Impact of Family History on Prognosis of Patients with Sporadic Colorectal Cancer.

PURPOSE: A family history (FH) of colorectal cancer (CRC) increases the risk for development of CRC, but the impact of FH of CRC on survival from sporadic CRC is unclear. This study investigated the prognostic impact of FH of CRC on the recurrence and survival of patients with sporadic CRC. METHODS: We reviewed the records of patients with sporadic CRC from two tertiary referral hospitals in Korea who underwent surgical resection between May 2007 and September 2013. The clinicopathologic features and oncologic outcomes of those with and without FHs of CRC were compared. RESULTS: We examined the records of 2960 eligible patients, 163 (5.5%) of whom had first-degree relatives with CRC. Patients with and without FHs of CRC had similar baseline characteristics. Multivariable analysis indicated that a FH of CRC was not significantly associated with disease-free survival but was significantly associated with better overall survival (OS) [adjusted hazard ratio = 0.539, 95% confidence interval (CI) 0.330-0.881, P = 0.014]. Subgroup analysis indicated that females and rectal cancer patients with FHs of CRC had significantly better prognoses. Microsatellite status did not affect the improved survival rate associated with FH. CONCLUSIONS: This study of patients with sporadic CRC indicated that those who had FHs of CRC had better OS but similar cancer recurrence as those who had no FH of CRC. The effect of FH of CRC on OS was independent of microsatellite status. Further studies are needed to identify underlying mechanisms and determine the optimal clinical management of CRC according to FH.

Does routine colonoscopy help diagnose familial adenomatous polyposis in patients presenting with desmoid tumors but no gastrointestinal symptoms?

PURPOSE: Desmoid tumor (DT) is a rare myofibroblastic proliferative neoplasm, but can occur in up to 26% of patients with familial adenomatous polyposis (FAP). Therefore, DT may be an extraintestinal manifestation of FAP that precedes the development of advanced malignancies. The aim of this study was to identify the incidence of polyps in DT patients and investigate value of colonoscopy for diagnosis of FAP in DT patients without gastrointestinal symptoms. MATERIALS AND METHODS: The records of patients diagnosed with DT were retrospectively reviewed using the clinical data warehouse (CDW) system. Clinical data, including location of tumor, type(s) of treatment, and colonoscopic findings, were collected. RESULTS: Sixty-five patients were diagnosed with DT during the study period; 10 patients received colonoscopies before diagnosis of DT, and 20 patients received colonoscopies after diagnosis of DT. The mean age at diagnosis of DT was 41.9 ± 16.7 years old (range 17-74). Most tumors were extra-abdominal (n = 24, 80.0%), and fewer were intra-abdominal (n = 4, 13.3%) or in an abdominal wall (n = 2, 6.7%). The colonoscopy results revealed one or two tubular adenomas in 11 patients (36.6%), although none of the patients had colorectal polyposis or colorectal cancer. CONCLUSION: None of the patients in our study population had colorectal polyposis. Routine colonoscopy of DT patients without gastrointestinal symptoms seems to have low diagnostic yield for detection of FAP.

Comparison of anastomotic configuration after laparoscopic right hemicolectomy under enhanced recovery program: side-to-side versus end-to-side anastomosis.

BACKGROUND: Stapled technique for ileocolic anastomosis is largely supported in previous studies. However, standard anastomotic configuration is not conclusive and studies are limited. This study aims to compare postoperative outcomes between side to side (S-S) and end to side (E-S) stapled anastomosis after laparoscopic right hemicolectomy underenhanced recovery program (ERP). METHODS: Between October 2009 and November 2012, 89 patients (46 in S-S group, 43 in E-S group) who underwent laparoscopic right hemicolectomy for colon cancer and managed with ERP were included in the study. Recovery time and cumulative recovery rates, the length of hospital stays, complication rates were analyzed to compare both configurations. RESULTS: The recovery time were not different between groups (S-S group, 135 hours [84-183.5] vs E-S group, 117 hours [94-143]; P = 0.349). Difference of cumulative recovery rates were observed in postoperative day 7 (S-S group, 71.7 % vs E-S group, 93.0 %; P = 0.019). The postoperative hospital stay were shorter in E-S group (S-S, 7 days [6-9] vs E-S, 6 days [5-7]; P = 0.003). The overall complication rates were lower in E-S group (26.1 % vs 4.6 %; P = 0.008). Anastomotic leakage was not observed in both groups. CONCLUSIONS: E-S configuration after laparoscopic right hemicolectomy showed favorable outcomes under enhanced recovery program.

