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

Treatment Options for Distal Rectal Cancer in the Era of Organ Preservation

OPINION STATEMENT

The introduction of total mesorectal excision into the radical surgery of rectal cancer has significantly improved the oncological outcome with longer survival and lower local recurrence. Traditional treatment modalities of distal rectal cancer, relying on radical surgery, while effective, take their own set of risks, including surgical complications, potential damage to the anus, and surrounding structure owing to the pursuit of thorough resection. The progress of operating methods as well as the integration of systemic therapies and radiotherapy into the peri-operative period, particularly the exciting clinical complete response of patients after neoadjuvant treatment, have paved the way for organ preservation strategy. The non-inferiority oncological outcome of "watch and wait" compared with radical surgery underscores the potential of organ preservation not only to control local recurrence but also to reduce the need for treatments followed by structure destruction, hopefully improving the long-term quality of life. Radical radiotherapy provides another treatment option for patients unwilling or unable to undergo surgery. Organ preservation points out the direction of treatment for distal rectal cancer, while additional researches are needed to answer remaining questions about its optimal use.

Local versus radical surgery for early rectal cancer with or without neoadjuvant or adjuvant therapy

BACKGROUND

Total mesorectal excision is the standard of care for stage I rectal cancer. Despite major advances and increasing enthusiasm for modern endoscopic local excision (LE), uncertainty remains regarding its oncologic equivalence and safety relative to radical resection (RR).

OBJECTIVES

To assess the oncologic, operative, and functional outcomes of modern endoscopic LE compared to RR surgery in adults with stage I rectal cancer.

SEARCH METHODS

We searched CENTRAL, Ovid MEDLINE, Ovid Embase, Web of Science - Science Citation Index Expanded (1900 to present), four trial registers (ClinicalTrials.gov, ISRCTN registry, the WHO International Clinical Trials Registry Platform, and the National Cancer Institute Clinical Trials database), two thesis and proceedings databases, and relevant scientific societies' publications in February 2022. We performed handsearching and reference checking and contacted study authors of ongoing trials to identify additional studies.

SELECTION CRITERIA

We searched for randomized controlled trials (RCTs) in people with stage I rectal cancer comparing any modern LE techniques to any RR techniques with or without the use of neo/adjuvant chemoradiotherapy (CRT).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We calculated hazard ratios (HR) and standard errors for time-to-event data and risk ratios for dichotomous outcomes, using generic inverse variance and random-effects methods. We regrouped surgical complications from the included studies into major and minor according to the standard Clavien-Dindo classification. We assessed the certainty of evidence using the GRADE framework.

MAIN RESULTS

Four RCTs were included in data synthesis with a combined total of 266 participants with stage I rectal cancer (T1-2N0M0), if not stated otherwise. Surgery was performed in university hospital settings. The mean age of participants was above 60, and median follow-up ranged from 17.5 months to 9.6 years. Regarding the use of co-interventions, one study used neoadjuvant CRT in all participants (T2 cancers); one study used short-course radiotherapy in the LE group (T1-T2 cancers); one study used adjuvant CRT selectively in high-risk patients undergoing RR (T1-T2 cancers); and the fourth study did not use any CRT (T1 cancers). We assessed the overall risk of bias as high for oncologic and morbidity outcomes across studies. All studies had at least one key domain with a high risk of bias. None of the studies reported separate outcomes for T1 versus T2 or for high-risk features. Low-certainty evidence suggests that RR may result in an improvement in disease-free survival compared to LE (3 trials, 212 participants; HR 1.96, 95% confidence interval (CI) 0.91 to 4.24). This would translate into a three-year disease-recurrence risk of 27% (95% CI 14 to 50%) versus 15% after LE and RR, respectively. Regarding sphincter function, only one study provided objective results and reported short-term deterioration in stool frequency, flatulence, incontinence, abdominal pain, and embarrassment about bowel function in the RR group. At three years, the LE group had superiority in overall stool frequency, embarrassment about bowel function, and diarrhea. Local excision may have little to no effect on cancer-related survival compared to RR (3 trials, 207 participants; HR 1.42, 95% CI 0.60 to 3.33; very low-certainty evidence). We did not pool studies for local recurrence, but the included studies individually reported comparable local recurrence rates for LE and RR (low-certainty evidence). It is unclear if the risk of major postoperative complications may be lower with LE compared with RR (risk ratio 0.53, 95% CI 0.22 to 1.28; low-certainty evidence; corresponding to 5.8% (95% CI 2.4% to 14.1%) risk for LE versus 11% for RR). Moderate-certainty evidence shows that the risk of minor postoperative complications is probably lower after LE (risk ratio 0.48, 95% CI 0.27 to 0.85); corresponding to an absolute risk of 14% (95% CI 8% to 26%) for LE compared to 30.1% for RR. One study reported an 11% rate of temporary stoma after LE versus 82% in the RR group. Another study reported a 46% rate of temporary or permanent stomas after RR and none after LE. The evidence is uncertain about the effect of LE compared with RR on quality of life. Only one study reported standard quality of life function, in favor of LE, with a 90% or greater probability of superiority in overall quality of life, role, social, and emotional functions, body image, and health anxiety. Other studies reported a significantly shorter postoperative period to oral intake, bowel movement, and off-bed activities in the LE group.

