Conservative management of rectal adenocarcinoma by radiotherapy

Immunotherapy and radiotherapy for older patients with locally advanced rectal cancer unfit for surgery or decline surgery: a practical proposal by the International Geriatric Radiotherapy Group

The standard of care for locally advanced rectal cancer is total neoadjuvant therapy followed by surgical resection. Current evidence suggests that selected patients may be able to delay or avoid surgery without affecting survival rates if they achieve a complete clinical response (CCR). However, for older cancer patients who are too frail for surgery or decline the surgical procedure, local recurrence may lead to a deterioration of patient quality of life. Thus, for clinicians, a treatment algorithm which is well tolerated and may improve CCR in older and frail patients with rectal cancer may improve the potential for prolonged remission and potential cure. Recently, immunotherapy with check point inhibitors (CPI) is a promising treatment in selected patients with high expression of program death ligands receptor 1 (PD- L1). Radiotherapy may enhance PD-L1 expression in rectal cancer and may improve response rate to immunotherapy. We propose an algorithm combining immunotherapy and radiotherapy for older patients with locally advanced rectal cancer who are too frail for surgery or who decline surgery.

Contact X-ray brachytherapy for rectal cancer: Past, present, and future

The Papillon experience and the Lyon R96-02 trial have shown that contact X-ray brachytherapy of 50kV is efficient and safe to achieve long term local control and organ preservation for cT1 and early cT2-3 rectal cancers. The OPERA trial, using the Papillon 50™ machine, brings further support to this preservation strategy for selected T2T3ab lesions. Future trials using a contact X-ray boost will try to consolidate and enlarge its place in organ preservation for rectal cancers.

A novel rectal applicator for contact radiotherapy with HDR 192Ir sources

PURPOSE

Dose escalation to rectal tumors leads to higher complete response rates and may thereby enable omission of surgery. Important advantages of endoluminal boosting techniques include the possibility to apply a more selective/localized boost than using external beam radiotherapy. A novel brachytherapy (BT) rectal applicator with lateral shielding was designed to be used with a rectoscope for eye-guided positioning to deliver a dose distribution similar to the one of contact x-ray radiotherapy devices, using commonly available high-dose-rate ¹⁹²Ir BT sources.

METHODS AND MATERIALS

A cylindrical multichannel BT applicator with lateral shielding was designed by Monte Carlo modeling, validated experimentally with film dosimetry and compared with results found in the literature for the Papillon 50 (P50) contact x-ray radiotherapy device regarding rectoscope dimensions, radiation beam shape, dose fall-off, and treatment time.

RESULTS

The multichannel applicator designed is able to deliver 30 Gy under 13 min with a 20350 U (5 Ci) source. The use of multiple channels and lateral shielding provide a uniform circular treatment surface with 22 mm in diameter. The resulting dose fall-off is slightly steeper (maximum difference of 5%) than the one generated by the P50 device with the 22 mm applicator.

CONCLUSIONS

A novel multichannel rectal applicator for contact radiotherapy with high-dose-rate ¹⁹²Ir sources that can be integrated with commercially available treatment planning systems was designed to produce a dose distribution similar to the one obtained by the P50 device.

Age Is Not a Limiting Factor in Interventional Radiotherapy (Brachytherapy) for Patients with Localized Cancer

This review examines the role of interventional radiotherapy (IRT otherwise known as brachytherapy) in cancer treatment for elderly patients. Despite their advanced age and associated comorbidities, elderly patients should receive definitive cancer therapies, including surgery and radiotherapy (RT). In fact, RT becomes first-line option for patients who are not eligible for surgery (due to comorbidities, anticoagulant drugs, and risk of disfigurement) or those who refuse it. It emerged from this review of the literature as effective, simple, safe, and comfortable and was associated with good local control, low toxicity rates, and excellent cosmesis and provided a cost benefit. IRT may be used as sole treatment for small cancers or as a useful adjunct to surgery or external beam radiotherapy (EBRT) in more advanced (or lymph node positive) cases, especially when the aim is local control with adequate preservation of normal tissue function. As palliative treatment, IRT preserves quality of life and/or improves survival. It is to be hoped that this review will serve as a helpful guide for members of multidisciplinary teams that are involved in treating elderly patients with cancer.

