Conservative management of rectal cancer with local excision and postoperative adjuvant therapy

Report from the 24th Annual Western Canadian Gastrointestinal Cancer Consensus Conference on Colorectal Cancer, Richmond, British Columbia, 28-29, October 2022

The 24th annual Western Canadian Gastrointestinal Cancer Consensus Conference (WCGCCC) was held in Richmond, British Columbia, on 28-29 October 2022. The WCGCCC is an interactive multidisciplinary conference attended by healthcare professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals such as dieticians, nurses and a genetic counsellor participated in presentation and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer.

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.

Pitfalls in MRI of rectal cancer: What radiologists need to know and avoid

Preoperative staging of rectal cancer using magnetic resonance imaging (MRI) has become an important component of clinical management. Although MRI is the modality of choice for rectal cancer diagnosis and staging, there are certain inherent potential pitfalls that radiologists need to recognize in order to avoid imaging misinterpretation, including choice of MRI protocol; choice of MRI technique; potential mimickers of rectal cancer; mucinous rectal tumor; differentiation between extramural tumor invasion and desmoplastic reaction; differentiation between low rectal cancer and anal cancer; problems relating to nodal involvement, peritoneal reflection, and mesorectal fascia invasion; and, challenges associated with restaging, post-treatment changes, and complications. The aim of this article was to heighten radiologist awareness of these potential pitfalls in order to improve diagnosis, decision-making, and patient outcomes.

A multi-centred randomised trial of radical surgery versus adjuvant chemoradiotherapy after local excision for early rectal cancer

Background

Rectal cancer surgery is accompanied with high morbidity and poor long term functional outcome. Screening programs have shown a shift towards more early staged cancers. Patients with early rectal cancer can potentially benefit significantly from rectal preserving therapy. For the earliest stage cancers, local excision is sufficient when the risk of lymph node disease and subsequent recurrence is below 5 %. However, the majority of early cancers are associated with an intermediate risk of lymph node involvement (5–20 %) suggesting that local excision alone is not sufficient, while completion radical surgery, which is currently standard of care, could be a substantial overtreatment for this group of patients.

Methods/Study design

In this multicentre randomised trial, patients with an intermediate risk T1-2 rectal cancer, that has been locally excised using an endoluminal technique, will be randomized between adjuvant chemo-radiotherapylimited to the mesorectum and standard completion total mesorectal excision (TME). To strictly monitor the risk of locoregional recurrence in the experimental arm and enable early salvage surgery, there will be additional follow up with frequent MRI and endoscopy. The primary outcome of the study is three-year local recurrence rate. Secondary outcomes are morbidity, disease free and overall survival, stoma rate, functional outcomes, health related quality of life and costs. The design is a non inferiority study with a total sample size of 302 patients.

Discussion

The results of the TESAR trial will potentially demonstrate that adjuvant chemoradiotherapy is an oncological safe treatment option in patients who are confronted with the difficult clinical dilemma of a radically removed intermediate risk early rectal cancer by polypectomy or transanal surgery that is conventionally treated with subsequent radical surgery. Preserving the rectum using adjuvant radiotherapy is expected to significantly improve morbidity, function and quality of life if compared to completion TME surgery.

Trial registration

NCT02371304, registration date: February 2015

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.

A population-based comparison of overall and disease-specific survival following local excision or abdominoperineal resection for stage I rectal adenocarcinoma

PURPOSE

The use of local excision (LE) for early stage rectal adenocarcinoma is increasing due to the associated morbidity of radical resection. To determine if survival in stage I rectal cancer differs following LE or abdominoperineal resection (APR), we analyzed the Surveillance, Epidemiology, and End Results Database.

MATERIAL AND METHODS

We selected patients diagnosed between 1988 and 2002 with T1-2N0M0 rectal adenocarcinoma measuring ≤4 cm who underwent either local excision with (LE + RT) or without adjuvant radiation (LE alone) or APR alone. Overall survival (OS) and disease-specific survival (DSS) curves were calculated using the Kaplan-Meier method. Univariate and multivariate Cox regression was also performed to determine the effect of covariates on OS and DSS.

RESULTS

A total of 2,391 patients were identified including 981 (41 %) treated with APR, 1,018 (43 %) treated with LE alone, and 392 (16 %) treated with LE + RT. With a median follow-up of 69 months, there was no difference in OS or DSS seen between the three groups (p > 0.05 for all comparisons). When stratifying by T-stage, there was a significant difference in overall survival between LE alone and APR for T2 disease. However, there was no difference in DSS between these two subgroups. There were no other significant survival differences between all comparable subgroups.

CONCLUSIONS

In this large population-based study, there was no difference in long-term DSS between patients who underwent an APR compared to selected patients who underwent LE with or without adjuvant radiation. Although these data further reinforce the promising data regarding the selected use of LE, further prospective studies are needed to further elucidate the role of LE in this setting.

Local excision: is it an adequate substitute for radical resection in T1/T2 patients?

Local excision (LE) was historically developed to palliate patients with rectal adenocarcinoma who either are medically unfit or have adamantly refused to undergo transabdominal standard resection (SR) procedures. Over the years, the tradeoffs between the oncologic benefit and adverse functional sequelae associated with SR procedures have been increasingly recognized. In parallel, there has been growing interest in considering LE as an alternative to SR in select patients with early-stage disease. However, concerns regarding its oncologic adequacy remain. These concerns relate to the adequacy of tumor resection, the removal of mesorectal disease, the accuracy of preoperative selection, and the use of adjunctive treatment modalities. Evolving strategies that aim at improving the oncologic outcomes of LE for stage I T1/T2 rectal cancers include adoption of transanal endoscopic microsurgery and the addition of non-surgical modalities. Current evidence surrounding these approaches is examined to provide a basis for an informed discussion with patients. Key factors to be considered in formulating the treatment plan for an individual patient with T1/T2 rectal cancer are summarized.

