Local excision of rectal tumors

Current Surgical Methods in Local Rectal Excision

Background

The treatment of rectal cancer has evolved with the advancement of surgical techniques. Less invasive approaches are becoming more accepted as the primary treatment method.

Summary

Such methods as transanal excision, transanal endoscopic microsurgery, and transanal minimally invasive surgery can reduce morbidity and mortality rates. However, not all patients are suitable candidates for these procedures, and proper diagnostics are necessary to establish indications. Compared to total mesorectal excision, transanal excision techniques have been shown to have fewer complications and comorbidities while still being able to remove cancerous tissue entirely. Transanal excision is the simplest method, where the operator removes visible rectal lesions. The basic principle of transanal endoscopic microsurgery is to dilate the rectum mechanically and by air insufflation and then use special surgical instruments to remove suspicious lesions under the vision of a telescope. Transanal minimally invasive surgery combines transanal endoscopic microsurgery and single-incision laparoscopic surgery, making the hard-to-reach proximal rectum accessible to classic laparoscopic instruments.

Key Message

Local excision techniques, when used as a monotherapy for treating patients with rectal cancer, have established themselves as a curative and less radical treatment for strictly selected patients with early rectal carcinoma, leading to improved quality of life. When combined with other modalities such as neoadjuvant chemoradiotherapy, total neoadjuvant therapy, and immunotherapy, transanal surgery can be offered to patients with locally advanced rectal cancer as part of the organ preservation strategy. This review will discuss the patient selection and technical aspects of transanal surgery, showcasing its current role in treating rectal carcinoma.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Analysis of 116 cases of rectal cancer treated by transanal local excision

BACKGROUND

The purpose of this research was to evaluate the therapeutic effects and prognostic factors of transanal local excision (TAE) for rectal cancer.

METHODS

We retrospectively analyzed 116 cases that underwent TAE for rectal cancer from 1995 to 2008. A Cox regression analysis was used to analyze prognostic factors.

RESULTS

The survival times for the patients were from 14 to 160.5 months (median time, 58.5 months). The 5-year and 10-year overall survival rates were 72% and 53%, respectively. In all 16 cases experienced local recurrence (13.8%). Pathological type, recurrence or metastasis, and depth of infiltration (T stage) were the prognostic factors according to the univariate analysis, and the latter two were independent factors affecting patient prognosis. For patients with T1 stage who underwent adjuvant radiotherapy, there was no local recurrence; for those in T2 stage, the local recurrence rate was 14.6%. In addition, there was no difference between the patients who received radiotherapy and those who did not (T1: P = 0.260, T2: P = 0.262 for survival rate and T1: P = 0.480, T2: P = 0.560 for recurrence).

CONCLUSIONS

The result of TAE for rectal cancer is satisfactory for T1 stage tumors, but it is not suitable for T2 stage tumors.

Microcirurgia endoscópica transanal e tratamento adjuvante no câncer retal precoce

RACIONAL: A excisão total do mesorreto é considerada a operação padrão no tratamento dos tumores do reto, apesar de não existir comprovação científica de que ela deva ser usada para todos os estádios da doença. Tem sido demonstrado que em casos escolhidos de tumores retais, resultados promissores podem ser conseguidos com tratamento local por microcirurgia endoscópica transanal. Tais tumores, denominados de câncer retal precoce, são tumores T1 - menores do que 4 cm -, bem diferenciados sem invasão angiolinfática pT1 Sm1. Como o risco de comprometimento linfonodal nesses tumores é de aproximadamente 3%, a ressecção local teria grande chance de ser curativa. OBJETIVO: Apresentar os resultados de uma série prospectiva não randômica de pacientes portadores de câncer retal precoce submetidos ao tratamento local por microcirurgia endoscópica transanal. MÉTODOS: Entre 2002 e 2010, 38 pacientes avaliados por protocolo pré-operatório como portadores câncer retal precoce foram submetidos à ressecção local endoscópica microcirúrgica de toda a parede retal com o tumor quando localizado entre 2 e 8 cm da linha pectínea. A avaliação pré-operatória consistiu de toque retal, retossigmoidoscopia rígida para macrobiópsias, enema opaco e/ou colonoscopia, ultrassonografia endoretal e abdominal, tomografia axial computadorizada do abdome, radiografia do tórax e dosagem sérica do CEA. Realizou-se seguimento pós-operatório endoscópico e ultrassonográfico endoretal a cada três meses nos dois primeiros anos, e a cada seis nos próximos três anos, além de dosagem do CEA a cada seis meses nesse mesmo período de cinco anos. Avaliou-se a recidiva tumoral, morbidade e mortalidade. RESULTADOS: Após avaliação anatomopatológica da lesão, 29 cânceres retais precoces foram categorizados como de baixo risco e nove sendo de alto. O seguimento na série variou de um a sete anos. Recidiva tumoral foi confirmada em dois casos dos 38 (5,26%), uma lesão considerada de alto e a outra de baixo risco. CONCLUSÃO: Microcirurgia endoscópica transanal, associada ou não à quimioradioterapia, pode ser considerada atualmente o padrão-ouro na ressecção retal local, apresentando resultados animadores em casos escolhidos de tumores retais precoces de baixo risco.

