Endoscopic ultrasonography-related diagnostic accuracy and clinical significance on small rectal neuroendocrine neoplasms

This research aimed to examine the diagnostic accuracy and clinical significance of endoscopic ultrasonography(EUS)in the context of small rectal neuroendocrine neoplasms(NENs).A total of 108 patients with rectal subepithelial lesions(SELs)with a diameter of<20 mm were included in the analysis.The diagnosis and depth assessment of EUS was compared to the histology findings.The prevalence of NENs in rectal SELs was 78.7%(85/108).The sensitivity of EUS in detecting rectal NENs was 98.9%(84/85),while the specificity was 52.2%(12/23).Overall,the diagnostic accuracy of EUS in identifying rectal NENs was 88.9%(96/108).The overall accuracy rate for EUS in assessing the depth of invasion in rectal NENs was 92.9%(78/84).Therefore,EUS demonstrates reasonable diagnostic accuracy in detecting small rectal NENs,with good sensitivity but inferior specificity.EUS may also assist physicians in assessing the depth of invasion in small rectal NENs before endoscopic excision.

GATIS score for predicting the prognosis of rectal neuroendocrine neoplasms:A Chinese multicenter study of 12-year experience

BACKGROUND There is currently a shortage of accurate,efficient,and precise predictive instruments for rectal neuroendocrine neoplasms(NENs).AIM To develop a predictive model for individuals with rectal NENs(R-NENs)using data from a large cohort.METHODS Data from patients with primary R-NENs were retrospectively collected from 17 large-scale referral medical centers in China.Random forest and Cox proportional hazard models were used to identify the risk factors for overall survival and progression-free survival,and two nomograms were constructed.RESULTS A total of 1408 patients with R-NENs were included.Tumor grade,T stage,tumor size,age,and a prognostic nutritional index were important risk factors for prognosis.The GATIS score was calculated based on these five indicators.For overall survival prediction,the respective C-indexes in the training set were 0.915(95%confidence interval:0.866-0.964)for overall survival prediction and 0.908(95%confidence interval:0.872-0.944)for progression-free survival prediction.According to decision curve analysis,net benefit of the GATIS score was higher than that of a single factor.The time-dependent area under the receiver operating characteristic curve showed that the predictive power of the GATIS score was higher than that of the TNM stage and pathological grade at all time periods.CONCLUSION The GATIS score had a good predictive effect on the prognosis of patients with R-NENs,with efficacy superior to that of the World Health Organization grade and TNM stage.

Transanal Endoscopic Microsurgery (TEM) for Rectal Neoplasms

Introduction: The abdominal approach for the treatment of rectal tumors is associated with a considerable rate of morbidity. Transanal Endoscopic Microsurgery (TEM) is an alternative technique that is less invasive than radical surgery, and therefore has a lower associated morbidity. Moreover, with proper patient selection, TEM presents oncological outcomes comparable to radical surgery. The aim of this study is to review our results obtained with TEM and discuss its role in the treatment of malignant rectal lesions. Patients and Methods: A prospective descriptive study from June 2008 until February 2011. The indications for TEM were: early rectal neoplastic lesions (T1N0M0) with good prognostic factors;neoplastic lesions in more advanced stages in selected patients (high surgical risk, refusal of radical surgery or stoma, and palliative intention). Results: Resection by TEM was performed on 19 patients. The average hospital stay was 5.7 days with an associated morbidity of 16.7%. R0 resection was 88.8%. During the follow-up of 15 (3 - 31) months, no recurrence has been shown. Conclusions: TEM is a safe and effective procedure for the treatment of selected early malignant rectal lesions and is associated with low morbidity. It is a therapeutic strategy based on a multidisciplinary team, careful patient selection, an audited surgical technique and a strict follow-up protocol.