Radiotherapy in the treatment of resectable rectal adenocarcinoma

The goal of treatment is to cure whereas maintaining sphincter function and minimizing toxicity. Although the mainstay of the treatment is surgery, radiotherapy (RT) is used in a substantial proportion of patients depending on the location and extent of the tumor. The aim of this article is to discuss the role of RT in patients with resectable rectal adenocarcinoma. This article is a review of the pertinent literature. Results show that patients with T1N0 exophytic, well to moderately differentiated, mobile tumors < or = 3 cm in diameter may be treated with either transanal excision or endocavitary RT. The probability of cure with either approach is approximately 80% to 90% and depends on selection criteria. The advantages of endocavitary RT are that it is an outpatient procedure requiring, at most, local anesthesia and is suitable for elderly, infirm patients. The disadvantage is that few of these treatment units are available. Patients who experience a local-regional recurrence may be surgically salvaged. Patients who undergo transanal excision and have unfavorable pathologic findings including equivocal or close margins, poor differentiation, invasion of the muscularis propria, and/or endothelial-lined space invasion have a high risk of local-regional recurrence after surgery alone. The addition of postoperative RT improves the likelihood of cure from 85% to 90%. Patients presenting with unfavorable tumors that are borderline resectable with a transanal excision may be downstaged with preoperative RT and rendered suitable for a wide local excision. The addition of concomitant chemotherapy probably enhances downstaging and may improve the likelihood of sphincter preservation. Patients with T3 and/or N1 rectal cancers have a relatively high probability of local-regional recurrence after surgery alone. Preoperative RT and postoperative RT combined with adjuvant chemotherapy have been shown to significantly reduce the risk of local-regional recurrence and improve survival. Whether preoperative RT alone or combined with chemotherapy is more efficacious than postoperative chemoradiation remains unclear. Endocavitary RT or transanal excision is suitable for patients with T1N0 cancers. Depending on tumor location and extent, adjuvant RT may improve the probability of local-regional control and survival for patients with locally advanced rectal adenocarcinomas.

Brachytherapy and local excision for sphincter preservation in T1 and T2 rectal cancer

PURPOSE

To report long-term results of brachytherapy after local excision (LE) in the treatment of T1 and T2 rectal cancer at risk of recurrence due to residual subclinical disease.

METHODS AND MATERIALS

Between 1989 and 2007, 32 patients undergoing LE and brachytherapy were followed prospectively for a mean of 6.2 years. Estimates of local recurrence (LR), disease-specific survival (DSS), and overall survival (OS) were generated. Treatment-related toxicity and the effect of known prognostic factors were determined.

RESULTS

There were 8 LR (3 T1, 5 T2), of which 5 were salvaged surgically. Median time to the 8 LR was 14 months, and the 5-year rate of local control was 76%. Although there have been 9 deaths to date, only 5 were from disease. Five-year DSS and OS rates were 85% and 78%, respectively. There were 4 cases of Grade 2-3 radionecrosis and 1 case of mild stool incontinence. The sphincter was preserved in 27 of 32 patients.

CONCLUSION

Local excision and adjuvant brachytherapy for T1 and T2 rectal cancer is an appealing treatment alternative to immediate radical resection, particularly in the frail and elderly who are unable to undergo major surgery, as well as for patients wanting to avoid a permanent colostomy.

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.

Preoperative chemoradiation followed by transanal excision for rectal cancer

BACKGROUND

This study was conducted to assess the efficacy of preoperative chemoradiation followed by transanal excision among patients with locally advanced lower rectal cancer.

METHODS

Between May 1994 and June 2005, 73 patients with locally advanced lower rectal cancer were treated with curative intent by preoperative chemoradiation followed by surgical resection. Transanal excision was performed in 9 patients due to either the absolute refusal of a permanent stoma by the patient (n = 8) or medical comorbidity (n = 1). Sixty-four patients were treated by radical proctectomy. Preoperative 5-fluorouracil-based chemotherapy and pelvic radiation (4500 to 5040 cGy) were followed by surgery 6 wk after treatment, and all patients except one with transanal excision received postoperative 5-fluorouracil-based chemotherapy during the first year after surgery.

RESULTS

The mean follow-up period was 91 mo (range, 50 to 127 mo); median follow-up was 94 mo. One local recurrence occurred at 30 mo after transanal excision (11.1%); 5 in 64 patients who received radical proctectomy (7.8%) experienced local recurrences. The disease-free survival rate at 10 y was 77.8% in transanal excision group compared with a rate of 62.7% among radical proctectomy patients (P = 0.335). The overall survival rate at 10 y was 88.9% in transanal excision group compared with 74.2% among radical proctectomy patients (P = 0.424).

CONCLUSIONS

Transanal excision after preoperative chemoradiation in highly-selected patients with locally advanced lower rectal cancer could probably be an acceptable alternative to conventional radical surgery. However, this approach should be prospectively validated, and strict patient selection criteria should be used.

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.

T1 adenocarcinoma of the rectum: transanal excision or radical surgery?

BACKGROUND

Recent studies suggest local excision may be acceptable treatment of T1 adenocarcinoma of the rectum, but there is little comparative data with radical surgery to assess outcomes and quantify risk. We performed a retrospective evaluation of patients with T1 rectal cancers treated by either transanal excision or radical resection at our institution to assess patient selection, cancer recurrence, and survival.

METHODS

All patients who underwent surgery for T1 adenocarcinomas of the rectum (0-15 cm from anal verge) by either transanal excision (TAE) or radical resection (RAD) between January 1987 and January 2004 were identified from a prospective database. Data were analyzed using Fisher exact test, Kaplan-Meier method, and log-rank test.

RESULTS

Three hundred nineteen consecutive patients with T1 lesions were treated by transanal excision (n = 151) or radical surgery (n = 168) over the 17-year period. RAD surgery was associated with higher tumor location in the rectum, slightly larger tumor size, a similar rate of adverse histology, and a lymph node metastasis rate of 18%. Despite these features, patients who underwent RAD surgery had fewer local recurrences, fewer distant recurrences, and significantly better recurrence-free survival (P = 0.0001). Overall and disease-specific survival was similar for RAD and TAE groups.