Functional and clinical results of transanal endoscopic microsurgery combined with endoscopic posterior mesorectum resection for the treatment of patients with t1 rectal cancer

BACKGROUND

Rectum-sparing transanal endoscopic microsurgery (TEM) is a well-established treatment for T1 carcinomas of the rectum. However, it is associated with an increased rate of local recurrence compared with extended resection. In most cases, this failure is linked to the presence of clinically nondetectable metastases in the regional lymph nodes. Endoscopic posterior mesorectal resection (EPMR) makes it possible to remove the relevant lymphatic drainage of the lower third of the rectum in the minimally invasive way, which can help with adequate tumor staging. The study evaluated the influence of combined TEM and EPMR treatment on the anorectal functions of this group of patients.

METHODS

Six consecutive patients (3 women and 3 men; mean age, 71.3 years) with T1 cancer of the rectum were operated on using TEM in combination with EPMR as a two-stage procedure between 2007 and 2009.

RESULTS

After a median follow-up of 19 (range, 8-30) months, none of our patients complained of symptoms of incontinence during the postoperative period apart from one woman with gas incontinence, who was diagnosed preoperatively. There was no statistically significant difference in BAP, SAP, HPZL, or in fecal continence control assessed using the Fecal Incontinence Severity Index before and 1, 3, and 6 months after the procedure. We observed one case of intraoperative complication (perforation) and one case of minor postoperative complication (hematoma formation). There was no evidence of locoregional recurrence.

CONCLUSIONS

EPMR in combination with TEM seems to be safe, feasible, and with no impact on the basic anorectal functions.

Confocal chromolaser endomicroscopy: a supplemental diagnostic tool prior to transanal endoscopic microsurgery of rectal tumors?

PURPOSE

Due to diagnostic advancements, preoperative staging of rectal tumors was significantly improved. However, difficulties in obtaining accurate results can sometimes be observed in the staging of adenomas and early rectal carcinomas (pT1/2). The aim of this study was to test if confocal chromolaser endomicroscopy (cCLEM) can help minimize this diagnostic gap.

METHODS

cCLEM generates optical transversal sections at x1,000 magnification and allows for evaluation of the mucosal microarchitecture and differentiation of normal mucosa from adenomas and carcinomas. Cases with conflicting preoperative findings (adenoma vs. > or =uT2 categories), undetectable tumors after inadequate (R1/RX) snare polypectomy of carcinomas, and extremely flat adenoma areas were studied.

RESULTS

By cCLEM, in > or =uT2 carcinomas with an adenoma histology, malignoma-suspicious areas were identified and selected biopsies were done. In addition, re-epithelialized polypectomy areas of carcinomas were visualized and targeted reoperations could be carried out. Furthermore, the dignity and extension of extremely flat adenomas were determined and marked by clips for additional therapy.

CONCLUSIONS

In cases with rectal tumors, conflicting or unclear findings, and flat extending adenomas, the utilization of cCLEM should be considered. Especially in cases with early rectal carcinomas, unnecessary second operations and also recurrences can be minimized or even avoided by selective usage of cCLEM.

Local excision for more advanced rectal tumors

Over the past 20 years, local excision (LE) of T1 rectal cancer was increasingly established and represents an oncologically established technique. In contrast, the situation for T2 tumors is less clear and has only been investigated in small patient collectives. LE for T2 tumors is thus discussed controversially.

MATERIALS AND METHODS

In addition to our own patients with T2 rectal cancer treated locally (n=40), we have analysed the local recurrence (LR) rates after LE alone (n=124), after immediate conventional radical reoperation (n=29), after adjuvant (chemo)-radiotherapy (n=294) and those after neoadjuvant chemoradiotherapy (nCRT) (n=269) using a PubMed search.

