Long-term results of transanal endoscopic microsurgery after endoscopic polypectomy of malignant rectal adenoma

Transanal endoscopic microsurgery versus radical resection for early-stage rectal cancer: a systematic review and meta- analysis

PURPOSE

In the treatment of early-stage rectal cancer, a growing number of studies have shown that transanal endoscopic microsurgery is one of the alternatives to radical surgery adhering to total mesorectal excision that can reduce the incidence of adverse events without compromising treatment outcomes. The purpose of this meta-analysis is to compare the safety and treatment effect of transanal endoscopic microsurgery and radical surgery adhering to total mesorectal excision to provide a basis for clinical treatment selections.

METHOD

We searched the literatures of four major databases, PubMed, Embase, Web of science, and Cochrane Library, without limitation of time. The literatures included randomized controlled studies and cohort studies comparing two surgical procedures of transanal endoscopic microsurgery and radical surgery adhering to total mesorectal excision. Treatment effectiveness and safety results of transanal endoscopic microsurgery and radical surgery were extracted from the included literatures and statistically analyzed using RevMan5.4 and stata17.

RESULT

Ultimately, 13 papers were included in the study including 5 randomized controlled studies and 8 cohort studies. The results of the meta-analysis showed that the treatment effect and safety of both transanal endoscopic microsurgery and radical surgery in distant metastasis (RR, 0.59 (0.34, 1.02), P > 0.05), overall recurrence (RR, 1.49 (0.96, 2.31), P > 0.05), disease-specific-survival (RR, 0.74 (0.09, 1.57), P > 0.05), dehiscence of the sutureline or anastomosis leakage (RR, 0.57 (0.30, 1.06), P > 0.05), postoperative bleeding (RR, 0.47 (0.22, 0.99), P > 0.05), and pneumonia (RR, 0.37, (0.10, 1.40), P > 0.05) were not significantly different. However, they differ significantly in perioperative mortality (RR, 0.26 (0.07, 0.93, P < 0.05)), local recurrence (RR, 2.51 (1.53, 4.21), P < 0.05),_overall survival_ (RR, 0.88 (0.74, 1.00), P < 0.05), disease-free-survival (RR, 1.08 (0.97, 1.19), P < 0.05), temporary stoma (RR, 0.05 (0.01, 0.20), P < 0.05), permanent stoma (RR, 0.16 (0.08, 0.33), P < 0.05), postoperative complications (RR, 0.35 (0.21, 0.59), P < 0.05), rectal pain (RR, 1.47 (1.11, 1.95), P < 0.05), operation time (RR, -97.14 (-115.81, -78.47), P < 0.05), blood loss (RR, -315.52 (-472.47, -158.57), P < 0.05), and time of hospitalization (RR, -8.82 (-10.38, -7.26), P < 0.05).

CONCLUSION

Transanal endoscopic microsurgery seems to be one of the alternatives to radical surgery for early-stage rectal cancer, but more high-quality clinical studies are needed to provide a reliable basis.

The Role of Transanal Endoscopic Surgery for Early Rectal Cancer

Transanal endoscopic surgery (TES), which is performed through a variety of transanal endoluminal multitasking surgical platforms, was developed to facilitate endoscopic en bloc excision of rectal lesions as a minimally invasive alternative to radical proctectomy. Although the oncologic safety of TES in the treatment of malignant rectal tumors has been an area of vigorous controversy over the past two decades, TES is currently accepted as an oncologically safe approach for the treatment of carefully selected early and superficial rectal cancers. TES can also serve as both a diagnostic and potentially curative treatment of partially resected unsuspected malignant polyps. In this article, indications and contraindications for transanal endoscopic excision of early rectal cancer lesions are reviewed, as well as selection criteria for the most appropriate transanal excisional approach. Preoperative preparation and surgical technique for complications of TES will be reviewed, as well as recommended surveillance and management of upstaged tumors.

International consensus recommendations on key outcome measures for organ preservation after (chemo)radiotherapy in patients with rectal cancer

Multimodal treatment strategies for patients with rectal cancer are increasingly including the possibility of organ preservation, through nonoperative management or local excision. Organ preservation strategies can enable patients with a complete response or near-complete clinical responses after radiotherapy with or without concomitant chemotherapy to safely avoid the morbidities associated with radical surgery, and thus to maintain anorectal function and quality of life. However, standardization of the key outcome measures of organ preservation strategies is currently lacking; this includes a lack of consensus of the optimal definitions and selection of primary end points according to the trial phase and design; the optimal time points for response assessment; response-based decision-making; follow-up schedules; use of specific anorectal function tests; and quality of life and patient-reported outcomes. Thus, a consensus statement on outcome measures is necessary to ensure consistency and facilitate more accurate comparisons of data from ongoing and future trials. Here, we have convened an international group of experts with extensive experience in the management of patients with rectal cancer, including organ preservation approaches, and used a Delphi process to establish the first international consensus recommendations for key outcome measures of organ preservation, in an attempt to standardize the reporting of data from both trials and routine practice in this emerging area.