Endorectal Brachytherapy Boost After External Beam Radiation Therapy in Elderly or Medically Inoperable Patients With Rectal Cancer: Primary Outcomes of the Phase 1 HERBERT Study

PURPOSE

To evaluate the toxicity and efficacy of the combination of external beam radiation therapy (EBRT) followed by high-dose-rate endorectal brachytherapy (HDREBT) boost in elderly and medically inoperable patients with rectal cancer.

METHODS AND MATERIALS

A phase 1 dose-escalation study was performed. Treatment consisted of EBRT (13 × 3 Gy) followed by 3 weekly brachytherapy applications 6 weeks later. The HDREBT dose started at 5 Gy per fraction, increasing with 1 Gy per fraction if dose-limiting toxicity (DLT, defined as grade ≥3 proctitis <6 weeks after HDREBT) occurred in ≤2 patients per dose level. The primary endpoint was the maximum tolerated dose, defined as 1 dose level below the dose at which 3 patients experienced DLT. Secondary endpoints were toxicity, clinical tumor response, freedom from local progression, and local progression-free and overall survival (L-PFS and OS).

RESULTS

Thirty-eight patients with a median age of 83 years were included in the study. Thirty-two were evaluable for DLT and late toxicity and 33 for response evaluation. Maximum delivered dose was 8 Gy per fraction, resulting in a recommended dose of 7 Gy per fraction. Response occurred in 29 of 33 patients (87.9%), with 60.6% complete response (CR). The L-PFS and OS rates were 42% and 63%, respectively, at 2 years. Patients with CR showed a significantly improved L-PFS (60% at 2 years, P=.006) and a trend in improved OS (80% at 2 years, P=.11). Severe late toxicity occurred in 10 of 32 patients.

CONCLUSION

We found that HDREBT after EBRT results in a high overall response rate, with improved L-PFS for patients with a CR. The high observed rate of severe late toxicity requires further evaluation of the risks and benefits of an HDREBT boost.

Definitive Chemoradiotherapy ("Watch-and-Wait" Approach)

Preoperative chemoradiotherapy (CRT) followed by total mesorectal excision has been the standard of care for locally advanced patients with rectal cancer. Some patients achieve a pathologic complete response (pCR) to CRT and the oncologic outcomes are particularly favorable in this group. The role of surgery in patients with a pCR is now being questioned as radical rectal resection is associated with significant morbidity and long-term effects on quality of life. In an attempt to better tailor therapy, there is an interest in a "watch-and-wait" approach in patients who have a clinical complete response (cCR) after CRT with the goal of omitting surgery and allowing for organ preservation. However, a cCR does not always indicate a pCR, and improved clinical and imaging modalities are needed to better predict which patients have achieved a pCR and therefore can safely undergo a "watch-and-wait" approach. This article reviews the current data on nonoperative management and on-going controversies associated with this approach.

Impact of radiotherapy boost on pathological complete response in patients with locally advanced rectal cancer: a systematic review and meta-analysis

PURPOSE

We conducted a systematic review and meta-analysis to quantify the pathological complete response (pCR) rate after preoperative (chemo)radiation with doses of ⩾60Gy in patients with locally advanced rectal cancer. Complete response is relevant since this could select a proportion of patients for which organ-preserving strategies might be possible. Furthermore, we investigated correlations between EQD2 dose and pCR-rate, toxicity or resectability, and additionally between pCR-rate and chemotherapy, boost-approach or surgical-interval.

METHODS AND MATERIALS

PubMed, EMBASE and Cochrane libraries were searched with the terms 'radiotherapy', 'boost' and 'rectal cancer' and synonym terms. Studies delivering a preoperative dose of ⩾60 Gy were eligible for inclusion. Original English full texts that allowed intention-to-treat pCR-rate calculation were included. Study variables, including pCR, acute grade ⩾3 toxicity and resectability-rate, were extracted by two authors independently. Eligibility for meta-analysis was assessed by critical appraisal. Heterogeneity and pooled estimates were calculated for all three outcomes. Pearson correlation coefficients were calculated between the variables mentioned earlier.