RESULTS

LR rates of low-grade T2 tumors after R0 resection by LE alone was 19%. If additional prognostically unfavorable findings were present, the LR rate rose to 52%. By immediate radical reoperation the LR rate was decreased to 7%, whereas that after adjuvant therapy was 16%. In contrast, LE of more advanced tumors after nCRT resulted in LR rates of 9%.

DISCUSSION

LE alone of T2 rectal cancer should not be performed, and after adjuvant chemoradiotherapy the risk of developing LR was also high. In cases with unexpected T2 finding after LE, immediate conventional reoperation can represent an adequate oncological therapy, because it reveals comparable results to those obtained by primary radical resection. First results after nCRT followed by LE showed favorable results with low LR rates. If the indication for LE of T2 cancers can be extended to patients after nCRT in the future will have to be determined in prospective mutlticentre studies.

Oncological outcome after local excision of rectal carcinomas

BACKGROUND

Local excision (LE) of T1 rectal cancer yields low recurrence rates. However, more frequent recurrences with unknown states of high-risk T1/T2 tumors are risk factors. The purpose of this study was to evaluate if, after LE, immediate reoperation is required, or awaiting salvage surgery is sufficient.

METHODS

150 T1 and 42 T2 tumors were treated by LE. Immediate reoperation was attempted for unfavorable pT1 (G3-4/L1/V1/R1/Rx/R < or =1 mm) and all pT2 tumors. Three groups were formed. Group A included low-risk pT1 tumors after complete (R0) LE; unfavorable pT1 and all T2 tumors were divided in groups B (immediate reoperation) and C (salvage surgery).

RESULTS

Groups A (n = 93) and B (n = 39) showed high tumor-free (TFS) and tumor-related survival (TRS) rates: group A 92% and 98%; group B 86% and 89%. In group C (n = 43), the TFS und TRS were significantly lower with 54% and 72%. Group A showed low recurrence rates and a wide range of International Union Against Cancer (UICC) stages. In group B, similarly low recurrence rates were found, but, in contrast, all recurrences were UICC IV. Group C had significantly higher recurrences rates and, in addition, two-thirds of these patients showed advanced UICC stages (III-IV).

CONCLUSIONS

LE of low-risk T1 tumors represents an adequate therapy. Immediate reoperation after LE of pT1 tumors with unfavorable histological finding or pT2 tumors can avoid local recurrences. Thereafter, high TFS rates can be expected in these patients, but metastases cannot be prevented and adjuvant measures are necessary. Awaiting recurrences as in group C leads to bad oncological outcomes with high recurrences and low survival rates.

Management of early rectal cancer

BACKGROUND

Early rectal cancer (ERC) is adenocarcinoma that has invaded into, but not extended beyond, the submucosa of the rectum (that is a T1 tumour). Local excision is curative for low-risk ERCs but for high-risk cancers such management is controversial.

METHODS

This review is based on published literature obtained by searching the PubMed and Cochrane databases, and the bibliographies of extracted articles.

RESULTS AND CONCLUSION

ERC presents as a focus of malignancy within an adenoma, as a polyp, or as a small ulcerating adenocarcinoma. Preoperative staging relies on endorectal ultrasonography and magnetic resonance imaging. Pathological staging uses the Haggitt and Kikuchi classifications for adenocarcinoma in pedunculated and sessile polyps respectively. Lymph node metastases increase with the Kikuchi level, with a 1-3 per cent risk for submucosal layer (Sm) 1, 8 per cent for Sm2 and 23 per cent for Sm3 lesions. Low-risk ERCs may be treated endoscopically or by a transanal procedure. Transanal excision or transanal endoscopic microsurgery may be inadequate for high-risk ERCs and adjuvant chemoradiotherapy may be appropriate. There is a low rate of recurrence after local surgery for low-risk ERCs but this increases to up to 29 per cent for high-risk cancers.

Neoadjuvant chemoradiation and local excision for T2-3 rectal cancer

BACKGROUND

Local excision (LE) of T1 low-risk (G1-2/L0/V0) rectal cancer is an established approach with local recurrence (LR) rates of approximately 5%, whereas LE of > or = T2 high-risk tumors or inadequate resections (R1/RX/R < or = 1 mm) showed high recurrence rates. Because of the favorable results after neoadjuvant chemoradiotherapy (nCRT) and radical surgery of disease that completely responds (CR) with almost absent LR even of T3-4 tumors, an extension of the indication for LE is controversially discussed, and therefore, we assessed this therapeutic option.

