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.

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.

Genetic polymorphisms in genes regulating cell death and prognosis of patients with rectal cancer receiving postoperative chemoradiotherapy

Objective:The identification of biomarkers for predicting chemoradiotherapy efficacy is essential to optimize personalized treatment.This study determined the effects of genetic variations in genes involved in apoptosis,pyroptosis,and ferroptosis on the prognosis of patients with locally advanced rectal cancer receiving postoperative chemoradiotherapy(CRT).Methods:The Sequenom MassARRAY was used to detect 217 genetic variations in 40 genes from 300 patients with rectal cancer who received postoperative CRT.The associations between genetic variations and overall survival(OS)were evaluated using hazard ratios(HRs)and 95%confidence intervals(CIs)computed using a Cox proportional regression model.Functional experiments were performed to determine the functions of the arachidonate 5-lipoxygenase(ALOX5)gene and the ALOX5 rs702365 variant.Results:We detected 16 genetic polymorphisms in CASP3,CASP7,TRAILR2,GSDME,CASP4,HO-1,ALOX5,GPX4,and NRF2 that were significantly associated with OS in the additive model(P<0.05).There was a substantial cumulative effect of three genetic polymorphisms(CASP4 rs571407,ALOX5 rs2242332,and HO-1 rs17883419)on OS.Genetic variations in the CASP4 and ALOX5 gene haplotypes were associated with a higher OS.We demonstrated,for the first time,that rs702365[G]>[C]represses ALOX5 transcription and corollary experiments suggested that ALOX5 may promote colon cancer cell growth by mediating an inflammatory response.Conclusions:Polymorphisms in genes regulating cell death may play essential roles in the prognosis of patients with rectal cancer who are treated with postoperative CRT and may serve as potential genetic biomarkers for individualized treatment.

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.

External validation of the Moroccan Arabic version of the European Organization for Research and Treatment of Cancer colorectal(CR29)module:Monocentric study

BACKGROUND Quality of life(QoL)outcomes are a focal endpoint of cancer treatment strategies.AIM To externally validate the Moroccan Arabic version of the European Organization for Research and Treatment of Cancer(EORTC)QoL Questionnaire(QLQ)for colorectal cancer(CRC)patients(CR29).METHODS Both Moroccan Arabic modules of QLQ-CR29 and QLQ-C30 were administered to Moroccan CRC.Psychometric properties were retested by measuring Cronbach’s alpha coefficient for reliability and Intraclass correlation coefficient(ICC)to examine test-retest reproducibility.The multitrait-scaling analysis was performed to demonstrate the validity of the instrument and known-groups comparison was used to test the score’s ability to discriminate between different groups of patients.RESULTS In total,221 patients were included in our study and 34 patients completed the questionnaire twice.The Urinary Frequency scale and Stool Frequency scale had good internal consistency with alpha Cronbach coefficients of 0.79 and 0.83 respectively,while the same coefficients were moderately lower for the Blood and Mucus in Stool scale(0.61)and the Body Image scale(0.67).The ICCs ranged from 0.88 to 1 indicating good to excellent reproducibility.In multitrait scaling analyses,the criterion for item convergent and divergent validity was satisfactory.The known-group comparison showed statistically significant differences between patients according to age,gender,stoma status,tumor location,and radiotherapy.CONCLUSION The Moroccan Arabic version of the EORTC QLQ-CR29 is a valid and reliable tool that can be used safely for research and clinical purposes in Moroccan CRC patients.