CONCLUSION

Despite a similar risk profile in the 2 surgical groups, patients with T1 rectal cancer treated by local excision were observed to have a 3- to 5-fold higher risk of tumor recurrence compared with patients treated by radical surgery. Local excision should be reserved for low-risk cancers in patients who will accept an increased risk of tumor recurrence, prolonged surveillance, and possible need for aggressive salvage surgery. Radical resection is the more definitive surgical treatment of T1 rectal cancers.

Distal cT2N0 rectal cancer: is there an alternative to abdominoperineal resection?

PURPOSE

Patients with cT2N0 distal rectal cancer do not require adjuvant therapy. However, when a patient refuses an abdominoperineal resection (APR), is there an alternative? The purpose of this trial is to determine whether preoperative external-beam radiation therapy can increase the rate of sphincter preservation for patients with distal cT2N0 adenocarcinoma of the rectum.

PATIENTS AND METHODS

Between April 1988 and October 2003, 27 patients with distal rectal adenocarcinoma staged T2 by clinical and/or endorectal ultrasound who were judged by the operating surgeon to require an APR were treated with preoperative pelvic radiation alone (50.4 Gy). Surgery was performed 4 to 7 weeks later. If pathologic positive pelvic nodes were identified, postoperative adjuvant chemotherapy was recommended. The median follow-up was 55 months (range, 9 to 140 months).

RESULTS

The pathologic complete response rate was 15% and 78% of patients underwent a sphincter-sparing procedure. The crude incidence of local failure for patients undergoing a sphincter sparing procedure was 10% and the 5-year actuarial incidence was 13%. The actuarial 5-year survival for patients undergoing sphincter preservation was as follows: disease-free, 77%; colostomy-free, 100%; and overall, 85%. Using the Memorial Sloan-Kettering Cancer Center sphincter function score, 54% of those undergoing a sphincter-sparing procedure had good/excellent bowel function at 12 to 24 months after surgery, and 77% had good/excellent function at 24 to 36 months after surgery.

CONCLUSION

Our data suggest that for patients with cT2N0 distal rectal cancer who require an APR, preoperative pelvic radiation improves sphincter preservation without an apparent compromise in local control or survival.

Transanal endoscopic microsurgery: a prospective evaluation of functional results

PURPOSE

Local excision is a commonly used technique for many benign and selected malignant rectal lesions. Compared with radical resection, it is associated with decreased morbidity and mortality and improved functional results. Transanal endoscopic microsurgery is gaining popularity because of its ability to access the upper rectum and its precise excision techniques. However, the functional consequences have not been extensively studied.

METHODS

All patients subject to transanal endoscopic microsurgery prospectively completed preoperative and postoperative (6 weeks) surveys including Fecal Incontinence Severity Index, Fecal Incontinence Quality of Life, number of bowel movements per 24 hours, and ability to defer defecation. All data were collected by an independent research coordinator. Demographics, operative details, and complications were also collected prospectively.

RESULTS

Forty-one patients successfully underwent transanal endoscopic microsurgery. Fourteen patients had malignant lesions and 27 had benign lesions. Two patients required abdominoperineal resection based on postoperative diagnosis. Thirty-nine patients have completed follow-up and were available for review. Mean length of surgery was 64 minutes and length of stay was 0.9 day. Average distance from the anal verge to the proximal tumor margin was 11.4 cm and mean tumor size was 8.75 cm. Twenty-three patients had full-thickness excision with primary closure, ten had full-thickness excision without closure, five had partial-thickness excision, one had an excision of a mass in the anovaginal septum, and one had resection of an anastomotic stricture. Each patient served as his own control. Preoperative and postoperative number of bowel movements per 24 hours were 2.0 and 2.0, respectively. Preoperative vs. postoperative urgency (ability to defer defecation less than ten minutes) was unchanged. Mean preoperative and postoperative Fecal Incontinence Severity Index scores were 2.4 (range, 0-43) and 2.4 (range, 0-17), respectively (higher scores indicate worse function). In addition, the four parameters measured by the Fecal Incontinence Quality of Life survey were unchanged when preoperative and postoperative data were compared.

CONCLUSIONS

Transanal endoscopic microsurgery allows precise excision of tumors throughout the rectum. However, it involves inserting a 40-mm-diameter operating proctoscope and significant operating times. Despite this, as measured by ability to defer defecation, number of bowel movements per 24 hours, Fecal Incontinence Severity Index, and Fecal Incontinence Quality of Life survey, transanal endoscopic microsurgery has no detrimental affect on fecal continence.

Is local excision of T2/T3 rectal cancers adequate?

In selected patients, local excision of rectal cancer may be an alternative to radical surgery such as abdominoperineal excision of the rectum or anterior resection. Local excision carries lower mortality and morbidity, without the functional disturbance or alteration in body image that can be associated with radical surgery. There are several techniques of local therapy for rectal cancer, with most experience being available in transanal excision. Transanal endoscopic microsurgery is also used but experience with this newer technique is limited. Patient selection is the most important factor in successful local excision; however, specific criteria for selecting patients have not been universally accepted. Review of the published literature is difficult because of the variation in adjuvant therapy regimes and follow-up strategies, as well as results reported in terms of local recurrence and survival rates. There is increasing evidence to suggest that local excision should be restricted to patients with T1-stage rectal cancer without high-risk factors. The place for local excision in patients with T2 or high-risk T1 tumours requires prospective, randomised multicentre trials comparing radical surgery with local excision, with or without adjuvant therapy. Local excision for T3 tumours should be restricted to the palliative setting or patients unfit for radical surgery.

The management of rectal cancer in the elderly

INTRODUCTION

The majority of patients with rectal cancer are elderly. Due to the increasingly aging population the number of people with colorectal cancer is increasing. As medical advances in the areas of local therapy, radiation therapy, and surgical technique, such as, laparoscopy are made more elderly patients are offered various types of treatment for rectal cancer. As the number of treatment options increase, the debate on how to treat elderly patients' with rectal cancer intensifies.

METHODS

A Medline search using "rectal cancer," "elderly," "local therapy," "radical surgery," and "radiation therapy" as key words was performed for English-language articles. Further references were obtained through cross-referencing the bibliography cited in each work.

