Local excision of rectal cancer followed by radical surgery because of poor prognostic features does not compromise the long term oncologic outcome

The Outcome of Local Excision of Rectal Adenomas with High-Grade Dysplasia by Transanal Endoscopic Microsurgery: A Single-Center Experience

Background: Local excision by transanal endoscopic microsurgery (TEM) is considered an acceptable treatment for rectal adenomas with high-grade dysplasia (HGD). This study aims to assess the likelihood of harboring an invasive carcinoma in preoperatively diagnosed HGD polyps and evaluate the risk factors for tumor recurrence in patients with final HGD pathology. Methods: Data from patients who underwent TEM procedures for adenomatous lesions with HGD from 2005 to 2018 at the Rabin Medical Center, Hasharon Hospital, were analyzed. Collected data included patient demographics, preoperative workup, tumor characteristics and postoperative results. Follow-up data including recurrence assessment and further treatments were reviewed. The analysis included two subsets: preoperative pathology of HGD (sub-group 1) and postoperative final pathology of HGD (sub-group 2) patients. Results: Forty-five patients were included in the study. Thirty-six patients had a preoperative diagnosis of HGD, with thirteen (36%) showing postoperative invasive carcinoma. Thirty-two patients had a final pathology of HGD, and three (9.4%) experienced tumor recurrence. Large tumor size (>5 cm) was significantly associated with recurrence (p = 0.03). Conclusions: HGD rectal polyps are associated with a significant risk of invasive cancer. Tumor size was a significant factor in predicting tumor recurrence in patients with postoperative HGD pathology. The TEM procedure is an effective first-line treatment for such lesions.

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.

Transanal Local Excision of Rectal Cancer after Neoadjuvant Chemoradiation: Is There a Place for It or Should Be Avoided at All Costs?

Tumor response to neoadjuvant chemoradiation (nCRT) with tumor downsizing and downstaging has significantly impacted the number of patients considered to be appropriate candidates for transanal local excision (TLE). Some patients may harbor small residual lesions, restricted to the bowel wall. These patients, who exhibit major response ("near-complete") by digital rectal examination, endoscopic assessment, and radiological assessment may be considered for this approach. Although TLE is associated with minimal postoperative morbidity, a few clinical consequences and oncological outcomes must be evaluated in advance and with caution. In the setting of nCRT, a higher risk for clinically relevant wound dehiscences leading to a considerable risk for readmission for pain management has been observed. Worse anorectal function (still better than after total mesorectal excision [TME]), worsening in the quality of TME specimen, and higher rates of abdominal resections (in cases requiring completion TME) have been reported. The exuberant scar observed in the area of TLE also represents a challenging finding during follow-up of these patients. Local excision should be probably restricted for patients with primary tumors located at or below the level of the anorectal ring (magnetic resonance defined). These patients are otherwise candidates for abdominal perineal resections or ultra-low anterior resections with coloanal anastomosis frequently requiring definitive stomas or considerably poor anorectal function.

Long-term outcomes of transanal endoscopic microsurgery for clinical complete response after neoadjuvant treatment in T2-3 rectal cancer

BACKGROUND

Organ sparing by the transanal endoscopic microsurgery (TEM) procedure is a treatment for patients with locally advanced rectal cancer after chemoradiotherapy (CRT) and complete clinical response (cCR).

AIMS

To assess the surgical and long-term oncological outcomes of TEM for the treatment in T2-3 rectal cancer after CRT and cCR.

METHODS

This study was a retrospective review of a prospective database of patients with rectal cancer who underwent TEM after CRT and cCR from April 2011 to March 2020.

RESULTS

52 patients underwent TEM during a period of 9 years. This group of patients included 27 females and 25 males. The median age was 62 (32-86) years, lesion size was 2.5 (1-4) cm, and lesion distance from the anal verge 7.3 (4-10) cm. Median operative time was 79.5 (25-120) min and hospital stay was 1 day (14 h-4 days). Morbidity rate was 13.5% and reoperation rate due to major complications was 3.8%. Final histological findings confirmed 34 (65.4%) patients with ypT0, 7 (13.5%), 6 (11.5%), and 5 (9.6%) patients with carcinoma ypT1, ypT2, and ypT3, respectively. After a median follow-up period of 86 (5-107) months, 1 (2.4%) patient had local recurrences and 3 (7.3%) distant metastases. The 5-year disease-free survival was 91.7% and 5-year overall survival 89.5%.