Selective lateral lymph node dissection after neoadjuvant chemoradiotherapy in rectal cancer

BACKGROUND Lateral lymph node metastasis is one of the leading causes of local recurrence in patients with advanced mid or low rectal cancer.Neoadjuvant chemoradiotherapy(NCRT)can effectively reduce the postoperative recurrence rate;thus,NCRT with total mesorectal excision(TME)is the most widely accepted standard of care for rectal cancer.The addition of lateral lymph node dissection(LLND)after NCRT remains a controversial topic.AIM To investigate the surgical outcomes of TME plus LLND,and the possible risk factors for lateral lymph node metastasis after NCRT.METHODS This retrospective study reviewed 89 consecutive patients with clinical stage II-III mid or low rectal cancer who underwent TME and LLND from June 2016 to October 2018.In the NCRT group,TME plus LLND was performed in patients with short axis(SA)of the lateral lymph node greater than 5 mm.In the non-NCRT group,TME plus LLND was performed in patients with SA of the lateral lymph node greater than 10 mm.Data regarding patient demographics,clinical workup,surgical procedure,complications,and outcomes were collected.Multivariate logistic regression analysis was performed to evaluate the possible risk factors for lateral lymph node metastasis in NCRT patients.RESULTS LLN metastasis was pathologically confirmed in 35 patients(39.3%):26(41.3%)in the NCRT group and 9(34.6%)in the non-NCRT group.The most common site of metastasis was around the obturator nerve(21/35)followed by the internal iliac artery region(12/35).In the NCRT patients,46%of patients with SA of LLN greater than 7 mm were positive.The postoperative 30-d mortality rate was 0%.Two(2.2%)patients suffered from lateral local recurrence in the 2-year follow up.Multivariate analysis showed that cT4 stage(odds ratio[OR]=5.124,95%confidence interval[CI]:1.419-18.508;P=0.013),poor differentiation type(OR=4.014,95%CI:1.038-15.520;P=0.044),and SA≥7 mm(OR=7.539,95%CI:1.487-38.214;P=0.015)were statistically significant risk factors associated with LLN metastasis.CONCLUSION NCRT is not sufficient as a stand-alone therapy to eradicate LLN metastasis in lower rectal cancer patients and surgeons should consider performing selective LLND in patients with greater LLN SA diameter,poorer histological differentiation,or advanced T stage.Selective LLND for NCRT patients can have a favorable oncological outcome.

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.

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.

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).

Expression of p53 and p21 Protein in Transitional Mucosa Adjacent to Rectal Carcinoma and Its Clinical Implication

To study the biopathological characteristics of the transitional mucosa adjacent to rectal carcinoma, 34 cases were subjected to mucin histochemical and immunohistochemical study to observe the expression of p53 and p21 protein in distal mucosa adjacent to rectal carcinoma and its relationship to the mucin change. The expression of p53 protein was found in 29. 4 % (10/34) of distal transitional mucosa in the cytoplasm of goblet cells, and its positive staining was within 4 cm from carcinoma margin. A11 p53 positive mucosa was transitional mucosa. Overexpression of p21 protein was found in 26.5 % (9/34) of distal transitional mucosa in cytoplasm of crypt cells, and its positive staining was within 2 cm from carcinoma margin. There was no relationship between the expression of p53 and p21 protein in carcinoma and that in transitional mucosa ( P >0.05). These findings indicated that there was aberrant alteration of p53 and p21 genes in transitional mucosa adjacent to colorectal carcinoma, which provided further evidence that transitional mucosa was an unstable pre cancerous change. The aberrant mucin change and genetic alteration in distal mucosa of rectal cancer is within 4 cm.

Preoperative rectal tumor embolization as an adjunctive tool for bloodless abdominoperineal excision:A case report

BACKGROUND Abdominoperineal excision(APE)-related hemorrhage can be challenging due to difficult access to pelvic organs and the risk of massive blood loss.The objective of the present study was to demonstrate the use of preoperative embolization(PE)as a strategy for blood preservation in a patient with a large low rectal tumor with a high risk of bleeding,scheduled for APE.CASE SUMMARY A 56-year-old man presented to our institution with a one-year history of anal bleeding and rectal tenesmus.The patient was diagnosed with bulky adenocarcinoma limited to the rectum.As the patient refused any clinical treatment,surgery without previous neoadjuvant chemoradiation was indicated.The patient underwent a tumor embolization procedure,two days before surgery performed via the right common femoral artery.The tumor was successfully devascularized and no major bleeding was noted during APE.Postoperative recovery was uneventful and a one-year follow-up showed no signs of recurrence.CONCLUSION Therapeutic tumor embolization may play a role in bloodless surgeries and increase surgical and oncologic prognoses.We describe a patient with a bulky low rectal tumor who successfully underwent preoperative embolization and bloodless abdominoperineal resection.

