Significance of Adjuvant Chemotherapy for Obstructive Colorectal Cancer After Stent Placement: A Multicenter Retrospective Study.

BACKGROUND/AIM: To explore the survival benefit of adjuvant chemotherapy for obstructive colorectal cancer (OCRC) managed by self-expandable metallic stent (SEMS) placement as a bridge to surgery (BTS). PATIENTS AND METHODS: One hundred twenty-nine patients with pathological stage II/III OCRC who underwent BTS using a SEMS were included in this multicenter retrospective study. Patients were divided into the no-adjuvant chemotherapy group (No-Adj group) (n=52) and adjuvant chemotherapy group (Adj group) (n=77), and relapse-free survival (RFS) was compared. RESULTS: The No-Adj group had more fragile patient background factors, such as higher age, higher American Society of Anesthesiologists score, and lower preoperative albumin compared with the Adj group. The 3-year RFS rates for the overall cohort were significantly different between the No-Adj and Adj groups (56.4% and 78.5%, respectively; p=0.003). Significant RFS benefits of adjuvant chemotherapy were observed in both pathological stage II and III cancer. Characteristics of more advanced cancer, such as high carcinoembryonic antigen (CEA), pathological T4, and lymphovascular invasion, were associated with survival improvement by adjuvant chemotherapy. T4 and adjuvant chemotherapy were significantly associated with RFS in the multivariate Cox proportional analysis. CONCLUSION: To our knowledge, this is the first study to show a survival benefit of adjuvant chemotherapy in patients with OCRC undergoing BTS using a SEMS. Adjuvant chemotherapy is basically recommended regardless of the cancer stage and is strongly recommended with more advanced characteristics, such as high CEA, T4, and lymphovascular invasion.

The benefits of interval appendectomy and risk factors for nonoperative management failure in the therapeutic strategy for complicated appendicitis.

PURPOSE: Emergency surgery (ES) for complicated appendicitis (CA) is associated with high morbidity. Interval appendectomy (IA) decreases this rate; however, nonoperative management (NOM) is not always successful. Some patients require unplanned ES due to NOM failure (IA failure: IA-F). This study aimed to verify the benefits of IA and to evaluate the risk factors for NOM failure. METHODS: Patients diagnosed with CA who underwent surgery between January 2012 and December 2021 were included in this study. We compared the surgical outcomes of the ES group with those of the IA success (IA-S) and IA-F groups. We also analyzed 14 factors that predicted NOM failure. RESULTS: Among 302 patients, the rate of severe complications (Clavien-Dindo grade ≥ III) was significantly higher in the ES group (N = 165) than in the IA-S group (N = 102). The rates were equal between the ES (N = 165) and IA-F (N = 35) groups. NOM was successful in 110 patients and failed in 27. Lack of abscesses, comorbidities, high WBC count, and free air were independent risk factors for NOM failure. CONCLUSIONS: Considering the benefits of IA and the non-inferior surgical outcomes of IA-F compared to ES, IA is a good therapeutic strategy for CA. However, in patients exhibiting four independent risk factors for NOM failure, careful monitoring of unplanned ES is necessary.

Oncologic investigation of the interval from stent placement to surgery in patients with obstructive colorectal cancer.

PURPOSE: Self-expandable metallic stent (SEMS) placement is widely used as a bridge to surgery (BTS) procedure for obstructive colorectal cancer. However, evidence regarding the optimal interval between SEMS placement and elective surgery is lacking. METHODS: We retrospectively collected data from patients with BTS between January 2013 and October 2021. Inverse probability treatment-weighted propensity score analyses were used to compare short- and long-term outcomes between the short-interval (SI) and long-interval (LI) groups, using a cutoff of 20 days. RESULTS: In total, 138 patients were enrolled in this study (SI group, n = 63; LI group, n = 75). In the matched cohort, the patients' backgrounds were well balanced. The incidence of Clavien-Dindo grade ≥ II postoperative complications was not significantly different between the SI and LI groups (19.0% vs. 14.0%, P = 0.47). There were no significant differences between the SI and LI groups in the 3-year recurrence-free survival (68.0% vs. 76.4%, P = 0.73) or 3-year overall survival rates (86.0% vs. 90.6%, P = 0.72). CONCLUSIONS: A longer interval did not deteriorate the oncological outcomes. Individual perioperative management with an appropriate interval to improve the patient's condition is required to ensure safe surgery.

