A selective sandwich technique of adjuvant radiotherapy in the treatment of rectal cancer: a preliminary experience

Low rectal cancer: impact of radiation and chemotherapy on surgical treatment

INTRODUCTION

The aim of this study was to evaluate the impact of combined radiotherapy and chemotherapy (leucovorin and 5-fluorouracil) on the treatment of potentially resectable low rectal cancer using the following end points: 1) toxicity of this combined modality regimen; 2) clinical and pathologic response rate and local control; 3) down-staging of the tumor and its influence on the number of sphincter-saving operations; 4) disease-free interval, patterns of relapse, and overall survival.

METHODS

From 1991 to 1996, 118 patients with potentially resectable cases of histologically proven adenocarcinoma and no distant metastases were enrolled into this protocol. All patients were evaluated by clinical and proctologic examination, abdominal computed tomography, transrectal ultrasound, and chest radiography. Therapy consisted of 5,040 cGy (6 weeks) and concurrent leucovorin (20/mg/m2/day) with bolus doses of 5-fluorouracil administered intravenously at 425 mg/m2/day for three consecutive days on the first and last three days of radiation therapy. After two months, all patients underwent repeat evaluation and biopsy of any suspected residual lesions or scar tissue.

RESULTS

Median follow-up was 36 months. Toxicity of chemotherapy regimen was minimum. Thirty-six patients (30.5 percent) were classified as being complete responders. In six of these patients, complete response was confirmed by the absence of tumor in the surgical specimens (3 abdominoperineal resections and 3 proctosigmoidectomies with coloanal anastomosis). In the remaining 30 patients, confirmation of a complete response was made by the absence of symptoms, negative findings on physical examination, and biopsy, transrectal ultrasound, and pelvic computed tomographic test results during follow-up. Eighty-two patients (69.4 percent) were considered incomplete responders. Residual lesions had already been identified during the first examination in 74 patients. In the other eight patients, residual tumor was only identified after 3 to 14 months. All patients underwent surgical treatment, except one patient who refused surgery. Eighty-seven patients underwent 90 surgical procedures: local excision, 9; coloanal anastomosis, 36; abdominoperineal resection, 4; Hartmann's procedure, 1. Isolated local recurrences occurred in five patients (4.3 percent) and combined local and distant failure in eight patients (6.7 percent). Ninety patients are alive and disease-free at a median follow-up of 36 months.

CONCLUSIONS

Combined up-front chemoradiotherapy was associated with tolerable and acceptable side effects. A significant number of patients had complete disappearance of their tumors (30.5 percent) within a median follow-up of 36 months. This regimen spared 26.2 percent of patients from surgical treatment and allowed sphincter-saving management in 38.1 percent of patients who may have required abdominoperineal resection. Preliminary results of this trial suggests a reduction in the number of local recurrences and reinforces the concept that infiltrative low rectal cancer may be initially treated by chemoradiotherapy.

Preoperative radiation therapy and sphincter preservation by the combined abdominotranssacral technique for selected rectal cancers

In an attempt to reduce the incidence of local recurrence and maintain normal sphincteric function in selected patients treated for rectal cancer, a clinical experience using full dose preoperative radiation therapy and a combined abdominotranssacral technique was begun in 1976. The first 24 of 55 patients treated have now been followed for 20 to 84 months, the median follow-up period being 39 months; sufficient data related to their clinical courses are available for analysis. Cancers were selected on the basis of unfavorability and location in the rectum (3- and 7-cm levels). Clinical staging of the disease was accurate and allowed selection and treatment of only those cancers considered unfavorable (stages B2 and C), thereby avoiding unnecessary radiation of more favorable tumors. One anastomotic disruption required reconstruction, but perioperative complications were otherwise unremarkable. Local recurrence in this group of highly unfavorable cancers has not been observed. Normal and sphincteric function has been preserved in each instance. Preliminary results indicate that full dose preoperative radiation therapy for selected unfavorable and low level cancers permits safe and effective sphincter preservation surgery by the combined abdominotranssacral technique. When proper precautionary measures are observed, surgery can be conducted with the expectation of normal continence and significant reduction in local recurrence.