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.

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.

Role of dynamic perfusion magnetic resonance imaging in patients with local advanced rectal cancer

BACKGROUND The management of rectal cancer patients is mainly based on the use of the magnetic resonance imaging(MRI)technique as a diagnostic tool for both staging and restaging.After treatment,to date,the evaluation of complete response is based on the histopathology assessment by using different tumor regression grade(TRG)features(e.g.,Dworak or Mandard classifications).While from the radiological point of view,the main attention for the prediction of a complete response after chemotherapy treatment focuses on MRI and the potential role of diffusion-weighted images and perfusion imaging represented by dynamiccontrast enhanced MRI.The main aim is to find a reliable tool to predict tumor response in comparison to histopathologic findings.AIM To investigate the value of dynamic contrast-enhanced perfusion-MRI parameters in the evaluation of the healthy rectal wall and tumor response to chemo-radiation therapy in patients with local advanced rectal cancer with histopathologic correlation.METHODS Twenty-eight patients with biopsy-proven rectal adenocarcinoma who underwent a dynamic contrast-enhanced MR study performed on a 1.5 T MRI system(Achieva,Philips),before(MR1)and after chemoradiation therapy(MR2),were enrolled in this study.The protocol included T1 gadolinium enhanced THRIVE sequences acquired on axial planes.A dedicated workstation was used to generate color permeability maps.Region of interest was manually drawn on tumor tissue and normal rectal wall,hence the following parameters were calculated and statistically analyzed:Relative arterial enhancement(RAE),relative venous enhancement(RVE),relative late enhancement(RLE),maximum enhancement(ME),time to peak and area under the curve(AUC).Perfusion parameters were related to pathologic TRG(Mandard’s criteria;TRG1=complete regression,TRG5=no regression).RESULTS Ten tumors(36%)showed complete or subtotal regression(TRG1-2)at histology and classified as responders;18 tumors(64%)were classified as non-responders(TRG3-5).Perfusion MRI parameters were significantly higher in the tumor tissue than in the healthy tissue in MR1(P<0.05).At baseline(MR1),no significant difference in perfusion parameters was found between responders and nonresponders.After chemo-radiation therapy,at MR2,responders showed significantly(P<0.05)lower perfusion values[RAE(%)54±20;RVE(%)73±24;RLE(%):82±29;ME(%):904±429]compared to non-responders[RAE(%):129±45;RVE(%):154±39;RLE(%):164±35;ME(%):1714±427].Moreover,in responders group perfusion values decreased significantly at MR2[RAE(%):54±20;RVE(%):73±24;RLE(%):82±29;ME(%):904±429]compared to the corresponding perfusion values at MR1[RAE(%):115±21;RVE(%):119±21;RLE(%):111±74;ME(%):1060±325];(P<0.05).Concerning the time-intensity curves,the AUC at MR2 showed significant difference(P=0.03)between responders and non-responders[AUC(mm2×10-3)121±50 vs 258±86],with lower AUC values of the tumor tissue in responders compared to nonresponders.In non-responders,there were no significant differences between perfusion values at MR1 and MR2.CONCLUSION Dynamic contrast perfusion-MRI analysis represents a complementary diagnostic tool for identifying vascularity characteristics of tumor tissue in local advanced rectal cancer,useful in the assessment of treatment response.

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.