Pks-positive Escherichia coli in tumor tissue and surrounding normal mucosal tissue of colorectal cancer patients.

A significant association exists between the gut microbiome and colorectal carcinogenesis, as well as cancer progression. It has been reported that Escherichia coli (E. coli) containing polyketide synthetase (pks) island contribute to colorectal carcinogenesis by producing colibactin, a polyketide-peptide genotoxin. However, the functions of pks+ E. coli in initiation, proliferation, and metastasis of colorectal cancer (CRC) remain unclear. We investigated the clinical significance of pks+ E. coli to clarify its functions in CRC. This study included 413 patients with CRC. Pks+ E. coli of tumor tissue and normal mucosal tissue were quantified using droplet digital PCR. Pks+ E. coli was more abundant in Stages 0-I tumor tissue than in normal mucosal tissue or in Stages II-IV tumor tissue. High abundance of pks+ E. coli in tumor tissue was significantly associated with shallower tumor depth (hazard ratio [HR] = 5.0, 95% confidence interval [CI] = 2.3-11.3, p < 0.001) and absence of lymph node metastasis (HR = 3.0, 95% CI = 1.8-5.1, p < 0.001) in multivariable logistic analyses. Pks+ E. coli-low and -negative groups were significantly associated with shorter CRC-specific survival (HR = 6.4, 95% CI = 1.7-25.6, p = 0.005) and shorter relapse-free survival (HR = 3.1, 95% CI = 1.3-7.3, p = 0.01) compared to the pks+ E. coli-high group. Pks+ E. coli was abundant in Stages 0-I CRC and associated with CRC prognosis. These results suggest that pks+ E. coli might contribute to carcinogenesis of CRC but might not be associated with tumor progression.

Successful management of malignant colovesical fistula using covered colonic self-expanding metallic stent: a case report.

BACKGROUND: A colovesical fistula (CVF) is commonly treated by resection of the intestine containing the fistula or creation of a defunctioning stoma. We herein report a case of successful fistula closure and avoidance of colostomy after placement of a covered colonic self-expanding metallic stent (SEMS) as a palliative treatment for a malignant CVF. CASE PRESENTATION: A 75-year-old man undergoing infusional 5-fluorouracil and irinotecan chemotherapy plus bevacizumab for recurrent peritoneal dissemination of rectal cancer was admitted to our hospital because of fecaluria with a high-grade fever. Blood tests showed a moderate inflammatory reaction (white blood cell count, 9200/mm3; C-reactive protein, 11.03 mg/dL; procalcitonin, 1.33 ng/mL). Urinary sediment examination showed severe bacteriuria. Abdominal contrast-enhanced computed tomography showed intravesical gas, thickening of the posterior wall of the bladder, and irregular thickening of the sigmoid colon wall contiguous with the posterior bladder wall. Magnetic resonance imaging (MRI) clearly showed a fistula between the bladder and sigmoid colon. Colonoscopy revealed a circumferential malignant stricture 15 cm from the anal verge, and a fistula to the bladder was identified by water-soluble contrast medium. We diagnosed a complicated urinary tract infection (UTI) associated with a CVF due to peritoneal dissemination and started empirical treatment with sulbactam/ampicillin. Given the absence of active inflammatory findings around the fistula on MRI and the patient's physical frailty, we decided to place a covered SEMS to close the fistula. Under fluoroscopic and endoscopic guidance, a covered colonic SEMS of 80-mm length and 20-mm diameter was successfully deployed, and the fistula was sealed immediately after placement. Urine culture on day 3 after stenting was negative for bacteria, and a contrast study on day 5 showed no fistula. The patient was discharged home on day 6 with no complications. The UTI did not recur for 4 months after discharge. CONCLUSIONS: A covered colonic SEMS was useful for sealing a malignant CVF in a patient unfit for surgery, and MRI was valuable to determine the status of the fistula. A covered colonic SEMS could be an alternative to surgical treatment for CVFs in patients who require palliative care.

