. No significant differences were noted in the sensitivity and specificity of any each modality. The prediction rate for CR of the combination method was 92.6% after the posttest probability test. CONCLUSION: Our study demonstrated that combining the interpretation of endoscopy with biopsy and MRI could provide a good prediction rate for CR in patients with rectal cancer after CRT.

Efficacy of biofeedback therapy for objective improvement of pelvic function in low anterior resection syndrome

PURPOSE: There is no established treatment of choice for low anterior resection syndrome (LARS). To evaluate the efficacy of biofeedback therapy for objective improvement of pelvic function in LARS, we performed the present study. METHODS: The primary endpoint was the change of Wexner score. Consenting patients between 20 and 80 years old with major LARS at least 2 months after sphincter preserving proctectomy for rectal cancer were enrolled. After recommendation of biofeedback therapy, patients who accept it were enrolled in the biofeedback group and patients who refuse were enrolled in the control group. Initial and follow-up evaluations were performed and analyzed. RESULTS: Fifteen and sixteen patients were evaluated in the control group and the biofeedback group, respectively. There was no statistically significant difference of LARS score between both groups. Decrease in Wexner score and increase in rectal capacity were significantly higher in the biofeedback group (odds ratio [OR], 5.386; 95% confidence interval [CI], 1.194–24.287; P = 0.028 and OR, 1.061; 95% CI, 1.002–1.123; P = 0.042). CONCLUSION: Biofeedback therapy was superior for objective improvement of pelvic function to observation in LARS. It can be considered to induce more rapid improvement of major LARS.

Additional 4-week capecitabine during the resting periods after 6-week neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer: long-term oncologic outcomes

PURPOSE: The aim of this study was to evaluate the long-term outcome of additional 4-week chemotherapy with capecitabine during the resting periods following a 6-week neoadjuvant chemoradiotherapy (NCRT) regimen, in patients with locally advanced rectal cancer. METHODS: Radiotherapy was delivered to the whole pelvis at a total dose of 50.4 Gy for 6 weeks. Oral capecitabine was administered at a dose of 825 mg/m2 twice daily for 10 weeks. Surgery was performed 2–4 weeks following the completion of chemotherapy. RESULTS: Between January 2010 and September 2011, 41 patients completed the scheduled neoadjuvant therapy and surgery. The pathologic complete response rate, 5-year overall survival, and 5-year disease-free survival rates were 22%, 85.4%, and 78.0%, respectively. The 5-year systemic recurrence and 5-year local recurrence rates were 22% and 0%, respectively. CONCLUSION: Additional 4-week chemotherapy with capecitabine, during the resting periods following a 6-week NCRT regimen, has favorable long-term oncologic outcomes. Further randomized controlled trials are however necessary to evaluate if substantial improvement in local control is achieved with this additional chemotherapy modality for locally advanced rectal cancer.

Feasibility and oncologic safety of low ligation of inferior mesenteric artery with D3 dissection in cT3N0M0 sigmoid colon cancer

PURPOSE: There is no standard consensus for the ligation level of the inferior mesenteric artery during radical resection of sigmoid colon cancer. Especially, there is little research about low ligation combined with D3 dissection. The study was performed to compare feasibility and oncologic safety between low ligation with D3 dissection to high ligation in intermediately advanced sigmoid colon cancer. METHODS: From January 2008 to December 2013, 134 patients who underwent radical surgery for cT3N0M0 sigmoid colon cancer were evaluated retrospectively. Clinicopathologic factors and oncologic outcomes of high ligation (HL, n = 51) and low ligation (LL, n = 83) groups were compared. RESULTS: The mean operative time was significantly shorter in LL, and there was no difference in complications, distal margin or number of retrieved lymph node. The tumor size was significantly larger in HL, but there was no difference in number of metastatic lymph node, pT or pN stage. There was no difference in overall survival, disease-free survival, or local and systemic recurrence. CONCLUSION: In cT3N0M0 sigmoid colon cancers, we suggest that low ligation with D3 dissection can be performed with feasibility and oncological safety.

Colorectal Perforation After Anorectal Manometry for Low Anterior Resection Syndrome

We experienced 3 cases of manometry-induced colon perforation. A 75-year-old man (case 1) underwent anorectal manometry (ARM) 3 years after radiotherapy for prostate cancer and a laparoscopic intersphincteric resection for rectal cancer. A 70-year-old man (case 2) underwent ARM 3 months after conventional neoadjuvant chemoradiotherapy and a laparoscopic low anterior resection for rectal cancer. A 78-year-old man (case 3) underwent ARM 2 months after a laparoscopic intersphincteric resection for rectal cancer. In all cases, a colon perforation with fecal peritonitis occurred. All were treated successfully using prompt and active operations and were discharged without any complications. ARM with a balloon, as a measure of rectal compliance, should be performed 2 months or longer after surgery. If a perforation occurs, prompt and active surgical intervention is necessary due to the high possibility of extensive fecal peritonitis.

Current Situation on the Diagnosis of Anismus-Discordances Between Imaging and a Physiologic Study

No abstract available.

