Oncological outcome after local excision of rectal carcinomas

Oncologic safety and technical feasibility of completion transanal total mesorectal excision after local excision; a cohort study from the International TaTME Registry

BACKGROUND

As part of an organ sparing strategy, a surgical local excision may be performed in patients with early-stage rectal cancer or following neoadjuvant (chemo)radiotherapy. In selected cases, a completion total mesorectal excision may be recommended which can be more complex because of the preceding local excision. A transanal approach to perform completion total mesorectal excision may offer an advantage through the better visualization of the surgical field in the distal rectum and less forceful retraction for exposure. However, the oncologic safety and technical feasibility of this approach have yet to be demonstrated in these patients. Therefore, the aim of this study was to evaluate the oncological and technical safety of completion transanal total mesorectal excision following a local excision in patients with rectal cancer.

METHODS

Patients from the prospective International Transanal Total Mesorectal Excision Registry who underwent a surgical local excision prior to completion transanal total mesorectal excision were retrospectively analyzed.

RESULTS

In total, 189 patients were included of which 22% received neoadjuvant radiotherapy. In 94% of the patients, a low anterior resection was performed. A primary anastomosis was constructed in 91% (n = 171/189) of the patients, with the majority also receiving a defunctioning stoma (84%, n = 144/171), of which 69% (n = 100/144) were reversed. Within 30 days, 7% developed an anastomotic leakage. The two-year local recurrence rate was 5% (n = 5/104) with an estimated rate of 3% (95% CI 0-7%). Two-year disease-free survival was 85% (n = 88/104) and overall survival was 95% (n = 99/104).

CONCLUSIONS

Transanal completion total mesorectal excision following local excision for rectal cancer is oncologically safe, with low complication rates and high restorative rates.

The value of machine learning based on CT radiomics in the preoperative identification of peripheral nerve invasion in colorectal cancer: a two-center study

BACKGROUND

We aimed to explore the application value of various machine learning (ML) algorithms based on multicenter CT radiomics in identifying peripheral nerve invasion (PNI) of colorectal cancer (CRC).

METHODS

A total of 268 patients with colorectal cancer who underwent CT examination in two hospitals from January 2016 to December 2022 were considered. Imaging and clinicopathological data were collected through the Picture Archiving and Communication System (PACS). The Feature Explorer software (FAE) was used to identify the peripheral nerve invasion of colorectal patients in center 1, and the best feature selection and classification channels were selected. Finally, the best feature selection and classifier pipeline were verified in center 2.

RESULTS

The six-feature models using RFE feature selection and GP classifier had the highest AUC values, which were 0.610, 0.699, and 0.640, respectively. FAE generated a more concise model based on one feature (wavelet-HLL-glszm-LargeAreaHighGrayLevelEmphasis) and achieved AUC values of 0.614 and 0.663 on the validation and test sets, respectively, using the "one standard error" rule. Using ANOVA feature selection, the GP classifier had the best AUC value in a one-feature model, with AUC values of 0.611, 0.663, and 0.643 on the validation, internal test, and external test sets, respectively. Similarly, when using the "one standard error" rule, the model based on one feature (wave-let-HLL-glszm-LargeAreaHighGrayLevelEmphasis) achieved AUC values of 0.614 and 0.663 on the validation and test sets, respectively.

CONCLUSIONS

Combining artificial intelligence and radiomics features is a promising approach for identifying peripheral nerve invasion in colorectal cancer. This innovative technique holds significant potential for clinical medicine, offering broader application prospects in the field.

CRITICAL RELEVANCE STATEMENT

The multi-channel ML method based on CT radiomics has a simple operation process and can be used to assist in the clinical screening of patients with CRC accompanied by PNI.

KEY POINTS

• Multi-channel ML in the identification of peripheral nerve invasion in CRC. • Multi-channel ML method based on CT-radiomics can detect the PNI of CRC. • Early preoperative identification of PNI in CRC is helpful to improve the formulation of treatment strategies and the prognosis of patients.

Weighing the benefits of lymphadenectomy in early-stage colorectal cancer

Recent advancements in endoscopic procedures have resulted in a growing diagnosis of early colorectal cancer (CRC) cases, where classical en bloc lymph node (LN) dissection is not performed and treatment is terminated with the removal of the main cancer lesion by endoscopy without pathologic LN staging. Although many studies report noninferior outcomes of endoscopic resection in comparison to surgical resection, a cautious approach to completing treatment with endoscopic resection alone is recommended because LN metastases may be present even in early-stage CRC. In most countries, including the United States, Europe, and South Korea, the guidelines for additional surgery after endoscopic resection are very similar. If LN metastasis is suspected, even in T1 stage or lower lesions, further surgery is an essential treatment modality, but confirmation of the presence of LN metastasis is perhaps the most difficult part of this process. Another paradoxical recent trend is the expansion of more extensive and complete surgical lymphadenectomy for CRC. The success rate of surgery has improved dramatically over the past decade with the introduction of surgical devices and minimally invasive surgery, and the associated risks have been significantly reduced. While the burden of surgery on patients is understandable, the indications for surgery in early colon cancer need to be carefully reviewed to improve cure rates. In this process, we believe that an integrated decision-making process with surgeons, radiologists, and pathologists, in addition to the opinions of endoscopists, will be an important process to improve the cure rate.

Computed tomography-based radiomics nomogram for the preoperative prediction of perineural invasion in colorectal cancer: a multicentre study

PURPOSE

To develop and validate a computed tomography (CT) radiomics nomogram from multicentre datasets for preoperative prediction of perineural invasion (PNI) in colorectal cancer.