Prognostic impact of postoperative infection after resection of biliary malignancy: A multicenter retrospective cohort study.

BACKGROUND: The aim of this study was to investigate the prognostic impact of postoperative infections in patients who underwent resection for biliary malignancy, including intrahepatic cholangiocarcinoma, perihilar cholangiocarcinoma, distal cholangiocarcinoma, gallbladder carcinoma, and carcinoma of the ampulla of Vater. METHODS: This study was conducted in an 11-center retrospective cohort study. Patients with biliary tract cancer who underwent curative resection between April 2013 and March 2015 at 11 institutions in Japan were enrolled. We analyzed the prevalence of postoperative infection, infection-related factors, and prognostic factors. RESULTS: Of the total 290 cases, 33 were intrahepatic cholangiocarcinoma, 60 were perihilar cholangiocarcinoma, 120 were distal cholangiocarcinoma, 55 were gallbladder carcinoma, and 22 were carcinoma of the ampulla of Vater. Postoperative infectious complications, including remote infection, were observed in 146 patients (50.3%), and Clavien-Dindo ≥III in 115 patients (39.7%). Postoperative infections occurred more commonly in the patients who received pancreaticoduodenectomy and bile duct resection. Patients with infectious complications had a significantly poorer prognosis than those without (median overall survival 38 months vs 62 months, P = .046). In a diagnosis-specific analysis, although there was no correlation between infectious complications and overall survival in intrahepatic cholangiocarcinoma, perihilar cholangiocarcinoma, distal cholangiocarcinoma, and carcinoma of the ampulla of Vater, infectious complications were a significantly poor prognostic factor in gallbladder carcinoma (P = .031). CONCLUSION: Postoperative infection after surgery for biliary tract cancer commonly occurred, especially in patients who underwent pancreaticoduodenectomy and bile duct resection. Postoperative infection is relatively associated with the prognosis of patients with biliary malignancy, especially gallbladder carcinoma.

Long-term outcomes between self-expandable metallic stent and transanal decompression tube for malignant large bowel obstruction: A multicenter retrospective study and meta-analysis.

Aim: To compare the oncological outcomes between self-expandable metallic stent (SEMS) as a bridge to surgery and transanal decompression tube (TDT) placement for malignant large bowel obstruction (MLBO). Methods: A total of 287 MLBO patients who underwent SEMS (n = 137) or TDT placement (n = 150) were enrolled in this multicenter retrospective study. Overall survival (OS) and disease-free survival (DFS) between the two groups were compared. A meta-analysis was performed using random-effects models to calculate odd ratios (OR) with 95% confidence intervals (CIs). Results: Postoperative complications of Clavien-Dindo grade ≥II and ≥III occurred frequently in the TDT group compared with the SEMS group (P = 0.002 and 0.005, respectively). The 3-y OS in the overall cohort and 3-y DFS in the pathological stage II/III cohort in the SEMS and TDT groups were 68.6% and 71.4%, and 71.0% and 72.6%, respectively. The survival differences were not significantly different in the OS and DFS analyses (P = 0.819 and P = 0.892, respectively). A meta-analysis of nine studies (including our cohort data) demonstrated no significant difference between the SEMS and TDT groups for 3-y OS and DFS (OR = 0.96, 95% CI = 0.57-1.62, P = 0.89 and OR = 0.69, 95% CI = 0.46-1.04, P = 0.07, respectively). Conclusion: Our study demonstrated that SEMS placement had no inferiority regarding long-term outcomes, including OS and DFS, compared with TDT placement. Considering the short-term benefits of SEMS placement, this could be a preferable preoperative decompression method for MLBO.