The Feasibility of Laparoscopic Surgery Compared to Open Surgery in Patients with T4 Colorectal Cancer Staged by Preoperative Computed Tomography

PURPOSE: Decision of laparoscopic surgery (LS) for locally advanced colorectal cancer is based on preoperative computed tomography (CT), notwithstanding the inaccuracy of T staging. The aim of this study was to compare the differences between LS and open surgery (OS) in their R0 resection rate, short-term results, and oncologic outcomes for T4 colorectal cancer staged by preoperative CT scanning. METHODS: A total of 101 patients who had undergone LS were compared with 46 patients who had undergone OS. Preoperative CT scans for all patients indicated T4. Emergency operation, distant metastases, chemoradiotherapy, and multivisceral resection were excluded from the study. RESULTS: The OS group showed a higher percentage of right-side colon cancer (p=0.028), larger tumor (p=0.039), and postoperative complication rate (p=0.002). There was no difference in R0 resection rate between the two groups (94.1% vs. 95.7%; p=1.000). The LS group showed significantly shorter hospital stays (p=0.001), but a similar operation time (p=0.103) compared with the OS group. No significant difference in five-year overall survival, disease-free survival, and local recurrence was observed between the two groups. CONCLUSION: The results of this study show that LS is feasible in the majority of patients with T4 colorectal cancer staged by CT scanning if multivisceral resection is not planned.

Long-term oncologic outcomes of neoadjuvant concurrent chemoradiotherapy with capecitabine and radical surgery in locally advanced rectal cancer: 10-year experiences at a single institution

PURPOSE: Oral capecitabine has demonstrated to be safe and efficient as neoadjuvant concurrent chemoradiotherapy (NCRT) for locally advanced rectal cancers. The aim of this study was to evaluate the long-term oncologic outcomes of NCRT with capecitabine and radical surgery. METHODS: From January 2000 to June 2010, 238 patients were treated at our center for locally advanced rectal cancers using conventional NCRT with capecitabine and radical surgery. Univariate and multivariate analyses were used to evaluate the factors associated with oncologic outcomes with log rank and Cox regression tests. RESULTS: The incidence of grade >3 capecitabine-related toxicity was found to be 4.6%. A pathologic complete response was observed in 14.7% of patients. The 5-year overall and 5-year disease-free survival rate, local and systemic recurrence rate were 82.8%, 75.1%, 4.8%, and 20.3%. Abdominoperineal resection and node-positive disease were independent prognostic factors of 5-year overall survival, 5-year disease-free survival, and systemic recurrence. CONCLUSION: NCRT with capecitabine and radical surgery showed favorable long-term oncologic outcomes with benefits of acceptable toxicity and convenience. We suggest that capecitabine can be one of the favorable therapeutic options for NCRT in rectal cancer.

TisN0M1 Sigmoid Colon Cancer: A Case Report

Distant metastasis of a colon carcinoma in situ has not yet been reported. We experienced a case of a sigmoid colon carcinoma in situ with common hepatic lymph node metastasis. After the first operation, we diagnosed dual intramucosal adenocarcinomas of the sigmoid colon without any regional lymph node metastasis. After the second operation, a metastatic adenocarcinoma was found in the common hepatic lymph nodes. We suggest that metastasis in cases of a colonic carcinoma in situ is rare, but possible. The parallel progression model of tumors can explain this early metastasis.

A Phase II Study of Additional Four-Week Chemotherapy With Capecitabine During the Resting Periods After Six-Week Neoadjuvant Chemoradiotherapy in Patients With Locally Advanced Rectal Cancer

PURPOSE: The aim of this study is to evaluate the efficacy and the safety of additional 4-week chemotherapy with capecitabine during the resting periods after a 6-week neoadjuvant chemoradiotherapy (NCRT) in patients with locally advanced rectal cancer. METHODS: Radiotherapy was delivered to the whole pelvis at a total dose of 50.4 Gy for 6 weeks. Oral capecitabine was administered at a dose of 825 mg/m2 twice daily for 10 weeks. Surgery was performed 2-4 weeks following the completion of chemotherapy. RESULTS: Between January 2010 and September 2011, 44 patients were enrolled. Forty-three patients underwent surgery, and 41 patients completed the scheduled treatment. Pathologic complete remission (pCR) was noted in 9 patients (20.9%). T down-staging and N down-staging were observed in 32 patients (74.4%) and 33 patients (76.7%), respectively. Grade 3 to 5 toxicity was noted in 5 patients (11.4%). The pCR rate was similar with the pCR rates obtained after conventional NCRT at our institute and at other institutes. CONCLUSION: This study showed that additional 4-week chemotherapy with capecitabine during the resting periods after 6-week NCRT was safe, but it was no more effective than conventional NCRT.

A Phase II Study of Additional Four-Week Chemotherapy With Capecitabine During the Resting Periods After Six-Week Neoadjuvant Chemoradiotherapy in Patients With Locally Advanced Rectal Cancer

PURPOSE: The aim of this study is to evaluate the efficacy and the safety of additional 4-week chemotherapy with capecitabine during the resting periods after a 6-week neoadjuvant chemoradiotherapy (NCRT) in patients with locally advanced rectal cancer. METHODS: Radiotherapy was delivered to the whole pelvis at a total dose of 50.4 Gy for 6 weeks. Oral capecitabine was administered at a dose of 825 mg/m2 twice daily for 10 weeks. Surgery was performed 2-4 weeks following the completion of chemotherapy. RESULTS: Between January 2010 and September 2011, 44 patients were enrolled. Forty-three patients underwent surgery, and 41 patients completed the scheduled treatment. Pathologic complete remission (pCR) was noted in 9 patients (20.9%). T down-staging and N down-staging were observed in 32 patients (74.4%) and 33 patients (76.7%), respectively. Grade 3 to 5 toxicity was noted in 5 patients (11.4%). The pCR rate was similar with the pCR rates obtained after conventional NCRT at our institute and at other institutes. CONCLUSION: This study showed that additional 4-week chemotherapy with capecitabine during the resting periods after 6-week NCRT was safe, but it was no more effective than conventional NCRT.