Impact of technology on indications and limitations for transanal surgical removal of rectal neoplasms

Transanal surgery has and continues to be well accepted for local excision of benign rectal disease not amenable to endoscopic resection. More recently, there has been increasing interest in applying transanal surgery to local resection of early malignant disease. In addition, some groups have started utilizing a transanal route in order to accomplish total mesorectal excision(TME) for more advanced rectal malignancies. We aim to review the role of various transanal and endoscopic techniquesin the local resection of benign and malignant rectal disease based on published trial data. Preliminary data on the use of transanal platforms to accomplish TME will also be highlighted. For endoscopically unresectable rectal adenomas, transanal surgery remains a widely accepted method with minimal morbidity that avoids the downsides of a major abdomino-pelvic operation. Transanal endoscopic microsurgery and transanal minimally invasive surgery offer improved visualization and magnification, allowing for finer and more precise dissection of more proximal and larger rectal lesions without compromising patient outcome. Some studies have demonstrated efficacy in utilizing transanal platforms in the surgical management of early rectal malignancies in selected patients. There is an overall higher recurrence rate with transanal surgery with the concern that neither chemoradiation nor salvage surgery may compensate for previous approach and correct the inferior outcome. Application of transanal platforms to accomplish transanal TME in a natural orifice fashion are still in their infancy and currently should be considered experimental. The current data demonstrate that transanal surgery remains an excellent option in the surgical management of benign rectal disease. However, care should be used when selecting patients with malignant disease. The application of transanal platforms continues to evolve. While the new uses of transanal platforms in TME for more advanced rectal malignancy are exciting, it is important to remain cognizant and not sacrifice long term survival for short term decrease in morbidity and improved cosmesis.

Feasibility and safety of minimally invasive multivisceral resection for T4b rectal cancer:A 9-year review

BACKGROUND Colorectal cancer is the third most common cancer and the second highest cause of cancer-related mortality worldwide.About 5%-10%of patients are diagnosed with locally advanced rectal cancer(LARC)on presentation.For LARC invading into other structures(i.e.T4b),multivisceral resection(MVR)and/or pelvic ex-enteration(PE)remains the only potential curative surgical treatment.MVR and/or PE is a major and complex surgery with high post-operative morbidity.Minimally invasive surgery(MIS)has been shown to improve short-term post-operative outcomes in other gastrointestinal malignancies,but there is little evi-dence on its use in MVR,especially so for robotic MVR.This is a single-center retrospective cohort study from 1st January 2015 to 31st March 2023.Inclusion criteria were patients diagnosed with cT4b rectal cancer and underwent MVR,or stage 4 disease with resectable systemic metastases.Pa-tients who underwent curative MVR for locally recurrent rectal cancer,or me-tachronous rectal cancer were also included.Exclusion criteria were patients with systemic metastases with non-resectable disease.All patients planned for elective surgery were enrolled into the standard enhanced recovery after surgery pathway with standard peri-operative management for colorectal surgery.Complex sur-gery was defined based on technical difficulty of surgery(i.e.total PE,bladder-sparing prostatectomy,pelvic lymph node dissection or need for flap creation).Our primary outcomes were the margin status,and complication rates.Cate-gorical values were described as percentages and analysed by the chi-square test.Continuous variables were expressed as median(range)and analysed by Mann-Whitney U test.Cumulative overall survival(OS)and recurrence-free survival(RFS)were analysed using Kaplan-Meier estimates with life table analysis.Log-rank test was performed to determine statistical significance between cumulative estimates.Statistical significance was defined as P<0.05.Meier estimates with life table analysis.Log-rank test was performed to determine statistical significance between cumulative estimates.Statistical significance was defined as P<0.05.RESULTS A total of 46 patients were included in this study[open MVR(oMVR):12(26.1%),miMVR:36(73.9%)].Patients’American Society of Anesthesiologists score,body mass index and co-morbidities were comparable between oMVR and miMVR.There is an increasing trend towards robotic MVR from 2015 to 2023.MiMVR was associated with lower estimated blood loss(EBL)(median 450 vs 1200 mL,P=0.008),major morbidity(14.7%vs 50.0%,P=0.014),post-operative intra-abdominal collections(11.8%vs 50.0%,P=0.006),post-operative ileus(32.4%vs 66.7%,P=0.04)and surgical site infection(11.8%vs 50.0%,P=0.006)compared with oMVR.Length of stay was also shorter for miMVR compared with oMVR(median 10 vs 30 d,P=0.001).Oncological outcomes-R0 resection,recurrence,OS and RFS were comparable between miMVR and oMVR.There was no 30-d mortality.More patients underwent robotic compared with laparoscopic MVR for complex cases(robotic 57.1%vs laparoscopic 7.7%,P=0.004).The operating time was longer for robotic compared with laparoscopic MVR[robotic:602(400-900)min,laparoscopic:Median 455(275-675)min,P<0.001].Incidence of R0 resection was similar(laparoscopic:84.6%vs robotic:76.2%,P=0.555).Overall complication rates,major morbidity rates and 30-d readmission rates were similar between la-paroscopic and robotic MVR.Interestingly,3-year OS(robotic 83.1%vs 58.6%,P=0.008)and RFS(robotic 72.9%vs 34.3%,P=0.002)was superior for robotic compared with laparoscopic MVR.CONCLUSION MiMVR had lower post-operative complications compared to oMVR.Robotic MVR was also safe,with acceptable post-operative complication rates.Prospective studies should be conducted to compare short-term and long-term outcomes between robotic vs laparoscopic MVR.