Segmental or right hemi-colectomy? The optimal surgical procedure for transverse colon cancer: a propensity score-matched, multicenter, retrospective study.

PURPOSE: Extended colectomy is sometimes chosen for treatment of transverse colon cancer (TCC) because of concerns about short- and long-term outcomes. However, there is still a lack of evidence regarding the optimal surgical procedure. METHODS: We retrospectively collected and analyzed data of patients who underwent surgical treatment of pathological stage II/III TCC at four hospitals from January 2011 to June 2019. We excluded the patients with TCC located at distal transverse colon, and just evaluated and analyzed proximal and middle third TCC. Inverse probability treatment-weighted propensity score analyses was used to compare short- and long-term outcomes between patients who underwent segmental transverse colectomy (STC) and those who underwent right hemicolectomy (RHC). RESULTS: In total, 106 patients were enrolled in this study (STC group, n = 45; RHC group, n = 61). The patients' backgrounds were well balanced after matching. The incidence of major postoperative complications (Clavien-Dindo grade ≥ III) was not significantly different between the STC and RHC groups (4.5% vs. 5.6%, respectively; P = 0.53). The 3-year recurrence-free survival and overall survival rates were not significantly different between the STC and RHC groups (88.2% vs. 81.8%, P = 0.86 and 90.3% vs. 91.9%, P = 0.79, respectively). CONCLUSION: RHC has no significant benefits over STC with respect to either short- or long-term outcomes. STC with necessary lymphadenectomy could be an optimal procedure for proximal and middle TCC.

Do postoperative infectious complications really affect long-term survival in colorectal cancer surgery? A multicenter retrospective cohort study.

Aim: To investigate the impact of postoperative infection (PI), surgical site infection, and remote infection (RI), on long-term outcomes in patients with colorectal cancer (CRC). Methods: The Japan Society for Surgical Infection conducted a multicenter retrospective cohort study involving 1817 curative stage I/II/III CRC patients from April 2013 to March 2015. Patients were divided into the No-PI group and the PI group. We examined the association between PI and oncological outcomes for cancer-specific survival (CSS) and overall survival (OS) using Cox proportional hazards models and propensity score matching. Results: Two hundred and ninety-nine patients (16.5%) had PIs. The 5-year CSS and OS rates in the No-PI and PI groups were 92.8% and 87.6%, and 87.4% and 83.8%, respectively. Both the Cox proportional hazards models and propensity score matching demonstrated a significantly worse prognosis in the PI group than that in the No-PI group for CSS (hazard ratio: 1.60; 95% confidence interval: 1.10-2.34; P = .015 and P = .031, respectively) but not for OS. RI and the PI severity were not associated with oncological outcomes. The presence of PI abolished the survival benefit of adjuvant chemotherapy. Conclusions: These results suggest that PI after curative CRC surgery is associated with impaired oncological outcomes. This survival disadvantage of PI was primarily derived from surgical site infection, not RI, and PI induced lower efficacy of adjuvant chemotherapy. Strategies to prevent PI and implement appropriate postoperative treatment may improve the quality of care and oncological outcomes in patients undergoing curative CRC surgery.

Postoperative infectious complications have a negative oncological impact in patients after stent placement with malignant large bowel obstruction.