CONCLUSION

Our experience has shown significant rates of ypT0 and ypT1 associated with excellent long-term results. Performing TEM to treat T2-3N0 rectal cancer after CRT and cCR appears to be an oncologically safe and effective procedure.

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.

Completion Surgery in Unfavorable Rectal Cancer after Transanal Endoscopic Microsurgery: Does It Achieve Satisfactory Sphincter Preservation, Quality of Total Mesorectal Excision Specimen, and Long-term Oncological Outcomes?

BACKGROUND

Unfavorable adenocarcinoma after transanal endoscopic microsurgery requires "completion surgery" with total mesorectal excision. The literature on this procedure is very limited.

OBJECTIVE

This study aims to assess the percentage of transanal endoscopic microsurgery that will require completion surgery.

DESIGN

This is an observational study with prospective data collection and retrospective analysis from patients who were operated on consecutively.

SETTINGS

The study was conducted at a single academic institution.

PATIENTS

Patients undergoing transanal endoscopic microsurgery from June 2004 to December 2018 who later required total mesorectal excision were included.

MAIN OUTCOME MEASURES

All the patients followed the same protocol: preoperative study, indication of transanal endoscopic microsurgery with curative intent, performance of transanal endoscopic microsurgery, and completion surgery indication 3 to 4 weeks after transanal endoscopic microsurgery.

RESULTS

Seven hundred seventy-four patients underwent transanal endoscopic microsurgery, 622 with curative intent (group I: adenoma, 517; group II: adenocarcinoma, 105). Completion surgery was indicated in 64 of 622 (10.3%) patients: group I, 40 of 517 (7.7%) and group II, 24 of 105 (22.9%). After applying exclusion criteria, completion surgery was performed in 55 patients (8.8%). Abdominoperineal resection was performed in 23 (45.1%); the initial lesion was within 6 cm of the anal verge in 19 of these 23 (82.6%). The clinical morbidity rate (Clavien Dindo> II) was 3 of 51 (5.9%). Total mesorectal excision was graded as complete in 42 of 49 (85.7%). The circumferential resection margin was tumor-free in 47 of 50 (94%). Median follow-up was 58 months. Local recurrence was recorded in 2 of 51 (3.9%) and systemic recurrence was recorded in 7 of 51 (13.7%); 5-year disease-free survival was 86%.

LIMITATIONS

The limitations are defined by the study's observational design and the retrospective analysis.

CONCLUSION

The indication of completion surgery after transanal endoscopic microsurgery is low, but is higher in the indication of adenocarcinoma. Compared with initial total mesorectal excision, completion surgery requires a higher rate of abdominoperineal resection, but has similar postoperative morbidity, total mesorectal excision quality, and oncological results. See Video Abstract at http://links.lww.com/DCR/B423.

CIRUGA COMPLEMENTARIA EN CNCER DE RECTO DESFAVORABLE DESPUS DE UNA TEM SE OBTIENE SATISFACTORIAMENTE PRESERVACIN DEL ESFNTER, CALIDAD DE MUESTRA DE ETM Y RESULTADOS ONCOLGICOS A LARGO PLAZO

