Is anterior resection of the rectosigmoid safe after preoperative radiation?

Effects of β-glucan on colon anastomotic healing in rats given preoperative irradiation

BACKGROUND

Radiation therapy is an essential therapeutic modality in the management of a wide variety of tumors. We aimed to investigate the short-term effects of pelvic irradiation on the healing of colon anastomoses and to determine the potential protective effects of β-glucan in this situation.

MATERIAL AND METHODS

Sixty Wistar albino rats were randomized into three experimental groups: a control group (n = 20), an irradiation (IR) group (n = 20), and an irradiation+β-glucan (IR+β-glucan) group (n = 20). Only segmental colonic resection and anastomosis were performed on the control group. The IR group underwent the same surgical procedure as the control group 5 days after pelvic irradiation. In the IR+β-glucan group, the same procedure was applied as in the IR group after β-glucan administration. The groups were subdivided into subgroups according to the date of euthanasia (third [n = 10] or seventh [n = 10] postoperative [PO] day), and anastomotic colonic segments were resected to evaluate bursting pressures and biochemical and histopathological parameters.

RESULTS

Bursting pressure values were significantly lower in the IR group (p < .001). Malondialdehyde (MDA) levels were significantly higher in the IR group, whereas β-glucan significantly decreased MDA levels on the third PO day (p < .001). Granulation tissue formation scores were significantly lower in the IR+β-glucan group compared with the control group and the IR group (p < .001).

CONCLUSIONS

The results of this study indicate that irradiation has negative effects on the early healing of colon anastomoses. The administration of β-glucan ameliorates these unfavorable effects by altering bursting pressures and biochemical parameters.

Preoperative cobalt60 irradiation delays the healing of rectal anastomoses in rats

The healing of colorectal anastomoses after irradiation therapy continues to be a major concern. The authors evaluated the healing of rectal anastomoses in a rat model after a preoperative 500-cGy dose of cobalt60 irradiation. Thirty-six male Wistar rats were divided into two equal groups: control (group A), and irradiation group (group B). Group B received a single 500-cGy dose of irradiation, and a rectal resection and end-to-end anastomosis was performed in both groups on the 7th day after irradiation. Parameters of the healing process included bursting pressure and collagen content on the 5th, 7th, and 14th days after surgery. In the irradiation group, the mean bursting pressure on the 5th, 7th, and 14th days was 116, 218, and 273 mmHg, respectively. The collagen content assessed by histomorphometry was 9.0, 20.8, and 32%, respectively. In contrast, the control group had a mean bursting pressure of 175, 225 and 263 mmHg, and a collagen content of 17.8, 28.1, and 32.1%, respectively. The adverse effect of irradiation on healing was detectable only on the 5th postoperative day, as demonstrated by lower bursting pressure (P < 0.013) and collagen content (P < 0.008). However, there was no failure of anastomotic healing such as leakage or dehiscence due to irradiation. We conclude that a single preoperative 500-cGy dose of irradiation delays the healing of rectal anastomosis in rats.

Preoperative combined radiotherapy and chemotherapy for rectal cancer does not affect early postoperative morbidity and mortality in low anterior resection

PURPOSE

It is not yet known whether preoperative combined radiotherapy and chemotherapy for rectal cancer affects postoperative mortality and morbidity. We therefore evaluated early postoperative complications in patients given adjuvant radiotherapy and chemotherapy before surgery for middle and lower rectal adenocarcinoma.

METHODS

Between 1994 and 1998, 41 patients underwent combined preoperative pelvic radiotherapy and chemotherapy at our institution. Most of the patients had 45 Gy (1.8 Gy/day/25 fractions) during five weeks plus 5-fluorouracil (350 mg/m2/day) and low-dose leucovorin (10 mg/m2/day) bolus on Days 1 to 5 and 29 to 33. Surgery was performed four to six weeks after completion of adjuvant therapy. The 41 patients (Group A) were retrospectively compared with 30 patients (Group B) who, in the same period, underwent surgery without preoperative adjuvant therapy. The groups were homogeneous for age, gender, preoperative risk factors, operating surgeon, and pathologic stage. Mean distance of the tumor from the anal verge was shorter in Group A patients (P = 0.031).