PURPOSE: In this study, we aimed to investigate the oncological impact of postoperative infection in patients with malignant large bowel obstruction managed by self-expandable metallic stent placement as a bridge to surgery. METHODS: The cohort of this multicenter retrospective study comprised 129 patients with pathological stage II/III malignant large bowel obstruction who had undergone bridge to surgery. Patients were allocated to no-postoperative infection (n = 116) and postoperative infection groups (n = 13). RESULTS: The postoperative infection group had a significantly greater proportion of men, fewer harvested lymph nodes, and longer postoperative hospital stays than did the no-postoperative infection group. Self-expandable metallic stent-related variables, including clinical failure, were not associated with postoperative infection. Male sex and low body mass index were identified as risk factors for postoperative infection by multivariate logistic regression. Three-year relapse-free survival rates were 75.5% and 30.8% in the no-postoperative infection and postoperative infection groups, respectively; this difference is statistically significant. Male sex, postoperative infection, and T4 were identified as independent prognostic factors by multivariate Cox proportional hazard analysis. The postoperative infection group had a significantly higher total recurrence rate and shorter interval to recurrence than did the no-postoperative infection group. CONCLUSION: To the best of our knowledge, this is the first study to show that postoperative infection in bridge to surgery patients has a negative oncological impact. This finding indicates that further improvement in perioperative management of bridge to surgery patients is required to minimize postoperative infection and that patient-risk stratification and additional therapy would contribute to improving oncological outcomes.

The T-CEA score: a useful prognostic indicator based on postoperative CEA and pathological T4 levels for patients with stage II-III colorectal cancer.

PURPOSE: To investigate a prognostic score for stage II-III colorectal cancer (CRC) based on post-CEA and pT4 levels. METHODS: Two cohorts of stage II-III CRC patients who underwent curative surgery between 2011 and 2017 were included. The prognostic score (T-CEA score) was calculated as follows: T-CEA-0, post-CEA ≤ 5 ng/mL and pT1-3; T-CEA-1, post-CEA > 5 ng/mL or pT4; T-CEA-2, post-CEA > 5 ng/mL and pT4. RESULTS: The T-CEA scores of the 587 patients were as follows: T-CEA-0 (n = 436; 74%), T-CEA-1 (n = 129; 22%), and T-CEA-2 (n = 10; 2%). The 5-year recurrence-free survival (RFS) rates of the T-CEA-0, 1, and 2 groups were 80.3%, 54.8%, and 0%, respectively (P < 0.01), and the 5-year overall survival (OS) rates were 90.9%, 74.2%, and 0%, respectively (T-CEA-0 vs T-CEA-1: P < 0.01, T-CEA-1 vs T-CEA-2: P = 0.04). Multivariate analysis revealed that an elevated T-CEA score of 1 or 2 was a significant risk factor for poor RFS (HR: 2.89, P < 0.01) and OS (HR: 2.85, P < 0.01). CONCLUSION: The T-CEA score is a reliable and convenient prognostic score for stage II-III CRC.

Laparoscopic Repair Using Self-Fixating Mesh in an Adult Patient with a Sciatic Hernia and Irreducible Small Bowel: A Case Report and Literature Review.

Sciatic hernia is a rare type of pelvic floor hernia. The herniated tissue can include the ureter, small and large bowel, and ovary, among other tissues. Only a few cases of laparoscopic treatment for a sciatic hernia with small-bowel incarceration have been reported. We report our experience using a laparoscopic approach for treatment of sciatic hernia in an 83-year-old woman and review the literature on sciatic hernias. The patient was referred to our hospital complaining of constipation and abdominal bloating. Computed tomography (CT) scanning showed a right sciatic hernia containing the small bowel. Laparoscopic repair of the sciatic hernia was performed using a self-fixating mesh. The patient was discharged after an uneventful postoperative course and has not developed abdominal bloating or constipation postoperatively. In conclusion, a sciatic hernia was successfully repaired using a laparoscopic trans-preperitoneal approach and ProGrip Self-Fixating Mesh.

Biomarkers for anti-vascular endothelial growth factor drugs.

