Transanal endoscopic surgery is effective and safe after endoscopic polypectomy of potentially malignant rectal polyps with questionable margins

Management after non-curative endoscopic resection of T1 rectal cancer

Since the introduction of population-based screening, increasing numbers of T1 rectal cancers are detected and removed by local endoscopic resection. Patients can be cured with endoscopic resection alone, but there is a possibility of residual tumor cells remaining after the initial resection. These can be located intraluminally at the resection site or extraluminally in the form of (lymph node) metastases. To decrease the risk of residual cells progressing towards more advanced disease, additional treatment is usually needed. However, with the currently available risk stratification models, it remains challenging to determine who should and should not be further treated after non-curative endoscopic resection. In this review, the different management strategies for patients with non-curatively treated T1 rectal cancers are discussed, along with the available evidence for each strategy and relevant considerations for clinical decision making. Furthermore, we provide practical guidance on the management and surveillance following non-curative endoscopic resection of T1 rectal cancer.

How to Study the Location and Size of Rectal Tumors That Are Candidates for Local Surgery: Rigid Rectoscopy, Magnetic Resonance, Endorectal Ultrasound or Colonoscopy? An Interobservational Study

1.

BACKGROUND

Preoperative staging of rectal lesions for transanal endoscopic surgery (TES) comprises digital rectal examination, intraoperative rigid rectoscopy (IRR), endorectal ultrasound (EUS), colonoscopy and rectal magnetic resonance imaging (rMRI). The gold standard for topographic features is IRR. Are the results of the other tests sufficiently reliable to eliminate the need for IRR? rMRI is a key test in advanced rectal cancer and is not operator-dependent. Description of anatomical landmarks is variable. Can we rely on the information regarding topographic features provided by all radiologists? 2.

MATERIALS AND METHODS

This is a concordance interobservational study involving four diagnostic tests of anatomical characteristics of rectal lesions (colonoscopy, EUS, rectal MRI and IRR), performed by four expert radiologists, regarding topographic rectal features with rMRI. 3.

RESULTS

Fifty-five rectal tumors were operated on by using TES. The distance of the tumor from the anal verge, location by quadrants, size by quadrants and size of tumor were assessed (IRR as gold standard). For most of the tumors, the correlation between IRR and colonoscopy or EUS was very good (ICC > 0.75); the correlation between rMRI and IRR in respect of the size by quadrants (ICC = 0.092) and location by quadrants (ICC = 0.292) was weak. Topographic landmarks studied by the expert radiologists had an excellent correlation, except for distance from the peritoneal reflection to the anal verge (ICC = 0.606). 4.

CONCLUSIONS

Anatomical description of rectal lesions by IRR, EUS, colonoscopy and rMRI is reliable. Topographic data obtained by EUS and colonoscopy can serve as a reference to avoid IRR. Determination of these topographic data by rMRI is less reliable. As performed by the expert radiologists, the anatomical study by rMRI is accurate and reproducible.

A population-based study of the management of rectal malignant polyps and the use of trans-anal surgery

INTRODUCTION

Rectal malignant polyps can be managed by use of trans-anal resections (TAR). Traditional techniques of resection have been replaced by use of platforms such as trans-anal minimally invasive surgery (TAMIS) or trans-anal endoscopic microsurgery (TEM). This study reviewed the management of rectal malignant polyps, in particular focussing on when clinicians used TAR.

METHODS

A population wide cohort study of all malignant rectal polyps diagnosed in Queensland, Australia from 2011 to 2018 was undertaken. Patient and pathological factors were compared across the management strategies of polypectomy, TAR and rectal resection.

RESULTS

Overall 430 patients were diagnosed with a malignant rectal polyp during the study period, with 103 undergoing a TAR. There was increasing use of TAR across the study period as a management strategy (P < 0.001). Polypectomy alone was more likely to be the management strategy over TAR or rectal resection if there were clear margins (P < 0.001). The distance to the closest polypectomy margin was also significantly higher in the polypectomy group with mean clearance 2.09 mm in polypectomy group versus 0.86 mm in TAR group and 0.99 mm in resection group (P < 0.001). Rectal resection was more likely to be the management strategy over TAR if there was LVI (P < 0.001), depth of invasion was deeper (P < 0.001) and there was tumour budding (P = 0.001).

CONCLUSION

TAR is an effective management strategy for rectal polyps and is utilized particularly in rectal malignant polyps when there are close or involved margins. Future guideline development should consider incorporation of TAR given the advances in techniques afforded by TAMIS or TEM platforms.

Full-Thickness Scar Resection After R1/Rx Excised T1 Colorectal Cancers as an Alternative to Completion Surgery

INTRODUCTION

Local full-thickness resections of the scar (FTRS) after local excision of a T1 colorectal cancer (CRC) with uncertain resection margins is proposed as an alternative strategy to completion surgery (CS), provided that no local intramural residual cancer (LIRC) is found. However, a comparison on long-term oncological outcome between both strategies is missing.