Effects of Preoperative Chemoradiotherapy on the Likelihood of Sphincter Preservation Surgery in Locally Advanced Distal Rectal Cancer: A Longitudinal Study Based on Pelvic Magnetic Resonance Imaging.

BACKGROUND: It is unclear whether preoperative chemoradiotherapy (pCRT) increases the rate of sphincter-preserving surgery (SPS), avoiding abdominoperineal resection (APR), for the treatment of distal rectal cancer. We examined whether pCRT increases the likelihood of SPS based on changes in tumor height using pelvic magnetic resonance imaging (MRI). METHODS: Between January 2009 and December 2013, 105 patients underwent long-course pCRT for locally advanced distal rectal cancer (≤5 cm from the anal verge) and were included in this study. The surgical procedures were analyzed in terms of radiologic findings, including the distance from the inferior margin of tumor to the superior margin of the anorectal ring (tumor height) measured by pelvic MRI before and after pCRT. RESULTS: Eighty-six (81.9 %) patients underwent SPS. Overall clinical downstaging occurred in 48 (45.7 %) patients. Tumor height increased significantly after pCRT (from 15.0 ± 15.3 to 18.1 ± 16.9 mm, change 3.1 ± 9.7 mm, p = 0.01). The mean change in tumor height was not significantly different between patients who underwent SPS or APR (mean change 3.3 ± 9.6 vs. 2.3 ± 10.5 mm, p = 0.68). The mean change was significantly greater in the double-stapled anastomosis group than in the handsewn anastomosis group (mean change 5.6 ± 9.9 vs. -0.6 ± 8.6 mm, p = 0.02). CONCLUSIONS: This was the first MRI-based longitudinal study to show that pCRT does not appear to increase the likelihood of SPS in locally advanced distal rectal cancer, although it could improve the potential of double-stapled anastomoses.

Loss of AT-rich interactive domain 1A expression in gastrointestinal malignancies.

OBJECTIVE: AT-rich interactive domain 1A (ARID1A) has recently been identified as a novel tumor suppressor in various tumor types. This study was designed to explore the clinical relevance and prognostic impact of ARID1A expression loss in colorectal cancer (CRC) and gastric cancer (GC). METHODS: Immunohistochemistry for ARID1A was performed using tissue microarray blocks containing 196 CRCs and 275 GCs, along with paired normal mucosa. Data on clinicopathologic variables and oncologic outcomes of patients were collected and analyzed. RESULTS: We identified 6.1% (12/196) CRC and 8.0% (22/275) GC cases showing loss of ARID1A expression. Expression of ARID1A in paired mucosal epithelial cells was normal in all patients. Loss of ARID1A expression was significantly correlated with negative lymphatic invasion (p = 0.003) in CRC, with large tumor size (p = 0.037) in GC, and with expanding tumor border in both tumor types (CRC, p = 0.010; GC, p = 0.031). However, no association was evident between ARID1A expression and 5-year overall survival in both tumor types. CONCLUSIONS: Loss of ARID1A expression is uncommon and not associated with oncologic outcome but may be related to less invasive clinicopathologic features in CRC and GC. Further studies with a larger number of subjects are needed to establish the possible prognostic impact of ARID1A expression loss.

Cultural adaptation and validation of the Korean version of the EORTC QLQ-CR29 in patients with colorectal cancer.

PURPOSE: We aimed to evaluate the psychometric properties of the Korean version of the European Organization for Research and Treatment of Cancer (EORTC) Colorectal Cancer-Specific Quality of Life Questionnaire (QLQ-CR29), based on a sample of patients with colorectal cancer. METHODS: A total of 123 patients treated for colorectal cancer participated in the validation study. Test-retest reliability was assessed using intra-class correlations from a random sample. Internal consistency reliability was estimated using Cronbach's α coefficient. Convergent and discriminant validity was analyzed with multi-trait scaling. Clinical validity was assessed in terms of clinical differences using known-group comparisons. Concurrent validity was determined by correlations with the EORTC QLQ-C30, which was a generic core questionnaire to evaluate issues common to different cancer sites and treatments. RESULTS: The test-retest, administered to 35 patients, showed acceptable reproducibility (0.62-1.00) except the constipation scale of the QLQ-C30 (0.43). Cronbach's α coefficient (0.70-0.87) exceeded the 0.7 criterion. Multi-trait scaling analysis showed that multi-item scales met standards of convergent and discriminant validity. The known-group comparisons showed quality of life (QOL) differences between groups of patients based on tumor location, receipt of neoadjuvant therapy, and with/without a stoma. Correlations between the scales of the QLQ-CR29 and QLQ-C30 were low in most areas, whereas correlations in several areas with related content were higher. CONCLUSION: This study shows that the Korean version of the EORTC QLQ-CR29 is a reliable and valid tool for measuring QOL, as determined by application to a sample of Korean colorectal cancer patients.