METHODS

A total of 299 patients with histologically confirmed colorectal cancer from three hospitals were enrolled in this retrospective study. Radiomic features were extracted from the whole tumour volume. The least absolute shrinkage and selection operator logistic regression was applied for feature selection and radiomics signature construction. Finally, a radiomics nomogram combining the radiomics score and clinical predictors was established. The receiver operating characteristic curve and decision curve analysis (DCA) were used to evaluate the predictive performance of the radiomics nomogram in the training cohort, internal validation and external validation cohorts.

RESULTS

Twelve radiomics features extracted from the whole tumour volume were used to construct the radiomics model. The area under the curve (AUC) values of the radiomics model in the training cohort, internal validation cohort, external validation cohort 1, and external validation cohort 2 were 0.82 (0.75-0.90), 0.77 (0.62-0.92), 0.71 (0.56-0.85), and 0.73 (0.60-0.85), respectively. The nomogram, which combined the radiomics score with T category and N category by CT, yielded better performance in the training cohort (AUC = 0.88), internal validation cohort (AUC = 0.80), external validation cohort 1 (AUC = 0.75), and external validation cohort 2 (AUC = 0.76). DCA confirmed the clinical utility of the nomogram.

CONCLUSIONS

The CT-based radiomics nomogram has the potential to accurately predict PNI in patients with colorectal cancer.

Completion Total Mesorectal Excision After Transanal Local Excision of Early Rectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Completion total mesorectal excision is recommended when local excision of early rectal cancers demonstrates high-risk histopathological features. Concerns regarding the quality of completion resections and the impact on oncological safety remain unanswered.

OBJECTIVE

This study aims to summarize and analyze the outcomes associated with completion surgery and undertake a comparative analysis with primary rectal resections.

DATA SOURCES

Data sources included PubMed, Cochrane library, MEDLINE, and Embase databases up to April 2021.

STUDY SELECTION

All studies reporting any outcome of completion surgery after transanal local excision of an early rectal cancer were selected. Case reports, studies of benign lesions, and studies using flexible endoscopic techniques were not included.

INTERVENTION

The intervention was completion total mesorectal excision after transanal local excision of early rectal cancers.

MAIN OUTCOME MEASURES

Primary outcome measures included histopathological and long-term oncological outcomes of completion total mesorectal excision. Secondary outcome measures included short-term perioperative outcomes.

RESULTS

Twenty-three studies including 646 patients met the eligibility criteria, and 8 studies were included in the meta-analyses. Patients undergoing completion surgery have longer operative times (standardized mean difference, 0.49; 95% CI, 0.23-0.75; p = 0.0002) and higher intraoperative blood loss (standardized mean difference, 0.25; 95% CI, 0.01-0.5; p = 0.04) compared with primary resections, but perioperative morbidity is comparable (risk ratio, 1.26; 95% CI, 0.98-1.62; p = 0.08). Completion surgery is associated with higher rates of incomplete mesorectal specimens (risk ratio, 3.06; 95% CI, 1.41-6.62; p = 0.005) and lower lymph node yields (standardized mean difference, -0.26; 95% CI, -0.47 to 0.06; p = 0.01). Comparative analysis on long-term outcomes is limited, but no evidence of inferior recurrence or survival rates is found.

LIMITATIONS

Only small retrospective cohort and case-control studies are published on this topic, with considerable heterogeneity limiting the effectiveness of meta-analysis.

CONCLUSIONS

This review provides the strongest evidence to date that completion surgery is associated with an inferior histopathological grade of the mesorectum and finds insufficient long-term results to satisfy concerns regarding oncological safety. International collaborative research is required to demonstrate noninferiority.

REGISTRATION NO

CRD42021245101.

Completion surgery vs. primary TME for early rectal cancer: a national study

PURPOSE

While local excision by transanal endoscopic microsurgery (TEM) or transanal minimally invasive surgery (TAMIS) is an option for low-risk early rectal cancers, inaccuracies in preoperative staging may be revealed only upon histopathological evaluation of the resected specimen, demanding completion surgery (CS) by formal resection. The aim of this study was to evaluate the results of CS in a national cohort.

METHOD

This was a retrospective analysis of national registry data, identifying and comparing all Norwegian patients who, without prior radiochemotherapy, underwent local excision by TEM or TAMIS and subsequent CS, or a primary total mesorectal excision (pTME), for early rectal cancer during 2000-2017. Primary endpoints were 5-year overall and disease-free survival, 5-year local and distant recurrence, and the rate of R0 resection at completion surgery. The secondary endpoint was the rate of permanent stoma.

RESULTS

Forty-nine patients received CS, and 1098 underwent pTME. There was no difference in overall survival (OR 0.73, 95% CI 0.27-2.01), disease-free survival (OR 0.72, 95% CI 0.32-1.63), local recurrence (OR 1.08, 95% CI 0.14-8.27) or distant recurrence (OR 0.67, 95% CI 0.21-2.18). In the CS group, 53% had a permanent stoma vs. 32% in the pTME group (P = 0.002); however, the difference was not significant when adjusted for age, sex, and tumor level (OR 2.17, 0.95-5.02).

CONCLUSIONS

Oncological results were similar in the two groups. However, there may be an increased risk for a permanent stoma in the CS group.