RESULTS

The search identified 3377 original articles, of which 18 met our inclusion criteria (1106 patients). Fourteen studies were included for meta-analysis (487 patients treated with ⩾60 Gy). pCR-rate ranged between 0.0% and 44.4%. Toxicity ranged between 1.3% and 43.8% and resectability-rate between 34.0% and 100%. Pooled pCR-rate was 20.4% (95% CI 16.8-24.5%), with low heterogeneity (I2 0.0%, 95% CI 0.00-84.0%). Pooled acute grade ⩾3 toxicity was 10.3% (95% CI 5.4-18.6%) and pooled resectability-rate was 89.5% (95% CI 78.2-95.3%).

CONCLUSION

Dose escalation above 60 Gy for locally advanced rectal cancer results in high pCR-rates and acceptable early toxicity. This observation needs to be further investigated within larger randomized controlled phase 3 trials in the future.

Organ-preserving therapy for rectal cancer

SUMMARY Total mesorectal excision has resulted in low local recurrence rates in rectal cancer patients; however, it is associated with a significant impairment in quality of life. The operation may be disfiguring and cause permanent effects on gastrointestinal, genitourinary and sexual function. Recently, researchers have identified subgroups of rectal cancer patients who may be able to forgo total mesorectal excision without compromising their oncological outcomes. Two groups of patients are candidates for organ preservation: those with early-stage disease that may be adequately addressed by a more limited resection, and those with locally advanced disease that has responded completely to neoadjuvant therapy. Additionally, radiation alone may be curative in both early and locally advanced disease. This article reviews the data regarding these approaches.

Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data

BACKGROUND

Locally advanced rectal cancer is usually treated with preoperative chemoradiation. After chemoradiation and surgery, 15-27% of the patients have no residual viable tumour at pathological examination, a pathological complete response (pCR). This study established whether patients with pCR have better long-term outcome than do those without pCR.

METHODS

In PubMed, Medline, and Embase we identified 27 articles, based on 17 different datasets, for long-term outcome of patients with and without pCR. 14 investigators agreed to provide individual patient data. All patients underwent chemoradiation and total mesorectal excision. Primary outcome was 5-year disease-free survival. Kaplan-Meier survival functions were computed and hazard ratios (HRs) calculated, with the Cox proportional hazards model. Subgroup analyses were done to test for effect modification by other predicting factors. Interstudy heterogeneity was assessed for disease-free survival and overall survival with forest plots and the Q test.

FINDINGS

484 of 3105 included patients had a pCR. Median follow-up for all patients was 48 months (range 0-277). 5-year crude disease-free survival was 83.3% (95% CI 78.8-87.0) for patients with pCR (61/419 patients had disease recurrence) and 65.6% (63.6-68.0) for those without pCR (747/2263; HR 0.44, 95% CI 0.34-0.57; p<0.0001). The Q test and forest plots did not suggest significant interstudy variation. The adjusted HR for pCR for failure was 0.54 (95% CI 0.40-0.73), indicating that patients with pCR had a significantly increased probability of disease-free survival. The adjusted HR for disease-free survival for administration of adjuvant chemotherapy was 0.91 (95% CI 0.73-1.12). The effect of pCR on disease-free survival was not modified by other prognostic factors.

INTERPRETATION

Patients with pCR after chemoradiation have better long-term outcome than do those without pCR. pCR might be indicative of a prognostically favourable biological tumour profile with less propensity for local or distant recurrence and improved survival.

FUNDING

None.

Can endoscopic ultrasound predict early rectal cancers that can be resected endoscopically? A meta-analysis and systematic review

BACKGROUND

Rectal cancers that are confined to the mucosa (T0) can be resected endoscopically. This can help the patient avoid transabdominal surgery. The published data on accuracy of endoscopic ultrasound (EUS) to predict T0 stage of rectal cancers has been varied.