Risk factors and preventive measures for acute urinary retention after rectal cancer surgery.

BACKGROUND: Although several risk factors for acute urinary retention after rectal cancer surgery have been proposed, few studies have enrolled a homogeneous group of patients without preoperative urinary dysfunction. We aimed to identify risk factors and preventive measures for acute urinary retention after rectal cancer surgery. METHODS: This study was a retrospective review of prospectively collected data from included patients who underwent rectal cancer surgery at a single center. Preoperative urinary function was evaluated using the International Prostate Symptom Score (IPSS). Clinical data were collected prospectively and analyzed to assess the risk factors for acute urinary retention, which was defined as the inability to self-void after removing the urinary catheter requiring catheterization or reinsertion of an indwelling catheter. RESULTS: Of 352 patients with mild preoperative IPSS (0-7), 48 (13.6 %) experienced acute urinary retention. Multivariate logistic regression analysis showed that male sex (odds ratio [OR] 2.240, p = 0.039), laparoscopic operation (OR 2.421, p = 0.024), intraoperative intravenous fluid ≥ 2,000 mL (OR 3.794, p < 0.001), and urinary catheter removal on postoperative day 1 or 2 (OR 3.650, p = 0.017) were independent risk factors for acute urinary retention after rectal cancer surgery. Patients with two risk factors had a significantly higher risk of acute urinary retention than patients with none or one risk factor. CONCLUSIONS: This study suggests the maintenance of a urinary catheter for a period longer than 2 days and intraoperative fluid restriction to prevent acute urinary retention after rectal cancer surgery.

Incidental cholecystectomy in patients with asymptomatic gallstones undergoing surgery for colorectal cancer.

BACKGROUND AND AIMS: The feasibility of incidental cholecystectomy during colorectal cancer (CRC) surgery has not been determined as yet. We aimed to investigate the feasibility of incidental cholecystectomy during CRC surgery. METHODS: The clinicopathologic data of patients who underwent CRC surgery between January 2004 and May 2011 were assessed. Patients with asymptomatic cholelithiasis were divided into groups that did and did not undergo incidental cholecystectomy. Their in-hospital morbidity and long-term biliary complications were compared. RESULTS: Of the 282 patients identified, 143 (50.7%) underwent incidental cholecystectomy and 139 (49.3%) were observed without cholecystectomy. The two groups were similar in clinical characteristics, except for gender and operation time. Only one patient (0.7%) in the cholecystectomy group experienced an intraoperative biliary complication. There was no significant difference in overall in-hospital morbidity between the two groups. After a median follow-up period of 33 months, long-term biliary complications developed in 12 patients (8.6%) in the observation group, with 9 undergoing cholecystectomy. CONCLUSIONS: Incidental cholecystectomy was not associated with increased postoperative morbidity, whereas previously asymptomatic patients were at substantial long-term risk of becoming symptomatic. Thus, in the absence of clear contraindications, concomitant cholecystectomy might be a desirable treatment option during CRC surgery in patients with asymptomatic gallstones.

Risk factors for bowel dysfunction after sphincter-preserving rectal cancer surgery: a prospective study using the Memorial Sloan Kettering Cancer Center bowel function instrument.