RESULTS

There were seven major postoperative complications in each group. No significant differences were found between the groups for morbidity and mortality rates. Considering all patients, more postoperative complications were found in patients scored as American Society of Anesthesiologists 3, in those with a preoperative hemoglobin value < 10 g/dl, and in those without a diverting stoma (P = 0.0048, P = 0.0453, and P = 0.0033, respectively). At multivariate analysis, independent predictors of major complications were American Society of Anesthesiologists score (relative risk, 343; P = 0.022), diverting stoma (relative risk, 159; P = 0.010), type of surgical procedure (relative risk, 38.9; P = 0.048), preoperative hemoglobin value (relative risk, 9.72; P = 0.061), and intraoperative blood loss (relative risk, 1; P = 0.027). In Group A patients, the absence of diverting stomas was associated with major postoperative complications (P = 0.0307), and independent predictors of major complications were American Society of Anesthesiologists score (relative risk, 56; P = 0.111) and absence of a diverting stoma (relative risk, 22.42; P = 0.222).

CONCLUSION

Early postoperative complications after resection for middle and lower rectal adenocarcinoma are affected by intraoperative and preoperative risk factors and absence diverting stomas, but not by preoperative adjuvant therapy.

Preoperative radiotherapy for rectal cancer: implications for surgeons, pathologists and radiologists

BACKGROUND

Over 10,000 new cases of rectal cancer are reported in the UK each year and adjuvant treatments, such as preoperative radiotherapy, are now being used almost routinely.

METHODS

A literature review was performed on the Medline database for English language publications on preoperative radiotherapy and rectal cancer. The radioresponsiveness of rectal cancer, tumour downstaging, radiological staging of irradiated rectal cancer, effects of radiotherapy on anastomotic integrity, anorectal and genitourinary function, the role of preoperative radiotherapy in local excision of rectal cancer, and the histological changes peculiar to radiotherapy were evaluated.

RESULTS AND CONCLUSION

Following preoperative radiotherapy, rectal cancer may be downstaged or, occasionally, eradicated histologically. Rectal cancer can now be staged accurately before operation, but this is significantly less reliable following irradiation. The pathological specimen must be examined thoroughly before a tumour can be reported to have been eradicated, especially as unique histological changes are produced by radiotherapy. There is no evidence to suggest that preoperative radiotherapy adversely affects anastomotic integrity. It appears that preoperative radiotherapy has some adverse affects on long-term anorectal dysfunction, but this must not distract from its main objectives in rectal cancer, namely reduced local recurrence rates and improved overall survival.

Brachytherapy in the treatment of colorectal malignancies

By precisely delivering a single, high dose fraction of intraoperative radiation under direct visualization while excluding surrounding normal dose-limiting tissues, IORT has improved the therapeutic ratio of tumor control to morbidity. Both IOERT and HDR-IORT represent effective means of delivering this therapy, and either may be chosen with equal confidence, depending upon the facilities available, physician preference, and the clinical situation. The extraordinary efforts often required in the management of these highly selected patients is justified by the improvement achieved in the enhanced local control rates and increased cure rates. Preoperative chemoradiation therapy followed by gross total resection and IORT affords the patient the highest likelihood of local control and survival. The importance of aggressive surgery in achieving gross total resection with pathologically negative margins is reflected by the dramatic correlation reported between margin status and local control. The high complication rate associated with this multidisciplinary therapy is, no doubt, multifactorial and may be attributed to the advanced disease state at presentation and the intensive multidisciplinary treatments administered. In an effort to eradicate disease and prolong survival, many consider these elevated complication rates acceptable, particularly in light of the complexity of these cases, as well as the morbidity and mortality associated with persistent disease in the pelvis.