AUTHORS' CONCLUSIONS

Based on low-certainty evidence, LE may decrease disease-free survival in early rectal cancer. Very low-certainty evidence suggests that LE may have little to no effect on cancer-related survival compared to RR for the treatment of stage I rectal cancer. Based on low-certainty evidence, it is unclear if LE may have a lower major complication rate, but probably causes a large reduction in minor complication rate. Limited data based on one study suggest better sphincter function, quality of life, or genitourinary function after LE. Limitations exist with respect to the applicability of these findings. We identified only four eligible studies with a low number of total participants, subjecting the results to imprecision. Risk of bias had a serious impact on the quality of evidence. More RCTs are needed to answer our review question with greater certainty and to compare local and distant metastasis rates. Data on important patient outcomes such as sphincter function and quality of life are very limited. Results of currently ongoing trials will likely impact the results of this review. Future trials should accurately report and compare outcomes according to the stage and high-risk features of rectal tumors, and evaluate quality of life, sphincter, and genitourinary outcomes. The role of neoadjuvant or adjuvant therapy as an emerging co-intervention for improving oncologic outcomes after LE needs to be further defined.

Prognosis of Patients Over 60 Years Old With Early Rectal Cancer Undergoing Transanal Endoscopic Microsurgery – A Single-Center Experience

Aim

Transanal endoscopic microsurgery (TEM) is widely performed in early rectal cancer. This technique offers greater organ preservation and decreases the risk of subsequent surgery. However, postoperative local recurrence and distant metastasis remain challenges for patients with high-risk pathological factors. This single-center study reports the prognosis of early rectal cancer patients over 60 years old after TEM.

Methods

The data of the patients over 60 years old who underwent local anal resection were collected retrospectively. Moreover, the 5-year follow-up data were analyzed to determine the 5-year DFS and OS.

Results

47 early rectal cancer patients over 60 years old underwent TEM. There were 27 patients with high-risk factors and 20 patients without high-risk factors. Two patients underwent radical surgery after TEM and ten patients received adjuvant treatment. Local recurrence occurred in 7 patients, of which 4 underwent salvage surgery. The 5-year progression-free survival rate was 75.6%, which was lower in the high-risk patients group (69.6%) than in the non-high-risk patients group (83.3%) (P>0.05). The 5-year OS was 90.2%, but there was no statistically significant difference between the two groups (high-risk patients 87.0%, non-high-risk patients 94.4%). Furthermore, there was no significant difference in DFS and OS between people over and under 70 years old.

Conclusion

Some high-risk factor patients over 60 years old do not have inferior 5-year DFS and OS to the non-high-risk patients. TEM is an option for old patients with high surgical risks. Even if postoperative pathology revealed high-risk factors, timely surgical treatment after local recurrence would be beneficial to improve the 5-year DFS and OS.

SEOM-GEMCAD-TTD clinical guidelines for localized rectal cancer (2021)

The management of localized rectal cancer requires a multidisciplinary approach to optimize outcomes, reduce morbidity and prevent under or overtreatments. While early stages may obtain benefit of local resections without any additional therapies, locally advanced rectal cancer becomes a challenge defining the better sequential strategy of surgery, radiotherapy and chemotherapy. The latest results of international phase III studies have positioned the total neoadjuvant therapy as a potential new standard of care in high risk rectal cancers, however, the best schedule is still not well defined.

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.

