Long-term follow-up of local excision and radiation therapy for invasive rectal cancer

Long-term follow-up of patients with rectal cancer managed by local excision with and without adjuvant irradiation

OBJECTIVE

The long-term outcomes of patients undergoing local excision with or without pelvic irradiation were examined to define the role of adjuvant irradiation after local excision of T1 and T2 rectal cancers.

METHODS

Ninety-nine patients with T1 or T2 rectal cancers underwent local excision with or without adjuvant irradiation at Massachusetts General Hospital and Emory University Hospital between January 1966 and January 1997. Of these, 52 patients were treated by local excision alone and 47 patients by local excision plus adjuvant irradiation. Twenty-six of these 47 patients were treated by irradiation in combination with 5-fluorouracil chemotherapy. The outcomes of these groups were compared.

RESULTS

The 5-year actuarial local control and recurrence-free survival rates were 72% and 66%, respectively, for the local excision alone group and 90% and 74%, respectively, for the adjuvant irradiation group. This improvement in outcome was evident despite the presence of a higher-risk patient population in the adjuvant irradiation group. Adverse pathologic features such as poorly differentiated histology and lymphatic or blood vessel invasion decreased local control and recurrence-free survival rates in the local excision only group. Adjuvant irradiation significantly improved 5-year outcomes in patients with high-risk pathologic features. Four cases of late local recurrence were seen at 64, 72, 86, and 91 months in the adjuvant irradiation group.

CONCLUSIONS

The authors recommend adjuvant chemoradiation for all patients undergoing local excision for T2 tumors, and for T1 tumors with high-risk pathologic features. The four cases of late local failures beyond 5 years in the adjuvant irradiation group underscores the need for careful long-term follow-up in these patients.

Outcome of local excision for locally invasive rectal carcinomas with special reference to histological features at the invasive margin

BACKGROUND

Several researchers reported promising results that local excision with or without postoperative chemo-radiation therapy is an alternative approach for sphincter preservation in patients with locally invasive rectal carcinomas. However, indications and long-term results have not yet been determined.

METHODS

Demographic and pathological characteristics of eight patients with locally invasive tumors undergoing initially local excision were reviewed with reference to histological features at the invasive margin.

RESULTS

All the tumors were well differentiated adenocarcinomas. In all but two tumors, the invasion was limited within the proper muscle layer. Radiation therapy was given preoperatively in one patient and postoperatively in two patients. Additional bowel resection was not attempted in these three cases. Among the remaining five patients, two received additional bowel resection with lymph node dissection. No lymph node metastasis was observed in these two patients. During the average follow-up period of 55 months, three patients had regional lymph node metastases at 7, 36 and 72 months, respectively. Another patient had regional lymph node and distant metastases at 5 months. Three out of five patients with moderate to severe grade of dedifferentiated histology at the invasive margin (H-inv) had regional lymph node metastases. On the other hand, one out of three patients with mild H-inv had lymph node metastases.

CONCLUSIONS

H-inv may be useful as a clinical predictor of lymph node metastasis. However, more experience is needed to confirm the usefulness of H-inv in selecting invasive rectal cancer patients in whom local excision is safe and appropriate.

Transanal treatment of rectal cancer: ablative methods and open resection

Conservative surgical techniques are an alternative to radical surgery for selected patients with rectal carcinoma. The goals of conservative management are to select patients with low risk for nodal metastases and achieve local tumor control while preserving anal sphincter function. Patient selection is critical to achieve this outcome because properly selected patients can obtain results comparable to radical surgery. Selection is based on preoperative histologic characteristics and endorectal ultrasonography. Predictors of pelvic lymph node metastasis risk include tumor grade, depth of penetration, mucinous features, and vascular and lymphatic invasion. Endorectal ultrasound (ERUS) is important in accurately staging the lesion by identifying both depth of invasion and presumptive nodal status. The options for local therapy reviewed include techniques of full-thickness local excision and ablative procedures including endocavitary irradiation, electrocoagulation, and laser therapy. The techniques of full-thickness transanal excision and endocavitary irradiation are described with results from the University of Minnesota experience.

Transanal local excision of selected low rectal cancers

BACKGROUND

To determine if transanal local excision (TALE) of selected early low rectal cancer is an effective alternative to more radical resection and to determine the need for adjuvant radiotherapy in these patients.

METHODS

A retrospective analysis of all 47 cases referred for consideration of radiotherapy after TALE for low rectal cancer.

RESULTS

Indications for TALE were elective, 32; concurrent medical problems, 11; and refusal of radical resection, 4. Median follow-up was 52 months. Local recurrence occurred in 7 of 27 T1 cases, 5 of 17 T2, and 2 of 3 T3. Three of 23 irradiated patients developed local recurrence, compared with 11 of 24 unirradiated (P = 0.023). Of 28 cases with favorable histological features, 1 of 13 irradiated patients developed local recurrence, compared with 4 of 16 unirradiated (P = 0.22). Seven patients had salvage resection, and 3 of these are alive with no evidence of disease at 21, 39, and 71 months postsalvage. Recurrence-free survival at 5 years was 81 % in the irradiated patients and 52% in the unirradiated (P = 0.025).