DISCUSSION

Numerous treatment options exists for elderly patients with rectal cancer. These range from transanal local excision to radical surgery. The best treatment option for a certain elderly patient is multifactorial and includes tumor stage, operative curability, preoperative functioning of the patient, patient comorbidities, quality of life goals, and patient preference.

CONCLUSION

Age, taken as an independent variable, is not a contraindication to any specific type of therapy, including radical surgery with primary anastomsis. Patients' who meet the criteria for local resection should undergo this procedure. However, for tumors which are not amenable to local resection, these patients should be considered for radical surgery if this provides the best chance for cure. Elderly patients who can tolerate a major operation, and have good preoperative sphincter function should undergo a resection with primary anastomosis.

Combined modality treatment for rectal cancer

Significant gains have been achieved in the integration of radiation therapy (RT) and chemotherapy with surgery in the management of patients with localized rectal cancer. Treatment combinations of RT and chemotherapy with surgery have evolved to neoadjuvant approaches of these modalities to enhance sphincter preservation, tumor control, and reduction of acute and late treatment-related morbidity. Although 5-fluorouracil (5-FU)-based chemotherapy in combination with RT remains the standard adjuvant therapy for rectal cancer, the integration of novel chemotherapeutic agents and biologic modulators is being actively investigated.

Long-term results using local excision after preoperative chemoradiation among selected T3 rectal cancer patients

PURPOSE

To assess the pelvic failure among patients with T3 rectal cancer treated with local excision after preoperative chemoradiation.

METHODS AND MATERIALS

Between January 1990 and June 2002, 431 patients with clinically staged T3 rectal cancer were treated with preoperative chemoradiation followed by surgical resection. Full-thickness local excision [Kraske (n = 3) or a transanal excision (n = 23)] was performed in 26 patients because of patient refusal of abdominoperineal resection (APR) (n = 13), medical comorbidity (n = 4), physician preference after a complete clinical response (n = 6), and other reasons (n = 3). All patients were treated with continuous-infusion 5-fluorouracil (5-FU) (300 mg/m(2) Monday to Friday) and concomitant pelvic radiation (45 Gy in 25 fractions with a 3-field belly board technique). Ten local-excision patients received a concomitant boost during the last week of therapy (1.5-Gy second daily fractions) for a total dose of 52.5 Gy. Similar preoperative treatment was followed by total mesorectal excision in 405 patients. Among the local-excision patients, the median tumor size was 3.5 cm (range, 0.5-7 cm). Well-differentiated or moderately-differentiated histology was present in all but 3 cases, and endoscopic ultrasound staging examination was performed in 25 of 26 patients. Based on CT findings, 1 patient was node positive. The median circumference involved by tumor was 33%, (20%-75%). The median distance from the anal verge was 3 cm (range, 1-8 cm).

RESULTS

The mean follow-up was 46 months (range, 5-109 months) in the local-excision group. In the local-excision group, 19 of 26 patients had only residual scarring noted on digital rectal examination and rigid proctoscopy before surgery. Fourteen patients (54%) had a complete histologic response to chemoradiation, 9 patients (35%) had microscopic residual disease, and 3 patients (12%) had gross residual disease. Two intrapelvic recurrences occurred at 76 and 20 months among the 26 patients treated with local excision (6% 5-year actuarial pelvic recurrence rate). This rate compared with an 8% 5-year actuarial pelvic recurrence rate among T3 patients treated with mesorectal excision and a 6% pelvic recurrence rate in the subgroup of mesorectal-excision patients with a complete clinical response to preoperative chemoradiation. One additional local-excision patient recurred in an inguinal lymph node after local excision and subsequently died of metastatic disease. A total of 2 local-excision patients died of metastatic rectal cancer. Actuarial overall survival at 5 years was 86% in the local-excision group compared with 81% among mesorectal-excision patients (p = NS), and 85% in patients with a complete clinical response to chemoradiation followed by mesorectal excision by APR or LAR (p = NS).

CONCLUSIONS

In an experience stimulated by patient refusal of APR, highly selected patients who responded well to conventional external-beam radiotherapy (CXRT) were selected to undergo local excision. Most of these patients had pathologic complete response. Local control and survival rates are comparable to those achieved with chemoradiation followed by mesorectal excision. This strategy should be prospectively studied in a group of patients with low rectal cancer who have no clinical evidence of tumor after chemoradiation.

Outcome of local excision of rectal carcinoma

PURPOSE

This study was designed to determine the results of patients with rectal adenocarcinoma treated with local excision.

METHODS

A retrospective, chart review was conducted for all patients treated with local excision for rectal adenocarcinoma from 1984 to 1998.

RESULTS

Sixty-four patients were retained for analysis. The median follow-up was 37 (range, 9-125) months. There were 15 local failures with a median time to local failure of 12 months. Seven patients were salvaged with further operation (4 by repeat local excision, 4 by abdominoperineal resection, and 1 by low anterior resection). The incidence of local recurrence increased with advancing stage of the carcinoma (T1, 13 percent; T2, 24 percent; T3, 71 percent), histologic grade of differentiation, (well, 12 percent; moderately, 24 percent; poorly, 44 percent), and margin status (negative, 16 percent; close (within 2 mm), 33 percent; positive, 50 percent). Sixteen percent of carcinomas < or = 3 cm failed compared with 47 percent for carcinomas > 3 cm. Nine percent (1/11) of T2 patients treated with adjuvant radiation therapy recurred locally compared with 36 percent (5/14) without radiation therapy. Three of four T3 patients who received radiation therapy failed locally compared with two of three who did not. Using the Kaplan-Meier method, the overall survival at five years was 71 percent, and disease-free survival was 83 percent. Actuarial local failure was 27 percent and freedom from distant metastasis was 86 percent. The sphincter preservation rate was 90 percent at five years.

CONCLUSIONS

Local excision alone is an acceptable option for well-differentiated, T1 carcinomas, < or = 3 cm. Adjuvant radiation is recommended for T2 lesions. The high local recurrence rate in patients after local excision of T3 lesions with or without adjuvant radiotherapy would mandate a radical resection.