T1 Rectal Adenocarcinoma: a Different Way to Measure Tumoral Invasion Based on the Healthy Residual Submucosa with Its Prognosis and Therapeutic Implications

BACKGROUND

Surgical treatment of early rectal cancer T1 is either local excision or total mesorectal excision. The choice of surgery is based on the risk of metastatic lymph node involvement. The most important factor to consider is the degree of submucosal invasion. We present a different way to measure tumoral invasion derived from the measurement of the healthy residual submucosa with its prognosis and therapeutic implications METHODS: Observational study of tumor submucosal invasion in patients undergoing transanal endoscopic microsurgery was conducted. Parameters evaluated are submucosal invasion, measuring the healthy residual submucosa at the point of maximum invasion; macroscopic morphology of the tumor; presence of muscularis mucosa, muscularis propria, and measurement of submucosa in the tumor area and the healthy area. The classification proposed is compared with the ones previously published.

RESULTS

Eighty consecutive patients diagnosed with T1 rectal cancer underwent transanal endoscopic microsurgery. Seventeen tumors (21.3%) were polypoid. En bloc resection was achieved in 77 (96.3%). The muscularis mucosa was present in 28 (35%), and the muscularis propria in 77 (96.3%) (p < 0.001). The healthy residual submucosa in the tumor area measured 2,343 ± 1,869 μm. Agreement was moderate with the Kikuchi classification (kappa 0.58) and very good with the Kudo classification (kappa 0.87).

CONCLUSIONS

We describe a method for measuring submucosal invasion in T1 rectal cancer which does not depend on the morphology of the lesion or on the presence of the muscularis mucosa. It can be applied to all T1 classifications of the digestive tract in which the muscularis propria is present.

The impact of transanal local excision of early rectal cancer on completion rectal resection without neoadjuvant chemoradiotherapy: a systematic review

BACKGROUND

The impact of transanal local excision (TAE) of early rectal cancer (ERC) on subsequent completion rectal resection (CRR) for unfavorable histology or margin involvement is unclear. The aim of this study was to provide a comprehensive review of the literature on the impact of TAE on CRR in patients without neoadjuvant chemoradiotherapy (CRT).

METHODS

We performed a systematic review of the literature up to March 2020. Medline and Cochrane libraries were searched for studies reporting outcomes of CRR after TAE for ERC. We excluded patients who had neoadjuvant CRT and endoscopic local excision. Surgical, functional, pathological and oncological outcomes were assessed. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed.

RESULTS

Sixteen studies involving 353 patients were included. Pathology following TAE was as follows T0 = 2 (0.5%); T1 = 154 (44.7%); T2 = 142 (41.2%); T3 = 43 (12.5%); Tx = 3 (0.8%); T not reported = 9. Fifty-three percent were > T1. Abdominoperineal resection (APR) was performed in 80 (23.2%) patients. Postoperative major morbidity and mortality occurred in 22 (11.4%) and 3 (1.1%), patients, respectively. An incomplete mesorectal fascia resulting in defects of the mesorectum was reported in 30 (24.6%) cases. Thirteen (12%) patients developed recurrence: 8 (3.1%) local, 19 (7.3%) distant, 4 (1.5%) local and distant. The 5-year cancer-specific survival was 92%. Only 1 study assessed anal function reporting no continence disorders in 11 patients. In the meta-analysis, CRR after TAE showed an increased APR rate (OR 5.25; 95% CI 1.27-21.8; p 0.020) and incomplete mesorectum rate (OR 3.48; 95% CI 1.32-9.19; p 0.010) compared to primary total mesorectal excision (TME). Two case matched studies reported no difference in recurrence rate and disease free survival respectively.

CONCLUSIONS

The data are incomplete and of low quality. There was a tendency towards an increased risk of APR and poor specimen quality. It is necessary to improve the accuracy of preoperative staging of malignant rectal tumors in patients scheduled for TAE.

Novel imaging techniques for intraoperative margin assessment in surgical oncology: A systematic review

Inadequate margins continue to occur frequently in patients who undergo surgical resection of a tumor, suggesting that current intraoperative methods are not sufficiently reliable in determining the margin status. This clinical demand has inspired the development of many novel imaging techniques that could help surgeons with intraoperative margin assessment. This systematic review provides an overview of novel imaging techniques for intraoperative margin assessment in surgical oncology, and reports on their technical properties, feasibility in clinical practice and diagnostic accuracy. PubMed, Embase, Web of Science and the Cochrane library were systematically searched (2013‐2018) for studies reporting on imaging techniques for intraoperative margin assessment. Patient and study characteristics, technical properties, feasibility characteristics and diagnostic accuracy were extracted. This systematic review identified 134 studies that investigated and developed 16 groups of techniques for intraoperative margin assessment: fluorescence, advanced microscopy, ultrasound, specimen radiography, optical coherence tomography, magnetic resonance imaging, elastic scattering spectroscopy, bio‐impedance, X‐ray computed tomography, mass spectrometry, Raman spectroscopy, nuclear medicine imaging, terahertz imaging, photoacoustic imaging, hyperspectral imaging and pH measurement. Most studies were in early developmental stages (IDEAL 1 or 2a, n = 98); high‐quality stage 2b and 3 studies were rare. None of the techniques was found to be clearly superior in demonstrating high feasibility as well as high diagnostic accuracy. In conclusion, the field of imaging techniques for intraoperative margin assessment is highly evolving. This review provides a unique overview of the opportunities and limitations of the currently available imaging techniques.

What's new?

While surgical resection is critical in the treatment of primary solid tumors, resection at tumor margins remains problematic, with inadequately resected margins facilitating tumor recurrence. In this systematic review, the authors collected information on novel imaging techniques applied to the intraoperative assessment of tumor margins across cancer types. A total of 16 groups of techniques were identified, with many in early stages of clinical application. Following comparison, no single technique was clearly superior in clinical feasibility or diagnostic accuracy. The review highlights the evolving nature of imaging techniques for intraoperative margin assessment and identifies opportunities and limitations in the field.

