Interaction analysis of high-risk pathological features on adjuvant chemotherapy survival benefit in stage II colon cancer patients: a multi-center, retrospective study.

BACKGROUND: We aimed to analyze the benefit of adjuvant chemotherapy in high-risk stage II colon cancer patients and the impact of high-risk factors on the prognostic effect of adjuvant chemotherapy. METHODS: This study is a multi-center, retrospective study, A total of 931 patients with stage II colon cancer who underwent curative surgery in 8 tertiary hospitals in China between 2016 and 2017 were enrolled in the study. Cox proportional hazard model was used to assess the risk factors of disease-free survival (DFS) and overall survival (OS) and to test the multiplicative interaction of pathological factors and adjuvant chemotherapy (ACT). The additive interaction was presented using the relative excess risk due to interaction (RERI). The Subpopulation Treatment Effect Pattern Plot (STEPP) was utilized to assess the interaction of continuous variables on the ACT effect. RESULTS: A total of 931 stage II colon cancer patients were enrolled in this study, the median age was 63 years old (interquartile range: 54-72 years) and 565 (60.7%) patients were male. Younger patients (median age, 58 years vs 65 years; P < 0.001) and patients with the following high-risk features, such as T4 tumors (30.8% vs 7.8%; P < 0.001), grade 3 lesions (36.0% vs 22.7%; P < 0.001), lymphovascular invasion (22.1% vs 6.8%; P < 0.001) and perineural invasion (19.4% vs 13.6%; P = 0.031) were more likely to receive ACT. Patients with perineural invasion showed a worse OS and marginally worse DFS (hazardous ratio [HR] 2.166, 95% confidence interval [CI] 1.282-3.660, P = 0.004; HR 1.583, 95% CI 0.985-2.545, P = 0.058, respectively). Computing the interaction on a multiplicative and additive scale revealed that there was a significant interaction between PNI and ACT in terms of DFS (HR for multiplicative interaction 0.196, p = 0.038; RERI, -1.996; 95%CI, -3.600 to -0.392) and OS (HR for multiplicative interaction 0.112, p = 0.042; RERI, -2.842; 95%CI, -4.959 to -0.725). CONCLUSIONS: Perineural invasion had prognostic value, and it could also influence the effect of ACT after curative surgery. However, other high-risk features showed no implication of efficacy for ACT in our study. TRIAL REGISTRATION: This study is registered on ClinicalTrials.gov, NCT03794193 (04/01/2019).

Surgical site infection after intracorporeal and extracorporeal anastomosis in laparoscopic left colectomy for colon cancer: a multicenter propensity score-matched cohort study.

BACKGROUND: Intracorporeal anastomosis (IA) is associated with reduced surgical site infection (SSI) and other postoperative complications in laparoscopic right colectomy (LRC). However, evidence is inadequate for IA in laparoscopic left colectomy (LLC). This study aimed to determine the effect of IA and extracorporeal anastomosis (EA) on SSI and other short-term postoperative complications in LLC. METHODS: In this retrospective multicenter propensity score-matched (PSM) cohort study, we enrolled consecutive patients who underwent LLC with IA (TLLC/IA) and laparoscopic-assisted left colectomy with EA (LALC/EA) at two medical centers between January 2015 and September 2021. Propensity score matching with a 1:2 ratio was employed. The primary outcome was SSI occurrence. Secondary outcomes were operating time, intraoperative hemorrhage, other postoperative complications, and pathological outcomes. RESULTS: Overall, 574 and 99 patients received LALC/EA and TLLC/IA, respectively. After PSM, 84 patients with TLLC/IA were matched with 141 patients with LALC/EA. Thirty patients (13.3%) patients experienced SSI (17.0% in LALC/EA vs 7.1% in TLLC/IA). IA was associated with a reduced risk of overall SSI and superficial/deep SSI compared with EA after PSM, with OR of 0.375 (95% CI, 0.147-0.959, P = 0.041). and 0.148 (95% CI, 0.034-0.648, P = 0.011), respectively. Multivariate analysis of unmatched patients indicated similar results. In the analysis of secondary outcomes, LALC/EA may have a shorter operating time (absolute mean difference - 13.41 [95% CI, - 23.76 to - 3.06], P = 0.002) and a higher risk of intraoperative hemorrhage (absolute risk difference 4.96 [95% CI, - 0.09 to 9.89], P = 0.048). CONCLUSIONS: IA in LLC is associated with a reduced risk of overall SSI and superficial/deep SSI. However, it may require a longer operating time.

Comparison of safety of loop ileostomy and loop transverse colostomy for low-lying rectal cancer patients undergoing anterior resection: A retrospective, single institution, propensity score-matched study.