METHODS

A large cohort of patients with consecutive T1 CRC between 2000 and 2017 was used. Patients were selected if they underwent a macroscopically complete local excision of a T1 CRC but positive or unassessable (R1/Rx) resection margins at histology and without lymphovascular invasion or poor differentiation. Patients treated with CS or FTRS were compared on the presence of CRC recurrence, a 5-year overall survival, disease-free survival, and metastasis-free survival.

RESULTS

Of 3,697 patients with a T1 CRC, 434 met the inclusion criteria (mean age 66 years, 61% men). Three hundred thirty-four patients underwent CS, and 100 patients underwent FTRS. The median follow-up period was 64 months. CRC recurrence was seen in 7 patients who underwent CS (2.2%, 95% CI 0.9%-4.6%) and in 8 patients who underwent FTRS (9.0%, 95% CI 3.9%-17.7%). Disease-free survival was lower in FTRS strategy (96.8% vs 89.9%, P = 0.019), but 5 of the 8 FTRS recurrences could be treated with salvage surgery. The metastasis-free survival (CS 96.8% vs FTRS 92.1%, P = 0.10) and overall survival (CS 95.6% vs FTRS 94.4%, P = 0.55) did not differ significantly between both strategies.

DISCUSSION

FTRS after local excision of a T1 CRC with R1/Rx resection margins as a sole risk factor, followed by surveillance and salvage surgery in case of CRC recurrence, could be a valid alternative strategy to CS.

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.

Preoperative Diagnostic Uncertainty in T2-T3 Rectal Adenomas and T1-T2 Adenocarcinomas and a Therapeutic Dilemma: Transanal Endoscopic Surgery, or Total Mesorectal Excision?

BACKGROUND

Endorectal ultrasound and rectal magnetic resonance are sometimes unable to differentiate between stages T2 and T3 in rectal adenomas that are possible adenocarcinomas, or between stages T1 and T2 in rectal adenocarcinomas. These cases of diagnostic uncertainty raise a therapeutic dilemma: transanal endoscopic surgery (TES) or total mesorectal excision (TME)?

METHODS

An observational study of a cohort of 803 patients who underwent TES from 2004 to 2021. Patients operated on for adenoma (group I) and low-grade T1 adenocarcinoma (group II) were included. The variables related to uncertain diagnosis, and to the definitive pathological diagnosis of adenocarcinoma stage higher than T1, were analyzed.

RESULTS

A total of 638 patients were included. Group I comprised 529 patients, 113 (21.4%) with uncertain diagnosis. Seventeen (15%) eventually had a pathological diagnosis of adenocarcinoma higher than T1. However, the variable diagnostic uncertainty was a risk factor for adenocarcinoma above T1 (OR 2.3, 95% CI 1.1-4.7). Group II included 109 patients, eight with uncertain diagnosis (7.3%). Two patients presented a definitive pathological diagnosis of adenocarcinoma above T1.

CONCLUSIONS

On the strength of these data, we recommend TES as the initial indication in cases of diagnostic uncertainty. Multicenter studies with larger samples for both groups should now be performed to further assess this strategy of initiating treatment with TES.

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.

Oncological outcome after local treatment for early stage rectal cancer

BACKGROUND

Treatment of early rectal cancer is evolving towards organ-preserving therapy which includes endoscopic resection and transanal approaches. We aimed to explore the role of local treatments such as endoscopic polypectomy (Endoscopic Mucosal Resection (EMR) or Endoscopic submucosal dissection (ESD)) and transanal endoscopic microsurgery/ transanal minimal invasive surgery (TEM/TAMIS) in patients who had early rectal cancer. We considered these outcomes alongside conventional major surgery using total mesorectal excision (TME) for early stage disease.

METHODS

All patients identified at MDT with early stage rectal cancer at our institution between 2010 and 2019 were included. Long-term outcomes in terms of local recurrence, survival and procedure-specific morbidity were analysed.

RESULTS

In total, 536 patients with rectal cancer were identified, of which 112 were included based on their pre-operative identification at the MDT on the basis that they had node-negative early rectal cancer. Among these, 30 patients (27%) had the lesion excised by flexible endoscopic polypectomy techniques (EMR/ESD), 67 (60%) underwent TEM/TAMIS and 15 (13%) had major surgery. There were no differences in patient demographics between the three groups except for TEM/TAMIS patients being more likely to be referred from another hospital (p < 0.001) and they were less active (WHO performance status p = 0.04). There were no significant differences in overall survival rates and cancer-specific survival between the three treatment groups. The 5-year overall survival rate for endoscopic polypectomy, TEM/TAMIS or major resection was 96% versus 90% and 88%, respectively (p = 0.89). The 5- year cancer-specific survival rate was 96%, versus 96% and 100%, respectively (p = 0.74).