Early-rectal Cancer Treatment: A Decision-tree Making Based on Systematic Review and Meta-analysis

Local excision (LE) has arisen as an alternative to total mesorectal excision for the treatment of early rectal cancer. Despite a decreased morbidity, there are still concerns about LE outcomes. This systematic-review and meta-analysis design is based on the "PICO" process, aiming to answer to three questions related to LE as primary treatment for early-rectal cancer, the optimal method for LE, and the potential role for completion treatment in high-risk histology tumors and outcomes of salvage surgery. The results revealed that reported overall survival (OS) and disease-specific survival (DSS) were 71%-91.7% and 80%-94% for LE, in contrast to 92.3%-94.3% and 94.4%-97% for radical surgery. Additional analysis of National Database studies revealed lower OS with LE (HR: 1.26; 95%CI, 1.09-1.45) and DSS (HR: 1.19; 95%CI, 1.01-1.41) after LE. Furthermore, patients receiving LE were significantly more prone develop local recurrence (RR: 3.44, 95%CI, 2.50-4.74). Analysis of available transanal surgical platforms was performed, finding no significant differences among them but reduced local recurrence compared to traditional transanal LE (OR:0.24;95%CI, 0.15-0.4). Finally, we found poor survival outcomes for patients undergoing salvage surgery, favoring completion treatment (chemoradiotherapy or surgery) when high-risk histology is present. In conclusion, LE could be considered adequate provided a full-thickness specimen can be achieved that the patient is informed about risk for potential requirement of completion treatment. Early-rectal cancer cases should be discussed in a multidisciplinary team, and patient's preferences must be considered in the decision-making process.

Local recurrence after local excision of early rectal cancer: a meta-analysis of completion TME, adjuvant (chemo)radiation, or no additional treatment

BACKGROUND

The risks of local recurrence and treatment-related morbidity need to be balanced after local excision of early rectal cancer. The aim of this meta-analysis was to determine oncological outcomes after local excision of pT1-2 rectal cancer followed by no additional treatment (NAT), completion total mesorectal excision (cTME) or adjuvant (chemo)radiotherapy (aCRT).

METHODS

A systematic search was conducted in PubMed, Embase and the Cochrane Library. The primary outcome was local recurrence. Statistical analysis included calculation of the weighted average of proportions.

RESULTS

Some 73 studies comprising 4674 patients were included in the analysis. Sixty-two evaluated NAT, 13 cTME and 28 aCRT. The local recurrence rate for NAT among low-risk pT1 tumours was 6·7 (95 per cent c.i. 4·8 to 9·3) per cent. There were no local recurrences of low-risk pT1 tumours after cTME or aCRT. The local recurrence rate for high-risk pT1 tumours was 13·6 (8·0 to 22·0) per cent for local excision only, 4·1 (1·7 to 9·4) per cent for cTME and 3·9 (2·0 to 7·5) per cent for aCRT. Local recurrence rates for pT2 tumours were 28·9 (22·3 to 36·4) per cent with NAT, 4 (1 to 13) per cent after cTME and 14·7 (11·2 to 19·0) per cent after aCRT.

CONCLUSION

There is a substantial risk of local recurrence in patients who receive no additional treatment after local excision, especially those with high-risk pT1 and pT2 rectal cancer. The lowest recurrence risk is provided by cTME; aCRT has outcomes comparable to those of cTME for high-risk pT1 tumours, but shows a higher risk for pT2 tumours.

Clinical outcomes of positive resection margin after endoscopic mucosal resection of early colon cancers

BACKGROUND/AIMS

When determining the subsequent management after endoscopic resection of the early colon cancer (ECC), various factors including the margin status should be considered. This study assessed the subsequent management and outcomes of ECCs according to margin status.

METHODS

We examined the data of 223 ECCs treated by endoscopic mucosal resection (EMR) from 215 patients during 2004 to 2014, and all patients were followed-up at least for 2 years.

RESULTS

According to histological analyses, the margin statuses of all lesions after EMR were as follows: 138 cases (61.9%) were negative, 65 cases (29.1%) were positive for dysplastic cells on the resection margins, and 20 cases (8.9%) were uncertain. The decision regarding subsequent management was affected not only by pathologic outcomes but also by the endoscopist's opinion on whether complete resection was obtained. Surgery was preferred if the lesion extended to the submucosa (odds ratio [OR], 25.46; 95% confidence interval [CI], 7.09-91.42), the endoscopic resection was presumed incomplete (OR, 15.55; 95% CI, 4.28-56.56), or the lymph system was invaded (OR, 13.69; 95% CI, 1.76-106.57). Fourteen patients (6.2%) had residual or recurrent malignancies at the site of the previous ECC resection and were significantly associated with presumed incomplete endoscopic resection (OR, 4.59; 95% CI, 1.21-17.39) and submucosal invasion (OR, 5.14; 95% CI, 1.18-22.34).

CONCLUSIONS

Subsequent surgery was associated with submucosa invasion, lymphatic invasion, and cancer-positive margins. Presumed completeness of the resection may be helpful for guiding the subsequent management of patients who undergo endoscopic resection of ECC.

Survival outcome of adjuvant radiotherapy after local excision for T2 early rectal cancer: An analysis based on the surveillance, epidemiology, and end result registry database

BACKGROUND

Major resection (MR) is recommended for cases with T2 finding after local excision (LE) of early rectal cancer, but the revision procedure is accompanied with high morbidity. We evaluated the oncological safety of LE followed by adjuvant radiotherapy as a rectum-preserving alternative to MR for T2 early rectal cancer.

