Long-Term Results of Local Excision with and Without Chemoradiation for Adenocarcinoma of the Rectum

Executive Summary of the American Radium Society Appropriate Use Criteria for Local Excision in Rectal Cancer

The goal of treatment for early stage rectal cancer is to optimize oncologic outcome while minimizing effect of treatment on quality of life. The standard of care treatment for most early rectal cancers is radical surgery alone. Given the morbidity associated with radical surgery, local excision for early rectal cancers has been explored as an alternative approach associated with lower rates of morbidity. The American Radium Society Appropriate Use Criteria presented in this manuscript are evidence-based guidelines for the use of local excision in early stage rectal cancer that include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) used by a multidisciplinary expert panel to rate the appropriateness of imaging and treatment procedures. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. These guidelines are intended for the use of all practitioners and patients who desire information regarding the use of local excision in rectal cancer.

ACR Appropriateness Criteria® Local Excision in Early Stage Rectal Cancer

Low anterior resection or abdominoperineal resection are considered standard treatments for early rectal cancer but may be associated with morbidity in selected patients who are candidates for early distal lesions amenable to local excision (LE). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. The panel recognizes the importance of accurate staging to identify patients who may be candidates for a LE approach. Patients who may be candidates for LE alone include those with small, low-lying T1 tumors, without adverse pathologic features. Several surgical approaches can be utilized for LE however none include lymph node evaluation. Adjuvant radiation±chemotherapy may be warranted depending on the risk of nodal metastases. Patients with high-risk T1 tumors, T2 tumors not amenable to radical surgery may also benefit from adjuvant treatment; however, patients with positive margins or T3 lesions should be offered abdominoperineal resection or low anterior resection. Neoadjuvant radiation±chemotherapy followed by LE in higher risk patients results in excellent local control, but it is not clear if this approach reduces recurrence rates over surgery alone.

Lymphatic drainage of the rectum, preoperative assessment and its relevance to malignant polyp and rectal cancer management

SUMMARY The importance of lymph node metastasis in rectal cancer is well recognized with regards to prognosis, staging and treatment. Accurate staging is particularly important where neoadjuvant treatment has been shown to downsize and downstage locally advanced tumors. Vascular invasion, poor differentiation and increasing depth of invasion are related to a higher risk of lymph node metastasis in early cancers while advanced, poorly differentiated and low rectal cancers are more likely to have lateral pelvic sidewall nodal involvement. Nodal staging is crucial in the management of malignant rectal polyps, as is the deferral of surgery in patients who have a complete clinical and radiological response to chemoradiotherapy. In all of these situations nodal staging is vital and warrants ongoing evaluation to improve its accuracy.

The indication and surgical results of local excision following radiotherapy for low rectal cancer

AIM

Radical surgery of rectal cancer is associated with significant morbidity, and some patients with low-lying lesions must accept a permanent colostomy. The objective of this study was to evaluate the outcome of local excision followed by adjuvant radiotherapy for rectal cancer for curative purposes.

METHOD

One hundred and seven patients with rectal carcinoma performed with local excision were analysed retrospectively.

RESULTS

The procedures of local excision were trans-anal resection in 83 patients, trans-sacral resection in 16, trans-sphincteric local resection in five, and trans-vaginal resection in three. The overall disease-free survival rate was 80.4% (86/107), including 90.0% (54/60) for T1 and 72.3% (34/47) for T2 tumours, respectively. Eighty-two of 107 patients underwent adjuvant postoperative radiotherapy after local excision, and 25 did not, and the DFS rates between radiation and nonradiation group were significantly different for T2 [81.6% (31/38) vs 33.3% (3/9), P < 0.05], but not for T1 tumours (90.9%vs 87.5%, P > 0.05). The rates of local recurrence and distant metastasis were 13.1% (14/107) and 4.7% (5/106), respectively, and the median time to relapse was 15 months (range: 10-53) for local recurrence and 30 months (21-65) for distant recurrence. The risk factors for local recurrence were large tumour (≥3 cm), poorly differentiated adenocarcinoma and T2 tumour.

CONCLUSIONS

Local excision followed adjuvant radiotherapy is an alternative and feasible technique for small T1 rectal cancer in selected cases.

