Clinical characteristics and survival of colorectal cancer patients in Korea stratified by age

Background/Aims@#This nationwide study was undertaken to determine differences in clinicopathologic characteristics and survival of patients with colorectal cancer (CRC) according to age using big data from the Korean National Health Insurance Service (NHIS). @*Methods@#The NHIS data including quality assessment of CRC by the Health Insurance Review & Assessment Service in Korea between 2011 and 2014 were analyzed. Based on age, patients were divided into three groups: not-old patients (< 65), young-old patients (65 to 74 years old) and old-old patients (≥ 75 years old). @*Results@#We included 71,513 CRC patients. The median follow-up duration was 3.2 years (range, 0.003 to 5.5). Male patients constituted 60%. The median age of patients was 65 years (range, 18 to 102). Colon was the cancer site in 59.8% of not-old patients, 62.9% of young-old patients, and 66.1% of old-old patients. Compared to not-old patients, young-old and old-old patients were more likely to be diagnosed with colon adenocarcinoma and well/moderate differentiation or adequate differentiation (all p < 0.001). Old patients underwent more emergency operation (p < 0.001) and received less adjuvant therapy in stage I–III (p < 0.001). The probability of 3-year survival of young-old or old-old patients was worse than that for not-old patients (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.46 to 1.64) (HR, 3.19; 95% CI, 3.03 to 3.37). @*Conclusions@#Old patients with CRC show different histology from younger patients. They are more frequently to have colon as primary lesion. They undergo less adjuvant therapy. Further studies and evidence-based guidelines for older patients with CRC are warranted to improve their outcome.

Clinical characteristics and survival of colorectal cancer patients in Korea stratified by age

Background/Aims@#This nationwide study was undertaken to determine differences in clinicopathologic characteristics and survival of patients with colorectal cancer (CRC) according to age using big data from the Korean National Health Insurance Service (NHIS). @*Methods@#The NHIS data including quality assessment of CRC by the Health Insurance Review & Assessment Service in Korea between 2011 and 2014 were analyzed. Based on age, patients were divided into three groups: not-old patients (< 65), young-old patients (65 to 74 years old) and old-old patients (≥ 75 years old). @*Results@#We included 71,513 CRC patients. The median follow-up duration was 3.2 years (range, 0.003 to 5.5). Male patients constituted 60%. The median age of patients was 65 years (range, 18 to 102). Colon was the cancer site in 59.8% of not-old patients, 62.9% of young-old patients, and 66.1% of old-old patients. Compared to not-old patients, young-old and old-old patients were more likely to be diagnosed with colon adenocarcinoma and well/moderate differentiation or adequate differentiation (all p < 0.001). Old patients underwent more emergency operation (p < 0.001) and received less adjuvant therapy in stage I–III (p < 0.001). The probability of 3-year survival of young-old or old-old patients was worse than that for not-old patients (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.46 to 1.64) (HR, 3.19; 95% CI, 3.03 to 3.37). @*Conclusions@#Old patients with CRC show different histology from younger patients. They are more frequently to have colon as primary lesion. They undergo less adjuvant therapy. Further studies and evidence-based guidelines for older patients with CRC are warranted to improve their outcome.

Effect of Adjuvant Chemotherapy on Stage II Colon Cancer: Analysis of Korean National Data / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Debates exist regarding the effectiveness of adjuvant chemotherapy for stage II colon cancer. This study aimed to investigate the current status of adjuvant chemotherapy and its impact on survival for Korean stage II colon cancer patients by analyzing the National Quality Assessment data. MATERIALS AND METHODS: A total of 7,880 patientswho underwent curative resection for stage II colon adenocarcinoma between January 2011 andDecember 2014 in Koreawere selected randomly as evaluation subjects for the quality assessment. The factors that influenced overall survival were identified. The high-risk group was defined as having at least one of the following: perforation/obstruction, lymph node harvest less than 12, lymphovascular/perineural invasion, positive resection margin, poor differentiation, or pathologic T4 stage. RESULTS: The median follow-up period was 38 months (range, 1 to 63 months). Chemotherapy was a favorable prognostic factor for either the high- (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.38 to 0.59; p < 0.001) or low-risk group (HR, 0.74; 95% CI, 0.61 to 0.89; p=0.002) in multivariate analysis. This was also the case in patients over 70 years of age. The hazard ratio was significantly increased as the number of involved risk factors was increased in patients who didn’t receive chemotherapy. Adding oxaliplatin showed no difference in survival (HR, 1.36; 95% CI, 0.91 to 2.03; p=0.132). CONCLUSION: Adjuvant chemotherapy can be recommended for stage II colon cancer patients, but the addition of oxaliplatin to the regimen must be selective.