INTRODUCTION: This study was to compare the prevalence of stoma-related complications and stoma reversal perioperative complications of patients with low-lying rectal cancer who received preventative loop ileostomy and those who underwent loop transverse colostomy. METHODS: This retrospective single-center study analyzed the clinicopathologic and surgical data of 288 patients with pathologically proven primary rectal cancer who underwent anterior resection with either preventative loop ileostomy (n = 82) or loop transverse colostomy. To achieve comparability of a propensity score matching method was used to match patients from each group in a 1:2 ratio. Determinants of stoma-related complications were analyzed by multivariate logistic regression analysis. RESULTS: Forty-nine (74.3%) patients in the loop ileostomy group experienced stoma-related complications versus 48.7% in the loop transverse colostomy group (P < 0.01). Irritant dermatitis was the most frequent complication in both groups. The loop ileostomy group had a significantly higher rate (24.24%) of stoma reversal perioperative complications than the loop transverse colostomy group. Multivariate logistic regression analysis showed that ileostomy versus loop transverse colostomy was a significant independent risk for stoma-related complications and stoma reversal perioperative complications. Furthermore, by Clavien-Dindo classification, patients receiving loop ileostomy had an overall higher rate of complications and stoma reversal perioperative complications versus those undergoing loop transverse colostomy (P < 0.01). The rate of grade II complications was significantly higher in the loop ileostomy group (43.9%) than that of loop transverse colostomy group (13.5%, P < 0.01), whereas the rate of grade I, and grade IIIa and IIIb complications and stoma reversal perioperative complications was comparable between the two groups. CONCLUSION: The study has demonstrated that loop transverse colostomy is associated with significantly lower rates of stoma-related complications and stoma reversal perioperative complications compared to loop transverse colostomy.

Short-term Outcomes of Laparoscopy-Assisted vs Open Surgery for Patients With Low Rectal Cancer: The LASRE Randomized Clinical Trial.

Importance: The efficacy of laparoscopic vs open surgery for patients with low rectal cancer has not been established. Objective: To compare the short-term efficacy of laparoscopic surgery vs open surgery for treatment of low rectal cancer. Design, Setting, and Participants: This multicenter, noninferiority randomized clinical trial was conducted in 22 tertiary hospitals across China. Patients scheduled for curative-intent resection of low rectal cancer were randomized at a 2:1 ratio to undergo laparoscopic or open surgery. Between November 2013 and June 2018, 1070 patients were randomized to laparoscopic (n = 712) or open (n = 358) surgery. The planned follow-up was 5 years. Data analysis was performed from April 2021 to March 2022. Interventions: Eligible patients were randomized to receive either laparoscopic or open surgery. Main Outcomes and Measures: The short-term outcomes included pathologic outcomes, surgical outcomes, postoperative recovery, and 30-day postoperative complications and mortality. Results: A total of 1039 patients (685 in laparoscopic and 354 in open surgery) were included in the modified intention-to-treat analysis (median [range] age, 57 [20-75] years; 620 men [59.7%]; clinical TNM stage II/III disease in 659 patients). The rate of complete mesorectal excision was 85.3% (521 of 685) in the laparoscopic group vs 85.8% (266 of 354) in the open group (difference, -0.5%; 95% CI, -5.1% to 4.5%; P = .78). The rate of negative circumferential and distal resection margins was 98.2% (673 of 685) vs 99.7% (353 of 354) (difference, -1.5%; 95% CI, -2.8% to 0.0%; P = .09) and 99.4% (681 of 685) vs 100% (354 of 354) (difference, -0.6%; 95% CI, -1.5% to 0.5%; P = .36), respectively. The median number of retrieved lymph nodes was 13.0 vs 12.0 (difference, 1.0; 95% CI, 0.1-1.9; P = .39). The laparoscopic group had a higher rate of sphincter preservation (491 of 685 [71.7%] vs 230 of 354 [65.0%]; difference, 6.7%; 95% CI, 0.8%-12.8%; P = .03) and shorter duration of hospitalization (8.0 vs 9.0 days; difference, -1.0; 95% CI, -1.7 to -0.3; P = .008). There was no significant difference in postoperative complications rate between the 2 groups (89 of 685 [13.0%] vs 61 of 354 [17.2%]; difference, -4.2%; 95% CI, -9.1% to -0.3%; P = .07). No patient died within 30 days. Conclusions and Relevance: In this randomized clinical trial of patients with low rectal cancer, laparoscopic surgery performed by experienced surgeons was shown to provide pathologic outcomes comparable to open surgery, with a higher sphincter preservation rate and favorable postoperative recovery. Trial Registration: ClinicalTrials.gov Identifier: NCT01899547.

Anorectal dysfunction in patients with mid-low rectal cancer after surgery: A pilot study with three-dimensional high-resolution manometry.