BACKGROUND: Until recently, no studies have prospectively evaluated bowel function after sphincter-preserving surgery for rectal cancer with the use of a validated bowel function scoring system. OBJECTIVE: The aim of this study was to investigate possible risk factors for altered bowel function after sphincter-preserving surgery. DESIGN: This was a prospective study. SETTINGS: The study was conducted between January 2006 and May 2012 at the authors' institution. PATIENTS: Patients who underwent sphincter-preserving rectal cancer surgery were recruited. MAIN OUTCOME MEASURES: Bowel function was assessed 1 day before (baseline) and at 1 year after sphincter-preserving surgery or temporary ileostomy takedown with the use of the Memorial Sloan Kettering Cancer Center questionnaire. Multivariable analysis was performed to identify the factors associated with altered bowel function after surgery. RESULTS: Overall, 266 patients were eligible for the analysis. The tumor was located in the upper, middle, and lower rectum in 68 (25.5%), 113 (42.5%), and 85 (32.0%) patients. Intersphincteric resection and temporary ileostomy were performed in 18 (6.8%) and 129 (48.5%) patients. The mean Memorial Sloan Kettering Cancer Center score was 64.5 ± 7.6 at 1 year after sphincter-preserving surgery or temporary ileostomy takedown. The Memorial Sloan Kettering Cancer Center score decreased in 163/266 patients (61.3%) between baseline and 1 year after surgery. Tumor location (p = 0.01), operative method (p = 0.03), anastomotic type (p = 0.01), and temporary ileostomy (p = 0.01) were associated with altered bowel function after sphincter-preserving surgery in univariate analyses. In multivariable analysis, only tumor location was independently associated with impaired bowel function after sphincter-preserving rectal cancer surgery. LIMITATIONS: This study was limited by its nonrandomized design and the lack of measurement before preoperative chemoradiotherapy. CONCLUSION: We suggest that preoperative counseling should be implemented to inform patients of the risk of bowel dysfunction, especially in patients with lower rectal cancer, although this study cannot exclude the effect of chemoradiotherapy owing to the limitation of study.

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.

Risk factors for prolonged hospitalization and delayed treatment completion after laparoscopic appendectomy in patients with uncomplicated acute appendicitis.

PURPOSE: We sought to identify the risk factors for prolonged hospitalization and delayed treatment completion after laparoscopic appendectomy in patients with uncomplicated acute appendicitis. METHODS: The study retrospectively analyzed 497 patients who underwent laparoscopic appendectomies for uncomplicated appendicitis between January 2018 and December 2020. The patients were divided into an early discharge group (≤2 days) and a late discharge group (>2 days) based on the length of hospital stay (LOS). The patients were also divided into uneventful and complicated groups according to the need for additional treatment after standard follow-up. RESULTS: Thirty-seven patients (7.4%) were included in the late discharge group. The mean LOS of the late discharge groups was 3.9 days. There were significant differences according to age, preoperative C-reactive protein (CRP), and operative time between the 2 groups. Only operative time was significantly associated with prolonged LOS in multivariate analysis. Thirty-five patients (7.0%) were included in the complicated group. The mean duration of treatment in the uneventful and complicated groups was 7.4 and 25.3 days, respectively. Significant differences existed between the uneventful and complicated groups in preoperative body temperature, preoperative CRP levels, maximal appendix diameter, and the presence of appendicoliths. In multivariate analysis, preoperative CRP levels and maximal appendix diameter were independent predictors of delayed treatment completion. CONCLUSION: Shorter operative time is desirable to ensure minimal hospital stay in patients with uncomplicated appendicitis. Further efforts are needed to ensure that patients with uncomplicated appendicitis do not experience delayed treatment completion after laparoscopic appendectomies.

Effect of Age on Laparoscopic Surgery and Postoperative Chemotherapy in Elderly Patients With Colorectal Cancer.

PURPOSE: We aimed to evaluate the postoperative complications of laparoscopic colorectal cancer (CRC) surgery and the adverse events of postoperative chemotherapy in elderly patients compared to younger patients and to identify the factors influencing the termination of postoperative chemotherapy. METHODS: Between June 2015 and May 2018, 188 patients with CRC underwent laparoscopic surgery with curative intent. Patients aged ≥ 70 were defined as elderly. Postoperative complications and adverse events of chemotherapy were assessed by using the Clavien-Dindo classification and the Common Terminology Criteria for Adverse Events, respectively. The clinicopathological factors were analyzed retrospectively. RESULTS: Seventy-eight patients were considered elderly with a mean age of 77.5 ± 5.5 years. Overall postoperative complications occurred in 68 patients (36.2%). Age and primary tumor location were independent predictors of overall postoperative complications. Smoking history was the only independent predictor of major postoperative complications. Of 113 patients who were recommended postoperative chemotherapy, 90 patients (79.6%) received postoperative chemotherapy. Overall adverse events occurred in 40 patients (44.4%). The American Society of Anesthesiologists physical status classification and chemotherapy regimen were significantly associated with overall adverse events. The chemotherapy regimen was the only factor significantly associated with severe adverse events. Of 90 patients, postoperative chemotherapy could not be completed in 11 (12.2%). Age was the only factor significantly associated with stopping postoperative chemotherapy (P = 0.003). CONCLUSION: This study shows that laparoscopic CRC surgery and postoperative chemotherapy were feasible in elderly patients. Further efforts are needed to ensure that elderly patients have the opportunity to make informed decisions regarding postoperative chemotherapy.