Current status of surgical treatment of rectal cancer in China

With the changing lifestyle and the acceleration of aging in the Chinese population, the incidence and mortality of colorectal cancer (CRC) have risen in the last decades. On the contrary, the incidence and mortality of CRC have continued to decline in the USA since the 1980s, which is mainly attributed to early screening and standardized diagnosis and treatment. Rectal cancer accounts for the largest proportion of CRC in China, and its treatment regimens are complex. At present, surgical treatment is still the most important treatment for rectal cancer. Since the first Chinese guideline for diagnosis and treatment of CRC was issued in 2010, the fourth version has been revised in 2020. These guidelines have greatly promoted the standardization and internationalization of CRC diagnosis and treatment in China. And with the development of comprehensive treatment methods such as neoadjuvant chemoradiotherapy, targeted therapy, and immunotherapy, the post-operative quality of life and prognosis of patients with rectal cancer have improved. We believe that the inflection point of the rising incidence and mortality of rectal cancer will appear in the near future in China. This article reviewed the current status and research progress on surgical therapy of rectal cancer in China.

Changes in the quality of care of colorectal cancer in Estonia: a population-based high-resolution study

OBJECTIVES

Large disparities in colorectal cancer (CRC) management and survival have been observed across Europe. Despite recent increases, the survival deficit of Estonian patients with CRC persists, particularly for rectal cancer. The aim of this study was to examine diagnostic, staging and treatment patterns of CRC in Estonia, comparing clinical data from 1997 and 2011.

DESIGN

Nationwide population-based retrospective study.

SETTING

Estonia.

PARTICIPANTS

All incident cases of colon and rectal cancer diagnosed in 1997 and 2011 identified from the Estonian Cancer Registry. Clinical data gathered from medical records.

OUTCOME MEASURES

Differences in diagnostic, staging and treatment patterns; 5-year relative survival ratios.

RESULTS

The number of colon cancer cases was 337 in 1997 and 498 in 2011; for rectal cancer, the respective numbers were 209 and 349. From 1997 to 2011, large increases were seen in the use of colonoscopy and lung and liver imaging. Radical resection rate increased from 48% to 59%, but emergency surgeries showed a rise from 18% to 26% in colon and from 7% to 14% in rectal cancer. The proportion of radically operated patients with ≥12 lymph nodes examined pathologically increased from 2% to 58% in colon cancer and from 2% to 50% in rectal cancer. The use of neoadjuvant radiotherapy increased from 6% to 39% among stage II and from 20% to 50% among patients with stage III rectal cancer. The use of adjuvant chemotherapy in stage III colon cancer increased from 42% to 63%. The 5-year RSR increased from 50% to 58% in colon cancer and from 37% to 64% in patients with rectal cancer.

CONCLUSIONS

Major improvements were seen in the diagnostics, staging and treatment of CRC in Estonia contributing to better outcomes. Increase in emergency surgeries highlights possible shortcomings in timely diagnosis and treatment.

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.

Surveillance Intensity Comparison by Risk for T1NX Locally Excised Rectal Adenocarcinoma: a Cost-Effective Analysis

BACKGROUND

Controversy exists regarding the optimal surveillance strategy following local excision of T1NX rectal adenocarcinoma. This study aims to determine the cost-effectiveness of surveillance strategies for locally excised T1NX rectal adenocarcinoma based on histopathologic and local staging risk factors.

METHODS

A Markov model with 10-year follow-up was developed for cost-effectiveness analysis of high-, medium-, and low-intensity surveillance strategies after local excision of T1NX rectal adenocarcinoma. Literature review and expert consensus were utilized to populate state/transition probabilities and rewards. Based on this data, 87% of T1NX patients undergoing local excision were low risk. Healthcare utilization costs were based on Centers for Medicare and Medicaid Services data. The primary outcomes were costs in 2018 US dollars and effectiveness in life-years presented as net monetary benefit and incremental cost-effectiveness ratios. One-way sensitivity and probabilistic sensitivity analyses were performed.

RESULTS

Net monetary benefit for low-, medium-, and high-intensity surveillance strategies ($393,117.00, $397,978.80, and $397,290.00) shows medium-intensity surveillance to be optimal. One-way sensitivity analysis shows medium-intensity surveillance to be optimal when the cohort is 73-94% low risk. High-intensity surveillance is preferred when less than 73% of the cohort is low risk. Low-intensity surveillance is preferred when greater than 94% is low risk. Probabilistic sensitivity analysis of the base-case shows medium-intensity surveillance is the optimal strategy for 51.5% of the iterations performed.

CONCLUSIONS

Medium-intensity surveillance is the most cost-effective surveillance strategy for locally excised T1NX rectal adenocarcinoma in a clinically representative population model.

Can less be more? Organ preservation strategies in the management of rectal cancer

Background

Total mesorectal excision (tme) is the current standard of care for the treatment of rectal cancer. However, that surgery is associated with significant morbidity and mortality. Clinicians and patients are seeking alternatives to radical resection. Currently, prevalent organ-sparing strategies under investigation include local excision and nonoperative management (nom).