CONCLUSION

Endoscopic polypectomy by EMR/ESD is an appropriate local treatment for early stage rectal cancer in selected patients. It is possible to achieve good oncological outcomes with a polypectomy similar to TEM/TAMIS and major surgery; however, a multidisciplinary approach is necessary enabling close surveillance and the use of adjuvant radiotherapy.

Low value of second-look endoscopy for detecting residual colorectal cancer after endoscopic removal

BACKGROUND AND AIMS

Endoscopic resection is often feasible for submucosal invasive colorectal cancers (T1 CRCs) and usually judged as complete. If histology casts doubt on the radicality of resection margins, adjuvant surgical resection is advised, although residual intramural cancer is found in only 5% to 15% of patients. We assessed the sensitivity of biopsy specimens from the resection area for residual intramural cancer as a potential tool to estimate the preoperative risk of residual intramural cancer in patients without risk factors for lymph node metastasis (LNM).

METHODS

In this multicenter prospective cohort study, patients with complete endoscopic resection of T1 CRC, scheduled for adjuvant resection due to pathologically unclear resection margins, but absent risk factors for LNM, were asked to consent to second-look endoscopy with biopsies. The results were compared with the pathology results of the surgical resection specimen (criterion standard).

RESULTS

One hundred three patients were included. In total, 85% of resected lesions were unexpectedly malignant, and 45% were removed using a piecemeal resection technique. Sixty-four adjuvant surgical resections and 39 local full-thickness resections were performed. Residual intramural cancer was found in 7 patients (6.8%). Two of these patients had cancer in second-look biopsy specimens, resulting in a sensitivity of 28% (95% confidence interval, <58%). The preoperative risk of residual intramural cancer in the case of negative biopsy specimens was not significantly reduced (P = .61).

CONCLUSIONS

The sensitivity of second-look endoscopy with biopsies for residual intramural cancer after endoscopic resection of CRC is low. Therefore, it should not be used in the decision whether or not to perform adjuvant resection. (Clinical trial registration number: NCT02328664.).

Is Local Resection of Anal Canal Tumors Feasible with Transanal Endoscopic Surgery?

BACKGROUND

An important drawback of local surgery for lesions in the anal canal is the difficulty of achieving en bloc full-thickness resections. The aim of this study is to evaluate TEM/TEO in lesions of this type from the point of view of morbidity, mortality and the quality of the pathology specimen.

METHODS

This is an observational study with prospective data collection from June 2004 to July 2018. Two groups are defined: group A (rectal tumors with proximal margin between 0 and ≤4 cm from anal verge) and group B (distal margin > 4 cm from anal verge). A technical description is provided; resections and postoperative complications in both groups are compared.

RESULTS

During the study period, 757 patients underwent TEM/TEO. Finally, 692 patients were included, 192 patients in group A and 500 patients in group B. An en bloc surgical specimen was obtained in 176/192 patients (91.7%), although the defect was completely sutured in 132 (68.8%). In the comparative analysis, group A did not present significantly greater fragmentation of the resected piece [16/192 (8.3%) vs. 36/500 (7.2%), p = 0.630], although group A was associated with greater involvement of the surgical margin [28/192 (14.6%), 32/500 (6.4%), p = 0.001] and clinically relevant morbidity [16/192 (8.3%), 20/500 (4%), p = 0.034]. There was no mortality.

CONCLUSIONS

The use of TEM/TEO to remove lesions originating in the anal canal is feasible. But we have to take into account that there is an increase in complications, technical difficulties and affected margins resection.

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.

Incidental diagnosis of very small rectal neuroendocrine neoplasms: when should endoscopic submucosal dissection be performed? A single ENETS centre experience

PURPOSE

The management of small (≤5 mm) rectal neuroendocrine neoplasms (r-NENs), incidentally removed during colonoscopy, still remains under debate.

METHODS

All consecutive patients affected by r-NENs from January 2013 to December 2017 were studied. The inclusion criteria were: (1) patients having an incidental pathological diagnosis of very small (≤5 mm) polypoid r-NENs; (2) patients treated with a standard polypectomy as first-line therapy and (3) patients treated by endoscopic submucosal dissection (ESD) as salvage therapy. The primary endpoint was to identify the factors related to residual disease after a standard polypectomy. The secondary endpoint was to calculate the accuracy of endoscopic ultrasound (EUS), grading and size in predicting residual disease.

RESULTS

Starting from a prospective database of 123 consecutive patients affected by r-NENs, only 31 met the inclusion criteria. A final pathological examination of an ESD specimen showed residual disease in 7 out of 31 patients (22.6%). A multivariate analysis showed that the size of the polyps was the only independent factor related to residual disease with an odds ratio of 8.7 ± 7.5 (P = 0.013) for each millimetre. The accuracy of EUS, grading and tumour size (3.1 mm cut-off point) and area under the curves were 0.661 ± 0.111, 0.631 ± 0.109 and 0.821 ± 0.109, respectively.

CONCLUSIONS

When the r-NEN polyp was larger than 3 mm, ESD was indicated. Unlike the size of the tumour, grading and EUS features did not accurately predict residual disease.