Critical analysis of the literature investigating urogenital function preservation following robotic rectal cancer surgery

AIM To analyses the current literature regarding the urogenital functional outcomes of patients receiving robotic rectal cancer surgery. METHODS A comprehensive literature search of electronic databases was performed in October 2015. The following search terms were applied: "rectal cancer" or "colorectal cancer" and robot* or "da Vinci" and sexual or urolog* or urinary or erect* or ejaculat* or impot* or incontinence. All original studies examining the urological and/or sexual outcomes of male and/or female patients receiving robotic rectal cancer surgery were included. Reference lists of all retrieved articles were manually searched for further relevant articles. Abstracts were independently searched by two authors. RESULTS Fifteen original studies fulfilled the inclusion criteria. A total of 1338 patients were included; 818 received robotic, 498 laparoscopic and 22 open rectal cancer surgery. Only 726(54%) patients had their urogenital function assessed via means of validated functional questionnaires. From the included studies, three found that robotic rectal cancer surgery leads to quicker recovery of male urological function and five of male sexual function as compared to laparoscopic surgery. It is unclear whether robotic surgery offers favourable urogenital outcomes in the long run for males. In female patients only two studies assessed urological and threesexual function independently to that of males. In these studies there was no difference identified between patients receiving robotic and laparoscopic rectal cancer surgery. However, in females the presented evidence was very limited making it impossible to draw any substantial conclusions. CONCLUSION There seems to be a trend towards earlier recovery of male urogenital function following robotic surgery. To evaluate this further, larger well designed studies are required.

Down-staging depth score to predict outcomes in locally advanced rectal cancer achieving ypl stage after neoadjuvant chemo-radiotherapy versus de novo stage pl cohort:A propensity score-matched analysis

Objective：Prognosis of patients with locally advanced rectal cancer（LARC）but achieving yp T1–2N0 stage after neoadjuvant concurrent chemo-radiotherapy（CRT）has been shown to be favorable.This study aims to determine whether the long-term outcome of yp T1–2N0 cases can be comparable to that of p T1–2N0 cohort that received definitive surgery for early disease.Method：From January 2008 to December 2013,449 consecutive patients with rectal cancer were treated and their outcome maintained in a database.Patients with LARC underwent total mesorectal excision（TME）surgery at4–8 weeks after completion of CRT,and those achieving stage yp I were identified as a group.As a comparison,stage p I group pertains to patients whose initially limited disease was not upstaged after TME surgery alone.After propensity score matching（PSM）,comparisons of local regional control（LC）,distant metastasis-free survival（DMFS）,disease-free survival（DFS）and overall survival（OS）were performed using Kaplan-Meier analysis and log-rank test between yp I and p I groups.Down-staging depth score（DDS）,a novel method of evaluating CRT response,was used for subset analysis.Results：Of the 449 patients,168 matched cases were generated for analysis.Five-year LC,DMFS,DFS and OS for stage p I vs.yp I groups were 96.7%vs.96.4%（P=0.796）,92.7%vs.73.6%（P=0.025）,91.2%vs.73.6%（P=0.080）and 93.1%vs.72.3%（P=0.040）,respectively.In the DDS-favorable subset of the yp I group,LC,DMFS,DFS and OS resulted in no significant differences in comparison with the p I group（P=0.384,0.368,0.277 and0.458,respectively）.Conclusions：LC was comparable in both groups;however,distant metastasis developed more frequently in down-staged LARC than de novo early stage cases,reflecting the need to improve the efficacy of systemic treatment despite excellent pathologic response.DDS can be an indicator to identify a subset of the yp I group whose longterm oncologic outcomes are as good as those of stage p I cohort.

