Diagnostic value of whole-body MRI with diffusion-weighted sequence for detection of peritoneal metastases in colorectal malignancy

Objective：To assess the diagnostic accuracy of whole-body MRI using diffusion-weighted sequence（WB-DWI）to determine the peritoneal cancer index（PCI）in correlation with surgical and histopathological findings.Methods：Twenty-seven patients underwent preoperative WB-MRI,followed by cytoreductive surgery for primary tumors of the appendix（n=15）,colorectum（n=12）,and associated peritoneal disease.A total of 351 regions were retrospectively reviewed.The sensitivity,specificity,and accuracy were calculated at 13 anatomical sites.The WB-DWI PCI and PCI type were compared with surgical and histopathological findings.Results：No statistical difference was found between the WB-DWI PCI and surgical PCI（P=0.574）.WB-DWI correctly predicted the PCI type in 24 of 27 patients with high accuracy（88.9%）,including 10 of 10 patients with small-volume tumor,12 of 14 with moderate-volume tumor,and 2 of 3 with large-volume tumor.WB-DWI correctly depicted tumors in 163 of 203 regions,with 40false-negative and 23 false-positive regions.The overall sensitivity,specificity,and accuracy of WB-DWI for the detection of peritoneal tumors were 80.3%,84.5%,and 82.1%,respectively.For lesions＆lt;0.5 cm in diameter,WB-DWI demonstrated good sensitivity（69.4%）.Conclusions：WB-DWI accurately predicted PCI before surgery in patients undergoing evaluation for cytoreductive surgery.

Long-term outcomes after endoscopic removal of malignant colorectal polyps:Results from a 10-year cohort

BACKGROUND Choosing an optimal post-polypectomy management strategy of malignant colorectal polyps is challenging,and evidence regarding a surveillance-only strategy is limited.AIM To evaluate long-term outcomes after endoscopic removal of malignant colorectal polyps.METHODS A single-center retrospective cohort study was conducted to evaluate outcomes after endoscopic removal of malignant colorectal polyps between 2010 and 2020.Residual disease rate and nodal metastases after secondary surgery and local and distant recurrence rate for those with at least 1 year of follow-up were invest-igated.Event rates for categorical variables and means for continuous variables with 95%confidence intervals were calculated,and Fisher’s exact test and Mann-Whitney test were performed.Potential risk factors of adverse outcomes were RESULTS In total,135 lesions(mean size:22.1 mm;location:42%rectal)from 129 patients(mean age:67.7 years;56%male)were enrolled.The proportion of pedunculated and non-pedunculated lesions was similar,with en bloc resection in 82%and 47%of lesions,respectively.Tumor differentiation,distance from resection margins,depth of submucosal invasion,lymphovascular invasion,and budding were reported at 89.6%,45.2%,58.5%,31.9%,and 25.2%,respectively.Residual tumor was found in 10 patients,and nodal metastasis was found in 4 of 41 patients who underwent secondary surgical resection.Univariate analysis identified piecemeal resection as a risk factor for residual malignancy(odds ratio:1.74;P=0.042).At least 1 year of follow-up was available for 117 lesions from 111 patients(mean follow-up period:5.59 years).Overall,54%,30%,30%,11%,and 16%of patients presented at the 1-year,3-year,5-year,7-year,and 9-10-year surveillance examinations.Adverse outcomes occurred in 9.0%(local recurrence and dissemination in 4 patients and 9 patients,respectively),with no difference between patients undergoing secondary surgery and surveillance only.CONCLUSION Reporting of histological features and adherence to surveillance colonoscopy needs improvement.Long-term adverse outcome rates might be higher than previously reported,irrespective of whether secondary surgery was performed.

Clinical application of self-expanding metallic stent in the management of acute left-sided colorectal malignant obstruction

AIM： To summarize our experience with the application of self-expanding metallic stent （SEMS） in the management of acute left-sided colorectal malignant obstruction. METHODS： A retrospective chart review of all patients undergoing placement of SENS between April 2000 and January 2004 was performed. RESULTS： Insertion of SENS was attempted in 26 patients under fluoroscopic guidance with occasional endoscopic assistance. The sites of lesions were located in splenic flexure of two patients, left colon of seven patients, sigmoid colon of eight patients and rectum of nine patients. The intended uses of SENS were for palliation in 7 patients and as a bridge to elective surgery in 19 patients. In the latter group, placement of SENS allowed for preoperative systemic and bowel preparation and the following one-stage anastomosis. Successful stent placement was achieved in 22 （85%） of the 26 patients. The clinical bowel obstruction resolved 24 hours after successful stent placement in 21 （95%） patients. Three SENS-related minor complications occurred, two stents migrated and one caused anal pain. CONCLUSION： SEMS represents an effective and safe tool in the management of acute malignant colorectal obstruction. As a bridge to surgery, SEMS can provide time for systematic support and bowel preparation and obviate the need for fecal diversion or on-table lavage. As a palliative measure, SEMS can eliminate the need for emergent colostomy.

Role of one-step nucleic acid amplification in colorectal cancer lymph node metastases detection

Current histopathological staging procedures in colorectal cancer(CRC)depend on midline division of the lymph nodes(LNs)with one section of hematoxylin and eosin staining.Cancer cells outside this transection line may be missed,which could lead to understaging of Union for International Cancer Control Stage II high-risk patients.The one-step nucleic acid amplification(OSNA)assay has emerged as a rapid molecular diagnostic tool for LN metastases detection.It is a molecular technique that can analyze the entire LN tissue using a reversetranscriptase loop-mediated isothermal amplification reaction to detect tumorspecific cytokeratin 19 mRNA.Our findings suggest that the OSNA assay has a high diagnostic accuracy in detecting metastatic LNs in CRC and a high negative predictive value.OSNA is a standardized,observer-independent technique,which may lead to more accurate staging.It has been suggested that in stage II CRC,the upstaging can reach 25%and these patients can access postoperative adjuvant chemotherapy.Moreover,intraoperative OSNA sentinel node evaluation may allow early CRC to be treated with organ-preserving surgery,while in more advanced-stage disease,a tailored lymphadenectomy can be performed considering the presence of aberrant lymphatic drainage and skip metastases.

Indocyanine Green Fluorescence Imaging-Guided Lymphangiography in Colorectal Oncologic Practice:Current Use and Future Considerations

The clearance of lesions during surgery for colorectal cancer encompasses the removal of both the primary tumour and its concomitant lymphatic drainage.Huge strides have been made in identifying the precise location of not only the primary tumour,but also the lymph nodes(LNs),owing to the use of intraoperative navigation techniques.Among these techniques,indocyanine green-enhanced fluorescence imaging(ICG-FI)has revolutionized colorectal oncologic surgery by providing clear visualization during lymphangiography.ICG-FI has emerged as a powerful tool for sentinel lymph node procedures that allows for local excision instead of radical D3 lymphadenectomy.It also makes it possible to identify potential metastatic lateral pelvic lymph nodes,which enables simultaneous lymphadenectomy of the pelvic side-wall during the resection of middle-lower rectal cancer.This review provides an update on the current use of and research on ICG-FI-guided LNs mapping for colorectal malignancies,and also discusses its drawbacks and future prospects.