Angiogenesis is regulated by interactions between vascular endothelial growth factors (VEGFs) and VEGF receptors. VEGF-A, VEGF-D, placental growth factor (PlGF) and plasminogen activator inhibitor-1 (PAI-1) have tumor angiogenic activity. VEGF-A and PAI-1 levels in the blood may impact the activity of bevacizumab, and VEGF-D levels may similarly diminish the efficacy of ramucirumab. However, the dynamics of these angiogenic biomarkers for anti-VEGF therapy have not been well established; therefore, they were evaluated in this retrospective study, which included two cohorts. Cohort 1 included patients who were treated with cytotoxic agents and bevacizumab as first-line chemotherapy, and Cohort 2 comprised patients who were treated with cytotoxic agents and anti-VEGF drugs (bevacizumab, ramucirumab or aflibercept) as second-line chemotherapy. VEGF-A, VEGF-D, PlGF and PAI-1 levels were measured before starting chemotherapy and were re-assessed every 1-2 months until disease progression. Bevacizumab had reduced benefit as a first-line chemotherapeutant in patients with very low or very high levels of VEGF-A. Bevacizumab increased VEGF-A and PlGF levels, but not VEGF-D or PAI-1. Anti-VEGF drugs offered the greatest benefit to patients with high PAI-1 before first- and second-line chemotherapy. PAI-1 levels were not affected by anti-VEGF drugs. Since ramucirumab increased VEGF-D, it offered less benefit to patients with high VEGF-D in second-line chemotherapy. Conversely, aflibercept offered greater benefits to patients with high VEGF-D, without increasing VEGF-D. These biomarkers may be useful for the prediction of drug efficacy and may predict resistance to anti-VEGF drugs.

Prognostic impact of postoperative infection in patients with pancreatic cancer: A multicenter cohort study.

BACKGROUND: Postoperative infection after pancreatectomy in patients with pancreatic cancer often leads to poor prognosis. The aim of this study was to determine the prognostic effect of postoperative infection in patients with pancreatic cancer. METHODS: A multicenter cohort study was performed using a common database of patients with pancreatic cancer who underwent curative pancreatic resections between April 2013 and March 2015 at 15 high-volume centers in Japan. The rate of postoperative infection was determined, and patient demographic characteristics, clinicopathologic factors, and prognostic factors for overall survival were analyzed. RESULTS: Of the 462 eligible patients who underwent curative pancreatectomy, postoperative infection occurred in 141 patients (31%), including 114 surgical site infections (25%), 50 remote infections (11%), and 23 combined infections (5%). Risk factors for postoperative infection included high body mass index, nondiabetes, and longer operation time. In the survival analysis, patients with postoperative infection had significantly worse overall survival than patients without postoperative infection. The median survival times were 21.9 and 33.0 months (P = .023), respectively, for patients with and without postoperative infection. According to the multivariate analysis for overall survival, lack of adjuvant therapy (P = .002), but not postoperative infection (P = .829), predicted poor prognosis. The multivariate analysis revealed that postoperative infection (P < .001) was an independent risk factor for lack of adjuvant therapy. CONCLUSION: Postoperative infection in patients with pancreatic cancer may indirectly worsen the prognosis by preventing timely adjuvant therapy.

Clinical impact of laparoscopic surgery and adhesion prevention material for prevention of small bowel obstruction.