Low ligation has a lower anastomotic leakage rate after rectal cancer surgery

BACKGROUND For laparoscopic rectal cancer surgery,the inferior mesenteric artery(IMA)can be ligated at its origin from the aorta[high ligation(HL)]or distally to the origin of the left colic artery[low ligation(LL)].Whether different ligation levels are related to different postoperative complications,operation time,and lymph node yield remains controversial.Therefore,we designed this study to determine the effects of different ligation levels in rectal cancer surgery.AIM To investigate the operative results following HL and LL of the IMA in rectal cancer patients.METHODS From January 2017 to July 2019,this retrospective cohort study collected information from 462 consecutive rectal cancer patients.According to the ligation level,235 patients were assigned to the HL group while 227 patients were assigned to the LL group.Data regarding the clinical characteristics,surgical characteristics and complications,pathological outcomes and postoperative recovery were obtained and compared between the two groups.A multivariate logistic regression analysis was performed to evaluate the possible risk factors for anastomotic leakage(AL).RESULTS Compared to the HL group,the LL group had a significantly lower AL rate,with 6(2.8%)cases in the LL group and 24(11.0%)cases in the HL group(P=0.001).The HL group also had a higher diverting stoma rate(16.5%vs 7.5%,P=0.003).A multivariate logistic regression analysis was subsequently performed to adjust for the confounding factors and confirmed that HL(OR=3.599;95%CI:1.374-9.425;P=0.009),tumor located below the peritoneal reflection(OR=2.751;95%CI:0.772-3.985;P=0.031)and age(≥65 years)(OR=2.494;95%CI:1.080-5.760;P=0.032)were risk factors for AL.There were no differences in terms of patient demographics,pathological outcomes,lymph nodes harvested,blood loss,hospital stay and urinary function(P>0.05).CONCLUSION In rectal cancer surgery,LL should be the preferred method,as it has a lower AL and diverting stoma rate.

Using Materialise’s interactive medical image control system to reconstruct a model of a patient with rectal cancer and situs inversus totalis: A case report

BACKGROUND Situs inversus totalis(SIT)is a rare congenital anomaly that refers to a completely reversed location of abdominal and thoracic organs.An extremely small number of patients with this condition,especially those with rectal neoplasms,have been reported.Surgery in these patients is technically challenging.Therefore,we reconstructed a three-dimensional(3D)digital model with the Materialise’s interactive medical image control system(Mimics)as a guide for laparoscopic resection.CASE SUMMARY We report the case of a 68-year-old woman with rectal neoplasms and SIT diagnosed by electronic colonoscopy biopsy and enhanced computed tomography(CT),which showed that there was a soft tissue mass protruding into the lumen in the lower rectal segment,a lesion that involved the serosal layer,multiple enlarged peripheral lymph nodes,and visceral situs abnormalities.Based on the CT images,we reconstructed a 3D model with Mimics to assist with our surgical planning.Then,we performed laparoscopyassisted radical resection of the rectal neoplasms and total excision of the lesion.Adjuvant chemotherapy with the XELOX regimen(oxaliplatin 150 mg,D1+Xeloda 1.0 g,Bid,D1-14)was initiated 1 mo after the operation.The patient recovered well after surgery,and her physical condition remained stable.CONCLUSION Preoperative 3D reconstruction of the imaging results could help reduce the unknown risks during surgery caused by anatomical abnormalities and improvethe perioperative safety for patients.