BACKGROUND: The quality of life in patients who develop low anterior resection syndrome (LARS) after surgery for mid-low rectal cancer is seriously impaired. The underlying pathophysiological mechanism of LARS has not been fully investigated. AIM: To assess anorectal function of mid-low rectal cancer patients developing LARS perioperatively. METHODS: Patients diagnosed with mid-low rectal cancer were included. The LARS score was used to evaluate defecation symptoms 3 and 6 mo after anterior resection or a stoma reversal procedure. Anorectal functions were assessed by three-dimensional high resolution anorectal manometry preoperatively and 3-6 mo after surgery. RESULTS: The study population consisted of 24 patients. The total LARS score was decreased at 6 mo compared with 3 mo after surgery (P < 0.05), but 58.3% (14/24) lasted as major LARS at 6 mo after surgery. The length of the high-pressure zone of the anal sphincter was significantly shorter, the mean resting pressure and maximal squeeze pressure of the anus were significantly lower than those before surgery in all patients (P < 0.05), especially in the neoadjuvant therapy group after surgery (n = 18). The focal pressure defects of the anal canal were detected in 70.8% of patients, and those patients had higher LARS scores at 3 mo postoperatively than those without focal pressure defects (P < 0.05). Spastic peristaltic contractions from the new rectum to anus were detected in 45.8% of patients, which were associated with a higher LARS score at 3 mo postoperatively (P < 0.05). CONCLUSION: The LARS score decreases over time after surgery in the majority of patients with mid-low rectal cancer. Anorectal dysfunctions, especially focal pressure defects of the anal canal and spastic peristaltic contractions from the new rectum to anus postoperatively, might be the major pathophysiological mechanisms of LARS.

Comparing the techniques and outcomes of laparoscopic transverse colectomy to laparoscopic hemicolectomy in mid-transverse colon cancer resection.

Introduction: The mid-transverse colon cancer is relatively uncommon in all colon cancers and the optimal surgical approach of mid-transverse colon cancer remains debatable. Aim and Objectives: Our study aimed to depict the techniques and outcomes of laparoscopic transverse colectomy in one single clinical center and compare this surgical approach to traditional laparoscopic right hemicolectomy and laparoscopic left hemicolectomy. Method: This was a retrospective cohort study of patients with mid-transverse colon cancer in one single clinical center from February 2012 to October 2020. The enrolled patients were divided into two groups undergoing laparoscopic transverse colectomy and laparoscopic right/left hemicolectomy, respectively. The intraoperative, postoperative complications, oncological outcomes and functional outcomes were compared between the two groups. The primary endpoint was disease free survival (DFS). Results: The study enrolled 70 patients with 40 patients undergoing laparoscopic transverse colectomy and 30 patients undergoing laparoscopic hemicolectomy. The intraoperative accidental hemorrhage and multiple organ resection occurred similarly in the two groups. In transverse colectomy, caudal-to-cephalic approach was likely to harvest more lymph nodes although require more operation time than cephalic-to-caudal approach (23.1 ± 14.3 vs. 13.4 ± 5.4 lymph nodes, P = 0.004; 184.3 ± 37.1 min vs. 146.3 ± 44.4 min, P = 0.012). The laparoscopic transverse colectomy was marginally associated with lower incidence of overall postoperative complications and shorter postoperative hospital stay although without statistical significance (8(20.0%) vs. 12(40.0%), P = 0.067; 7(5-12) vs. 7(5-18), P = 0.060). The 3-year DFS showed no significant difference (3-year DFS 89.7% in transverse colectomy vs. 89.9% in hemicolectomy, P = 0.688) between the two groups. The alternating consistency of defecation occurred significantly less after laparoscopic transverse colectomy than laparoscopic hemicolectomy (15(51.7%) vs. 20(80.0%), P = 0.030). Conclusion: The laparoscopic transverse colectomy is technically feasible with satisfactory oncological and functional outcomes for mid-transverse colon cancer. Performing the caudal-to-cephalic approach might be more advantageous in lymphadenectomy.

Risk factors for perioperative complications in laparoscopic surgeries of retrorectal cystic lesions.

BACKGROUND: The incidence of retrorectal lesions is low, and no consensus has been reached regarding the most optimal surgical approach. Laparoscopic approach has the advantage of minimally invasive. The risk factors influencing perioperative complications of laparoscopic surgery are rarely discussed. AIM: To investigate the risk factors for perioperative complications in laparoscopic surgeries of retrorectal cystic lesions. METHODS: We retrospectively reviewed the medical records of patients who underwent laparoscopic excision of retrorectal cystic lesions between August 2012 and May 2020 at our hospital. All surgeries were performed in the general surgery department. Patients were divided into groups based on the lesion location and diameter. We analysed the risk factors like type 2 diabetes mellitus, hypertension, the history of abdominal surgery, previous treatment, clinical manifestation, operation duration, blood loss, perioperative complications, and readmission rate within 90 d retrospectively. RESULTS: Severe perioperative complications occurred in seven patients. Prophylactic transverse colostomy was performed in four patients with suspected rectal injury. Two patients underwent puncture drainage due to postoperative pelvic infection. One patient underwent debridement in the operating room due to incision infection. The massive-lesion group had a significantly longer surgery duration, higher blood loss, higher incidence of perioperative complications, and higher readmission rate within 90 d (P < 0.05). Univariate analysis, multivariate analysis, and logistic regression showed that lesion diameter was an independent risk factor for the development of perioperative complications in patients who underwent laparoscopic excision of retrorectal cystic lesions. CONCLUSION: The diameter of the lesion is an independent risk factor for perioperative complications in patients who undergo laparoscopic excision of retrorectal cystic lesions. The location of the lesion was not a determining factor of the surgical approach. Laparoscopic surgery is minimally invasive, high-resolution, and flexible, and its use in retrorectal cystic lesions is safe and feasible, also for lesions below the S3 level.