Methods

We reviewed the current evidence in the literature to create an overview of the use of transanal endoscopic surgery and watch-and-wait strategies in the modern management of rectal cancer.

Results

Compared with radical resection, transanal endoscopic surgery in patients with early rectal cancer (cT1) having favourable histopathologic features is associated with an increased risk of local recurrence, but no difference in 5-year survival. In patients with T2 or early T3 cancer, strategies that use neoadjuvant or adjuvant therapy as adjuncts to local excision are under evaluation. Nonoperative management is a new option for patients who experience a complete clinical response after neoadjuvant chemoradiotherapy (ncrt). The selection criteria that will appropriately identify patients for whom nom will succeed are not established.

Conclusions

Local excision is appropriate for early rectal cancer with favourable histopathologic features. Although organ-preserving strategies are promising, the quality of the evidence to date is insufficient to replace the current standard care in most patients. Patients should be offered nom in the safe setting of a clinical trial or registry. Rigorous follow-up, including endoscopy and imaging at frequent intervals is recommended when radical resection is forgone.

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.

Appraisal and Current Considerations of Robotics in Colon and Rectal Surgery

BACKGROUND

Robotic technology aims to obviate some of the limitations of conventional laparoscopic surgery, yet the role of robotics in colorectal surgery is still largely undefined and varies with respect to its application in abdominal versus pelvic surgery.

METHODS

With this review, we aimed to highlight current developments in colorectal robotic surgery. We systematically searched the following databases: PubMed, EMBASE, and Cochrane Library. We critically reviewed the available literature on the use of robotic technology in colon and rectal surgery.

RESULTS

Robotic colorectal surgery is oncologically safe and has short-term outcomes comparable to conventional laparoscopy, with potential benefits in rectal surgery. It has a shorter learning curve but increased operative times and costs. It offers potential advantages in the resection of rectal cancer, due to lower conversion rates. There is also a trend toward better outcomes in anastomotic leak rates, circumferential margin positivity, and perseveration of autonomic function.

CONCLUSION

Laparoscopy remains technically challenging and conversion rates are still high. Therefore, most cases of colorectal surgery are still performed open. Robotic surgery aims to overcome the limits of the laparoscopic technique. This new technology has many advantages in terms of articulating instruments, advanced three-dimensional optics, surgeon ergonomics, and improved accessibility to narrow spaces, such as the pelvis. However, further studies are needed to assess long-term results and benefits.

Does previous transanal excision for early rectal cancer impair surgical outcomes and pathologic findings of completion total mesorectal excision? Results of a systematic review of the literature

BACKGROUND

Transanal excision (TAE) is increasingly used in the treatment of early rectal cancer because of lower rate of both postoperative complications and postsurgical functional disorders as compared with total mesorectal excision (TME) OBJECTIVE: To compare in a meta-analysis surgical outcomes and pathologic findings between patients who underwent TAE followed by completion proctectomy with TME (TAE group) for early rectal cancer with unfavorable histology or incomplete resection, and those who underwent primary TME (TME group).

METHODS

The Medline and Cochrane Trials Register databases were searched for studies comparing short-term outcomes between patients who underwent TAE followed by completion TME versus primary TME. Studies published until December 2016 were included. The meta-analysis was performed using Review Manager 5.0 (Cochrane Collaboration, Oxford, UK).

RESULTS

Meta-analysis showed that completion TME after TAE was significantly associated with increased reintervention rate (OR=4.28; 95% CI, 1.10-16.76; P≤0.04) and incomplete mesorectal excision rate (OR=5.74; 95% CI, 2.24-14.75; P≤0.0003), as compared with primary TME. However there both abdominoperineal amputation and circumferential margin invasion rates were comparable between TAE and TME groups.

CONCLUSIONS

This meta-analysis suggests that previous TAE impaired significantly surgical outcomes and pathologic findings of completion TME as compared with primary TME. First transanal approach during completion TME might be evaluated in order to decrease technical difficulties.

Robotic Assisted Transanal Polypectomies: Is There Any Indication?

OBJECTIVES

Robotic assisted transanal polipectomy may have advantages compared with the conventional transanal minimally invasive surgery technique. We evaluate the safety, feasibility and advantages of this technique.

METHODS

Between February 2014 and October 2015, 9patients underwent robotic transanal polypectomy. We performed a retrospective study in which we analyse prospectively collected data regarding patient and tumor characteristics, perioperative outcomes, pathological report, morbidity and mortality.