ACR Appropriateness Criteria: local excision in early-stage rectal cancer

Low anterior resection or abdominoperineal resection is considered standard treatment for early rectal cancer. These procedures, however, carry a risk of morbidity and mortality that may not be warranted for early distal lesions, which may be treated with local excision. Emerging data has investigated the efficacy of local excision in patients with early stage rectal cancers. An expert panel designated by the American College of Radiology has reviewed supporting data, from a few prospective multi-institutional trials and a number of single-institution, retrospective reviews. The consensus recognizes the importance of accurate staging to identify patients who may be candidates for a local excision approach. Optimal candidates for local excision alone include small, low-lying T1 tumors, without adverse pathologic features. A number of procedures may be safely used including transanal, posterior trans-sphincteric, posterior proctotomy, transanal excision, or transanal microsurgery. It is important to note that none of these include lymph node evaluation, and depending on the risk of lymph node metastases, adjuvant radiation with or without chemotherapy may be warranted. Patients with positive margins or T3 lesions are at high risk of local recurrence and should be offered immediate APR or LAR. However, patients with high-risk T1 tumors, T2 tumors, or those who are not amenable to more radical surgery may benefit from adjuvant treatment. Data have also reported excellent local control rates for neoadjuvant radiation +/- chemotherapy followed by local excision in higher risk patients, but it is not yet clear if this approach reduces recurrence rates over surgery alone.

Can depth of tumour invasion predict lymph node positivity in patients undergoing resection for early rectal cancer? A comparative study between T1 and T2 cancers

OBJECTIVE

The present study investigated the risk of lymph node metastasis according to the depth of tumour invasion in patients undergoing resection for rectal cancer.

METHOD

The histology of patients undergoing oncological resection with regional lymphadenectomy for rectal cancer at St Marks Hospital from 1971 to 1996 was reviewed. Of the total number of 1549 patients, 303 patients with T(1) or T(2) rectal cancers were selected. The tumour type, grade, evidence of vascular invasion, depth of submucosal invasion (classed into 'sm1-3') were evaluated as potential predictors of lymph node positivity using univariate and multi-level logistic regression analysis.

RESULTS

Tumour stage was classified as T(1) in 55 (18.2%) and T(2) in 248 (81.2%) patients. The incidence of lymph node metastasis in the T(1) group was 12.7% (7/55), compared to 19% (47/247) in the T(2) group. The node positive and negative groups were similar with regard to patient demographics, although the former contained a significantly higher number of poorly differentiated (P = 0.001) and extramural vascular invasion tumours (P = 0.002). There was no significant difference in the number of patients with sm1-3, or T(2) tumour depths within the lymph node positive and negative groups. On multivariate analysis the presence of extramural vascular invasion (odds ratio = 10.0) and tumour grade (odds ratio for poorly vs well-differentiated = 11.7) were independent predictors of lymph node metastasis.

CONCLUSION

Whilst the degree of vascular invasion and poor differentiation of rectal tumours were significant risk factors for lymph node metastasis, depth of submucosal invasion was not. This has important implications for patients with superficial early rectal cancers in whom local excision is being considered.

Accurate staging, selective preoperative therapy and optimal surgery improves outcome in rectal cancer: a review of the recent evidence

OBJECTIVE

The current optimal management of locally advanced rectal cancer has evolved from surgical excision followed by postoperative therapy in patients with involved margins, to an increasing use of a preoperative strategy to 'down-stage and/or down-size' the tumour. This treatment strategy is based on the relationship of the tumour to the mesorectal fascia, the optimal surgical circumferential resection margin that can be achieved by total mesorectal excision. We have reviewed the recent evidence for this strategy.

METHOD

An electronic literature search using PubMed identified articles on the subject of rectal cancer between January 2000 and December 2005. The search was limited to English language publications with secondary references obtained from key articles. Articles published in high impact factor journals formed the basis of the review, together with articles related to national programmes on the management of rectal cancer. This does lead to a selection bias, particularly as the articles identified had a European bias.

CONCLUSION

The UK NHS Cancer Plan has outlined the basis for the multidisciplinary team (MDT) management of rectal cancer. Advances in preoperative assessment through accurate staging and the recognition of the importance of the relationship of the tumour to the mesorectal fascia has allowed the selection of patients for a preoperative strategy to down-size/down-stage the tumour if this fascial layer is involved or threatened. Improvements in the quality of surgical resection through the acceptance of the principle of total mesorectal excision have ensured that optimal surgery remains the cornerstone to successful treatment. Further refinements of the MDT process strive to improve outcome. Accurate radiological staging, optimal surgery and detailed histopathological assessment together with consideration of a preoperative neoadjuvant strategy should now form the basis for current treatment and future research in rectal cancer.