Serial Circulating Tumor DNA in Predicting and Monitoring the Effect of Neoadjuvant Chemoradiotherapy in Patients with Rectal Cancer: A Prospective Multicenter Study.

PURPOSE: We investigated the value of circulating tumor DNA (ctDNA) in predicting tumor response to neoadjuvant chemoradiotherapy (nCRT), monitoring tumor burden, and prognosing survival in patients with locally advanced rectal cancer (LARC). EXPERIMENTAL DESIGN: This prospective multicenter trial recruited 106 patients with LARC for treatment with nCRT followed by surgery. Serial ctDNAs were analyzed by next-generation sequencing at four timepoints: at baseline, during nCRT, presurgery, and postsurgery. RESULTS: In total, 1,098 mutations were identified in tumor tissues of the 104 patients being analyzed (median, seven mutations/patient). ctDNA was detected in 75%, 15.6%, 10.5%, and 6.7% of cases at the four timepoints, respectively. None of the 29 patients with pathologic complete response (ypCR) had preoperative ctDNA detected. The preoperative ctDNA-positive rate was significantly lower in the well-responded patients with pathologic tumor regression grade of ypCAP 0-1 than ypCAP 2-3 group (P < 0.001), lower in ypCR than non-ypCR group (P = 0.02), and lower in pathologic T stage (ypT) 0-2 than ypT 3-4 group (P = 0.002). With a median follow-up of 18.8 months, 13 patients (12.5%) experienced distant metastasis. ctDNA positivity at all four timepoints was associated with a shorter metastasis-free survival (MFS; P < 0.05). Multivariate analyses showed that the median variant allele frequency (VAF) of mutations in baseline ctDNA was a strong independent predictor of MFS (HR, 1.27; P < 0.001). CONCLUSIONS: We show that ctDNA is a real-time monitoring indicator that can accurately reflect the tumor burden. The median VAF of baseline ctDNA is a strong independent predictor of MFS.

Neoadjuvant chemoradiotherapy might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer: A retrospective single-institution study with propensity score-matched comparative analysis.

BACKGROUND: Neoadjuvant chemoradiotherapy (NACRT) and total mesorectal excision (TME) are standard treatments of stage II/III locally advanced rectal cancer (LARC), currently. Here, we evaluated the oncological outcomes in LARC patients treated with NACRT compared to TME alone, and determined whether tumor regression grade (TRG) and pathologic response after NACRT was related to prognosis. METHODS: This is a retrospective comparison of 358 LARC patients treated with either TME alone (non-NACRT group, n = 173) or NACRT plus TME (NACRT group, n = 185) during 2003-2013. Perioperative and oncologic outcomes, like overall survival (OS), disease-free survival (DFS) and recurrence were compared using 1:1 propensity score matching analysis. RESULTS: A total of 133 patients were matched for the analysis. After a median follow-up of 45 months (8-97 months), the 5-year OS (NACRT vs non-NACRT: 75.42% vs 72.76%; P = 0.594) and 5-year DFS (NACRT vs non-NACRT: 74.25% vs 70.13%; P = 0.224) were comparable between NACRT and non-NACRT, whereas the 5-year DFS rate was higher in the NACRT group when only stage IIIb/IIIc patients were considered (NACRT vs. non-NACRT: 74.79% vs. 62.29%; P = 0.056). In the NACRT group of 185 patients, those with pCR/stage I (vs stage II/stage III disease) or TRG3/TRG4 disease (vs TRG0/TRG1/TRG2) had significantly better prognosis. CONCLUSION: NACRT might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer.

Laparoscopic resection of large retrorectal developmental cysts in adults: Single-centre experiences of 20 cases.