AIM

To evaluate the accuracy of EUS in T0 staging of rectal cancers. METHOD (STUDY SELECTION CRITERIA): Only EUS studies confirmed by surgery were selected. T0 was defined as tumor confined to the mucosa. DATA COLLECTION AND EXTRACTION: Articles were searched in Medline, PubMed, and CENTRAL.

STATISTICAL METHOD

Pooling was conducted by both the fixed-effects model and random-effects model.

RESULTS

An initial search identified 3,360 reference articles. Of these, 339 relevant articles were selected and reviewed. Eleven studies (N = 1,791) which met the inclusion criteria were included in this analysis. Pooled sensitivity of EUS in diagnosing T0 was 97.3% (95% CI: 93.7-99.1). EUS had a pooled specificity of 96.3% (95% CI: 95.3-97.2). The positive likelihood ratio of EUS was 21.9 (95% CI: 16.3-29.7) and negative likelihood ratio was 0.08 (95% CI: 0.04-0.15). All the pooled estimates, calculated by fixed and random effect models, were similar. The P-value for Chi-squared heterogeneity for all the pooled accuracy estimates was >0.10.

CONCLUSIONS

EUS has excellent sensitivity and specificity, this helps accurately diagnose T0 stage of rectal cancers. Over the past two decades, the sensitivity and specificity of EUS to diagnose T0 stage of rectal cancers has remained high. This can help physicians offer endoscopic treatment to these patients, therefore EUS should be strongly considered for staging of early rectal cancers.

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.

Rectal cancer

Rectal cancer is an important tumour from an epidemiological point of view and represents the benchmark for an optimal use of integrated treatments (surgery, radiotherapy and chemotherapy) in the oncological practice. The conventional use of total mesorectal excision and the integration with radiochemotherapy, better if preoperatively, are now able to increase survival, to decrease the occurrence of pelvic recurrence and to ameliorate the quality of life of patients. Updated recommendations for the management of these patients are here reported.

How good is endoscopic ultrasound in differentiating various T stages of rectal cancer? Meta-analysis and systematic review

Published data on accuracy of endoscopic ultrasound (EUS) in differentiating T stages of rectal cancers is varied. Study selection criteria were to select only EUS studies confirmed with results of surgical pathology. Articles were searched in Medline and Pubmed. Pooling was conducted by both fixed and random effects models. Initial search identified 3,630 reference articles, of which 42 studies (N = 5,039) met the inclusion criteria and were included in this analysis. The pooled sensitivity and specificity of EUS to determine T1 stage was 87.8% [95% confidence interval (CI) 85.3-90.0%] and 98.3% (95% CI 97.8-98.7%), respectively. For T2 stage, EUS had a pooled sensitivity and specificity of 80.5% (95% CI 77.9-82.9%) and 95.6% (95% CI 94.9-96.3%), respectively. To stage T3 stage, EUS had a pooled sensitivity and specificity of 96.4% (95% CI 95.4-97.2%) and 90.6% (95% CI 89.5-91.7%), respectively. In determining the T4 stage, EUS had a pooled sensitivity of 95.4% (95% CI 92.4-97.5%) and specificity of 98.3% (95% CI 97.8-98.7%). The p value for chi-squared heterogeneity for all the pooled accuracy estimates was > 0.10. We conclude that, as a result of the demonstrated sensitivity and specificity, EUS should be the investigation of choice to T stage rectal cancers. The sensitivity of EUS is higher for advanced disease than for early disease. EUS should be strongly considered for T staging of rectal cancers.

Evidence and research in rectal cancer

The main evidences of epidemiology, diagnostic imaging, pathology, surgery, radiotherapy, chemotherapy and follow-up are reviewed to optimize the routine treatment of rectal cancer according to a multidisciplinary approach. This paper reports on the knowledge shared between different specialists involved in the design and management of the multidisciplinary ESTRO Teaching Course on Rectal Cancer. The scenario of ongoing research is also addressed. In this time of changing treatments, it clearly appears that a common standard for large heterogeneous patient groups have to be substituted by more individualised therapies based on clinical-pathological features and very soon on molecular and genetic markers. Only trained multidisciplinary teams can face this new challenge and tailor the treatments according to the best scientific evidence for each patient.