Transanal minimally invasive surgery vs endoscopic mucosal resection for rectal benign tumors and rectal carcinoids: A retrospective analysis

BACKGROUND Transanal minimally invasive surgery(TAMIS)is a good choice for resection of rectal neoplasms.Endoscopic mucosal resection(EMR)is also widely used in the treatment of benign rectal tumors such as rectal polyps and rectal adenomas.However,no studies have compared the outcome of TAMIS and EMR.AIM To compare the short-term outcomes after TAMIS and EMR for rectal carcinoid and benign tumors(including rectal polyps and adenomas).METHODS From January 2014 to January 2019,44 patients who received TAMIS and 53 patients who received EMR at The Fifth People's Hospital of Shanghai were selected.Primary outcomes(surgical-related)were operating time,blood loss,length of postoperative hospital stay,rate of resection margin involvement and lesion fragmentation rate.The secondary outcomes were complications such as hemorrhage,urinary retention,postoperative infection and reoperation.RESULTS No significant differences were observed in terms of blood loss(12.48±8.00 mL for TAMIS vs 11.45±7.82 mL for EMR,P=0.527)and length of postoperative hospital stay(3.50±1.87 d for TAMIS vs 2.72±1.98 d for EMR,P=0.065)between the two groups.Operating time was significantly shorter for EMR compared with TAMIS(21.19±9.49 min vs 49.95±15.28 min,P=0.001).The lesion fragmentation rate in the EMR group was 22.6%(12/53)and was significantly higher than that(0%,0/44)in the TAMIS group(P=0.001).TAMIS was associated with a higher urinary retention rate(13.6%,6/44 vs 1.9%,1/53 P=0.026)and lower hemorrhage rate(0%,0/44 vs 18.9%,10/53 P=0.002).A significantly higher reoperation rate was observed in the EMR group(9.4%,5/53 vs 0%,0/44 P=0.036).

Neoadjuvant vs adjuvant pelvic radiotherapy for locally advanced rectal cancer: Which is superior?

The treatment of locally advanced rectal cancer including timing and dosage of radiotherapy, degree of sphincter preservation with neoadjuvant radiotherapy, and short and long term effects of radiotherapy are controversial topics. The MEDLINE, Cochrane Library databases, and meeting proceedings from the American Society of Clinical Oncology, were searched for reports of randomized controlled trials and meta-analyses comparing neoadjuvant and adjuvant radiotherapy with surgery to surgery alone for rectal cancer. Neoadjuvant radiotherapy shows superior results in terms of local control compared to adjuvant radiotherapy. Neither adjuvant or neoadjuvant radiotherapy impacts overall survival. Short course versus long course neoadjuvant radiotherapy remains controversial. There is insufficient data to conclude that neoadjuvant therapy improves rates of sphincter preserving surgery. Radiation significantly impacts anorectal and sexual function and includes both acute and long term toxicity. Data demonstrate that neoadjuvant radiation causes less toxicity compared to adjuvant radiotherapy, and specifically short course neoadjuvant radiation results in less toxicity than long course neoadjuvant radiation. Neoadjuvant radiotherapy is the preferred modality for administering radiation in locally advanced rectal cancer. There are significant side effects from radiation, including anorectal and sexual dysfunction, which may be less with short course neoadjuvant radiation.

Surgical resection of rectal adenoma:A rapid review

Transanal excision (TE), endoscopic transanal resection (ETAR) and transanal endoscopic microsurgery (TEM) can be used to remove adenomatous polyps. However, their use is limited by the size or location of the tumor. TE is limited to the lower rectum, TEM offers better access to lesions in the middle and upper rectum, and ETAR is used less frequently than it deserves for resection of rectal lesions.

Minilaparotomy to rectal cancer has higher overall survival rate and earlier short-term recovery