Context: Retrorectal tumours are rare with developmental cysts being the most common type. Conventionally, large retrorectal developmental cysts (RRDCs) require the combined transabdomino-sacrococcygeal approach. Aims: This study aims to investigate the surgical outcomes of the laparoscopic approach for large RRDCs. Settings and Design: A retrospective case series analysis. Subjects and Methods: Data of patients with RRDCs of 10 cm or larger in diameter who underwent the laparoscopic surgery between 2012 and 2017 at our tertiary centre were retrospectively analyzed. Statistical Analysis Used: Results are presented as median values or mean ± standard deviation for continuous variables and numbers (percentages) for categorical variables. Results: Twenty consecutive cases were identified (19 females; median age, 36 years). Average tumour size was 10.9 ± 1.1 cm. Cephalic ends of lesions ranged from S1/2 junction to S4 level. Caudally, 18 cysts extended to the sacrococcygeal hypodermis. Seventeen patients underwent the pure laparoscopy; three patients received a combined laparoscopic-posterior approach. The operating time was 167.1 ± 57.3 min for the pure laparoscopic group and 212.0 ± 24.5 min for the combined group. The intraoperative haemorrhage was 68.2 ± 49.7 and 66.7 ± 28.9 (mL), respectively. Post-operative complications included one trocar site hernia, one wound infection and one delayed rectal wall perforation. The median post-operative hospital stay was 7 days. With a median follow-up period of 36 months, 1 lesions recurred. Conclusions: The laparoscopic approach can provide a feasible and effective alternative for large RRDCs, with advantages of the minimally invasive surgery. For lesions with ultra-low caudal ends, especially those closely clinging to the rectum, a combined posterior approach is still necessary.

Serum extracellular vesicles contain SPARC and LRG1 as biomarkers of colon cancer and differ by tumour primary location.

BACKGROUND: Recently, the distinction between left- and right-sided colon cancer (LCC and RCC) has been brought into focus. RCC is associated with an inferior overall survival and progression-free survival. We aimed to perform a detailed analysis of the diversity of extracellular vesicles (EV) between LCC and RCC using quantitative proteomics and to identify for new diagnostic and prognostic biomarkers. METHODS: We isolated EVs from patients with LCC, RCC and healthy volunteers, and treated colorectal cancer cell line with serum-derived EVs. We then performed a quantitative proteomics analysis of the serum-derived EVs and cell line treated with EVs. Proteomic data are available via ProteomeXchange with the identifiers PXD012283 and PXD012304. In addition, we assessed the performance of EV SPARC and LRG1 as diagnosis and prognosis biomarkers in colon cancer. FINDINGS: The expression profile of the serum EV proteome in patients with RCC was different from that of patients with LCC. Serum-derived EVs in RCC promoted cellular mobility more significantly than EVs derived from LCC. EV SPARC and LRG1 expression levels demonstrated area under the receiver-operating characteristic curve values of 0.95 and 0.93 for discriminating patients with colon cancer from healthy controls. Moreover, the expression levels of SPARC and LRG1 correlated with tumour sidedness and were predictive of tumour recurrence. INTERPRETATION: We identified differences in EV protein profiles between LCC and RCC. Serum-derived EVs of RCC may promote metastasis via upregulation of extracellular matrix (ECM)-related proteins, especially SPARC and LRG1, which may serve as diagnosis and prognosis biomarkers in colon cancer.

Comparison of safety of loop ileostomy and loop transverse colostomy for low-lying rectal cancer patients undergoing anterior resection: A retrospective, single institute, propensity score-matched study.

PURPOSE: To compare the prevalence of stoma-related complications and stoma reversal perioperative complications of patients with low-lying rectal cancer who received preventative loop ileostomy and those who underwent loop transverse colostomy. METHODS: This retrospective single-center study analyzed the clinicopathologic and surgical data of 288 patients with pathologically proven primary rectal cancer who underwent anterior resection of rectal cancer with preventative loop ileostomy or loop transverse colostomy between January 2012 and July 2017 at the Department of General Surgery, Peking Union College Hospital. The patients were allocated to the ileostomy group (n=82) and the loop transverse colostomy group (n=206). To achieve comparability of the ileostomy group and the loop transverse colostomy group with regard to potential confounding variables, a propensity score-matching method was used to match patients from each group in a 1:2 ratio. Determinants of stoma-related complications were analyzed by multivariate logistic regression analysis. RESULTS: The propensity score-matched loop ileostomy group (n=66) and the loop transverse colostomy group (n=111) were comparable in patient demographic and baseline characteristics. Forty-nine (74.3%) patients in the loop ileostomy group experienced stoma-related complications vs 48.7% in the loop transverse colostomy group (p<0.001). Irritant dermatitis was the most frequent complication in both groups. The loop ileostomy group had a significantly higher rate (24.24%) of stoma reversal perioperative complications than the loop transverse colostomy group (9.01%, p=0.008). Multivariate logistic regression analysis showed that ileostomy vs loop transverse colostomy was a significant independent risk for stoma-related complications (Odds ratio/OR 3.495; 95%CI 1.741, 7.018; p<0.001) and stoma reversal perioperative complications (OR 2.124; 95%CI 1.010, 4.512; p< 0.05). CONCLUSION: This study has demonstrated that loop transverse colostomy is associated with significantly lower rates of stoma-related complications and stoma reversal perioperative complications compared to loop transverse colostomy. Prospective controlled studies with a larger patient population are warranted to examine the efficacy and safety of loop ileostomy and loop transverse colostomy.