Contact X-ray therapy for rectal cancer: experience in Centre Antoine-Lacassagne, Nice, 2002-2006

PURPOSE

To report the results of using contact X-ray (CXR), which has been used in the Centre-Lacassagne since 2002 for rectal cancer.

METHODS AND MATERIALS

A total of 44 patients were treated between 2002 and 2006 using four distinct clinical approaches. Patients with Stage T1N0 tumors were treated with transanal local excision (TLE) and adjuvant CXR (45 Gy in three fractions) (n = 7). The 11 inoperable (or who had refused surgery) patients with Stage T2-T3 disease were treated with CXR plus external beam radiotherapy (EBRT). Those with Stage T3N0-N2 tumors were treated with preoperative CXR plus EBRT (with or without concurrent chemotherapy) followed by surgery (n = 21). Finally, the patients with Stage T2 disease were treated with CXR plus EBRT followed by TLE (n = 5).

RESULTS

The median follow-up was 25 months. In the 7 patients who underwent TLE first, no local failure was observed, and their anorectal function was good. Of the 11 inoperable patients who underwent CXR plus EBRT alone, 10 achieved local control. In the third group (preoperative CXR plus EBRT), anterior resection was performed in 16 of 21 patients. Complete sterilization of the operative specimen was seen in 4 cases (19%). No local recurrence occurred. Finally, of the 5 patients treated with CXR plus EBRT followed by TLE, a complete or near complete clinical response was observed in all. TLE with a R0 resection margin was performed in all cases. The rectum was preserved with good function in all 5 patients.

CONCLUSION

These early results have confirmed that CXR combined with surgery (or alone with EBRT) can play a major role in the conservative and curative treatment of rectal cancer.

Whither Papillon? — Future Directions for Contact Radiotherapy in Rectal Cancer

Although contact radiotherapy was developed 70 years ago, and is highly effective with cure rates of over 90% for early rectal cancer, there are few centres that offer this treatment today. One reason is the lack of replacement of ageing contact X-ray machines, many of which are now over 30 years old. To address this problem, the International Contact Radiotherapy Evaluation (ICONE) group was formed at a meeting in Liverpool in 2005 with the aim of developing a new contact X-ray unit and to establish clinical protocols that would enable the new machine to safely engage in the treatment of rectal cancer. As a result of these efforts, a European company is starting production of the new Papillon RT-50 machine, which will be available shortly. In addition, the ICONE group is planning an observational study on contact X-ray and transanal endoscopic microsurgery (CONTEM) for curative treatment of rectal cancer. This protocol will ensure standardised diagnostic procedures, patient selection and treatment in centres across the world and the data will be collected prospectively for analysis and audit. It is hoped that the CONTEM trial will provide the scientific evidence that is needed to obtain a broader acceptance of local contact radiotherapy as a treatment option for selected cases with early stage rectal cancer.

Is there a limit to dose escalation for rectal cancer?

The radiation tolerance of the rectum is not fully understood. Published studies on the radiation treatment of cancers of the prostate, cervix and rectum have been reviewed to determine currently recommended dose-volume guidelines. The need for further studies directed specifically at the treatment of primary rectal cancer and perirectal node metastases is discussed. There seems to be room for escalation of the external beam doses currently given.

French experience with contact X-ray endocavitary radiation for early rectal cancer

This paper is an overview of the French experience with contact X-ray radiation for rectal cancer. The analysis was mainly carried out on 50 years of experience in Lyon or since 1980 in the Centre Hospitalier Universitaire Lyon Sud. The results obtained in Dijon and Nancy are also reported. In early rectal cancer, contact X-ray radiation can play an important role in three different situations: (1) small T1 less than 2 cm: adjuvant contact X-ray radiotherapy after local excision; (2) T2 N0 or large T1: first-line contact X-ray radiotherapy combined with external beam radiotherapy (+/- chemotherapy) followed by surgery (anterior resection or local excision); (3) early T3 N0 in frail patients: the same approach as for T2 N0 with, in case of clinical complete response, local excision or follow-up.