AIM:To report our experience using mini-laparotomy for the resection of rectal cancer using the total mesorectal excision (TME) technique METHODS:Consecutive patients with rectal cancer who underwent anal-colorectal surgery at the authors' hospital between March 2001 and June 2009 were included In total, 1415 patients were included in the study The cases were divided into two surgical procedure groups (traditional open laparotomy or mini-lap-arotomy) The mini-laparotomy group was defined as having an incision length ≤ 12 cm Every patient underwent the TME technique with a standard operation performed by the same clinical team The multimodal preoperative evaluation system and postoperative fast track were used To assess the short-term outcomes, data on the postoperative complications and recovery functions of these cases were collected and analysed The study included a plan for patient follow-up, to ob- tain the long-term outcomes related to 5-year survival and local recurrenceRESULTS: The mini-laparotomy group had 410 patients, and 1015 cases underwent traditional laparotomy There were no differences in baseline characteristics between the two surgical procedure groups The overall 5-year survival rate was not different between the mini-laparotomy and traditional laparotomy groups (80 6% vs 79 4%, P = 0 333), nor was the 5-year local recurrence (1 4% vs 1 5%, P = 0 544) However, 1-year mortality was decreased in the mini-laparotomy group compared with the traditional laparotomy group (0% vs 4 2%, P < 0 0001) Overall 1-year survival rates were 100% for Stage Ⅰ, 98 4% for Stage Ⅱ, 97 1% for Stage Ⅲ, and 86 6% for Stage Ⅳ Local recurrence did not differ between the surgical groups at 1 or 5 years Local recurrence at 1 year was 0 5% (2 cases) for mini-laparotomy and 0 5% (5 cases) for traditional laparotomy (P = 0 670) Local recurrence at 5 years was 1 5% (6 cases) for mini-laparotomy and 1 4% (14 cases) for traditional laparotomy (P = 0 544) Days to first ambulation (3.2 ± 0.8 dvs 3.9 ± 2.3 d, P = 0 000) and passing of gas (3.5 ± 1.1 d vs 4.3 ± 1.8 d, P = 0.000), length of hospital stay (6.4 ± 1.5 dvs 9.7 ± 2.2 d, P = 0 000), anastomotic leakage (0 5% vs 4 8%, P = 0 000), and intestinal obstruction (2 2% vs 7 3%, P = 0 000) were decreased in the mini-laparotomy group compared with the traditional laparotomy group The results for other postoperative recovery function indicators, such as days to oral feeding and defecation, were similar, as were the results for immediate postoperative complications, including the physiologic and operative severity score for the enumeration of mortality and morbidity score CONCLUSION:Mini-laparotomy, as conducted in a single-centre series with experienced TME surgeons, is a safe and effective new approach for minimally invasive rectal cancer surgery Further evaluation is required to evaluate the use of this approach in a larger patient sample and by other surgical teams.

Robotic surgery for rectal cancer: Current immediate clinical and oncological outcomes

Laparoscopic rectal surgery continues to be a challenging operation associated to a steep learning curve. Robotic surgical systems have dramatically changed minimally invasive surgery. Three-dimensional, magnified and stable view, articulated instruments, and reduction of physiologic tremors leading to superior dexterity and ergonomics. Therefore, robotic platforms could potentially address limitations of laparoscopic rectal surgery. It was aimed at reviewing current literature on short-term clinical and oncological(pathological) outcomes after robotic rectal cancer surgery in comparison with laparoscopic surgery. A systematic review was performed for the period 2002 to 2014. A total of 1776 patients with rectal cancer underwent minimally invasive robotic treatment in 32 studies. After robotic and laparoscopic approach to oncologic rectal surgery, respectively, mean operating time varied from 192-385 min, and from 158-297 min; mean estimated blood loss was between 33 and 283 mL, and between 127 and 300 mL; mean length of stay varied from 4-10 d; and from 6-15 d. Conversion after robotic rectal surgery varied from 0% to 9.4%, and from 0 to 22% after laparoscopy. There was no difference between robotic(0%-41.3%) and laparoscopic(5.5%-29.3%) surgery regarding morbidity and anastomotic complications(respectively, 0%-13.5%, and 0%-11.1%). Regarding immediate oncologic outcomes, respectively among robotic and laparoscopic cases, positive circumferential margins varied from 0% to 7.5%, and from 0% to 8.8%; the mean number of retrieved lymph nodes was between 10 and 20, and between 11 and 21; and the mean distal resection margin was from 0.8 to 4.7 cm, and from 1.9 to 4.5 cm. Robotic rectal cancer surgery is being undertaken by experienced surgeons. However, the quality of the assembled evidence does not support definite conclusions about most studies variables. Robotic rectal cancer surgery is associated to increased costs and operating time. It also seems to be associated to reduced conversion rates. Other short-term outcomes are comparable to conventional laparoscopy techniques, if not better. Ultimately, pathological data evaluation suggests that oncologic safety may be preserved after robotic total mesorectal excision. However, further studies are required to evaluate oncologic safety and functional results.