Simple instruments facilitating achievement of transanal total mesorectal excision in male patients

AIM To assess the efficacy of a modified approach with transanal total mesorectal excision(ta TME) using simple customized instruments in male patients with low rectal cancer.METHODS A total of 115 male patients with low rectal cancer from December 2006 to August 2015 were retrospectively studied. All patients had a bulky tumor(tumor diameter ≥ 40 mm). Forty-one patients(group A) underwent a classical approach of transabdominal total mesorectal excision(TME) and transanal intersphincteric resection(ISR), and the other 74 patients(group B) underwent a modified approach with transabdominal TME,transanal ISR, and ta TME. Some simple instruments including modified retractors and an anal dilator with a papilionaceous fixture were used to perform ta TME. The operative time, quality of mesorectal excision, circumferential resection margin, local recurrence, and postoperative survival were evaluated.RESULTS All 115 patients had successful sphincter preservation. The operative time in group B(240 min, range: 160-330 min) was significantly shorter than that in group A(280 min, range: 200-360 min; P = 0.000). Co m pa r e d w it h g r o up A, m o r e c o m p le t e d is t a l mesorectum and total mesorectum were achieved in group B(100% vs 75.6%, P = 0.000; 90.5% vs 70.7%, P = 0.008, respectively). After 46.1 ± 25.6 mo followup, group B had a lower local recurrence rate and higher disease-free survival rate compared with group A, but these differences were not statistically significant(5.4% vs 14.6%, P = 0.093; 79.5% vs 65.1%, P = 0.130). CONCLUSION Retrograde ta TME with simple customized instruments can achieve high-quality TME, and it might be an effective and economical alternative for male patients with bulky tumors.

Complete pathologic response after chemoradiotherapy in a patient with rectal squamous cell carcinoma： a case report

Squamous cell carcinoma(SCC)of the rectum is a rare disease.A 59-year-old man presented with SCC of the middle rectum located 10 cm from the anus.The stage of the tumor was revealed to be T3N+M0.The patient received a combined treatment with cisplatin and fluorouracil in concomitance with external radiation therapy.He then underwent an anterior resection of the rectum.The postoperative histopathological findings classified the tumor as yp T0N0 with cancer-free margins and lymph nodes.Treatment of SCC remains very challenging,and the acquisition of more consistent data is needed.

Evaluating the benefit of adjuvant chemotherapy in patients with ypT0-1 rectal cancer treated with preoperative chemoradiotherapy

BACKGROUND Adjuvant chemotherapy(ACTx)is recommended in rectal cancer patients after preoperative chemoradiotherapy(PCRT),but its efficacy in patients in the early post-surgical stage who have a favorable prognosis is controversial.AIM To evaluate the long-term survival benefit of ACTx in patients with ypT0–1 rectal cancer after PCRT and surgical resection.METHODS We identified rectal cancer patients who underwent PCRT followed by surgical resection at the Asan Medical Center from 2005 to 2014.Patients with ypT0–1 disease and those who received ACTx were included.The 5-year overall survival(OS)and 5-year recurrence-free survival(RFS)were analyzed according to the status of the ACTx.RESULTS Of 520 included patients,413 received ACTx(ACTx group)and 107 did not(no ACTx group).No significant difference was observed in 5-year RFS(ACTx group,87.9%vs no ACTx group,91.4%,P=0.457)and 5-year OS(ACTx group,90.5%vs no ACTx group,86.2%,P=0.304)between the groups.cT stage was associated with RFS and OS in multivariate analysis[hazard ratio(HR):2.57,95%confidence interval(CI):1.07–6.16,P=0.04 and HR:2.27,95%CI:1.09–4.74,P=0.03,respectively].Furthermore,ypN stage was associated with RFS and OS(HR:4.74,95%CI:2.39–9.42,P<0.00 and HR:4.33,95%CI:2.20–8.53,P<0.00,respectively),but only in the radical resection group.CONCLUSION Oncological outcomes of patients with ypT0–1 rectal cancer who received ACTx after PCRT showed no improvement,regardless of the radicality of resection.Further trials are needed to evaluate the efficacy of ACTx in these group of patients.