Multiple Myeloma Mimics Bone Metastasis From a Rectal Adenocarcinoma

A presumptive diagnosis of bone metastasis can be easily made when a patient with a history of colorectal cancer develops bone lesions that are seen on follow-up imaging. In this case report, we describe a patient whose multiple bone lesions were wrongly attributed to a recurrence of rectal cancer rather than being identified as multiple myeloma lesions. When clinicians detect new, abnormal, bony lesions in a patient with a previous history of cancer, they should consider diseases such as multiple myeloma in their differential diagnosis.

In Vitro Adenosine Triphosphate-Based Chemotherapy Response Assay as a Predictor of Clinical Response to Fluorouracil-Based Adjuvant Chemotherapy in Stage II Colorectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: We evaluated the usefulness of the in vitro adenosine triphosphate-based chemotherapy response assay (ATP-CRA) for prediction of clinical response to fluorouracil-based adjuvant chemotherapy in stage II colorectal cancer. MATERIALS AND METHODS: Tumor specimens of 86 patients with pathologically confirmed stage II colorectal adenocarcinoma were tested for chemosensitivity to fluorouracil. Chemosensitivity was determined by cell death rate (CDR) of drug-exposed cells, calculated by comparing the intracellular ATP level with that of untreated controls. RESULTS: Among the 86 enrolled patients who underwent radical surgery followed by fluorouracil-based adjuvant chemotherapy, recurrence was found in 11 patients (12.7%). The CDR ≥ 20% group was associated with better disease-free survival than the CDR < 20% group (89.4% vs. 70.1%, p=0.027). Multivariate analysis showed that CDR < 20% and T4 stage were poor prognostic factors for disease-free survival after fluorouracil-based adjuvant chemotherapy. CONCLUSION: In stage II colorectal cancer, the in vitro ATP-CRA may be useful in identifying patients likely to benefit from fluorouracil-based adjuvant chemotherapy.

Xanthogranulomatous Appendicitis Mimicking Residual Burkitt's Lymphoma After Chemotherapy

The case of a 23-year-old female treated with aggressive high-dose therapy for Burkitt's lymphoma is reported. A positron emission tomography and computed tomography scan after completion of chemotherapy revealed a residual hypermetabolic lesion in the right pelvic cavity. A pelvic magnetic resonance imaging scan showed circumferential wall thickening at the tip of the appendix. A laparoscopic exploration and appendectomy were performed, and a pathologic examination of the resected appendix revealed xanthogranulomatous appendicitis. This is a rare case of a xanthogranulomatous appendicitis mimicking remnant Burkitt's lymphoma after completion of chemotherapy.

Clinical Implications of Microsatellite Instability in T1 Colorectal Cancer

PURPOSE: The estimation of regional lymph node metastasis (LNM) risk in T1 colorectal cancer is based on histologic examination and imaging of the primary tumor. High-frequency microsatellite instability (MSI-H) is likely to decrease the possibility of metastasis to either regional lymph nodes or distant organs in colorectal cancers. This study evaluated the clinical implications of MSI in T1 colorectal cancer with emphasis on the usefulness of MSI as a predictive factor for regional LNM. MATERIALS AND METHODS: A total of 133 patients who underwent radical resection for T1 colorectal cancer were included. Genomic DNA was extracted from normal and tumor tissues and amplified by polymerase chain reaction (PCR). Five microsatellite markers, BAT-25, BAT-26, D2S123, D5S346, and D17S250, were used. MSI and clinicopathological parameters were evaluated as potential predictors of LNM using univariate and multivariate analyses. RESULTS: Among 133 T1 colorectal cancer patients, MSI-H, low-frequency microsatellite instability (MSI-L), and microsatellite stable (MSS) colorectal cancers accounted for 7.5%, 6%, and 86.5%, respectively. MSI-H tumors showed a female predominance, a proximal location and more retrieved lymph nodes. Twenty-two patients (16.5%) had regional LNM. Lymphovascular invasion and depth of invasion were significantly associated with LNM. There was no LNM in 10 MSI-H patients; however, MSI status was not significantly correlated with LNM. Disease-free survival did not differ between patients with MSI-H and those with MSI-L/MSS. CONCLUSION: MSI status could serve as a negative predictive factor in estimating LNM in T1 colorectal cancer, given that LNM was not detected in MSI-H patients. However, validation of our result in a different cohort is necessary.