METHODS

A total of 3786 patients with T2N0M0 rectal adenocarcinoma between 1998 and 2013 were included from the SEER database. Survival rates were compared using the Kaplan-Meier method with a log-rank test, and multivariate analyses were performed using Cox proportional regression models.

RESULTS

Of these patients included, 429 (11.3%) treated with LE alone (LE group), 3067 (81.0%) treated with MR (MR group), and 290 (7.7%) treated with LE followed by adjuvant radiotherapy (LE + adjuvant RT group). The 5-year cancer specific survival (CSS) rate and 5-year overall survival (OS) rate were significantly lower in LE patients group than those in MR patients group (70.5% vs. 81.8%, P < 0.001; 57.3% vs. 72.3%, P < 0.001). The 5-year CSS rate and 5-year OS rate were similar between LE + adjuvant RT and MR groups (78.4% vs. 81.8%, P = 0.975, and 70.7% vs. 72.3%, P = 0.311, respectively). Multivariate Cox regression revealed that treatment strategies, age and CEA status were independently associated with CSS and OS. After age adjustment, LE was associated with reduced CSS (using MR as a reference, HR, 1.784; P < 0.001) and reduced OS (HR, 1.739; P < 0.001). However, CSS and OS related to LE + adjuvant RT of T2 rectal cancer group weren't be affected (HR, 0.994; P = 0.962 and HR, 0.904; P = 0.302, respectively).

CONCLUSIONS

When MR is inappropriate for T2 early rectal cancer patients because of patients refusal or co-morbidities, LE + adjuvant RT can provide acceptable levels of long-term survival.

Morphological classifications of gastrointestinal lesions

In the era of spreading adoption of gastrointestinal endoscopy screening worldwide, endoscopists encounter an increasing number of complex lesions in the gastrointestinal tract. For decision-making on optimal treatment, precise lesion characterization is crucial. Especially the assessment of potential submucosal invasion is of utmost importance as this determines whether endoscopic removal is an option and which technique should be used. To describe a lesion and stratify for the risk of submucosal invasion, several morphological classification systems have been developed. In this manuscript, we thoroughly discuss a systematic approach for the endoscopic assessment of a lesion, which include location, size, Paris classification, lateral spreading tumor classification if applicable and evaluation of the surface pattern with advanced endoscopic imaging techniques. The use of advanced imaging techniques improves the characterization of mucosal surface patterns and helps to determine whether lesions are amenable to endoscopic resection.

Meta-analysis of oncological outcomes after local excision of pT1-2 rectal cancer requiring adjuvant (chemo)radiotherapy or completion surgery

BACKGROUND

Completion total mesorectal excision (TME) is advised for high-risk early (pT1/pT2) rectal cancer following transanal removal. The main objective of this meta-analysis was to determine oncological outcomes of adjuvant (chemo)radiotherapy as a rectum-preserving alternative to completion TME.

METHODS

A literature search using PubMed, Embase and the Cochrane Library was performed in February 2015. Studies had to include at least ten patients with pT1/pT2 adenocarcinomas that were removed transanally and followed by either adjuvant chemoradiotherapy or completion surgery. A weighted average of the logit proportions was determined for the pooled analyses of subgroups according to treatment modality and pT category.

RESULTS

In total, 14 studies comprising 405 patients treated with adjuvant (chemo)radiotherapy and seven studies comprising 130 patients treated with completion TME were included. Owing to heterogeneity it was not possible to compare the two strategies directly. However, the weighted average local recurrence rate for locally excised pT1/pT2 rectal cancer treated with adjuvant (chemo)radiotherapy was 14 (95 per cent c.i. 11 to 18) per cent, and 7 (4 to 14) per cent following completion TME. The weighted averages for distance recurrence were 9 (6 to 14) and 9 (5 to 16) per cent respectively. Weighted averages for local recurrence rate after adjuvant chemo(radiotherapy) and completion TME for pT1 were 10 (4 to 21) and 6 (3 to 15) per cent respectively. Corresponding averages for pT2 were 15 (11 to 21) and 10 (4 to 22) per cent respectively.

CONCLUSION

A higher recurrence rate after transanal excision and adjuvant (chemo)radiotherapy must be balanced against the morbidity and mortality associated with mesorectal excision. A reasonable approach is close follow-up and salvage mesorectal surgery as needed.

Management of colorectal T1 carcinoma treated by endoscopic resection from the Western perspective

Detection of early colorectal cancer is expected to rise in light of national colorectal cancer screening programs. This The present review article delineates current endoscopic risk assessments, differentiating invasive from non-invasive neoplasia, for high likelihood of lymph node metastasis in early colorectal cancer, also termed high-risk early colorectal cancer, and endoscopic and surgical resection methods from a Western hemisphere perspective.

Long-term Oncologic Outcome After Transanal Endoscopic Microsurgery for Rectal Carcinoma

BACKGROUND

Transanal endoscopic microsurgery is superior to other methods of local excision of rectal cancer, but few studies report long-term follow-up data.

OBJECTIVE

This study investigated the use of transanal endoscopic microsurgery alone as curative and compromise therapy based on long-term disease recurrence and mortality.

DESIGN

This was a retrospective review of prospectively collected data.

SETTINGS

The study was conducted at a tertiary care university medical center.

PATIENTS

The study included 133 patients treated between 1985 and 2007. There were 3 groups, including transanal endoscopic microsurgery in curative intent (low-risk rectal carcinoma, including pT1, G1/2, L0, and LX with clear margins and a minimal distance between tumor and resection margin of >1 mm (N = 64) or clear margins only (N = 18 ))) and as compromise therapy (high-risk or incompletely resected rectal carcinoma; N = 51).