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.

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 curative treatment of rectal cancer by radiotherapy alone

This paper is a short overview of the role of radiotherapy alone to locally control rectal cancer when surgery for any reason cannot be performed. High dose irradiation is necessary using endocavitary (contact X-ray, iridium brachytheraphy) techniques. For T2-3 lesions a combination of external beam radiotherapy and endocavitary irradiation can provide long term cure with limited toxicity. Surgery remains, by far, the main treatment of rectal cancer, preoperative radiotherapy may be used in low rectal cancer to improve the chance of sphincter saving procedure.

An evidence-based estimate of the appropriate radiotherapy utilization rate for colorectal cancer

PURPOSE

Current estimates of the proportion of cancer patients who will require RT are based almost entirely on expert opinion. The objective of this study was to estimate the proportion of incident cases of colorectal cancer that should receive RT using an evidence-based approach.

METHODS AND MATERIALS

A systematic review of the literature was undertaken to identify indications for RT for colorectal cancer, and to ascertain the level of evidence that supported each indication. An epidemiologic approach was then used to estimate the incidence of each indication for RT in a typical North American population of colorectal cancer patients. The effect of sampling error on the estimated appropriate rate of RT was calculated mathematically, and the effect of systematic error was estimated by sensitivity analysis.

RESULTS

It was estimated that 23.7% +/- 1.0% of colorectal cancer cases develop one or more indications for RT at some point in the course of the illness: 20.9% +/- 1.1% as part of their initial treatment, and 2.8% +/- 0.5% later for recurrence or progression. We estimated that 7.1% +/- 0.8% of colon carcinoma patients will require RT at some point in the course of the illness: 4.0% +/- 0.7% as part of their initial treatment, and 3.1% +/- 0.4% later for recurrence or progression. We estimated that 72.3% +/- 1.0% of rectal carcinoma patients will require RT at some point in the course of the illness: 69.6% +/- 0.9% as part of their initial treatment and 2.7% +/- 0.2% later for recurrence or progression.

CONCLUSIONS

This method provides a rational starting point for the long-term planning of radiation services, and for the audit of access to RT at the population level. By completing such evaluations in the major cancer sites, it will be possible to estimate the appropriate RT treatment rate for the cancer population as a whole.

Radiotherapy alone in the curative treatment of rectal carcinoma

Surgery is the standard treatment for rectal adenocarcinoma. The tumour is resistant to radiation; doses above 80 Gy are necessary and have to be delivered by endocavitary irradiation. Contact radiotherapy is a basic method of delivering a high dose in a small volume. Brachytherapy can be used to deliver a boost of radiation into a residual lesion. External-beam radiotherapy can be used to supplement the dose to the deep part of the primary tumour and to the perirectal lymph nodes. T1N0 tumours have been treated by contact radiotherapy, and local control was achieved in 85-90% of patients with no severe toxic effects. Combined endocavitary irradiation and external-beam irradiation can achieve local control in 80% of patients with T2 tumours and 60% of patients with T3 tumours with only moderate toxic effects and a 60% 5-year overall survival. Radiotherapy alone is suitable for patients with T1N0 lesions (contact radiotherapy) or patients with T2-3 (combined endocavitary and external-beam radiotherapy) who cannot undergo surgery. For T2 or early T3 tumours of the lower rectum requiring surgery and a permanent colostomy, combined irradiation can be used as a first-line treatment in an attempt to avoid abdominoperineal amputation.

[Brachytherapy in carcinomas of anal canal and rectum: techniques and results]

Conservative treatment of small anal canal and low rectal cancers is a valid alternative to radical surgery through combinated strategies including external beam and/or intracavitary irradiation, concomitant chemotherapy and 192 iridium implantation as a booster dose. Feasibility, tolerance and results are effective. Local control of the disease and the quality of the anal functions are good. The treatment requires great care in patient selection and follow-up.