Chemotherapeutic and biologic agents as radiosensitizers in rectal cancer

Over the past 25 years, important advances have been made in the management of patients with resectable rectal cancer. Clinical studies have shown the efficacy of combined chemoradiation therapy in enhancing resectability and sphincter preservation rates, decreasing local recurrence, and improving survival of patients with rectal cancer. Although 5-fluorouracil (5-FU) remains the standard chemotherapeutic agent used concurrently with radiation therapy, newer chemotherapeutic agents including capecitabine, irinotecan, and oxaliplatin have also been studied as radiosensitizers in this setting. Novel targeted biologic agents including celecoxib and bevacizumab are being explored in combination with standard chemotherapy and radiation therapy. In this review, we will discuss the mechanism of action and the key clinical studies of each agent as a radiosensitizer.

Treatment of T1–T2 rectal tumors by contact therapy and interstitial brachytherapy

BACKGROUND AND PURPOSE

We retrospectively analysed our experience of contact therapy alone and/or combined with interstitial brachytherapy as exclusive treatment of low lying rectal tumours.

PATIENTS AND METHODS

From 1971 to 2001, 124 patients (103 adenocarcinomas, 21 villous tumours) were treated by contact therapy alone or combined with interstitial brachytherapy. All patients were staged according to the Dijon classification. The average size of the lesions was 2.4 cm (max 7 cm), clinical aspect was polypoïd in 75% of the cases, flat in 17%. Sixty four patients received contact therapy in three fractions and 44 patients received four fractions, for an average delivered dose of 95 Gy. Interstitial brachytherapy boost delivered 24 Gy on a reference isodose of 55 cGy/h in 10 patients.

RESULTS

The local control was 83% for T1 and 38% for T2 tumours (p=0.004). For mobile tumours, the local control rate is 76%, significantly higher than for tumours with impaired mobility (55%, P=0.03). Thirty-nine patients experienced a local failure (31%). For patients amenable to surgery, a Miles procedure was performed in 25 patients. Ultimate local control rate is 93% for T1, 69% for T2 (P<0.05), 15 patients failed despite treatment for local recurrence (15%). No significant differences were observed in a comparison of adenocarcinoma and villous tumours according to initial and ultimate local control. The mean disease free survival rate for the whole population is 66 months. The 5-year disease free survival for T1a and T1b is, respectively, 82 and 78%, 40 and 25% for T2a and T2b, respectively. The overall 5-year survival for the whole group is 62.4%. At the end of the treatment, 75% of the patients described a very good sphincter function. No deleterious effect on continence was reported during the follow-up.

CONCLUSIONS

The control rate for T1 rectal cancer treated with contact therapy with or without brachytherapy is comparable to surgical series. The sphincter was preserved in 80% of the patients. Radiotherapy remains an efficient and cheap alternative to surgery, mainly for old and fragile patients, or refusing colostomy. The results of these approaches for tumors larger than 3 cm (T2) are not satisfactory. For patients not amenable to surgery, external beam radiation therapy and/or combined modality with chemoradiation should be discussed to increase the loco-regional control rate. A careful selection of patients based on rectal examination and trans-rectal ultrasound could select more accurately patients amenable to such an approach.

Local excision of rectal tumors

Local excision is increasingly being used to treat rectal cancer. It appears to be an attractive option because of low morbidity and excellent functional results. Controversies remain regarding available techniques, selection criteria and results with or without adjuvant therapy. Role of salvage therapy remains uncertain. This review examines available evidence in an attempt to clarify the role of local excision in the management of rectal cancer.

Multimodality Management of Locally Advanced Rectal Cancer

Despite the routine use of adjuvant chemoradiation for curatively resected stage II and III rectal cancer a significant percentage of patients ultimately fail locally and/or distally; this underscores the need for continued improvement in the efficacy of combined-modality therapy and quality of rectal cancer resection. The recognition of the significance of lateral or circumferential margins of resection has paralleled the widespread use of total mesorectal excision. In addition to facilitating negative margins of resection and local control, sharp mesorectal techniques also facilitate identification and preservation of pelvic autonomic nerves thereby greatly reducing the incidence of urinary and sexual dysfunction following radical resection. Lastly, restorative options can result in excellent bowel function in carefully selected patients undergoing a “very low” anterior resection. Efforts are currently directed at identifying the subset of locally advanced rectal cancer patients who may be adequately treated with a resection alone thereby avoiding the added morbidity of adjuvant radiation and chemotherapy.

Long-term results of local excision for rectal cancer

OBJECTIVE

To review the authors' experience with local excision of early rectal cancers to assess the effectiveness of initial treatment and of salvage surgery.

SUMMARY BACKGROUND DATA

Local excision for rectal cancer is appealing for its low morbidity and excellent functional results. However, its use is limited by inability to assess regional lymph nodes and uncertainty of oncologic outcome.

METHODS

Patients with T1 and T2 adenocarcinomas of the rectum treated by local excision as definitive surgery between 1969 to 1996 at the authors' institution were reviewed. Pathology slides were reviewed. Among 125 assessable patients, 74 were T1 and 51 were T2. Thirty-one patients (25%) were selected to receive adjuvant radiation therapy. Fifteen of these 31 patients received adjuvant radiation in combination with 5-fluorouracil chemotherapy. Median follow-up was 6.7 years. One hundred fifteen patients (92%) were followed until death or for greater than 5 years, and 69 patients (55%) were followed until death or for greater than 10 years. Recurrence was recorded as local, distant, and overall. Survival was disease-specific.