ANTECEDENTES:El adenocarcinoma con evolución desfavorable luego de una de microcirugía endoscópica transanal (TEM) requiere "cirugía de finalización" con la excisión total del mesorecto. La literatura sobre este procedimiento es muy limitada.OBJETIVO:Evaluar el porcentaje de microcirugía endoscópica transanal que requerió cirugía completa.DISEÑO:Estudio observacional con recolección prospectiva de datos y análisis retrospectivo de pacientes operados consecutivamente.AJUSTES:El estudio se realizó en una sola institución académica.PACIENTES:Aquellos pacientes sometidos a microcirugía endoscópica transanal desde junio de 2004 hasta diciembre de 2018 que luego requirieron excisón toztal del mesorecto.PRINCIPALES MEDIDAS DE RESULTADO:Todos los pacientes siguieron el mismo protocolo: estudio preoperatorio, indicación de microcirugía endoscópica transanal con intención curativa, realización de microcirugía endoscópica transanal e indicación de cirugía complementaria 3-4 semanas después de la microcirugía endoscópica transanal.RESULTADOS:Setecientos setenta y cuatro pacientes fueron sometidos a microcirugía endoscópica transanal, 622 con intención curativa (grupo I, adenoma: 517, grupo II, adenocarcinoma: 105). la cirugía complementaria fué indicada en 64/622 (10.3%), grupo I: 40/517 (7.7%) y grupo II 24/105 (22.9%). Después de aplicar los criterios de exclusión, la cirugía complementaria se realizó en 55 pacientes (8,8%). La resección abdominoperineal fué realizada en 23 (45,1%); en 19 de estos casos 23 (82,6%) la lesión inicial se encontraba dentro los 6 cm del margen anal. La tasa de morbilidad clínica (Clavien-Dindo > II) fue de 3/51 (5,9%). La excisión total del mesorecto se calificó como completa en 42/49 (85,7%). El margen de resección circunferencial se encontraba libre de tumor en 47/50 (94%). La mediana de seguimiento fue de 58 meses. La recurrencia local se registró en 2/51 (3.9%) y la recurrencia sistémica en 7/51 (13.7%); La supervivencia libre de enfermedad a 5 años fue del 86%.LIMITACIONES:Todas definidas por el diseño observacional y el análisis retrospectivo del mismo.CONCLUSIÓN:La indicación de completar la cirugía después de una TEM es baja, pero es más alta cuando la indicación es por adenocarcinoma. En comparación con la excisión total del mesorecto inicial, la cirugía complementaria requiere una tasa más alta de resección abdominoperineal, pero tiene una morbilidad postoperatoria, una calidad de excisión total del mesorecto y resultados oncológicos similares. ConsulteVideo Resumen en http://links.lww.com/DCR/B423. (Traducción-Dr. Xavier Delgadillo).

Local excision followed by early radical surgery in rectal cancer: long-term outcome

Background

In rectal cancers, radical surgery should follow local excisions, in cases of unexpected, unfavorable tumor characteristics. The oncological results of this completion surgery are inconsistent.

This retrospective cohort study assessed the clinical and long-term oncological outcomes of patients that underwent completion surgery to clarify whether a local excision compromised the results of radical surgery.

Methods

Forty-six patients were included, and the reasons for completion surgery, intraoperative complications, residual tumors, local recurrences (LRs), distant metastases, and cancer-specific survival (CSS) were assessed. The results were compared to 583 patients that underwent primary surgery without adjuvant therapy, treated with a curative intention during the same time period.

Results

The median follow-up was 14.6 years. The reasons for undergoing completion surgery were positive resection margins (24%), high-risk cancer (30%), or both (46%). Intraoperative perforations occurred in 10/46 (22%) cases. Residual tumor in the rectal wall or lymph node involvement occurred in 12/46 (26%) cases. The risk of intraoperative perforation and residual tumor increased with the pT category. Intraoperative perforations did not increase postoperative complications, but they increased the risk of LRs in cases of intramural residual tumors (p = 0.003). LRs occurred in 2.6% of pT1/2 and 29% of pT3 tumors. Both the 5- and 10-year CSS rates were 88.8% (95% CI 80.0–98.6). Moreover, the LRs of patients with pT1/2 cancers were lower in patients with completion surgery than in patients with primary surgery.

Conclusions

Rectal wall perforations at the local excision site and residual cancer were the main risks for poor oncological outcomes associated with completion surgery. Local excisions followed by early radical surgery did not appear to compromise outcomes compared to patients with primary surgery for pT1/2 rectal cancer. Improvements in clinical staging should allow more appropriate selection of patients that are eligible for a local excision of rectal cancer.