Can Ultrasound Elastography Discriminate between Rectal Adenoma and Cancer? A Systematic Review

BACKGROUND

Rectal cancer is a common malignancy. Since the introduction of bowel-screening programs, the number of patients with advanced adenomas and early rectal cancer has increased. Despite improved diagnostics, the discrimination between rectal adenomas and early rectal cancer (i.e., pT1-T2) remains challenging. The purpose of this systematic review was to evaluate the diagnostic performance of endorectal ultrasound (ERUS) elastography in discriminating rectal adenomas from cancer.

METHOD

Using PRISMA guidelines, a systematic search was performed on PubMed, Embase, and MEDLINE databases. Studies evaluating the primary staging of rectal adenomas and cancer using ERUS elastography were included.

RESULTS

Six studies were identified; three evaluated the discrimination between adenomas and cancer; two evaluated adenomas and early rectal cancer (i.e., pT1-T2); one evaluated performance on different T categories. All studies reported increased diagnostic accuracy of ERUS elastography compared to ERUS. Sensitivity, specificity and accuracy ranged 0.93-1.00, 0.83-1.00 and 0.91-1.00, respectively, when discriminating adenomas from cancer. In the differentiation between adenomas and early rectal cancer, the sensitivity, specificity and accuracy were 0.82-1.00, 0.86-1.00 and 0.84-1.00, respectively.

CONCLUSION

Elastography increases the accuracy of ERUS and may provide valuable information on malignant transformation of rectal lesions.

Local excision after polypectomy for rectal polyp cancer: when is it worthwhile?

AIM

The optimal management of a polyp cancer that has been removed endoscopically is unclear. Further local excision is often advocated to remove the polyp stalk or scar or to ensure clear margins, but the benefit of this is unclear. The aim of this paper is to determine whether the indications for further local excision can be better defined.

METHOD

Data were collected from two institutions (in UK and Denmark) which maintain prospective databases to collect information on all patients undergoing transanal endoscopic microsurgery (TEM). The study group was all patients who had a TEM after macroscopically complete polypectomy for rectal cancer. Data covering an 11-year period were analysed.

RESULTS

Sixty three patients had TEM with no residual cancer after macroscopically complete polypectomy. Residual adenoma was found in 23 (37%). A postpolypectomy endoscopy had not detected the residual adenoma in three. Malignant local recurrence occurred in five patients (8%) and distant metastases in another two (3%). Recurrence occurred in 4/23 (17%) when there was residual adenoma in the TEM specimen and in 3/40 (7.5%) where there was scar only, although this did not reach significance. In two instances recurrence was around 10 years after TEM. Those with residual adenoma at TEM tended to have poorer survival.

CONCLUSION

Further local excision often reveals no residual cancer despite microscopically involved polypectomy margins. Careful endoscopy is required to assess the polypectomy site as residual tumour can be missed. In the absence of residual adenoma, TEM does not appear to be of benefit, although a small risk of recurrence exists.

Minimally invasive transanal surgery is safe after incomplete polypectomy of low risk T1 rectal cancer: a systematic review

AIM

In patients who have undergone a polypectomy of a malignant rectal polyp without histopathological risk factors other than an involved or unclear resection margin, additional local excision is often performed. Evidence to support this approach is lacking. The aim of this systematic review and meta-analysis was to determine the outcome in terms of local recurrence, disease-free survival (DFS) and overall survival (OS) of additional local excision following incomplete polypectomy for low risk T1 rectal cancer.

METHODS

A comprehensive search for published studies was performed. Only studies in which there was incomplete (or ≤ 1 mm) removal of pT1 rectal polyps or in which the resection plane could not be assessed were included. For each included study data on tumour stage, histological factors, surgical technique, local recurrence rate, 5-year DFS and 5-year OS were extracted. The PROSPERO registration number is CRD42017062702.

RESULTS

A total of 580 studies were retrieved by the search in the MEDLINE database, Embase and the Cochrane Library. After careful appreciation, four studies were included in the analysis, comprising 102 patients of whom the majority had undeterminable (Rx) resection margins. Local excision via transanal endoscopic microsurgery was reported most frequently. Only 1% of patients developed a local recurrence. One study reported 5-year DFS and 5-year OS of 96% and 87% respectively.

CONCLUSION

This study supports the use of additional local excision techniques for rectal cancer patients who underwent an incomplete polypectomy for a malignant rectal polyp in the absence of risk factors other than an uncertain resection margin.