RESULTS

Ten-year local recurrence and survival rates were 17% and 74% for T1 rectal cancers and 26% and 72% for T2 cancers. Median time to relapse was 1.4 years (range 0.4-7.0) for local recurrence and 2.5 years (0.8-7.5) for distant recurrence. In patients receiving radiotherapy, local recurrence was delayed (median 2.1 years vs. 1.1 years), but overall rates of local and overall recurrence and survival rates were similar to patients not receiving radiotherapy. Among 26 cancer deaths, 8 (28%) occurred more than 5 years after local excision. On multivariate analysis, no clinical or pathologic features were predictive of local recurrence. Intratumoral vascular invasion was the only significant predictor of survival. Among 34 patients who developed tumor recurrence, the pattern of first clinical recurrence was predominantly local: 50% local only, 18% local and distant, and 32% distant only. Among the 17 patients with isolated local recurrence, 14 underwent salvage resection. Actuarial survival among these surgically salvaged patients was 30% at 6 years after salvage. CONCLUSIONS The long-term risk of recurrence after local excision of T1 and T2 rectal cancers is substantial. Two thirds of patients with tumor recurrence have local failure, implicating inadequate resection in treatment failure. In this study, neither adjuvant radiotherapy nor salvage surgery was reliable in preventing or controlling local recurrence. The postoperative interval to cancer death is as long as 10 years, raising concern that cancer mortality may be higher than is generally appreciated. Additional treatment strategies are needed to improve the outcome of local excision.

Local therapy for rectal cancer

Local procedures for carefully selected distal rectal cancer offer significant advantages such as sphincter preservation and avoidance of radical surgery. However, since preoperative selection criteria including current imaging modalities are unable to definitively stage regional lymph node status, local therapies for rectal cancer have the inherent potential disadvantage of undertreating a fraction of patients due to unresected mesorectal/regional lymph node disease. Current available data suggests that the local approach may be appropriate only for carefully selected T1 tumors with favorable pathologic features. Inferior local control and survival reported for T2 tumors and T1 tumors with unfavorable features, despite the addition of chemoradiation, outweigh the advantages of the local approach. Patients with unfavorable tumors who are unable to tolerate radical resection or who refuse surgery may be treated with local excision with or without adjuvant chemoradiation. Other modalities, such as electrocoagulation and endocavitary radiation, may also be valuable in this setting, as well as preoperative chemoradiation followed by local excision. Regardless of the approach used, all patients undergoing local therapy of a rectal cancer require careful long-term follow-up, because these patients remain at significant risk for local recurrence and distant failure.

Intraoperative radiation therapy for patients with recurrent rectal and sigmoid colon cancer in previously irradiated fields

A retrospective study evaluated 15 patients with pelvic recurrence of colorectal cancer in a previously irradiated region who received intraoperative radiation therapy (IORT) as part of salvage therapy. Total prior external beam radiation therapy (EBRT) doses ranged from 45 to 79.2 Gy. Tumor resection was accomplished in 14 patients, with an exenteration performed in seven. IORT dose was 15-20 Gy. Three patients received additional EBRT as a post-operative course of 25.2 Gy in 14 fractions. Actuarial 3-year local control rate was 25%. The 3-year overall survival rate was 29%. Patients with fixed and/or bulky pelvic tumors had a local control rate of 19% at 12 months and median overall survival of 9 months. Patients with less extensive clinical presentations of anastomotic non-fixed transmural recurrence, isolated pelvic node metastasis and rectal recurrence following local excision had a local control rate of 42% at 36 months and median survival of 43 months. We conclude that clinical presentation of recurrent disease is an important prognostic factor. The value of IORT may be limited to patients with less extensive clinical presentations.

Role of radiation therapy in the treatment of resectable rectal adenocarcinoma

The purpose of this study is to review the role of radiation therapy in the treatment of resectable rectal adenocarcinoma. Selection criteria, treatment techniques, and results are discussed.

Local excision of rectal cancer: what is the evidence?

PURPOSE

Although local excision of rectal cancers is a less morbid alternative to radical resection, its role as a curative procedure is unclear. The role of adjuvant therapy after local excision is also controversial. This review aims to examine current evidence on local excision of rectal cancers and how it fits into the management algorithm for rectal cancer.

METHODS

A literature review was undertaken through the MEDLINE database and by cross-referencing previous publications, thus identifying 41 studies on curative local excision of rectal cancer published in English. Details of preoperative staging, surgical procedures, adjuvant therapy, follow-up, and outcome measures, including complications, survival data, recurrences, and salvage were examined.

RESULTS

Preoperative staging of rectal cancers is variable. Digital rectal examination and computerized tomography are used in most studies. Endorectal ultrasound is used in some patients in 9 of 41 studies. Local excision preserves anorectal function, and seems to have limited morbidity (0-22 percent). Local excision alone is associated with local recurrences in 9.7 (range, 0-24) percent of T1, 25 (range, 0-67) percent of T2 and 38 (range, 0-100) percent of T3 cancers. The addition of adjuvant chemoradiotherapy after local excision yields local recurrence rates of 9.5 (range, 0-50) percent for T1, 13.6 (range, 0-24) percent for T2, and 13.8 (range, 0-50) percent for T3 cancers. Data on local excision after preoperative chemoradiotherapy for tumor down staging are limited. Factors other than T-stage that lead to higher local recurrence rates after local excision include poor histologic grade, the presence of lymphovascular invasion, and positive margins. Local recurrences after local excision can be surgically salvaged (84 of 114 patients in 15 studies), with a disease-free survival rates between 40 and 100 percent at a follow-up of 0.1 to 13.5 years.

CONCLUSIONS

Local excision for rectal cancers is associated with a low morbidity and provides satisfactory local control and disease-free survival rates for T1 rectal cancers. There is, however, a need for a randomized, controlled trial for T2 cancers, comparing local excision with adjuvant chemoradiotherapy to radical resection.

Local excision and postoperative radiotherapy for distal rectal cancer

PURPOSE

To assess the outcome following local excision and postoperative radiotherapy (RT) for distal rectal carcinoma.

MATERIALS AND METHODS

Seventy-three patients received postoperative radiotherapy following local surgery for primary rectal carcinoma at Princess Margaret Hospital from 1983 to 1998. Selection factors for postoperative RT were patient preference, poor operative risks, and "elective" where conservative therapy was regarded as optimal therapy. Median distance of the primary lesion from the anal verge was 4 cm (range, 1--8 cm). There were 24 T1, 36 T2, and 8 T3 lesions. The T category could not be determined in 5. Of 55 tumor specimens in which margins could be adequately assessed, they were positive in 18. RT was delivered using multiple fields by 6- to 25-MV photons. Median tumor dose was 50 Gy (range, 38--60 Gy), and 62 patients received 50 Gy in 2.5-Gy daily fractions. The tumor volume included the primary with 3--5 cm margins. No patients received adjuvant chemotherapy. Median follow-up was 48 months (range, 10--165 months).