Could tumor characteristics identified by colonoscopy predict the locally advanced rectal carcinoma？

Background Neoadjuvant chemoradiation is now considered the standard care for locally advanced rectal carcinoma （T3-4 or/and N1-2 lesions）, but the accuracy of staging examinations including endorectal ultrasonography （ERUS） and MRI is far from excellent. In addition, the above staging equipment or professionals who perform the examinations may not be available in some hospitals, while preoperative colonoscopy and biopsy are usually obtainable in most hospitals.The objective of the present study was to investigate the clinical and pathological characteristics of locally advanced rectal carcinoma and identify candidates for neoadjuvant chemoradiation.Methods This was a retrospective study. Patients who were treated for rectal cancer at Changhai Hospital from January 1999 to July 2008 were identified from our prospectively collected database. Statistical analysis was performed using SPSS Software System （version 15.0）. The Mann-Whitney test, chi-square test and multivariate Logistic regression analysis were performed,Results A total of 1005 cases were included in this research, of which 761 cases were identified as locally advanced rectal carcinoma depending on postoperative TNM staging. The results of multivariate Logistic regression analysis indicated seven independent risk factors that could be used to predict a locally advanced rectal carcinoma independently： a high grade （including poor differentiation and undifferentiation） （OR： 3.856; 95% CI： 2.064 to 7.204;P=0.000）; large tumor size （OR： 2.455; 95% CI： 1.755 to 3.436; P=0.000）; elevated preoperative serum CEA level （OR：1.823; 95% CI： 1.309 to 2.537; P=0.000）; non-polypoid tumor type （OR： 1.758; 95% CI： 1.273 to 2.427; P=0.001）; the absence of synchronous polyps （OR： 1.602; 95% CI： 1.103 to 2.327; P=0.013）; the absence of blood in stool （OR： 1.659;95% CI： 1.049 to 2.624; P=0.030）; and a greater circumferential tumor extent （OR： 1.813; 95% CI： 1.055 to 3,113;P=0.031）. Based on these findings, a Logistic equation was established, the accuracy of which was 64% according to the information of the additional 50 cases.Conclusions Some independent risk factors related with locally advanced rectal carcinoma were identified, based on which it is possible to establish a Logistic equation as a tool to predict candidates of neoadjuvant chemoradiation.Further research about optimization of the equation is warranted.

Anatomy of the perirectal fascia at the level of rectosacral fascia revisited

Background:The relative anatomical understanding of the perirectal fasciae is of paramount importance for the proper performance of total mesorectal excision(TME).This study was to demonstrate the planes of TME and validates the intraoperative findings using cadaveric observations.Methods:In this combined retrospective and prospective study,bilateral attachment of the rectosacral fascia(RSF)was observed in 28 cadaveric specimens(male,n=14;female,n=14).From January 2018 to December 2019,surgical videos of 67 patients who underwent laparoscopic TME at the Affiliated Union Hospital of Fujian Medical University(Fuzhou,China)were reviewed and interpreted with the cadaveric findings.Results:The RSF(synonym:Waldeyer’s fascia)is the end of the pre-hypogastric fascia at the level of S4 and comprises two layers(upper and lower).These two layers provide double fascial protection for the venous sacral plexus.It inserts into the fascia propria of the rectum along a broad horizontal arc that merges anterolaterally in an oblique downward direction until it meets the posterolateral merge of Denonvilliers’fascia at the lateral rectal ligament(LRL).This ligament does not look like a true ligament but is more likely to be a fascial combination that cushions the rectal innervation and middle rectal vessels.Conclusions:Understanding the lateral attachment of RSF and its contribution to LRL provides invaluable surgical guidance to dissect this critical area.Therefore,lateral dissection is proposed from the anterior to the posterior direction to find the correct plane that guarantees an intact mesorectal envelope to protect the important nearby nerve structures.