Usefulness of two independent hist classifications of tumor regression iUsefulness of two independent histopathological classifications of tumor regression in patients with rectal cancer submitted to hyperfractionated pre-operative radiotherapy

AIM: To assess the usefulness of two independent histopathological classifications of rectal cancer regression following neo-adjuvant therapy. METHODS: Forty patients at the initial stage cT3NxM0 submitted to preoperative radiotherapy (42 Gy during 18 d) and then to radical surgical treatment. The relationship between “T-downstaging” versus regressive changes expressed by tumor regression grade (TRG 1-5) and Nasierowska-Guttmejer classification (NG 1-3) was studied as well as the relationship between TRG and NG versus local tumor stage ypT and lymph nodes status, ypN. RESULTS: Complete regression (ypT0, TRG 1) was found in one patient. “T-downstaging” was observed in 11 (27.5%) patients. There was a weak statistical significance of the relationship between “T-downstaging” and TRG staging and NG stage. Patients with ypT1 were diagnosed as TRG 2-3 while those with ypT3 as TRG5. No lymph node metastases were found in patients with TRG 1-2. None of the patients without lymph node metastases were diagnosed as TRG 5. Patients in the ypT1 stage were NG 1-2. No lymph node metastases were found in NG 1. There was a significant correlation between TRG and NG. CONCLUSION: Histopathological classifications may be useful in the monitoring of the effects of hyperfractionated preoperative radiotherapy in patientswith rectal cancer at the stage of cT3NxM0. There is no unequivocal relationship between “T-downstaging” and TRG and NG. There is some concordance in the assessment of lymph node status with ypT, TRG and NG. TRG and NG are of limited value for the risk assessment of the lymph node involvement.

Risk of ileal pouch neoplasms in patients with familial adenomatous polyposis

Restorative proctocolectomy is the most common surgical option for patients with familial adenomatous polyposis(FAP). However,adenomas may develop in the ileal pouch mucosa over time,and even carcinoma in the pouch has been reported. We therefore reviewed the prevalence,nature,and treatment of adenomas and carcinoma that develop after proctocolectomy in the ileal pouch mucosa in patients with FAP. In 25 reports that were reviewed,the incidence of adenomas in the ileal pouch varied from 6.7% to 73.9%. Several potential factors that favor the development of pouch polyposis have been investigated,but many remain controversial. Nevertheless,it seems certain that the age of the pouch is important. The risk appears to be 7%to 16% after 5 years,35% to 42% after 10 years,and75% after 15 years. On the other hand,only 21 cases of ileal pouch carcinoma have been recorded in the literature to date. The diagnosis of pouch carcinoma was made between 3 to 20 years(median,10 years) after pouch construction. Although the risk of malignant transformation in ileal pouches is probably low,it is not negligible,and the long-term risk cannot presently be well quantified. Regular endoscopic surveillance,especially using chromoendoscopy,is recommended.

TELOMERASE ACTIVITY IN HUMAN GASTRIC AND COLORECTALCANCER AND SURROUNDING TISSUES

Objective: To study the telomerase activities in human gastric and colorectal tumors. Methods: The telomerase activity was assayed by the telomeric repeat amplification protocol (TRAP) technique. Forty human tumor samples including 9 colonic, 20 rectal and 11 gastric carcinomas and their surrounding tissues were used for the detection. Results: Thirty-six out of 40 human tumor samples exhibited telomerase activity regardless of the stages or the differentiation of the tumors. However, only 1 out of 39 tumor surrounding tissues showed telomerase activity. Conclusion: Telomerase may be a good diagnosis biomarker for tumor detection.