Aim: Adhesive small bowel obstructions (SBO) are one of the most common complications following abdominal surgery, and they decrease patient quality of life. Since 2000, laparoscopic surgery has been employed with increasing frequency, as has adhesion prevention material (APM). In this study we tried to evaluate whether laparoscopic surgery and APM reduce the incidence of SBO. Methods: In Cohort 1, we included patients who developed SBO and received inpatient treatment between 2015 and 2018. We evaluated the elapsed time between precedent surgery and the onset of SBO, and what kind of surgery most often causes SBO. In Cohort 2, we included patients who underwent digestive surgery between 2012 and 2014 and evaluated SBO incidence within 5 y after the precedent surgery. Results: In all, 2058 patients were included in Cohort 1. Of these, 164 had experienced no precedent surgery. Among patients with a history of abdominal surgery, 29.7% experienced SBO within 1 y after the precedent surgery and 48.1% within 3 y. Altogether, 18798 patients were analyzed in Cohort 2. The incidence of SBO after laparoscopic colorectal surgery was lower than that of open colorectal surgery (P < .001), and laparoscopic gastroduodenal surgery was also lower (P = .02). However, there were no differences between laparoscopic and open surgery for other types of surgery. The use of APM had no effect on SBO incidence in any type of abdominal surgery. Conclusions: Laparoscopic surgery helps to reduce SBO incidence only in colorectal surgery, and possibly in gastroduodenal surgery. APM does not reduce SBO after abdominal surgery.

Periappendiceal fluid collection on preoperative computed tomography can be an indication for interval appendectomy: a retrospective study.

BACKGROUND: The treatment strategies for acute appendicitis, such as emergency appendectomy (EA), interval appendectomy (IA), and repeating nonoperative management (NOM), are controversial. In this study, we examined the preoperative factors that can be used to distinguish which patients should undergo IA. METHODS: We retrospectively identified 902 patients who underwent surgery for appendicitis in our hospital from January 2010 to December 2021. Of these patients, 776 were included in this study. The patients were divided into two groups: those with a periappendiceal fluid collection (PAFC) on preoperative computed tomography (PAFC-positive group, n = 170) and those without a PAFC (PAFC-negative group, n = 606). In each group, we compared patients who underwent EA and IA. RESULTS: In the PAFC-positive group, patients who underwent EA had a significantly higher postoperative complication rate than those who underwent IA (40.5% vs. 24.0%, p = 0.037). In the multivariate analysis, only the presence of PAFC was significantly associated with an increased risk of postoperative complications (odds ratio, 7.11; 95% confidence interval, 2.73-18.60; p < 0.001). The presence of PAFC alone was not significantly associated with an increased risk of IA or NOM failure (odds ratio, 1.48; 95% confidence interval, 0.19-11.7; p = 0.71). The rate of neoplasia on pathologic examination was significantly higher in the PAFC-positive than PAFC-negative group (7.6% vs. 1.5%, p < 0.001); the rate of carcinoma was also higher in the PAFC-positive group (2.4% vs. 0.17%, p = 0.02). CONCLUSIONS: The presence of PAFC on preoperative computed tomography was found to be a risk factor for postoperative complications but not IA or NOM failure. It was also correlated with neoplasia as the etiology of appendicitis. Therefore, PAFC positivity is useful as an indication for IA.

A Trial Protocol to Investigate the Incidence of Postoperative Bowel Obstruction after Laparoscopic Colorectal Cancer Surgery Using an Absorbable Adhesion Barrier Material (INTERCEEDⓇ) (Balsam CEED Study): A Prospective, Multicenter, Observational Study.

BACKGROUND: Some studies have reported that adhesion prevention barriers (APBs) reduce adhesion after abdominal surgery; however, evidence showing that APBs reduce the incidence of postoperative small bowel obstruction (SBO), one of the most serious complications after abdominal surgery, is little. One concern is that APBs are usually applied only under the midline incision, although adhesion can occur at any place in the peritoneum where an incision is made during surgery. INTERCEEDⓇ is an APB that reportedly prevents postoperative SBO after surgery. This study aims to assess the clinical utility of INTERCEEDⓇ for the prevention of SBO after laparoscopic colorectal cancer surgery and determine whether the application site of INTERCEEDⓇ affects the incidence of SBO. METHODS/DESIGN: This study is a prospective, multicenter, observational study conducted in Japan. The primary end point is the incidence of postoperative SBO 2 years after laparoscopic colorectal cancer surgery. The secondary end points include whether the site of the application of INTERCEEDⓇ affects the incidence of SBO. Each surgeon selects one of the following three procedures: 1) INTERCEEDⓇ is placed only under the midline incision; 2) INTERCEEDⓇ is placed at the site of bowel mobilization and/or lymph node dissection, but not under the midline incision; and 3) INTERCEEDⓇ is placed at both sites. DISCUSSION: This is the first study to assess whether the placement of APBs affects the incidence of SBO. The study results may lead to a subsequent randomized study.