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.

Transanal endoscopic microsurgical excision of rectal tumors: indications and results

Transanal endoscopic microsurgery (TEM) allows local excision of rectal tumors located 4 to 18 cm above the anal verge. The technique is not yet generally established because of the necessary special instrumentation and tools, the unusual technical aspects of the approach, and the stringent patient selection criteria. The aim of this prospective, descriptive study was to analyze the currently accepted indications for TEM and to evaluate the use of this procedure for treating rectal cancer. Over a 4-year period 50 patients aged 31 to 86 years (mean 64 years) underwent TEM for treatment of rectal tumors located 12 cm above the anal verge (range 4-18 cm). The local complication rate was 4%. Altogether, 76% of lesions were benign, and 24% were T1 and T2 tumors. Of 12 cancer cases, 4 required reoperation by total mesorectal resection; the other 8 are currently under follow-up management. Over the follow-up period of 30.6 months (range 11-54 months) the recurrence rate of T1 tumors was 8.3%. TEM is a minimally invasive surgical technique that may benefit a small, specific population of patients with rectal tumors. Compared with conventional transanal resection, TEM provides superior exposure of tumors higher up in the rectum (i.e., up to 18 cm from the anal verge). The greater precision of resection combined with low morbidity (10%, relative to that of anterior resection) and short duration of hospitalization (5.5 days) make this technique a reliable and in some cases more effective surgical approach than laparotomy and low anterior resection.

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.

Factors affecting local control and survival after treatment of carcinoma of the rectum by endocavitary radiation: a retrospective study of 97 cases

PURPOSE

Endocavitary radiation therapy constitutes an alternative to surgical therapy for some early rectal carcinomas. We studied the prognostic factors for locoregional or metastatic relapse after endocavitary radiation, and their impact for therapeutic strategy.

METHODS AND MATERIALS

Our study reports the outcome of 97 patients with adenocarcinomas of the rectum treated from 1978 to 1998 by endocavitary irradiation (100 Gy), exclusive or combined with an interstitial brachytherapy boost of 20 Gy. The indications consisted mostly of polypoid, mobile tumors, less than 4 cm in diameter, and well differentiated. But the indications were extended to elderly patients, who presented with a high surgical risk or who refused mutilating surgery.

RESULTS

The mean follow-up was 82 months. One patient presented with an isolated distant metastatic relapse, and 27 patients presented with locoregional recurrence, surgically salvaged in 16 cases. Disease-free survival was 71% at 5 years and 68% at 10 years. Multifactorial analysis suggests that clinical stage T1A, well-differentiated tumors, and early and complete response are favorable prognostic factors for disease-free survival. Response to therapy is the most powerful prognostic factor for relapse.

CONCLUSION

This retrospective study confirms the efficacy of endocavitary radiotherapy combined with brachytherapy as a safe conservative treatment in well-selected patients.

Local methods of treatment of rectal cancer

Over 11 000 new cases of rectal cancer are reported in the UK each year. Recent technical advances have increased interest in local management of the disease. The introduction of screening for colorectal cancer will potentially lead to an increased number of early rectal cancers suitable for local curative treatment. In addition, as the proportion of elderly patients in the population rises, local methods of treatment of rectal cancer will become increasingly important in this group of patients with comorbid disease. A literature search was performed on Medline database for English language publications on local treatments of rectal carcinoma. Preoperative assessment, selection of patients, local therapeutic and palliative methods of treatment were evaluated. Local methods of treatment can be used for potentially curative operations for rectal cancer. Preoperative endoanal ultrasound appears to be the most useful investigation for determining depth of local invasion. Transanal endoscopic microsurgery has extended the boundaries of local surgery and permits access to the mid and upper rectum with results similar to those of conventional local techniques. Laser therapy and transanal resection provide the best form of palliation for more advanced rectal carcinomas.