MAIN OUTCOME MEASURES

Log-rank tests were used to compare overall and cancer-specific survival.

RESULTS

The median follow-up time was 8.6 years (range, 0.2-25.1 years), and a total of 131 of 133 patients (98.5%) were followed >5 years or until death. The preoperative diagnosis of carcinoma was not associated with belonging into 1 of the 3 categories. In patients with low-risk completely (>1 mm) resected carcinoma, the 5- and 10-year local recurrence rates were 6.6% and 11.6%. In patients with high-risk or incompletely resected carcinoma, the rates were 32.5% and 35.0% (p = 0.006). The 5- and 10-year cancer-specific survival rates for low-risk patients were 98.0% and 91.0% and 84.3% and 74.3% for high-risk patients (p = 0.05).

LIMITATIONS

The study was limited by its retrospective design and small subgroups.

CONCLUSIONS

The high cancer-specific survival justifies transanal endoscopic microsurgery alone as curative treatment in low-risk rectal carcinoma. Complete resection is essential to lower the risk of local recurrence. The high local recurrence rate in patients with high-risk rectal carcinoma restricts the use of TEM alone as compromise therapy.

ACR Appropriateness Criteria® Local Excision in Early Stage Rectal Cancer

Low anterior resection or abdominoperineal resection are considered standard treatments for early rectal cancer but may be associated with morbidity in selected patients who are candidates for early distal lesions amenable to local excision (LE). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. The panel recognizes the importance of accurate staging to identify patients who may be candidates for a LE approach. Patients who may be candidates for LE alone include those with small, low-lying T1 tumors, without adverse pathologic features. Several surgical approaches can be utilized for LE however none include lymph node evaluation. Adjuvant radiation±chemotherapy may be warranted depending on the risk of nodal metastases. Patients with high-risk T1 tumors, T2 tumors not amenable to radical surgery may also benefit from adjuvant treatment; however, patients with positive margins or T3 lesions should be offered abdominoperineal resection or low anterior resection. Neoadjuvant radiation±chemotherapy followed by LE in higher risk patients results in excellent local control, but it is not clear if this approach reduces recurrence rates over surgery alone.

Practice parameters for early colon cancer management: Italian Society of Colorectal Surgery (Società Italiana di Chirurgia Colo-Rettale; SICCR) guidelines

Early colon cancer (ECC) has been defined as a carcinoma with invasion limited to the submucosa regardless of lymph node status and according to the Royal College of Pathologists as TNM stage T1 NX M0. As the potential risk of lymph node metastasis ranges from 6 to 17% and the preoperative assessment of lymph node metastasis is not reliable, the management of ECC is still controversial, varying from endoscopic to radical resection. A meeting on recent advances on the management of colorectal polyps endorsed by the Italian Society of Colorectal Surgery (SICCR) took place in April 2014, in Genoa (Italy). Based on this material the SICCR decided to issue guidelines updating the evidence and to write a position statement paper in order to define the diagnostic and therapeutic strategy for ECC treatment in context of the Italian healthcare system.

Replacing Transanal Excision with Transanal Endoscopic Microsurgery and/or Transanal Minimally Invasive Surgery for Early Rectal Cancer

The use of local resection of rectal polyps and early rectal cancer has progressed to become the standard of care in most institutions with a colorectal surgery specialist. The use of transanal excision (TAE) with anorectal retractors and standard instrumentation has been supplanted by the application of endoscopic techniques which allow direct video augmented visualization. The transanal endoscopic microsurgery method provides a 3D view and works under a constant flow of air to keep the rectal vault open. Instruments capable of accomplishing a surgical excision and suture closure work through a long 4 cm tube set at the anal canal. The newest version of TAE is transanal minimally invasive surgery which is similar to a single-site laparoscopic technique using a hand access port at the anal canal to maintain a seal for insufflation of the rectum, regular 2D video camera for visualization, and laparoscopic instrumentation through the port in the anus. Each of these techniques is described in detail and the outcomes compared, which show the progress being made in this area of colorectal surgery.

Transanal endoscopic surgery in rectal cancer

Total mesorectal excision (TME) is the standard treatment for rectal cancer, but complications are frequent and rates of morbidity, mortality and genitourinary alterations are high. Transanal endoscopic microsurgery (TEM) allows preservation of the anal sphincters and, via its vision system through a rectoscope, allows access to rectal tumors located as far as 20 cm from the anal verge. The capacity of local surgery to cure rectal cancer depends on the risk of lymph node invasion. This means that correct preoperative staging of the rectal tumor is necessary. Currently, local surgery is indicated for rectal adenomas and adenocarcinomas invading the submucosa, but not beyond (T1). Here we describe the standard technique for TEM, the different types of equipment used, and the technical limitations of this approach. TEM to remove rectal adenoma should be performed in the same way as if the lesion were an adenocarcinoma, due to the high percentage of infiltrating adenocarcinomas in these lesions. In spite of the generally good results with T1, some authors have published surprisingly high recurrence rates; this is due to the existence of two types of lesions, tumors with good and poor prognosis, divided according to histological and surgical factors. The standard treatment for rectal adenocarcinoma T2N0M0 is TME without adjuvant therapy. In this type of adenocarcinoma, local surgery obtains the best results when complete pathological response has been achieved with previous chemoradiotherapy. The results with chemoradiotherapy and TEM are encouraging, but the scientific evidence remains limited at present.