A single-center, prospective, randomized clinical trial to investigate the optimal removal time of the urinary catheter after laparoscopic anterior resection of the rectum: study protocol for a randomized controlled trial.

BACKGROUND: Urinary catheter placement is essential before laparoscopic anterior resection for rectal cancer. Whether early removal of the catheter increases the incidence of urinary retention and urinary tract infection (UTI) is not clear. This study aims to determine the optimal time for removal of the urinary catheter after laparoscopic anterior resection of the rectum. METHODS/DESIGN: A total of 220 participants meeting the inclusion criteria will be randomly assigned to an experimental group or a control group. The experimental group will have their urethral catheters removed on postoperative day 2 and the control group will have their urethral catheters removed on postoperative day 7. In both groups, catheter removal will be performed when the bladder is full. The incidence of urinary retention and UTI in the two groups will be compared to determine the optimal catheter removal time. DISCUSSION: This is a prospective, single-center, randomized controlled trial to determine whether early removal of the urinary catheter after laparoscopic anterior resection of the rectum will help to decrease the incidence of postoperative acute urinary retention and UTI. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03065855 . Registered on 23 February 2017.

[Transanal endoscopic microsurgery for local excision of rectal gastrointestinal stromal tumors].

OBJECTIVE: To investigate the efficacy of transanal endoscopic microsurgery (TEM) combined with imatinib for rectal gastrointestinal stromal tumors(GIST). METHODS: Clinical data of 35 patients with rectal GIST undergoing TEM at Peking Union Medical College Hospital from February 2008 to May 2017 were analyzed retrospectively. Operation details, postoperative recovery condition, and follow-up information were reviewed. The differences in clinicopathological features and perioperative parameters were compared between patients who received neoadjuvant therapy (12 patients, imatinib mesylate, oral, 400 mg daily for 6 months before surgery) and those without neoadjuvant therapy (23 patients). RESULTS: Of 35 patients, 18 were males and 17 were females with the mean age of (49.3±13.3) years. Mean tumor diameter was (1.8±1.1) cm and mean distance from lower tumor margin to anal verge was (4.0±1.8) cm. Mean operative time was (82.4±21.1) minutes and mean blood loss was (11.7±7.5) ml. No conversion to laparotomy occurred. Complete resection with negative margins was achieved in all cases. Complications were classified according to Clavien-Dindo system: 4 cases of grade I, 3 of grade II and 1 of grade IIIb. The tumor size in patients who received neoadjuvant therapy reduced from (3.1±1.2) cm to (2.6±1.2) cm, though it was still larger than the tumor size in patients without neoadjuvant therapy[(1.5±0.8) cm, P<0.01]. No significant difference in operative time was found between patients with and without neoadjuvant therapy [(76.7±24.8) minutes vs. (85.4±18.8) minutes, P>0.05]. Thirty patients (85.7%) were followed up for (50.3±36.6) months, and no local recurrence or metastasis was observed. CONCLUSIONS: TEM is safe and effective in the treatment of rectal GIST. Preoperative neoadjuvant therapy is beneficial to TEM in treating larger tumors without increasing operating time. Satisfactory follow-up result is observed.

[Treatment of anastomotic tubular stricture after anterior resection of rectal cancer].