Does transanal local resection increase morbidity for subsequent total mesorectal excision for early rectal cancer?

AIM

Local excision is recommended for early rectal cancer (pT1). Complementary total mesorectal excision (cTME) is warranted when bad pathological features are present. The impact of a prior local resection on the outcome remains unclear. The aim of this study was to assess if prior local excision increases the morbidity of a subsequent cTME compared with primary TME.

METHODS

From 2001 to 2016 all patients who underwent TME after local excision for rectal adenocarcinoma were studied. All were matched (1:1) with patients who underwent primary TME, without neoadjuvant radiochemotherapy. The matching factors included age, sex, body mass index, American Society of Anesthesiologists score and type of surgery. Short-term morbidity and pathological examination of the resected specimen were compared.

RESULTS

Forty-one patients were included (14 women, 34%, mean age 65 ± 11 years), comprising classic transanal excision (66%) and transanal endoscopic microsurgery (34%), and were matched to 41 patients who had primary TME. cTME was significantly longer (315 min ± 87 vs 275 min ± 58, P = 0.03). The overall morbidity was 48.8% in the local excision group vs 31.7% in the control group (P = 0.18). Surgical morbidity was 31.7% vs 26.8% (P = 0.8). Anastomotic related morbidity was similar (local excision 17% vs TME 14.6%, P = 0.84) and the mean length of stay was similar (14 days) in both groups. There was a tendency to a worse quality of mesorectal excision in the cTME group (17% vs 5%, P = 0.15).

CONCLUSION

Local excision prior to TME for early rectal cancer tends to increase overall morbidity and may worsen the quality of the mesorectal plane but should be considered as a surgical approach in select cases.

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.

Are we doing too much?: local excision before radical surgery in early rectal cancer

PURPOSE

In early rectal cancer cases, the use of local excision is increasing. The general indication for local excision is based on the preoperative stage, but there is often a discrepancy between pre and postoperative stages. We sought to determine the indications for local excision in T1 rectal adenocarcinoma patients by comparing the preoperative clinical and postoperative pathological stages. A second aim was to compare the oncologic outcomes between local excision and radical resection.

METHODS

Between 2004 and 2014, 152 T1 rectal adenocarcinoma patients were enrolled. We divided the subjects into two groups, local excision and radical resection, depending on the modality of treatment the patients initially received. The group of patients who underwent radical resection was subsequently subdivided into "excisable" and "non-excisable" groups based on the postoperative pathology.

RESULTS

Of 152 patients, 28 patients (18.4%) underwent local excision, while 124 patients (81.6%) underwent radical resection. Of 124 patients, in clinically suspected T2 or less and N0 (93) cases, 50 patients (53.8%) needed treatment beyond local excision, and local excision was sufficient for 43 patients (46.2%). The 3-year overall survival (p = 0.393) and 3-year disease-free survival (p = 0.076) between the local excision and radical resection groups showed no significant difference.

CONCLUSIONS

The clinical T stage was overestimated in more than half of the cases. Therefore, if cT1/2 tumors with cN0 are suspected preoperatively, local excision is initially recommended and will allow for determination of underlying pathology. The clinician can then decide whether to monitor or intervene with radical resection.

Local Excision and Endoscopic Resections for Early Rectal Cancer

Radical surgery is considered as the standard treatment for rectal cancer. Transanal local excision has been considered an interesting alternative for the management of selected patients with rectal cancers for many decades. Different approaches had been considered for local excision, from endoscopic submucosal dissection to resections using platforms, such as transanal endoscopic microsurgery or transanal minimally invasive surgery. Identifying the ideal candidate for this approach is crucial, as a local failure after local excision is associated with poor outcomes, even for an initial early rectal tumor. In this article, the diagnostic tools and criteria to select patients for local excision, the different modalities used, and the outcomes are discussed.