Transanal endoscopic surgery with total wall excision is required with rectal adenomas due to the high frequency of adenocarcinoma

BACKGROUND

Colorectal adenomatous polyps are considered premalignant lesions, although a high percentage are already malignant at the time of their removal. Full-thickness excision in patients with adenoma detected in preoperative biopsy enables much more accurate pathology examination and has shown that local surgery is appropriate for T1 adenocarcinoma.

OBJECTIVE

To determine whether full-thickness excision during transanal endoscopic surgery is the treatment of choice for rectal adenoma, and to identify possible predictors of invasive adenocarcinoma associated with this type of lesion.

DESIGN

Prospective, observational study.

SETTING

The study was conducted at a university teaching hospital.

PATIENTS

All patients scheduled for transanal endoscopic surgery after detection of adenoma in a preoperative biopsy between June 2004 and February 2013 entered the study.

MAIN OUTCOME MEASURES

The principal variable was the presence of invasive adenocarcinoma in the pathology study. Other study variables were the epidemiological variables sex and age; the clinical variables tumor size, number of quadrants affected, distance from the anal verge, and tumor location; and the morphological variables tumor aspect, degree of dysplasia, preoperative biopsy (tubulo-villous), endorectal ultrasound, and pelvic MRI stage. Variables found to be related to the risk of malignancy in rectal adenomas were evaluated using univariate and multivariate analysis.

RESULTS

Of 471 patients who underwent surgery, 277 had a preoperative diagnosis of adenoma. Final pathology studies showed 52 (18.8%) invasive adenocarcinomas, among which 27 were pT1 (52%), 16 pT2 (30.7%), and 9 pT3 (17.3%). Factors predictive of invasive adenocarcinoma were sessile morphology (OR 3.2, 95%CI 1.4-7.1), high-grade dysplasia (OR 2.3, 95%CI 1.2-4.8), and endorectal ultrasound stage uT2-T3 (OR 3.8, 95%CI 1.6-9).

LIMITATIONS

The limitations are derived from the observational design.

CONCLUSIONS

In this sample, half of the adenocarcinomas from adenomas were T1 adenocarcinomas. Because a high proportion of rectal adenomas are, in fact, invasive adenocarcinomas, full-thickness excision is appropriate.

Hospital variation in sphincter preservation for elderly rectal cancer patients

BACKGROUND

The primary goal of an operation for rectal cancer is to cure cancer and, where possible, preserve continence. A wide range of sphincter preservation rates have been reported. This study evaluated hospital variation in the use of low anterior resection (LAR), local excision (LE), and abdominoperineal resection (APR) in the treatment of elderly rectal cancer patients.

METHODS

Using Surveillance, Epidemiology, and End Results-Medicare linked data, we identified 4959 patients older than 65 y with stage I-III rectal cancer diagnosed from 2000-2005 who underwent operative intervention at one of 370 hospitals. We evaluated the distribution of hospital-specific procedure rates and used generalized mixed models with random hospital effects to examine the influence of patient characteristics and hospital on operation type, using APR as a reference.

RESULTS

The median hospital performed APR on 33% of elderly patients with rectal cancer. Hospital was a stronger predictor of LAR receipt than any patient characteristic, explaining 32% of procedure choice, but not a strong predictor of LE, explaining only 3.8%. Receipt of LE was primarily related to tumor size and tumor stage, which combined explained 31% of procedure variation.

CONCLUSIONS

Receipt of LE is primarily determined by patient characteristics. In contrast, the hospital where surgery is performed significantly influences whether a patient undergoes an LAR or APR. Understanding the factors that cause this institutional variation is crucial to ensuring equitable availability of sphincter preservation.

The transanal endoscopic microsurgery procedure: standards and extended indications

Transanal endoscopic microsurgery (TEM) was developed in the early 1980s as a minimally invasive technique allowing the resection of benign rectal adenomas. For this indication, TEM was reported to be safe and effective and even exceeded the results compared to classical local excision. Unsurprisingly, the indication expanded to small rectal cancer. There is still much debate, though, whether it is oncologically safe to perform TEM for rectal cancer. Much has been published about the need for proper patient selection, i.e. patients presenting a low-risk T1 rectal cancer seem to be the most adequate subgroup for this technique. Nevertheless, TEM remains controversial concerning high-risk T1 rectal adenocarcinomas and deeper infiltrating tumors. Several retrospective case series and a small prospective study suggest that radiochemotherapy before local excision reduces recurrence to a level comparable with classic radical surgery (total mesorectal excision). However, these studies are collectively limited, and prospective data from larger multicenter trials are awaited. Reports about functional results after TEM have shown that the procedure has no permanent impact on anorectal function. Even if transient anal resting pressure weakening has been repeatedly described, patients do not suffer from any long-term functional sequelae. Nor do they complain of quality of life impairment.

Oncological outcomes of transanal local excision for high risk T1 rectal cancers

AIM: To evaluate the oncological outcomes of transanal local excision and the need for immediate conventional reoperation in the treatment of patients with high risk T₁ rectal cancers.

METHODS: Twenty five high risk T₁ rectal cancers treated by transanal local excision at the Guangdong General Hospital were analyzed retrospectively. Twelve patients received transanal local excision and 13 patients underwent subsequent immediate surgical rescue after transanal local excision within 4 wk. Differences in the local recurrence rates and 5-year overall survival rates between the two groups were analyzed. The prognostic value of immediate conventional reoperation for high risk T₁ rectal cancers was also evaluated.