RESULTS

Overall 5-year survival and disease-free survival were 67% and 55%, respectively. Tumor recurrence was observed in 23 patients. There were 14 isolated local relapses; 6 patients developed local and distant disease; and 3 relapsed distantly only. For patients with T1, T2, and T3 lesions, 5-year local relapse-free rates were 61%, 75%, and 78%, respectively, and 5-year survival rates were 76%, 58%, and 33%, respectively. The 5-year local relapse-free rate was lower in the presence of lymphovascular invasion (LVI) compared to no LVI, 52% vs. 89%, p = 0.03, or where tumor fragmentation occurred during local excision compared to no fragmentation, 51% vs. 76%, p = 0.02. Eleven of 14 patients with local relapse only underwent abdominoperineal resection, 8 achieved local control, and 4 remained cancer free. The ultimate local control, including salvage surgery, was 86% at 5 and 10 years. The 5-year colostomy-free rate was 82%. There were 2 patients who experienced RTOG Grade 3 late complications, and 1 with Grade 4 complication (bowel obstruction requiring surgery).

CONCLUSION

The local relapse rate for patients with T1 disease was high compared to other series of local excision and postoperative RT. Patients with LVI or tumor fragmentation during excision have high local relapse rates and may not be good candidates for conservative surgery and postoperative RT.

Local therapy for rectal cancer

In selected patients with early rectal cancer, local therapy is an effective alternative to radical resection and offers minimal morbidity and the avoidance of a colostomy. Several techniques are described: transanal excision, dorsal approaches (York-Mason or Kraske procedures), transanal endoscopic microsurgery, endocavitary radiation, and transanal fulguration. Among these, transanal excision is favored for the low rate of complications, promising outcomes, and ability to secure tissue for pathology. Patients with T1 lesions with favorable histologic features may undergo local excision alone, while those with T2 lesions require adjuvant chemoradiation. The data currently available do not support the use of local therapy with curative intent for tumors that are advanced (T3 or T4), poorly differentiated, or have other negative pathologic characteristics. In carefully selected patients for local excision, local recurrence and survival rates are similar to traditional radical resection. Following local excision, patients require close observation for recurrence. Most patients with local recurrence can be salvaged by radical resection, though the long-term outcome is unknown.

Radiation therapy in the management of rectal cancer

Substantial advances have been made in the adjuvant management of patients with resectable rectal cancer. Increasing interest in patient quality of life has promoted the use of radiation therapy to enhance sphincter-preserving surgical approaches as an alternative to the standard abdominoperineal resection. Because of the suggestion of enhanced sphincter preservation with preoperative therapy and the potential advantage of decreased acute morbidity, randomized trials comparing preoperative and postoperative adjuvant combined modality therapy are ongoing. Recent progress in adjuvant postoperative treatment regimens relates to the integration of systemic therapy to radiation, and redefining the techniques for both modalities. The incorporation of improved radiation planning may reduce treatment-related bowel toxicity. The integration of novel chemotherapeutic agents in the adjuvant therapy of rectal cancer remains an active area of investigation.

CONSERVATIVE TREATMENT OF RECTAL ADENOCARCINOMA

Endocavitary radiotherapy and transrectal excision are highly effective treatments for properly selected patients with favorable early-stage rectal adenocarcinoma. The likelihood of local control and survival after treatment with either modality is similar, and differences among various series probably reflect selection. The parameter most predictive of local control and survival in the authors' series was tumor configuration. As has been previously observed, "selection is the silent partner of success." Suitable candidates for endocavitary radiotherapy or wide local excision are patients whose tumors are 3 cm or less in diameter, well-to-moderately differentiated, exophytic, mobile, limited to the submucosa on transrectal ultrasound, and within 10 cm of the anal verge. The advantages of endocavitary irradiation are (1) it is an outpatient procedure, (2) it does not require anesthesia, and (3) it is less expensive than transrectal excision. The advantages of transrectal excision are (1) it may be performed during one brief hospitalization (as opposed to four outpatient visits), and (2) a small subset of patients will have pathologic findings predicting an increased risk of regional lymph node involvement, revealing the need to treat the nodes with external-beam radiotherapy. A disadvantage of wide local excision is that some patients who would be suitable for a local procedure alone must be subjected to a course of external-beam radiotherapy when they are found to have equivocal or positive margins. Patients who are treated with transrectal excision and external-beam radiotherapy have less favorable lesions and are not comparable with patients who are treated with endocavitary radiotherapy or wide local excision alone. They are best compared with patients who have undergone major surgery consisting of abdominoperineal resection or low anterior resection. Because the risk of positive nodes is significantly increased with adverse pathologic findings such as poor differentiation, invasion of the muscularis propria, and endothelial-lined space invasion, a subset of these patients treated with wide local excision would have positive nodes. This subset of patients is not comparable with patients with stage pT1N0 and pT2N0 tumors treated with major surgery. The latter group of patients undergo complete surgical staging, whereas the pathologic staging for patients who undergo wide local excision and radiotherapy is limited to the extent of the primary tumor. With this caveat in mind, wide local excision and radiotherapy seem to result in locoregional control and survival rates similar to the rates obtained with major surgery for patients with pT1 and pT2 cancers (Table 5). Patients who should receive postoperative irradiation have tumors that exhibit one or more of the following characteristics: size greater than 3 cm in diameter, poorly differentiated, invasion of the muscularis propria, endothelial-lined space invasion, fragmented resection, equivocal or positive margins, or perineural invasion. Patients with gross residual disease are not suitable candidates for radiotherapy and require further surgery. The authors' policy is to treat these patients with chemoradiation followed by resection. Patients thought to have transmural invasion before treatment are probably best treated with preoperative chemoradiation combined with major surgery, although a subset of patients can be downstaged and rendered suitable for a wide local excision.