METHODS

Including our own data, seven studies about LE after nCRT of cT2-3 tumors (n = 237) were analyzed after a PubMed search for cT categories, tumor height, nCRT regimens, schedule and technique of surgery, complications, freedom of stoma, response rates (ypT0-3), length of follow-up, LR, and metastases.

RESULTS

Subgroups that we formed (retrospective vs. prospective/retractor vs. transanal endoscopic microsurgery) showed differences in the distribution of cT categories. However, neither the studies we considered nor our own patients showed LR in CR (ypT0). In addition, patients with ypT1 tumor consistently showed low LR rates of 2% (range, 0%-6%), whereas in ypT2 findings, less favorable LR rates of 6% to 20% were observed, and disease that did not respond to therapy (ypT3) displayed LR rates in up to 42%.

CONCLUSIONS

Despite of a highly selected patient collective, an extended indication for LE of cT2-3 rectal cancer after nCRT may be considered. The strongest prognostic factors were a CR (ypT0) or responses on submucosa level (ypT1). These first results will have to be confirmed in a prospective trial with an appropriate sample size to ensure high statistical power.

Transanal endoscopic microsurgical excision of pT2 rectal cancer: results and possible indications

PURPOSE

In previous studies, local excision was predominantly established for "low-risk" pT1 rectal cancer. The results obtained with T2 tumors are unclear; recurrence rates of 0 to 67 percent were reported. This study was designed to determine the value of local excision for T2 rectal carcinomas, prognostic factors, and the need for reoperation.

METHODS

After local excision of 649 patients with rectal tumors, pT2 carcinoma was found in 44 patients. In general, immediate reoperation was recommended; however, 24 patients declined further surgery or were not reoperated because of comorbidities. The results were analyzed separately for local R0 resection of low-risk carcinomas and for prognostically unfavorable criteria (R1/RX/R < or = 1mm/G3-4/L1/V1). Reoperation was performed within four weeks. Recurrences also were divided by previous local R0 resection of low-risk tumors as well as by unfavorable results and were analyzed in a long-term, follow-up study. Patients with palliative therapy were excluded, and follow-up was obtained in 90 percent (20 transanal endoscopic microsurgical excision alone, 17 transanal endoscopic microsurgical excision and reoperation).

RESULTS

Local recurrence rates after local R0 resection alone of low-risk T2 carcinomas were 29 percent, whereas patients with unfavorable criteria developed recurrences in 50 percent. After immediate reoperation, the local recurrence risk in patients without lymph node filiae was significantly reduced to 7 percent.

CONCLUSIONS

Local R0 resection of low-risk pT2 carcinomas represents an inadequate therapy. In pT2N0M0 rectal carcinomas, the recurrence rate can be reduced through immediate reoperation to a level similar to primary radical surgery. An initial poor local resection result (R1/RX/R < or = 1 mm/G3-4/L1/V1) has no negative influence on further oncologic outcome.

Transanal endoscopic microsurgery for carcinoma of the rectum

BACKGROUND

The authors present their experience with rectal cancers managed by transanal endoscopic microsurgery (TEM).

METHODS

This prospective study investigated patients undergoing primary TEM excision for definitive treatment of rectal cancer between January 1996 and December 2003 by a single surgeon in a tertiary referral colorectal surgical unit.

RESULTS

For this study, 52 patients (30 men and 22 women) underwent TEM excision of a rectal cancer. Their mean age was 74.3 years (range, 48-93 years). The median diameter of the lesions was 3.44 cm (range, 1.6-8.5 cm). The median distance of the lesions from the anal verge was 8.8 cm (range, 3-15 cm), with the tumor more than 10 cm from the anal verge in 36 patients. The median operating time was 90 min (range, 20-150 min), and the median postoperative stay was 2 days. All patients underwent full-thickness excisions. There were 11 minor complications, 2 major complications, and no deaths. The mean follow-up period was 40 months (range, 22-82 months). None of the pT1 rectal cancers received adjuvant therapy. Eight patients with pT2 rectal cancer and two patients with pT3 rectal cancer received postoperative adjuvant therapy. The overall local rate of recurrence was 14%, and involved cases of T2 and T3 lesions, with no recurrence after excision of T1 cancers. Three patients died during the follow-up period, but no cancer-specific deaths occurred.