Use of preoperative ultrasound staging for treatment of rectal cancer

INTRODUCTION

Transrectal ultrasound is the standard method for preoperative staging of rectal cancer. This study reviews the accuracy of transrectal ultrasound staging for T3 disease and its use in the selection of patients for neoadjuvant chemoradiation.

METHODS

One hundred seventeen patients underwent preoperative transrectal ultrasound evaluation for rectal cancer. Accuracy of transrectal ultrasound was evaluated among 70 patients not receiving preoperative chemoradiation. Forty-seven patients received neoadjuvant chemoradiation based on transrectal ultrasound results. Tumor downstaging and early recurrence were evaluated among 45 of 47 patients receiving neoadjuvant chemoradiation.

RESULTS

Among 70 nonirradiated patients, 19 were pathologic Stage pT3. Transrectal ultrasound correctly identified 18 of 19 patients with Stage pT3 (sensitivity, 94.7 percent). Transrectal ultrasound correctly identified 44 of 51 patients with less than pT3 disease (specificity, 86.3 percent). After preoperative chemoradiation in 45 patients with ultrasound Stage uT3 or uT4 tumors, 56 percent of them experienced a reduction in T stage. Residual nodal disease was found in 31 percent of patients. A complete pathologic response with no residual disease at operation was observed in 22 percent of patients. During a median follow-up period of 21 months after diagnosis, seven patients experienced a recurrence of their disease at a median of 12 months after diagnosis. Five of seven patients with recurrence were among a subgroup of ten patients who both failed to downstage T and had residual nodal disease at operation.

CONCLUSION

Transrectal ultrasound is an accurate modality for selecting patients for neoadjuvant treatment. Preoperative chemoradiation produced downstaging in 56 percent of patients. Factors related to early recurrence included residual nodal disease and failure to downstage T after neoadjuvant chemoradiation.

Surgical adjuvant therapy for rectal cancer: present options

Recent advances have been made with the publication of the results of GITSG and NCCTG trials, which demonstrated the significant improvement of survival by combined postoperative radiochemotherapy protocols for Stage II and III rectal cancer. These data show that systemic chemotherapy has a decisive role to play in this policy. Some of the advantages of preoperative irradiation compared with postoperative radiation therapy consist of the improvement of resectability of T4 tumors and the anal preservation for low-lying cancers. These data suggest that preoperative chemoradiotherapy should be applied not only to T4 tumors but also to all T3 tumors even when the transrectal extension is limited. The most usual protocol combines 5-fluorouracil (300-350 mg/m2/day) and leucovorin (20 mg/m2/day) for 5 days, followed by radiation therapy (30-35 Gy in 10 fractions within 12-15 days), with surgery taking place 4 to 8 weeks later, after the tumor has been restaged. Systemic therapy is continued for four more months. T2 cancers should not be excluded from the benefit of preoperative irradiation.

Reirradiation for rectal cancer and surgical resection after ultra high doses

PURPOSE

Local recurrence of rectal cancer following high-dose pelvic radiation presents a difficult management challenge. Conventional wisdom suggests that reirradiation should be avoided and radical pelvic surgery is hazardous after ultra high-dose radiation.

METHODS AND MATERIALS

In a unique Phase I/II pilot study, 32 patients with recurrent rectal cancers following previous pelvic radiation underwent planned reirradiation to the pelvis. Initial radiation doses had ranged from 30-64.87 Gy (median dose 45 Gy). Seventeen patients underwent reirradiation followed by radical resection. Fifteen patients were reirradiated for palliative relief of symptoms. Treatment techniques consisted of two lateral fields (7 x 7 to 12 x 10 cm) encompassing the tumor with 2 cm margins. Reirradiation doses ranged from 19.80-47.66 Gy, (median 34.2 Gy). Patients also received concurrent low-dose continuous infusion chemotherapy, (5-FU 200-300 mg/day). Total cumulative radiation doses ranged from 70.6 to 111.6 Gy.