RESULTS

A total of 5 male and 4 female patients underwent robotic TAMIS. Lesions were 6,22cm from the anal verge. Mean size was 15,8cm². All procedures were performed in the lithotomy position. Closure of the defect was performed in all cases. Mean blood loss was 39,8ml. Mean operative time was 71,9min. No severe postoperative complications or readmissions occured. Median hospital stay was 2,5 days.

CONCLUSIONS

Robotic TAMIS is useful to treat complex rectal lesions. Our transanal platform allowed a wider range of movements of the robotic arms and to perform all procedures in the lithotomy position.

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

BACKGROUND

There is no consensus on the treatment and prognosis of malignant rectal polyps. The aim of the present study was to determine the role of transanal endoscopic microsurgery (TEM) after endoscopic complete polypectomy of malignant rectal adenomas with long-term follow-up.

METHODS

Of 105 patients with pT1 rectal carcinoma in 32 patients TEM followed complete endoscopic polypectomy while 73 had primary TEM. Local recurrence (LR), distant metastasis, overall and cancer-specific survival were determined by the Kaplan-Meier method.

RESULTS

Median follow-up was 9.1 years. In 32 patients with TEM following complete polypectomy no residual cancer was found. LR occurred in 3/28 (11%) patients with low-risk carcinoma (pT1 G1/2/X, L0/X, R0) and in 1/4 (25%) with high-risk carcinoma (pT1 G3/4 or L1). After primary TEM with complete resection (minimal distance >1 mm) LR occurred in 6/60 (10%) with low-risk carcinoma. After incomplete TEM resection (minimal distance ≤1 mm) LR occurred in 3/8 (38%) patients with low-risk and in 1/5 (20%) patients with high-risk carcinoma. Grading was the only significant risk factor for LR after endoscopic polypectomy followed by TEM (p = 0.002). At all outcomes did not differ between postpolypectomy TEM and primary TEM.

CONCLUSIONS

Patients with malignant rectal polyps removed by endoscopic polypectomy have a substantial risk of LR even if TEM of polyp site is cancer free. Risk of LR depends on tumor characteristics. In low-risk carcinoma long-term follow-up is necessary. The high LR rate in patients with high-risk rectal carcinoma restricts the use of TEM alone.

Analysis of local recurrences after transanal endoscopic microsurgery for low risk rectal carcinoma

AIM

Rates of local recurrence (LR) after transanal endoscopic microsurgery (TEM) for rectal carcinoma vary; the reasons remain unclear. We analyzed LR after TEM for low-risk pT1 (G1/2/X, L0/X) rectal carcinoma to investigate the influence of completeness of resection and occult lymph node metastasis on risk of LR.

METHOD

LR location and stage, completeness of resection of primary carcinoma (minimal distance between tumor and resection line ≤1 mm vs >1 mm), and incidence of involved lymph nodes in resected LR specimens were collected, and tumor characteristics of LR were compared with primary carcinoma. Distant metastasis and overall and cancer-specific survival were determined.

RESULTS

LR developed in 14 patients; in 2/4 with R1/X resection, in 3/8 (38%) with clear margins (R0) but a minimal distance of ≤1 mm, and in 9/88 (10%) with formally complete resection. Six of nine patients with formally complete resection underwent radical surgery for LR; in five out of these six, lymph nodes were not involved. In 5/14 patients, LR was poorly differentiated compared to primary carcinoma. Main LR causes were incomplete tumor resection or tumor persistence after formally complete resection. Overall (p = 0.008) and cancer-specific (p < 0.001) survival was lower in LR patients compared to non-LR patients, even if lymph nodes were uninvolved.

CONCLUSIONS

The results suggest that most LRs after TEM for low-risk rectal cancer were caused by residual tumor at the previous excision site and not by undetected lymph node metastases. By improved standardization of surgical techniques to ensure complete resection of carcinomas and thorough pathological assessments, most LRs seem to be avoidable.

SEOM Clinical Guideline of localized rectal cancer (2016)

Localized rectal adenocarcinoma is a heterogeneous disease and current treatment recommendations are based on a preoperative multidisciplinary evaluation. High-resolution magnetic resonance imaging and endoscopic ultrasound are complementary to do a locoregional accurate staging. Surgery remains the mainstay of treatment and preoperative therapies with chemoradiation (CRT) or short-course radiation (SCRT) must be considered in more locally advanced cases. Novel strategies with induction chemotherapy alone or preceding or after CRT (SCRT) and surgery are in development.