CONCLUSIONS

The findings warrant the conclusion that TEM is a safe, effective treatment for selected cases of rectal cancer, with low morbidity and no mortality. The TEM procedure broadens the range of lesions suitable for local resection to include early cancers (pTis and pT1) and more advanced cancers only in frail people.

The influence of histopathologic criteria on the long-term prognosis of locally excised pT1 rectal carcinomas: results of local excision (transanal endoscopic microsurgery) and immediate reoperation

PURPOSE

Local excision of early rectal cancer is a controversial issue, which is in part because of differences in the evaluation of histopathologic criteria. This prospective study was designed to determine prognostic factors for recurrences and the need for reoperation.

METHODS

In 105 of 118 patients with pT1 carcinomas and local excision, results of recurrence rates and ten-year cancer-free survival were studied separately according to different histologic criteria (R0, R1, Rx, R < or = 1 mm, high-/low-risk situation), tumor localization (anterior, posterior, lateral wall and third of rectum), size, and degree of resection (full-thickness/partial wall). Patients were grouped into local excision (n = 89) and local excision followed by reoperation (n = 21). Risk classification was performed by division into "low-risk" carcinomas after local R0-resection (Group A) and unfavorable histologic results after local resection (R1, Rx, R < or = 1 mm, high-risk situation; Group B).

RESULTS

Local recurrence rates after local R0-resection of low-risk carcinomas were 6 percent, whereas patients in Group B with local resection were 39 percent. The recurrence risk in those patients was significantly reduced to 6 percent by reoperation (P = 0.015). In addition, ten-year, cancer-free survival was 93 percent in Group B after reoperation compared with 89 percent in patients of Group A after local excision alone.

CONCLUSIONS

Local R0-resection in cases with low-risk pT1 carcinomas represents an oncologically adequate therapy, which results in similar survival rates compared with primary radical surgery of pT1N0M0 rectal carcinomas. High recurrence rates are observed in tumors with unfavorable histologic result (Group B) requiring further treatment. In these cases immediate reoperation reduces the recurrence rate to 6 percent.

Transanale endoskopische Mikrochirurgie beim pT1-Low-risk-Rektumkarzinom

BACKGROUND

The association between submucosal infiltration and tumor recurrence was analyzed by long-term follow-up of patients with pT1 "low risk" rectal carcinoma.

PATIENTS AND METHODS

Forty patients with pT1 rectal cancer of the upper and middle rectum were treated by transanal endoscopic microsurgery. All carcinomas fulfilled the low-risk criteria, and were completely resected. No further treatment was carried out. Follow-up data were available for all 40 patients, with a median follow-up of 5.4 years.

RESULTS

Two patients (5.0%) developed local tumor recurrence after 14 and 18 months, respectively, and had curative rectal resection after neoadjuvant radiochemotherapy. In the histology of the initial specimens, both patients had deep submucosal infiltration (sm3). Another patient, primarily sm2 without local recurrence, developed a metachronous singular liver metastasis which was curatively resected. The risk of developing a recurrent tumor was significant for sm3 carcinomas (sm1+sm2 vs sm3, P=0.046).

CONCLUSION

Transanal endoscopic microsurgery is an excellent method of treating low-risk pT1 carcinomas of the rectum. Deep submucosal infiltration (sm3) seems to be an additional high-risk factor for developing local recurrence.

A current perspective on local excision of rectal cancer

Local excision of rectal cancer is appealing because of its technical ease and excellent functional results, but concern over inadequate pathologic staging and inferior treatment outcomes when compared with radical surgery remain a major hurdle for its widespread use. Local failure rates in modern series for local excision are 4%-18% for T1 rectal cancers and 22%-67% for T2 cancers, and cancer cure rates are only 70%-80%. In addition, data from the past decade suggest that preoperative staging with endorectal ultrasound, use of postoperative adjuvant chemotherapy/radiation therapy, and aggressive salvage surgery have not been reliable methods of limiting local tumor recurrence or improving long-term cure rates. At present, highly stringent criteria for patient selection are recommended, yet such stringency decreases the utility of the procedure. What are needed are new approaches to an old problem. Novel strategies under evaluation include enhanced imaging modalities for lymph node metastases, neoadjuvant chemotherapy/radiation therapy, and more liberal use of immediate salvage resection for high-risk pathologic features. Molecular profiling of tumors with genetic markers and better integration of traditional and gene-targeted systemic therapy are promising approaches for the future. This review of the literature evaluates the recent successes and failures of local excision of rectal cancer and provides a current perspective on the expanded use of local excision without compromising care.