Operative Outcomes of Open versus Laparoscopic Total Proctocolectomy with Ileal Pouch Anal Anastomosis in Ulcerative Colitis

PURPOSE: During the course of disease, nearly 30% of ulcerative colitis patients receive surgical therapy. Total proctocolectomy with ileal pouch anal anastomosis is a standard procedure. However, the effectiveness of laparoscopic surgery in ulcerative colitis has not yet been proven. We aimed to evaluate the clinical course of both laparoscopic and open surgeries of a total proctocolectomy with ileal pouch anal anastomosis. METHODS: We reviewed charts of 34 patients who underwent a total proctocolectomy with ileal pouch anal anastomosis between April 2005 and April 2014. The laparoscopic group (n=21) and the open group (n=13) were compared retrospectively in accordance with patients' demographics, clinical features, operative data, and postoperative complications within and after 30 days after the operation. RESULTS: Patient characteristics were not significantly different between the two groups. The laparoscopic group had a longer duration of disease before the operation (42.3+/-48.5 vs. 105+/-97.6, p=0.019). The operative results, including operation time and estimated blood loss, were not different in both groups. The postoperative outcomes of laparoscopic surgery were not different from those of open surgery in postoperative complications within and after 30 postoperative days. The rate of reoperation and readmission was not different, and the days until first gas passing and soft diet were not significantly different. CONCLUSION: Laparoscopic surgery in ulcerative colitis is a feasible and safe procedure. Laparoscopic surgery may provide an alternative approach to open surgery in carefully selected ulcerative colitis patients.

Associations of Colorectal Cancer Incidence with Nutrient and Food Group Intakes in Korean Adults: A Case-Control Study

This study aimed to examine the associations between intakes of various nutrients and food groups and colorectal cancer risk in a case-control study among Koreans aged 20 to 80 years. A total of 150 new cases and 116 controls were recruited with subjects' informed consent. Dietary data were collected using the food frequency questionnaire developed and validated by the Korea Centers for Disease Control and Prevention. Multivariate logistic regression models were used to estimate odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for colorectal cancer incidence. High intakes of total lipid (OR(T3 vs T1) = 4.15, 95% CI: 1.33-12.96, p for trend = 0.034), saturated fatty acid (OR(T3 vs T1) = 2.96, 95% CI: 1.24-7.04, p for trend = 0.016) and monounsaturated fatty acid (OR(T3 vs T1) = 3.04, 95% CI: 1.23-7.54, p for trend = 0.018) were significantly associated with increased incidence of colorectal cancer. High dietary fiber (OR(T3 vs T1) = 0.22, 95% CI: 0.08-0.56, p for trend = 0.002) and vitamin C (OR(T3 vs T1) = 0.38, 95% CI: 0.14-1.05, p for trend = 0.021) intakes were significantly associated with reduced colorectal cancer incidence. From the food group analysis, bread (OR(T3 vs T1) = 2.26, 95% CI: 0.96-5.33, p for trend = 0.031), red meat (OR(T3 vs T1) = 7.33, 95% CI: 2.98-18.06, p for trend < 0.001), milk.dairy product (OR(T3 vs T1) = 2.42, 95% CI: 1.10-5.31, p for trend = 0.071) and beverage (OR(T3 vs T1) = 3.17, 95% CI: 1.35-7.48, p for trend = 0.002) intakes were positively associated with colorectal cancer risk. On the other hand, high intake of traditional rice cake (OR(T3 vs T1) = 0.35, 95% CI: 0.14-0.86, p for trend = 0.024) was linked with lower colorectal cancer incidence. In conclusion, eating a diet high in total lipid, saturated fatty acids and monounsaturated fatty acids is associated with higher incidence of colorectal cancer, whereas a diet high in dietary fiber and vitamin C was found to lower the incidence in Korean adults. Interestingly high traditional rice cake consumption is associated inversely with colorectal cancer incidence, warranting a future study.