Management of Rectal Polyps

Colorectal cancer is one of the most common causes of cancer and cancer morbidity in the United States. In comparison to colon polyps, rectal polyps pose a unique challenge. Advances in endoscopic techniques have allowed for more thorough rectal adenoma detection and removal; however, there remains a concern over piecemeal resection and negative resection margins. Advances in transanal excision techniques, such as transanal endoscopic microsurgery, have been proposed for the removal of benign polyps as well as some early stage rectal cancers, with emphasis on proper patient selection. This review will discuss the current endoscopic and surgical considerations of both benign and malignant rectal polyps.

Preoperative chemoradiotherapy followed by transanal local excision for T3 distal rectal cancer: A case report

Local excision (LE) for rectal cancer is currently indicated for selected T1 stage tumors. However, preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer not only improves local disease control, but also leads to a decrease in the stage and size of the primary mural tumor, along with a decrease in the risk of regional lymphadenopathy. The present study reports the outcome of a patient with T3N0M0 rectal cancer who was treated with LE following preoperative CRT. The distal pole of the tumor was located 2 cm from the anal verge. Preoperative pelvic radiotherapy of 50.4 Gy was administered in 28 fractions. Chemotherapy using 5-fluorouracil and leucovorin was administered during the first and last weeks of radiotherapy. The tumor response to CRT, was found to be marked at 7 weeks after CRT completion, and a complete response was presumed clinically. Transanal full-thickness LE was performed, and pathological examination revealed the absence of residual cancer cells. After 30 months of close follow-up, the patient was alive with no evidence of disease, and treatment-associated severe toxicities were not observed. Although a longer follow-up period is required, this case report suggests that LE may also be a feasible alternative treatment for T3 rectal cancer, which exhibits a marked response to preoperative CRT, particularly in elderly and comorbid patients contraindicated for radical surgery, or patients who are reluctant to undergo sphincter-ablation surgery.

Endoscopic Criteria for Evaluating Tumor Stage after Preoperative Chemoradiation Therapy in Locally Advanced Rectal Cancer

Purpose

Local excision may be an another option for selected patients with markedly down-staged rectal cancer after preoperative chemoradiation therapy (CRT), and proper evaluation of post-CRT tumor stage (ypT) is essential prior to local excision of these tumors. This study was designed to determine the correlations between endoscopic findings and ypT of rectal cancer.

Materials and Methods

In this study, 481 patients with locally advanced rectal cancer who underwent preoperative CRT followed by surgical resection between 2004 and 2013 at a single institution were evaluated retrospectively. Pathological good response (p-GR) was defined as ypT ≤ 1, and pathological minimal or no response (p-MR) as ypT ≥ 2. The patients were randomly classified according to two groups, a testing (n=193) and a validation (n=288) group. Endoscopic criteria were determined from endoscopic findings and ypT in the testing group and used in classifying patients in the validation group as achieving or not achieving p-GR.

Results

Based on findings in the testing group, the endoscopic criteria for p-GR included scarring, telangiectasia, and erythema, whereas criteria for p-MR included nodules, ulcers, strictures, and remnant tumors. In the validation group, the kappa statistic was 0.965 (p < 0.001), and the sensitivity, specificity, positive predictive value, and negative predictive value were 0.362, 0.963, 0.654, and 0.885, respectively.

Conclusion

The endoscopic criteria presented are easily applicable for evaluation of ypT after preoperative CRT for rectal cancer. These criteria may be used for selection of patients for local excision of down-staged rectal tumors, because patients with p-MR could be easily ruled out.

Organ preservation in rectal cancer: have all questions been answered?

Improved treatment strategies have eliminated local control as the major problem in rectal cancer. With increasing awareness of long-term toxic effects in survivors of rectal cancer, organ-preservation strategies are becoming more popular. After chemoradiotherapy, both watchful waiting and local excision are used as possible alternatives for radical surgery. Although these seem attractive strategies, many issues about the safety of organ preservation remain. Additionally, radiotherapy strategies are mainly aimed at intermediate and high-risk rectal tumours, and adaptation of this standard practice for a completely new treatment indication has yet to start. This Review will discuss the options and problems of organ preservation, and address the research questions that need to be answered in the coming years, with a specific focus on radiotherapy.