Overview of robotic colorectal surgery:Current and future practical developments

Minimal access surgery has revolutionised colorectal surgery by offering reduced morbidity and mortality over open surgery,while maintaining oncological and functional outcomes with the disadvantage of additional practical challenges. Robotic surgery aids the surgeon in overcoming these challenges. Uptake of robotic assistance has been relatively slow,mainly because of the high initial and ongoing costs of equipment but also because of limited evidence of improved patient outcomes. Advances in robotic colorectal surgery will aim to widen the scope of minimal access surgery to allow larger and more complex surgery through smaller access and natural orifices and also to make the technology more economical,allowing wider dispersal and uptake of robotic technology. Advances in robotic endoscopy will yield self-advancing endoscopes and a widening role for capsule endoscopy including the development of motile and steerable capsules able to deliver localised drug therapy and insufflation as well as being recharged from an extracorporeal power source to allow great longevity. Ultimately robotic technology may advance to the point where many conventional surgical interventions are no longer required. With respect to nanotechnology,surgery may eventually become obsolete.

Different oncological features of colorectal cancer codon-specific KRAS mutations:Not codon 13 but codon 12 have prognostic value

BACKGROUND Approximately 40%of colorectal cancer(CRC)cases are linked to Kirsten rat sarcoma viral oncogene homolog(KRAS)mutations.KRAS mutations are associated with poor CRC prognosis,especially KRAS codon 12 mutation,which is associated with metastasis and poorer survival.However,the clinicopathological characteristics and prognosis of KRAS codon 13 mutation in CRC remain unclear.AIM To evaluate the clinicopathological characteristics and prognostic value of codonspecific KRAS mutations,especially in codon 13.METHODS This retrospective,single-center,observational cohort study included patients who underwent surgery for stage I-III CRC between January 2009 and December 2019.Patients with KRAS mutation status confirmed by molecular pathology reports were included.The relationships between clinicopathological characteristics and individual codon-specific KRAS mutations were analyzed.Survival data were analyzed to identify codon-specific KRAS mutations as recurrence-related factors using the Cox proportional hazards regression model.RESULTS Among the 2203 patients,the incidence of KRAS codons 12,13,and 61 mutations was 27.7%,9.1%,and 1.3%,respectively.Both KARS codons 12 and 13 mutations showed a tendency to be associated with clinical characteristics,but only codon 12 was associated with pathological features,such as stage of primary tumor(T stage),lymph node involvement(N stage),vascular invasion,perineural invasion,tumor size,and microsatellite instability.KRAS codon 13 mutation showed no associations(77.2%vs 85.3%,P=0.159),whereas codon 12 was associated with a lower 5-year recurrence-free survival rate(78.9%vs 75.5%,P=0.025).In multivariable analysis,along with T and N stages and vascular and perineural invasion,only codon 12(hazard ratio:1.399;95%confidence interval:1.034-1.894;P=0.030)among KRAS mutations was an independent risk factor for recurrence.CONCLUSION This study provides evidence that KRAS codon 13 mutation is less likely to serve as a prognostic biomarker than codon 12 mutation for CRC in a large-scale cohort.

A case of postoperative spontaneous intussusception after laparoscopic low anterior resection for rectal cancer

Background:Intussusception refers to a condition in which a segment of the intestine invaginates into the lumen of an adjacent segment of the intestine.Postoperative intussusception after gastrointestinal surgery is an uncommon clinical condition,and there is only one case report of small bowel intussusception after rectal cancer surgery.Here,we report a case of spontaneous small bowel intussusception following laparoscopic total mesorectal excision for rectal cancer.Case presentation:A 56-year-old female military officer was referred to the Colorectal Surgical Department for midrectal cancer,8cm from the anal verge.The patient underwent laparoscopic low anterior resection and diverting loop ileostomy.On postoperative day 3,the patient complained of vomiting and abdominal pain,and a follow-up abdomino-pelvic computed tomography scan showed an ileo-ileal type intussusception.After two days of surgical observation,the clinical symptoms were not resolved.The patient underwent exploratory laparotomy.On exploration,intussusception was found 40 cm proximal to the loop ileostomy site.Segmental resection of the ileum was carried out,and there was no pathological leading point on the resected ileum.The patient was discharged on postoperative day 14 after the second operation and has remained in good health for two years.Conclusion:We present a case of spontaneous small bowel intussusception after laparoscopic total mesorectal excision for rectal cancer that was treated by surgical resection 5 days after the index surgery.