Sphincter preservation in rectal cancer

Distal rectal cancer poses two challenges to the oncologist: local tumor control and sphincter preservation. The abdominoperineal resection (APR), long considered the standard treatment of tumors with a distal edge located up to 6 cm from the anal verge, provides local control in many patients but results in sphincter loss with a permanent colostomy. This is a critical limitation. Consequently, there has been significant interest in sphincter-conserving approaches, frequently combining chemoradiation with surgery. These approaches have evolved along two fronts. For patients with small rectal cancers confined to the rectal wall, local excision techniques with and without chemoradiation may offer comparable local control and survival rates as an APR and preserve sphincter function. For patients with larger and more invasive tumors of the distal rectum where local excision is inappropriate, preoperative chemoradiation promotes tumor regression and may facilitate a resection sparing the sphincter with a coloanal anastomosis. Preliminary results from single institution studies appear promising. In both these settings (favorable and more invasive rectal cancer), chemoradiation is employed to compensate for the limitations of the sphincter-preserving surgical technique. In local excision procedures, the excision margins are invariably small, and the mesorectum (lymphatics, soft tissue) surrounding the tumor is not excised. For patients undergoing resection with coloanal anastomosis, there are narrow radial and distal surgical margins. With these approaches of chemoradiation and sphincter-sparing surgery, satisfactory local control and survival with avoidance of colostomy are possible for many patients with distal rectal cancer.

Adjuvant therapy for resectable rectal adenocarcinoma

The mainstay of treatment for rectal cancer over the past 100 years has been surgical resection. However, for the majority of rectal cancers treated conventionally by resection alone, locoregional recurrence is the major mode of failure. Over the past several decades, significant progress has been made in developing effective adjuvant regimens. In the United States, postoperative chemoradiation is standard treatment for T3 or node-positive patients. However, preoperative radiation with or without chemotherapy decreases local recurrence, increases sphincter preservation, and may improve survival. The purpose of this article is to review the role of adjuvant therapy in resectable rectal cancers and to update the status of ongoing randomized trials.

[Local treatment of rectal cancer]

Transanal local excision is only indicated in small rectal carcinomas with limited infiltration and high differentiation, and is followed by a 5-year survival rate around 90%. Endo-cavity irradiation has similar indications and results, but can only be performed by trained teams. The main risk of these local treatments is tumoral recurrence. A rigorous selection of patients is necessary and a rigorous postoperative survey.

Anal sphincter conservation for patients with adenocarcinoma of the distal rectum: long-term results of radiation therapy oncology group protocol 89-02

PURPOSE

To assess the outcome of a multi-institutional, national cooperative group study attempting functional preservation of the anorectum for patients with limited, distal rectal cancer.

METHODS AND MATERIALS

Between September 21, 1989 and November 1, 1992, a Phase II trial of sphincter-sparing therapy was conducted for patients with clinically mobile rectal cancers located below the pelvic peritoneal reflection. Protocol treatment was designed for patients who were, in the judgement of their attending surgeon, unsuitable for anal sphincter conservation in the context of anterior resection, and would have required abdominoperineal resection (APR) as conventional surgical therapy. Primary cancers were estimated to be 4 cm or less in largest clinical diameter, and occupied 40% or less of the rectal circumference. Chest radiography and computerized axial tomography (CT) of the abdomen and pelvis excluded patients with overt lymphatic or hematogenous metastases. Protocol surgery was intended to remove the primary cancer by en-bloc, transmural excision of an ellipse of rectal wall by transanal, transcoccygeal, or trans-sacral technique, while conserving the anal sphincter. Based on tumor size, T classification, grade, and adequacy of surgical margins, patients were allocated to one of three treatment assignments: observation, or adjuvant treatment with 5-fluorouracil (5-FU) and one of two different dose levels of local-regional radiation. After completion of protocol therapy, patients were observed with follow-up that included periodic general physical and rectal examination, determinations of CEA, abdominopelvic CT, chest radiography, and surveillance endoscopy. Sixty-five eligible and analyzable patients were registered.

RESULTS

With minimum follow-up of 5 years and median follow-up of 6.1 years, 11 patients have failed: 3 patients recurred local-regionally only, 3 patients had distant failure alone, and 5 patients manifested local-regional and distant failure. Eight patients died of intercurrent illness. Local-regional failure correlated with T-category revealed: T1 1/27 (4%), T2 4/25 (16%), and T3 3/13 (23%). Local-regional failure escalated with percentage involvement of the rectal circumference: 2/31 (6%) among patients with cancers involving 20% or less of the rectal circumference, and 6/34 (18%) among patients with cancers involving 21-40% of the circumference. Distant dissemination rose with T-category with 1/27 (4%) T1, 3/25 (12%) T2, and 4/13 (31%) T3 patients manifesting hematogenous spread. Eight patients (12%) required temporary or permanent colostomy. Five of 8 patients with local-regional recurrence achieved local-regional control with management including surgery, although 4 of these patients subsequently developed distant dissemination. Three patients (5%) had persistent, uncontrolled, local disease. Actuarial freedom from pelvic relapse at 5 years is 88% based on the entire study population, and 86% for the less favorable patients treated with adjuvant radiation and 5-FU.

CONCLUSION

Conservative, sphincter-sparing therapy is a feasible alternative treatment for selected patients with limited cancer involving the middle and lower rectum. Risk of both local and distant failure appears to escalate with increasing T-category (depth of invasion). Results achieved in the multi-institutional, cooperative group setting approximate results reported from single institutions.

Surgical management of primary colorectal cancer

Surgery for potentially curable colorectal cancer most commonly involves resection of the primary tumor and regional lymph nodes. However, the site, extent and presentation of disease have an impact on surgical strategy and the use of combined modality therapy. For colon cancer, complex presentations such as obstructing or perforated colon cancer may influence surgical therapy, and issues pertaining to en bloc resection and oophorectomy remain unresolved. For rectal cancer, surgical management may range from local excision to radical resection. Extent of resection and relatively new operative techniques such as coloanal anastomosis with or without a colonic pouch reservoir are directed towards optimizing both oncologic and functional results.