CONCLUSIONS

Transanal local excision of selected low rectal cancers, combined with adjuvant radiotherapy, results in a low recurrence rate and is, therefore, an effective alternative to more radical resection.

Clinical and molecular prognostic factors in sphincter-preserving surgery for rectal cancer

As many as a third of patients with rectal cancers may be candidates for sphincter preservation surgery. The goal of the conservative management of adenocarcinoma of the distal rectum is to preserve rectal sphincter function without sacrificing local tumor control. To achieve this goal, a combined modality approach is necessary because multimodality therapy for more advanced disease has improved both local control and survival. Candidates for local excision are those with adenocarcinomas with a maximal diameter of less than 4 cm, mobile, and not poorly differentiated or mucinous and within 10 cm of the anal verge--usually within 6 cm. These criteria should be defined objectively by biopsy combined with state-of-the-art endorectal imaging. Newer molecular markers that are associated with prognosis and response to therapy may also be important for assessing prognosis, probability of local recurrence, and whether conservative treatment is appropriate. Patients with T0-3 N0 lesions meeting these standard clinicopathologic criteria have been treated successfully with wide local excision combined with chemotherapy and radiotherapy. Patients with larger or more advanced lesions may undergo low anterior resection with coloanal anastomosis. After resection, radiotherapy to at least 45 to 50 Gy is delivered to the pelvis and tumor bed often with concomitant chemotherapy. The overall rate of local failure in prospective single-institution trials in which local excision is performed with postoperative chemoradiotherapy has been 5% for T1 lesions, 7% for T2 lesions and 24% for T3 lesions. Although single-institution studies have supported the concept of conservative therapy, the safety and efficacy of this approach must still be confirmed in a multicenter, prospective trial, such as that underway in several of the cooperative oncology groups, before it may be considered a standard of practice.

Sphincter preservation in rectal cancer. Local excision followed by postoperative radiation therapy

The management of distal rectal cancer is in evolution. Although abdominoperineal resection has been long regarded as the definitive treatment of distal rectal cancer, it is associated with significant morbidity--loss of anorectal function with a permanent colostomy and a high incidence of sexual and genitourinary dysfunction. To overcome these limitations, innovative efforts are underway studying the feasibility and efficacy of a variety of sphincter-preserving operations, usually in combination with radiation therapy and chemotherapy. Local excision procedures with adjuvant therapy represent one such treatment strategy that attempts to optimize local control and survival with preservation of sphincter integrity. This article summarizes the current role of local excision and postoperative irradiation and chemotherapy for patients with carcinoma of the rectum.

Sphincter preservation in rectal cancer. Surgical considerations for local excision

The principles involved in selecting patients for local excision of rectal cancers, as well as the various techniques and principles for local resection, are detailed in this article. The assessment of the current role of this technique awaits further maturation of data from phase II clinical trials. The addition of chemotherapy and radiation therapy may allow treatment of more advanced rectal cancers by these techniques.

Results of local excision followed by postoperative radiation therapy for rectal cancer

There is increasing interest in the use of local excision and postoperative radiation therapy (RT) as a sphincter-sparing approach for selected rectal cancers. The data suggest that this treatment approach should be limited to patients with either T1 tumors with adverse pathologic factors or T2 tumors. Transmural (T3) tumors have a 25% local recurrence rate with this technique and are treated more effectively with standard surgery and pre- or postoperative therapy. The results of local excision and postoperative RT are encouraging, however, more experience is needed to determine if this approach will have similar local control and survival rates as standard surgery.

Sphincter preservation therapy for distal rectal carcinoma: a review

BACKGROUND

There has been increasing interest in the use of sphincter-preserving therapy for patients with distal rectal carcinomas. The outcomes of conservative treatments for early stage rectal carcinoma appear to be comparable to that achieved with abdominoperineal resection.

METHODS

Retrospective and prospective clinical series of patients with distal rectal carcinoma treated by local excision alone, local excision with postoperative adjuvant therapy, preoperative radiation followed by local excision, or radical circumferential sphincter-sparing surgeries were reviewed. The local control rates, salvage rates, and treatment complications in patients treated by these various methods were examined.

RESULTS

Patients with T1 distal rectal carcinoma with favorable clinical and histopathologic characteristics treated with local excision alone had a local control rate of greater than 90% in most series. Postoperative chemoradiation improved local control for those with T1 disease with unfavorable characteristics, or those with T2 disease. Most T3 patients had failure rates of greater than 30% despite adjuvant local and systemic therapy. With high dose preoperative radiation, approximately 80% of patients with locally advanced or unresectable tumors were able to undergo sphincter-preservation treatment.

CONCLUSIONS

Patients with favorable T1 rectal carcinoma are likely to be adequately treated with local excision alone. Patients with T1 disease with unfavorable characteristics as well as T2 patients will benefit from postoperative chemoradiation. The use of local therapy in T3 patients needs to be carefully considered because these patients are at relatively high risk for local recurrence despite adjuvant therapy. Preoperative radiation followed by either local excision or radical circumferential sphincter-sparing resections appears promising in allowing sphincter preservation in patients with locally advanced tumors.