Metastatic cholangiocarcinoma as a cause of appendicitis: a case report and literature review

Metastatic carcinoma that causes appendicitis is extremely rare. To our knowledge, metastatic cholangiocarcinoma in the appendix has been reported in only 1 case in the English literature. We report herein the case of an 87-year-old woman who presented with abdominal pain and jaundice. Advanced cholangiocellular carcinoma and a proximal appendiceal mass with appendicitis were detected on contrast-enhanced computed tomography and positron emission tomography/computed tomography. After elective laparoscopic appendectomy and wedge resection of the cecum, pathologic results revealed metastatic adenocarcinoma from extrahepatic cholangiocellular carcinoma in the appendix.

Underweight Body Mass Index as a Predictive Factor for Surgical Site Infections after Laparoscopic Appendectomy

PURPOSE: Analyses of risk factors associated with surgical site infections (SSIs) after laparoscopic appendectomy (LA) have been limited. Especially, the association of an underweight body mass index (BMI) with SSIs has not been clearly defined. This study aimed to identify the impact of underweight BMI in predicting SSIs after LA. MATERIALS AND METHODS: The records of a total of 101 consecutive patients aged > or =16 years who underwent LA by a single surgeon between March 2011 and December 2012 were retrieved from a prospectively collected database. The rate of SSIs was compared among the underweight, normal and overweight and obese groups. Also, univariate and multivariate analyses were performed to identify the factors associated with SSIs. RESULTS: The overall rate of SSIs was 12.8%. The superficial incisional SSI rate was highest in the underweight group (44.4% in the underweight group, 11.0% in the normal group, and 0% in the overweight and obese group, p=0.006). In univariate analysis, open conversion and being underweight were determined to be risk factors for SSIs. Underweight BMI was also found to be a significant predictor for SSIs in multivariate analysis (odds ratio, 10.0; 95% confidence interval, 2.0-49.5; p=0.005). CONCLUSION: This study demonstrated underweight BMI as being associated with SSIs after LA. Surgeons should be more cautious to prevent SSIs in patients that are underweight when performing LA.

An Extragastrointestinal Stromal Tumor in the Omentum With Peritoneal Seeding Mimicking an Appendiceal Mucinous Cancer With Carcinomatosis

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. These tumors tend to present most frequently in the stomach, followed by the small intestine. GISTs can also arise from the omentum, retroperitoneum, mesentery, or pleura and are termed extragastrointestinal stromal tumors (EGISTs) when they do so. EGISTs arising from the omentum are very rare. Due to the limited incidence of EGISTs in the omentum, the diagnostic criteria are not well established, and making a correct diagnosis may be difficult. In this report, we present a case of an EGIST of the omentum with peritoneal metastasis that was initially suspected to be an appendiceal mucinous carcinoma with carcinomatosis on positron emission tomography/computed tomography imaging.

Feasibility and Safety of a Fold-Over Diverting Ileostomy Reversal After Rectal Cancer Surgery: Case-Matched Comparison to the Resection Technique

PURPOSE: Compared to the stapling technique, the fold-over technique (FO) has the benefit of avoiding the sacrifice of the bowel segment. The aim of this study was to compare short-term outcomes between the FO and a conventional resection. METHODS: Between June 2008 and March 2012, a total of 242 patients who underwent a diverting ileostomy reversal after rectal cancer surgery were selected. Among them, 29 patients underwent the FO. Using propensity scores to adjust for body mass index, previous abdominal surgery history, rectal cancer surgery type (open vs. minimally invasive), and reason for ileostomy (protective aim vs. leakage management), we created a well-balanced cohort by matching each patient who underwent the FO, as the study group, with two patients who underwent a stapled or a hand-sewn technique with bowel resection (RE), as the control group (FO : RE = 1 : 2). Morbidity and perioperative recovery were compared between the two groups. RESULTS: Twenty-four and forty-eight patients were allocated to the FO and the RE groups, respectively. The mean operation time was 91 +/- 26 minutes in the FO group and 97 +/- 34 minutes in the RE group (P = 0.494). The overall morbidity rates were not different between the two groups (12.5% in FO vs. 14.6% in RE, P = 1.000). The rate of postoperative ileus was similar between the two groups (8.3% in FO vs. 12.5% in RE, P = 0.710). Although time to resumption of soft diet was shorter in the FO group than in the RE group, the lengths of hospital stay were not different. CONCLUSION: The FO and the conventional resection have similar short-term clinical outcomes for diverting ileostomy reversal.