Detection of KRAS mutations in circulating tumour DNA from plasma and urine of patients with colorectal cancer.

BACKGROUND: Circulating tumour DNA (ctDNA) is very useful for purposes of cancer genetics; however, it has some limitations. Recently, ctDNA in body fluids, such as urine, sputum, and pleural effusion, has been investigated. The aim of this study was to evaluate the quantity of ctDNA derived from urine (trans-renal ctDNA) and the accuracy of KRAS mutation detection in relation to disease stage in colorectal cancer. METHODS: Urine, plasma, and tissue samples were collected from consecutively resected colorectal cancer patients. DNA was extracted from each sample and the quantity was determined. From each DNA sample, KRAS mutations were detected using droplet digital PCR. RESULTS: 200 patients participated and KRAS mutations were detected in 84 patients (42.0%) from tumour tissue. The concentration of trans-renal ctDNA (trtDNA) was significantly lower than that of plasma; however, there was no significant difference between the sensitivity using ctDNA and that using trtDNA (29.8% VS 33.3%, p = 0.62). Concordance between these two tests was only 17.5%. Combination analysis (ctDNA + trtDNA) improved the sensitivity to 53.6%, and sensitivity was significantly higher than that of corresponding single assays (p = 0.003). In early cancer stages, trtDNA had greater sensitivity for detecting KRAS mutations than ctDNA (37.7% vs. 21.3%, p = 0.047). Conversely, it was less useful for advanced cancer stages (21.7% vs. 52.2%, p = 0.07). Notably, KRAS mutations were detected using ctDNA or trtDNA in 12 of 116 (10.3%) patients who had no KRAS mutations in their tissue samples. CONCLUSIONS: trtDNA and ctDNA have equal potential and combination analysis significantly improved the sensitivity.

Elevated serum carcinoembryonic antigen level after curative surgery is a prognostic biomarker of stage II-III colorectal cancer.

BACKGROUND: High preoperative carcinoembryonic antigen (CEA) is a well-known risk factor for stage II-III colorectal cancer (CRC); however, in most cases, cancer does not recur. Conversely, postoperative CEA (post-CEA) is occasionally measured, and high post-CEA patients often develop recurrence; however, the clinical significance of post-CEA testing is unknown. The purpose of this study was to determine whether post-CEA elevation might indicate a poor prognosis for stage II-III CRC patients who underwent curative surgery. PATIENTS AND METHODS: 482 patients with pathological stage II-III CRC were included. Univariate and multivariate analyses were performed to evaluate post-CEA levels. RESULTS: Multivariate analysis showed that elevated post-CEA (hazard ratio (HR): 3.14, P < 0.001), pathological lymph node metastasis (pN+), and pathological T4 (pT4) are associated with poor recurrence-free survival (RFS), and that elevated post-CEA (HR: 3.12; P = 0.002), pN+, pT4, age >70, and smoking are independently associated with poor overall survival. Subgroup analysis among stage III patients, in combination with the risk classification of the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) study, showed that elevated post-CEA is a significant indicator of poor prognosis for RFS in both low-risk (73.8% vs. 21.2%, P < 0.001) and high-risk (49.9% vs. 25.0%, P = 0.04) groups. CONCLUSIONS: Post-surgical CEA elevation is independently associated with poor prognosis in stage II-III CRC. Adding post-CEA levels to the IDEA risk classification may provide a more reliable indicator of the need for individualized surveillance and adjuvant chemotherapeutic strategies.