Risk of osteoporosis and fracture in long-term breast cancer survivors.

Purpose: High incidence of osteoporosis has been reported in breast cancer patients due to early menopause triggered by adjuvant treatment and temporary ovarian function suppression. In this study, we sought to determine whether long-term breast cancer survivors had an elevated risk of low bone density compared to the general population. Methods: Long-term breast cancer survivors who had been treated for more than 5 years were selected for this study. Data were obtained from medical records and using a questionnaire from the Korea National Health and Nutrition Examination Survey (KNHANES). An age-matched non-cancer control group was selected from the KNHANES records. Incidence of fracture and bone mineral density (BMD) were compared between the two groups. Results: In total, 74 long-term breast cancer survivors and 296 non-cancer controls were evaluated. The incidence of fracture did not differ between the two groups (P=0.130). No differences were detected in lumbar BMD (P=0.051) following adjustment for body mass index, while hip BMD was significantly lower in breast cancer survivors (P=0.028). Chemotherapy and endocrine treatment were not related to low BMD in breast cancer survivors. In more than half of the survivors, the 10-year risk of osteoporotic fracture was less than 1%. Conclusion: Long-term breast cancer survivors had low bone density but a comparable risk of fracture compared to non-cancer age-matched controls. Further studies on the factors related to low bone density in long-term breast cancer survivors are required.

A case of thyroid metastasis originating from early gastric cancer.

We report a rare case of thyroid metastasis from early gastric cancer with lymph node metastasis in a 63-yr old woman. She was diagnosed with metastatic adenocarcinoma one and a half years after distal subtotal gastrectomy, by fine needle aspiration (FNA) using thyroid sonography. Thyroid metastasis from gastric cancer is extremely rare, and this case is particular in that it is the first report of thyroid metastasis from early gastric cancer.

Case report of laparoscopic reduction of retro-ureter incarcerated small bowel obstruction.

RATIONALE: Various types of internal hernias have been reported including paraduodenal, intersigmoidal, pericecal, foramen of Winslow, as well as transmesenteric and retroanastomotic hernias. However, small bowel obstruction secondary to an internal hernia caused by the ureter is rare, and only a few cases have been reported worldwide. We report a case of small bowel herniation caused by the ureter in a woman who underwent radical hysterectomy for cervical cancer. PATIENT CONCERNS: A 53-year-old woman presented with acute abdominal pain and vomiting and reported a history of radical hysterectomy for cervical cancer 6 years prior to presentation. DIAGNOSES: Computed tomography revealed segmental luminal dilatation of pelvic ileal loops, 2 transition zones with the beak sign in the left-sided pelvic cavity, and reduced enhancement of bowel loops. Hydronephrosis with abrupt luminal narrowing of the left distal ureter was also observed. INTERVENTIONS: Exploratory laparoscopy revealed incarcerated bowel segments beneath an adhesive band. We did not immediately cut the adhesive band and continued to trace the course of the small bowel and attempted reduction of the hernia. Reduction of the hernia was not difficult; therefore, the entire small bowel could be disentangled from the pelvic adhesions without any small bowel injury. After reduction of the herniated small bowel, we could confirm that the adhesive band was the left ureter (ureteral peristalsis was observed). The reduced segments of the small bowel appeared viable, and resection was not required. OUTCOMES: The patient was discharged 2 days postoperatively without any complication. LESSONS: Cutting band during adhesiolysis enables release of bowel obstruction. However, owing to the different types of internal hernias that are known to occur, it is essential to confirm the patient's history and preoperative CT findings to avoid complications.

Curative Resection for Metachronous Pulmonary Metastases from Colorectal Cancer: Analysis of Survival Rates and Prognostic Factors.