Clinical impact of fat clearing technique in nodal staging of rectal cancer after preoperative chemoradiotherapy / 대한외과학회지

PURPOSE: This study was designed to evaluate the efficacy of a fat clearing technique for accurate nodal staging of rectal cancer patients after preoperative chemoradiotherapy (CRT). METHODS: A total of 19 patients with rectal cancer within 10 cm from anal verge were divided into two groups: non-CRT group (n = 10) and CRT group (n = 9). For pathologic assessment, lymph node (LN) harvest was performed using conventional manual dissection followed by a fat clearing technique. RESULTS: A median of 3.0 additional LNs in non-CRT group and 3.8 LNs in CRT group were identified by the fat clearing technique. When subanalysis was performed in patients with fewer than 12 retrieved LNs, a median of 4.0 extra LNs in non-CRT group and 3.5 extra LNs in CRT group were identified after the fat clearing technique. None of additionally identified nodes were metastatic. In both groups, the median size of retrieved LNs following the fat clearing technique was smaller than that obtained by manual dissection (2.0 mm vs. 3.0 mm, P < 0.001). CONCLUSION: The fat clearing technique allowed detection of additional LNs that were missed by the manual method, but these detected LNs were not proven to be metastatic.

Circumferential Resection Margin Involvement in Stage III Rectal Cancer Patients Treated with Curative Resection Followed by Chemoradiotherapy: A Surrogate Marker for Local Recurrence?

PURPOSE: Circumferential resection margin (CRM) involvement is a well-known predictor for poor prognosis in rectal cancer. However, the significance is controversial in some studies. Accordingly, this study attempted to examine the prognostic impact of CRM involvement in stage III rectal cancer. MATERIALS AND METHODS: Between January 1990 and December 2007, a total of 449 patients who underwent curative resection followed by complete adjuvant chemoradiotherapy for stage III rectal cancer located within 12 cm from the anal verge were selected. Patients were divided into a CRM-positive group (n=79, 17.6%) and a CRM-negative group (n=370, 82.4%). RESULTS: With a median follow-up of 56.6 months, recurrent disease was seen in 53.2 and 43.5% of the CRM-positive and CRM-negative group, respectively. CRM involvement was an independent prognostic factor for 5-year systemic recurrence-free survival (HR: 1.5, CI: 1.0-2.2, p=0.017). However, no significant difference was observed for local recurrence rate between the two groups (13.0 and 13.5%, respectively, p=0.677). CONCLUSION: In this study, local recurrence rate did not differ according to CRM involvement status in stage III rectal cancer patients, although CRM involvement was shown to be an independent poor prognostic factor. Accordingly, validation of the results of this study by further large prospective randomized trials is warranted.

Contributing Factors on Lymph Node Yield after Surgery for Mid-Low Rectal Cancer

PURPOSE: The purpose of the present study was to evaluate the contributing factors to the lymph node status as well as to define the impact of preoperative concurrent chemoradiotherapy (CCRT) on the number of lymph nodes retrieved in mid-low rectal cancer. MATERIALS AND METHODS: We retrospectively analyzed 277 patients who underwent curative surgical resection for mid-low rectal cancer between 1998 and 2007. Eighty-two patients received long course preoperative CCRT followed by surgery. RESULTS: A mean of 13.12+/-9.28 lymph nodes was retrieved. In a univariate analysis, distance from the anal verge, pT stage, pN stage, lymphovascular invasion, preoperative CCRT had significant influence on the number of lymph nodes retrieved. In a multivariate model, patients in the CCRT group had fewer retrieved lymph nodes than the non-CCRT group (p<0.001). Both univariate and multivariate analyses showed that the ypN0 group had fewer retrieved lymph nodes than the ypN1-2 group (p=0.027) in the CCRT group. CONCLUSION: Preoperative CCRT was an independent risk factor for failure to harvest an appropriate number of lymph nodes, and node-negative patients who received CCRT had fewer lymph nodes harvested.

Clinical Impact of Tumor Regression Grade after Preoperative Chemoradiation for Locally Advanced Rectal Cancer: Subset Analyses in Lymph Node Negative Patients