OBJECTIVE: To investigate the treatment of colorectal anastomotic tubular stricture after anterior resection of rectal cancer. METHODS: A retrospective study on 23 cases of anastomotic tubular stricture after anterior resection of rectal cancer from 2008 to 2017 at the Division of Colorectal Surgery, Department of General Surgery of Peking Union Medical College Hospital was performed. The general conditions of the patients, surgical procedures of rectal cancer, perioperative treatment, specific conditions of anastomotic stricture, treatment methods and outcomes were summarized and analyzed. Anastomotic tubular stricture was defined as follows: (1) The length of scar stenosis was >1 cm with thickening anastomotic intestinal wall and a 12 mm diameter colonoscopy could not pass through the anastomosis; (2) Patients were often accompanied by left abdominal pain when exhaust and defecation, increased frequency of defecation, fecal thinning and difficulty in defecation; (3) Anastomotic stricture was indicated by anal examination, colonoscopy, transanal proctography, and rectal MRI. RESULTS: Among 2035 patients undergoing anterior resection of rectal cancer from 2008 to 2017, 23 patients (1.1%) had anastomotic tubular stricture after operation, including 20 males and 3 females with age of 36 to 78 (58.3±10.2) years old. The anastomotic distance from the anal verge was less than 6 cm in 7 cases, 6 to 10 cm in 12 cases, and more than 10 cm in 4 cases. Twelve patients received radiotherapy, among whom 6 patients received neoadjuvant chemoradiation before surgery, and 6 patients received postoperative radiotherapy and chemotherapy. The initial treatment after anastomotic stricture: 9 cases (39.1%) underwent balloon dilation; 1 case(4.3%) underwent stenting; 1 case (4.3%) underwent transanal endoscopic microsurgery (TEM); 7 cases (30.5%) underwent permanent stoma and 5 patients (21.7%) underwent digestive tract reconstruction. Of the 12 patients receiving radiotherapy, 4 cases initially failed to undergo balloon dilatation; 1 case initially received a bare stent to relieve obstruction due to intestinal obstruction, but had re-stricture 1 month after stent removal, then was followed by permanent stoma surgery; 7 cases underwent resection of stenosis and permanent stoma, because the remaining intestine was too short for anastomosis. Of the 11 patients without radiotherapy, 5 patients were treated with balloon dilatation to relieve stenosis; 1 patient was initially treated with TEM, while posterior urethra was injured intraoperatively, and the urinary fistula finally healed with indwelling catheter; 5 patients underwent resection of the anastomotic stenosis, and no stenosis occurred after reconstruction of digestive tract, but 1 patient suffered from intraoperative presacral bleeding. CONCLUSIONS: Balloon dilatation is considered an effective treatment of anastomotic tubular stricture following anterior resection of rectal cancer, but with the risk of re-stenosis. Stricture resection and digestive tract reconstruction can be a radical way to improve stricture but with high risk of complications.

Can Endorectal Ultrasound, MRI, and Mucosa Integrity Accurately Predict the Complete Response for Mid-Low Rectal Cancer After Preoperative Chemoradiation? A Prospective Observational Study from a Single Medical Center.

BACKGROUND: Patients with locally advanced rectal cancer could be managed by a watch-and-wait approach if they achieve clinical complete response after preoperative chemoradiotherapy. Mucosal integrity, endorectal ultrasound, and rectal MRI are used to evaluate clinical complete response; however, the accuracy remains questionable. Clinical practice based on those assessment methods needs more data and discussion. OBJECTIVE: The aim of this prospective study was to evaluate the accuracy of mucosal integrity, endorectal ultrasound, and rectal MRI to predict clinical complete response after chemoradiotherapy. DESIGN: Endorectal ultrasound and rectal MRI were undertaken 6 to 7 weeks after preoperative chemoradiation therapy. Patients then received radical surgery based on the principles of total mesorectal excision. Preoperative tumor staging achieved by endorectal ultrasound and rectal MRI was compared with postoperative staging by pathologic examination. Sensitivity, specificity, and accuracy of each evaluation method were calculated. SETTINGS: The study was conducted at a single tertiary care center. PATIENTS: Patients diagnosed with mid-low rectal cancer by biopsy between May 2014 and December 2016 were enrolled in this study. RESULTS: A total of 124 patients were enrolled in this study, and postoperative pathology revealed that 20 patients (16.13%) achieved complete response (ypT0N0). The sensitivity of mucosal integrity, endorectal ultrasound, and MRI to predict clinical complete response was 25%. The specificity of mucosal integrity, endorectal ultrasound, and MRI was 94.23%, 93.90%, and 93.27%. The combination of each 2 or all 3 methods did not improve accuracy. Regression analysis showed that none of these methods could predict postoperative ypT0. LIMITATIONS: The sample size is small, and we did not focus on the follow-up data and cannot compare prognosis data with previous research studies. CONCLUSIONS: Both single-method and combined mucosal integrity, endorectal ultrasound, and rectal MRI have poor correlation with postoperative pathologic examination. A watch-and-wait approach based on these methods might not be a proper strategy compared with radical surgery after neoadjuvant therapy. See Video Abstract at http://links.lww.com/DCR/A693.

Loop ostomy following laparoscopic low anterior resection for rectal cancer after neoadjuvant chemoradiotherapy.

BACKGROUND: Both loop ileostomy (LI) and loop transverse colostomy (LTC) could achieve absolute fecal diversion and have several advantages. This study compared LI and LTC following laparoscopic low anterior resection for rectal cancer after neoadjuvant chemoradiotherapy. METHODS: Between January 2009 and December 2016, 186 patients who underwent laparoscopic low anterior resection for rectal cancer and loop ostomy were included. All patients received preoperative neoadjuvant chemoradiotherapy. Of these, 77 underwent LI and 109 underwent LTC. Demographic characteristics, operative details, and complications were analyzed. RESULTS: In the fecal diversion period, the LTC group showed significantly less dermatitis (p = 0.001) and electrolyte disturbance (p = 0.002), while LI group showed significantly shorter time to first defecation (p = 0.006) and lower incidence of parastomal hernia (p = 0.014). In the stoma closure period, a significantly higher incidence of wound infection was found in LTC group (p = 0.001). CONCLUSIONS: Both LI and LTC have advantages and disadvantages. For its lower wound infection rate, lower incidence of parastomal hernia, and shorter time to first defecation, LI is recommended for all patients except those with potential electrolyte disturbance and sensitive skin.