PURPOSE: Prognostic factors in patients with pulmonary metastases (PM) from colorectal cancer (CRC) are still controversial. This study assessed oncologic outcomes and prognostic factors in patients with metachronous PM from CRC. MATERIALS AND METHODS: Between June 2003 and December 2011, 122 patients with CRC underwent curative resection of PM detected at least 4 months after CRC resection. Clinico-pathological factors selected from the prospectively maintained database were analyzed retrospectively. RESULTS: The median disease-free interval (DFI) between resection of the primary tumor and detection of PM was 22.0 months (range, 4 to 85 months). Solitary PM were detected in 77 patients (63.1%), with a median maximal tumor diameter of 12.0 mm (range, 2 to 70 mm). Of 52 patients who underwent mediastinal lymph node (LN) dissection, eight patients had LN involvement. Five-year overall survival and disease-free survival (DFS) rates after initial pulmonary metastasectomy were 66.4% and 50.9%, respectively. DFI, mediastinal LN involvement, and the number and distribution of PM were significantly prognostic factors for DFS. In multivariable analysis DFI ≥ 12 months, solitary lesion, and absence of mediastinal LN involvement were independently prognostic for DFS. Of the 122 patients, 48 patients (39.3%) developed recurrent PM a median 13.0 months after initial pulmonary metastasectomy. Recurrent DFI was independently prognostic of DFS in patients who underwent repeated pulmonary metastasectomy. CONCLUSION: There is a potential survival benefit for patients with metachronous PM from CRC who undergo pulmonary metastasectomy, even those with recurrent PM. Pulmonary metastasectomy should be considered in selected patients, particularly those with longer DFI, solitary lesions, and absence of mediastinal LN involvement.

Use of a Comprehensive Geriatric Assessment to Predict Short-Term Postoperative Outcome in Elderly Patients With Colorectal Cancer.

PURPOSE: This study was conducted to identify the effectiveness of a preoperative comprehensive geriatric assessment (CGA) for predicting postoperative morbidity in elderly patients who underwent surgery for colorectal cancer. METHODS: Elderly patients (≥70 years old) who underwent surgery for colorectal cancer at a tertiary hospital in Korea were identified, and their cases were analyzed using data from a prospectively collected database to establish an association between major postsurgical complications and 'high-risk' patient as defined by the CGA. RESULTS: A total of 240 patients, with a mean age of 76.7 ± 5.2 years, were enrolled. Ninety-five patients (39.6%) were classified as "high-risk" and 99 patients (41.3%) as having postoperative complications. The univariate analysis indicated that risk factors for postoperative complications were age, American Society of Anesthesiologists physical status classification, serum hemoglobin, carcinoembryonic antigen, cancer stage, and "high-risk" status. The multivariable analyses indicated that "high-risk" status (odds ratio, 2.107; 95% confidence interval, 1.168-3.804; P = 0.013) and elevated preoperative carcinoembryonic antigen (odds ratio, 2.561; 95% confidence interval, 1.346-4.871, P = 0.004) were independently associated with postoperative complications. A multivariable analysis of the individual CGA domains indicated that high comorbidities and low activities of daily living were significantly related with postoperative complications. CONCLUSION: A preoperative CGA indicating "high-risk" was associated with major postoperative complications in elderly patients who underwent surgery for colorectal cancer. Thus, using the CGA to identify elderly colorectal-cancer patients who should be given more care during postoperative management may be clinically beneficial.

Validation of Prediction Models for Mismatch Repair Gene Mutations in Koreans.

PURPOSE: Lynch syndrome, the commonest hereditary colorectal cancer syndrome, is caused by germline mutations in mismatch repair (MMR) genes. Three recently developed prediction models for MMR gene mutations based on family history and clinical features (MMRPredict, PREMM(1,2,6), and MMRPro) have been validated only in Western countries. In this study, we propose validating these prediction models in the Korean population. MATERIALS AND METHODS: We collected MMR gene analysis data from 188 individuals in the Korean Hereditary Tumor Registry. The probability of gene mutation was calculated using three prediction models, and the overall diagnostic value of each model compared using receiver operator characteristic (ROC) curves and area under the ROC curve (AUC). Quantitative test characteristics were calculated at sensitivities of 90%, 95%, and 98%. RESULTS: Of the individuals analyzed, 101 satisfied Amsterdam criteria II, and 87 were suspected hereditary nonpolyposis colorectal cancer. MMR mutations were identified in 62 of the 188 subjects (33.0%). All three prediction models showed a poor predictive value of AUC (MMRPredict, 0.683; PREMM(1,2,6), 0.709; MMRPro, 0.590). Within the range of acceptable sensitivity (> 90%), PREMM(1,2,6) demonstrated higher specificity than the other models. CONCLUSION: In the Korean population, overall predictive values of the three models (MMRPredict, PREMM(1,2,6), MMRPro) for MMR gene mutations are poor, compared with their performance in Western populations. A new prediction model is therefore required for the Korean population to detect MMR mutation carriers, reflecting ethnic differences in genotype-phenotype associations.