BACKGROUND: We investigated the prognostic significance of tumor regression grade (TRG) after preoperative chemoradiation therapy (preop-CRT) for locally advanced rectal cancer especially in the patients without lymph node metastasis. METHODS: One-hundred seventy-eight patients who had cT3/4 tumors were given 5,040 cGy preoperative radiation with 5-fluorouracil/leucovorin chemotherapy. A total mesorectal excision was performed 4-6 weeks after preop-CRT. TRG was defined as follows: grade 1 as no cancer cells remaining; grade 2 as cancer cells outgrown by fibrosis; grade 3 as a minimal presence or absence of regression. The prognostic significance of TRG in comparison with histopathologic staging was analyzed. RESULTS: Seventeen patients (9.6%) showed TRG1. TRG was found to be significantly associated with cancer-specific survival (CSS; P = 0.001) and local recurrence (P = 0.039) in the univariate study, but not in the multivariate analysis. The ypN stage was the strongest prognostic factor in the multivariate analysis. Subgroup analysis revealed TRG to be an independent prognostic factor for the CSS of ypN0 patients (P = 0.031). TRG had a stronger impact on the CSS of ypN (-) patients (P = 0.002) than on that of ypN (+) patients (P = 0.521). In ypT2N0 and ypT3N0, CSS was better for TRG2 than for TRG3 (P = 0.041, P = 0.048), and in ypN (-) and TRG2 tumors, CSS was better for ypT1-2 than for ypT3-4 (P = 0.034). CONCLUSION: TRG was found to be the strongest prognostic factor in patients without lymph node metastasis (ypN0), and different survival was observed according to TRG among patients with a specific histopathologic stage. Thus, TRG may provide an accurate prediction of prognosis and may be used for f tailoring treatment for patients without lymph node metastasis.

Clinical Characteristics and Treatment Outcomes of Colorectal Cancer in Renal Transplant Recipients in Korea

PURPOSE: Transplant recipients in Asia appear to be at a higher risk for developing colorectal cancer (CRC). This study was performed to identify the clinicopathological features and oncologic outcomes of CRC in post-renal transplants in Korea. MATERIALS AND METHODS: We retrospectively reviewed the records of 17 patients with CRC out of 2,630 recipients who underwent renal transplantation between 1994 and 2007. These patients (transplant group) were compared with general CRC patients (n=170, control group) matched, based on the closest date of surgery to the transplant group. RESULTS: During 29.7 months of the median follow-up period, the recurrent and survival rates from recurrence were worse in the transplant group than in the control group (35.2% versus 15.2%; p=0.048 and p=0.025). The 2-year patient survival rate of the transplant group was significantly worse than the control group in advanced cancer (stages III-IV; 45.7% versus 71.6%; p=0.023). In early cancer (stages 0-I), there was no significant difference in 5-year patient survival rate between the two groups (100% versus 92.6%, respectively; p=0.406). CONCLUSION: In spite of a poor prognosis of advanced CRC in the transplant group, the early stage CRC of the transplant group showed a comparable oncologic outcome compared with the control group. Regular screening and early detection of CRC are essential in the post-transplant setting.

Cessation or dose reduction of Capecitabine due to Complications in Patients with Colon Cancer

No abstract available.

A Prospective, Multicenter, Randomized Trial for Duration of the Prophylactic Antibiotics after Elective Colorectal Surgery: 3 Days versus 5 Days

PURPOSE: The use of prophylactic antibiotics in elective colorectal surgery is essential. Although postoperative prophylactic antibiotics are recommended within 24 hr, the optimal duration of the use of prophylactic antibiotics after colorectal surgery has not yet been fully proven in Korea. The aim of this study was to compare infectious outcomes in elective colorectal cancer surgery between postoperative 3-day antibiotic therapy and 5-day therapy. METHODS: We conducted a multicenter, randomized trial of a 3-day use vs. a 5-day use of the second-generation cephalosporin cefotetan after elective colorectal surgery. The main outcome measures were the incidences of surgical site infection and all other infectious complications within 21 days after surgery. RESULTS: A total of 306 patients were enrolled. Fifty-one patients were excluded because they received additional surgery or dropped out during the study. Two-hundred fifty-five patients were analyzed in this study. The two groups were similar in terms of demographics, ASA score, tumor location, tumor stage, surgical approach (conventional open vs. laparoscopy-assisted vs. robotic-assisted), and type of operation. The incidences of surgical site infection were not significantly different between the 3-day use group (4/130 or 3.1%) and the 5-day use group (3/125 or 2.4%) (P=1.000). Incidences of overall infectious diseases did not differ significantly between the two groups. Postoperatively, both groups had similar values in their white blood cell count, absolute neutrophil count, and C-reactive protein levels. However, the number of patients is small to draw a definite conclusion in this study. CONCLUSION: Three-day cefotetan administration may be not inferior in preventing surgical site infection compared to 5-day antibiotic administration. However, further studies with a large number of patients are needed before a definite conclusion can be drawn.