RESULTS: The median follow-up period was 62 mo. The local recurrence rates after transanal local excision for high risk T₁ rectal cancer were 50%. By immediate conventional reoperation, the local recurrence rates were significantly reduced to 7.7%. The difference between these two groups was statistically significant (P = 0.030). Kaplan-Meier survival analysis showed a trend for decreased 5-year overall survival rates for patients treated by transanal local excision compared with immediate conventional reoperation (63% vs 89%).

CONCLUSION: Transanal local excision cannot be considered sufficient treatment for patients with high risk T₁ rectal cancers. Immediate conventional reoperation should be performed if the pathology of the local excision is high risk.

Transanal endoscopic microsurgery for rectal cancer. Long-term oncologic results

PURPOSE

Local excision of malignant rectal tumors remains controversial due to the lack of prospective studies. The principal aim of this paper is to analyze survival and recurrence of patients with rectal cancer who were operated by transanal endoscopic microsurgery with curative intention.

METHODS

In 1997, we started a prospective protocol for patients who had T1/T2 rectal tumors: transanal local full-thickness excision was considered curative in T1 low risk (group A); patients with T1 high-risk and T2 low-risk tumors received postoperative radiotherapy (group B). From 1997 to 2006, 88 patients were enrolled. Sixty eight entered the study after the preoperative workup and 20 patients with an initial diagnosis of adenoma after postoperative definitive pathological assessment.

RESULTS

After definitive histological findings, 54 patients were to group A, 28 to group B, and 6 had immediate radical surgery. One patient was lost for follow-up. At a mean follow-up of 71 months, 7 (4 from group A and 3 from group B) out of 81 patients recurred. Five-year overall survival was of 94% and cancer-specific survival of 96%.

CONCLUSIONS

Our data support that transanal endoscopic microsurgery is an adequate treatment for T1 low-risk tumor, and no additional measures are required. For T2 low-risk lesions, our study showed a higher local recurrence rate than that reported after radical surgery but a similar survival outcome.

Oncological outcome of T1 rectal cancer undergoing standard resection and local excision

AIM

We studied the outcome and prognostic factors for T1 rectal cancer patients undergoing standard resection or transanal excision.

METHOD

One hundred and twenty-four patients with T1 rectal cancer were included in the study, of whom 66 (53.2%) underwent standard resection and 58 (46.8%) underwent transanal excision. Survival analysis was performed to compare the outcome.

RESULTS

The 5-year local recurrence rate was 11.0% in the transanal excision group versus 1.6% in the standard resection group (P = 0.031) but the 5-year disease-free survival and overall survival rates were not significantly different between the two groups. Multivariate analysis suggested that a high tumour grade and perineural or lymphovascular invasion were independent risk factors for local recurrence and recurrence-free survival. For high-risk patients (with at least one of the above risk factors), the 5-year local recurrence and 10-year recurrence-free survival rates were 21.2% and 74.5%, versus 1.2% and 92.0% in low-risk patients (P = 0.00003 and P = 0.003). In patients undergoing transanal excision, none in the low-risk group had local recurrence during follow up, while 40% (6 of 15) of patients in the high-risk group developed local recurrence within 5 years after surgery. The 5-year local recurrence rate was 45.0%.

CONCLUSION

Transanal excision in T1 rectal cancer may result in a high rate of local failure for patients with a high-grade tumour, or perineural or lymphovascular invasion. Local excision should be avoided as a curative treatment in high-risk patients.

ACR Appropriateness Criteria: local excision in early-stage rectal cancer

Low anterior resection or abdominoperineal resection is considered standard treatment for early rectal cancer. These procedures, however, carry a risk of morbidity and mortality that may not be warranted for early distal lesions, which may be treated with local excision. Emerging data has investigated the efficacy of local excision in patients with early stage rectal cancers. An expert panel designated by the American College of Radiology has reviewed supporting data, from a few prospective multi-institutional trials and a number of single-institution, retrospective reviews. The consensus recognizes the importance of accurate staging to identify patients who may be candidates for a local excision approach. Optimal candidates for local excision alone include small, low-lying T1 tumors, without adverse pathologic features. A number of procedures may be safely used including transanal, posterior trans-sphincteric, posterior proctotomy, transanal excision, or transanal microsurgery. It is important to note that none of these include lymph node evaluation, and depending on the risk of lymph node metastases, adjuvant radiation with or without chemotherapy may be warranted. Patients with positive margins or T3 lesions are at high risk of local recurrence and should be offered immediate APR or LAR. However, patients with high-risk T1 tumors, T2 tumors, or those who are not amenable to more radical surgery may benefit from adjuvant treatment. Data have also reported excellent local control rates for neoadjuvant radiation +/- chemotherapy followed by local excision in higher risk patients, but it is not yet clear if this approach reduces recurrence rates over surgery alone.

Quality management in rectal carcinoma: what is feasible?

PURPOSE

A cohort study was carried out to analyse quality indicators in the diagnosis and treatment of rectal carcinoma.

METHODS

A total of 2,470 patients with rectal carcinoma treated between 1985 and 2007 at the Department of Surgery, University of Erlangen, were analysed and compared within four time intervals.

RESULTS

Most of the indicators analysed from 2004 to 2007 fulfilled the defined target values. The indicators for process quality of surgical treatment and the surrogate indicators of outcome quality in surgery showed excellent results. Comparing this to previous data, it displays the new developments such as introduction of multimodal treatment for high-risk patients. While the rate of locoregional recurrences decreased, no significant improvement in survival was found.

CONCLUSIONS

Careful analysis of quality indicators is important for both quality management and comparison of treatment results. The progress in diagnosis and treatment requires a continuous update of definitions and target values.