Transanal Endoscopic Microsurgery for Patients with Rare Rectal Tumors.

BACKGROUND: Transanal endoscopic microsurgery (TEM) has been accepted worldwide for the treatment of local rectal lesions. Rare rectal tumors consist of several different types of malignant or benign tumors. Surgical management is considered to be the only curative option. The aim of this study is to investigate the role of TEM in the treatment of rare rectal tumors. MATERIALS AND METHODS: A total of 147 patients with rare rectal tumors underwent TEM in our center from April 2006 to May 2017. Clinical data were collected and a retrospective accurate database was constructed. Demographic characteristics, operative details, tumor details, complications, and follow-up data were analyzed. RESULTS: Seventy-eight patients were male. Mean tumor diameter was 1.2 ± 0.7 cm and mean distance from the anal verge was 6.6 ± 2.3 cm. Full-thickness and complete resection with negative margins was achieved in all patients. Complications occurred in 3 patients during surgery and in 20 patients after surgery. Histopathologic results were neuroendocrine tumors in 104 patients; gastrointestinal stromal tumors in 35; melanoma, lymphoma, and leiomyoma each in 2; lipoma, and squamous carcinoma each in 1. One hundred thirty-five patients were followed up for 49.3 ± 33.2 months. Two patients died, 1 had local recurrence and 1 had a rectovaginal fistula 1 month after surgery. No local recurrence or metastasis, or fecal incontinence was observed in the remaining patients. CONCLUSION: TEM is an optimal treatment option for selected rare rectal tumors. The complication rate is low and the therapeutic effect is satisfactory.

Laparoscopic-Assisted Resection for Advanced Colorectal Cancer in Solid Organ Transplant Recipients.

AIM: To evaluate the feasibility, short- and long-term outcomes, and safety of laparoscopic resection for advanced colorectal cancer (CRC) in solid organ transplant recipients. METHODS: Between September 2001 and April 2016, five patients who underwent laparoscopic-assisted resection for CRC after solid organ transplantation were included in this study. Their clinical data were retrospectively analyzed with regard to patient demographics, immunosuppressive therapy, tumor characteristics, surgical outcomes, and follow-up data. RESULTS: Four kidney and one heart transplant recipients were included. Laparoscopic-assisted low anterior resection was performed in four patients with rectal or rectosigmoid junction cancer, and sigmoidectomy was done in one with sigmoid colon cancer. One kidney transplant patient received a protective loop transverse colostomy. All resections achieved complete tumor removal with tumor-free margins and total mesorectal excision, with an average number of 14 lymph nodes harvested. Most tumors were in stage III (n = 3), one was in stage II, and one in stage IV. The mean duration of surgery, intraoperative blood loss, and postoperative hospital stay were 144 min, 105 mL, and 8.8 days, respectively. No major complications occurred and graft function stayed well. During a mean follow-up period of 62 months, two patients developed metastasis and died eventually. CONCLUSION: Laparoscopic resection for advanced CRC in organ transplant recipients is technically feasible and therapeutically safe, and seems to have the advantages of few postoperative complications, short recovery time, and acceptable oncological outcomes.

A novel heterozygous germline deletion in MSH2 gene in a five generation Chinese family with Lynch syndrome.

Lynch syndrome (LS) is one of the most common familial forms of colorectal cancer predisposing syndrome with an autosomal dominant mode of inheritance. LS is caused by the germline mutations in DNA mismatch repair (MMR) genes including MSH2, MLH1, MSH6 and PMS2. Clinically, LS is characterized by high incidence of early-onset colorectal cancer as well as endometrial, small intestinal and urinary tract cancers, usually occur in the third to fourth decade of the life. Here we describe a five generation Chinese family with LS clinically diagnosed according to the Amsterdam II criteria. Immuno-histochemical staining of MSH2 and MSH6 shows only foci nuclear positive on the surface of the tumor with strong expression of MLH1 and PMS2 with diffuse immunoreactivity. In order to dig into the molecular basis of this LS pedigree, we collected the proband's blood sample, extracted the genomic DNA and applied the genetic screening. As a result, we identified a novel heterozygous deletion in MSH2 gene by targeted next generation sequencing, which is also proved to be co-segregated among other affected family members by following validation. To our knowledge, this novel heterozygous deletion (c.1676_1679 delTAAA) in MSH2 gene causes frameshift mutation (p.Asn560Lysfs*29) and leads to the formation of a truncated MSH2 protein which is confirmed to be a deleterious mutation according to the variant interpretation guidelines of American College of Medical Genetics and Genomics (ACMG). Identification of novel DNA mismatch repair (MMR) gene mutations can definitely benefit to the clinical diagnosis and management.