Rectal cancer: extent of disease and radiotherapeutic effects by computed tomography

The CT scans of 54 patients with carcinoma of the rectum were studied in an attempt to assess the value of computed tomography in the initial evaluation and therapeutic management of these patients. Thirty-five of the examined patients received full dose preoperative radiation therapy for sphincter preservation purposes, and had two or more computed tomography studies to delineate the progression of the disease and the response to radiotherapy. In 70% of these patients, changes in tumor size were demonstrated. Various aspects in the CT diagnosis of the primary or recurrent tumor extent, distant metastatic spread or involvement of surrounding tissues are discussed.

Adjuvant postoperative radiation therapy for Dukes C adenocarcinoma of the rectum

This study was designed to explore the effects of adjuvant postoperative radiation therapy on the course and survival of patients with Dukes C adenocarcinoma of the rectum. Moderate dose radiotherapy was offered to 64 patients. Twenty-four accepted and were treated, while the remainder refused. With a mean follow-up of 32.3 months, the overall survival rate was 63% (40/64) and the mean disease-free survival rate at the time of this report was 45%. The following variables were analyzed separately: operative procedure, distance of the tumor from the anal verge, tumor size, and transmural, vascular, lymphatic and perineural invasion of tumor. The most significant differences between irradiated and non-irradiated patients were found in the group of patients whose lesions were 6 cm or less from the anal verge. Of the 19 such patients with an average follow-up of 36.4 months, ten patients were irradiated and nine were not irradiated. The irradiated group had a 90% (9/10) survival rate and 70% (7/10) of them were disease free; the non-irradiated group had a 44% (4/9) survival rate and 22% (2/9) of them disease free. It is concluded that patients with adenocarcinoma of the rectum metastatic to lymph nodes, whose lesions' lower border is measured 6 cm or less from the anal verge, benefit significantly from adjuvant postoperative radiotherapy.

Adjuvant radiotherapy with selective sandwich technique in treatment of rectal cancer: results of a continuing study

Sixty-two patients with carcinoma of the rectum were treated with "selective sandwich" adjuvant radiotherapy in a pilot study which began in September 1976 at Thomas Jefferson University Hospital. All patients received 500 rads preoperative irradiation on the day of or day preceding surgery. Following surgery, the lesions were staged pathologically according to Astler-Coller's modification of Dukes' staging. Patients with poor prognostic characteristics (Stages B2, C1, and C2) were treated with aggressive postoperative pelvic irradiation (4500 rads in five weeks). All 62 patients received the single preoperative dose of 500 rads. Forty-four patients underwent abdominoperineal resection, four patients, a low anterior resection, ten patients, a combined abdominotranssacral resection, and four patients found to have liver metastasis at laparotomy had colostomy followed by palliative therapy. Twenty-one patients found to have early disease (Stages A or B1) were given no further therapy. Of 37 patients with Stages B2 or C disease, 21 received postoperative irradiation. Follow-up ranged from 6 months to 36 months, with a median of 18 months. Of patients with Stage A or B1 disease, one patient has died with metastasis. Two of 21 patients receiving postoperative irradiation have developed metastatic disease; neither has failed in the pelvis. Of 16 patients who did not receive postoperative irradiation, three have had metastasis to the pelvis and two others have developed distant metastasis.

Adjuvant "sandwich" radiation therapy for bladder cancer

Preliminary results of a study using a new concept of adjuvant "sandwich" radiotherapy in bladder cancer are presented. In this approach low-dose preoperative irradiation (500 rads) is delivered prior to cystectomy, and then on the basis of histopathologic staging patients with superficial tumors (Stage A and B) are followed with no further treatment; patients with deeply invasive tumors (Stage B, Grade III or IV, B2 or C) are treated with high-dose postoperative irradiation (4,500 rads in five weeks); and patients with advanced or metastatic disease (Stage D) are treated palliatively. Eighteen patients were treated with this approach, and all patients have been followed for at least one year. Sixteen (89 per cent) are alive with no evidence of tumor. One patient died of distant metastasis, and 1 patient died of peritonitis without evidence of disease. Since recurrence is known to develop in 50 per cent of patients within the first year after treatment, the low rate of failure obtained using this approach of adjuvant "sandwich" radiotherapy with a minimum follow-up of one year appears to be promising. This approach ideally balances the risk versus benefit ratio of adjuvant therapy sparing patients with superficial tumors from unnecessary treatment while treating patients with more advanced disease aggressively.