RESULTS

Treatment was well tolerated. Four patients had radiation interrupted/discontinued for diarrhea or leukopenia. Follow-up ranges from 6 months to 36 months. No late sequelae of radiation have been observed to date. Seventeen patients underwent surgical exploration 6-8 weeks following reirradiation. Two patients had extensive disease and were not resected. Fifteen patients underwent radical resection of residual tumor (4 posterior exenterations, 6 APR, 3 transanal abdominal transanal proctocolectomy with coloanal anastomosis (TAATA), and 2 LAR). No patients died postoperatively. No excessive edema, hemorrhage, or adhesions were observed. Two patients developed pelvic abscess and one developed a coloanal stricture. Eleven of 15 resected patients are alive from 6 to 36 months with a 2-year survival of 66%. Of the patients treated palliatively, symptomatic relief was observed in 13/15 patients. No objective complete response was observed, but 6/15 patients had measurable partial response. Median survival in this group was 14 months.

CONCLUSION

Based on this experience, we believe that in selected patients radical surgical resection after cumulative ultra high doses (70-90 Gy) of radiation can be performed safely. A viable anastomosis is also possible in spite of these high doses. Planned reirradiation for palliative relief of symptoms can be effective without unusual risks of complication. Long-term effects of such ultra high dose radiation and surgery continue to be monitored.

Radiation therapy for colorectal cancer

The role of radiation therapy in the management of colorectal cancer has become more clearly defined as the number of clinical studies has grown. It is now evident that radiation is capable of sterilizing subclinical deposits of cancer at doses tolerable by adjacent normal tissues, and to a lesser extent, these doses can control more bulky cancers. The integration of radiation and chemotherapy has already led to some improvement in survival rates in the adjuvant treatment of rectal cancer. The further development of such combinations seems likely to improve tumor control and survival rates in many stages of cancer. In the next decade, it is also likely that there will be refinement of the use of radiation through better understanding of the biology of colorectal cancer, perhaps supplemented by the development of predictive assays that can guide both the selection of patients for treatment and the choice of the most effective radiation schedule.

Adjuvant radiation therapy for colorectal cancer

BACKGROUND

Despite apparently complete resection of cancers of the rectum or colon, many patients have recurrences in the area from which their primary cancer was excised and in more distant organs. Radiation therapy has been used either alone or in combination with chemotherapy as an adjuvant to surgery to reduce the risk of recurrence.

METHODS

The literature describing the results of adjuvant radiation treatment for colorectal cancer was reviewed.

RESULTS

In randomized studies in patients with moderately advanced rectal cancers (T2-4 N0, M0 or N1-3, M0) adjuvant radiation therapy has often reduced the risk of pelvic recurrence, but has had little effect on survival rates or the risk of extrapelvic metastases. Recent reports show that combined radiation and chemotherapy can improve both disease-free survival and survival rates. Such treatment has caused only moderate toxicity in most studies. Nonrandomized studies in patients in whom small superficial rectal cancers are treated by local excision suggest that adjuvant radiation therapy reduces the risk of pelvic recurrence after this limited surgery and allows anorectal function to be preserved. Strategies similar to those developed for the treatment of rectal cancer are being studied in patients with colon cancer.

CONCLUSIONS

In moderately advanced rectal cancers, the combination of chemotherapy and radiation is more effective than radiation alone in reducing local recurrence and increasing survival rates. Additional trials are needed to improve results and to refine drug and radiation schedules. Radiation alone may be sufficient as an adjuvant treatment when combined with local excision of small rectal cancers. The role of radiation in the adjuvant treatment of colon cancer is investigational. There is a need to more accurately delineate the patients with colorectal cancer most likely to benefit from adjuvant therapy.

Rectal carcinoma. Long-term experience with moderately high-dose preoperative radiation and low anterior resection

This report updated an analysis of a 14-year experience of moderately high-dose (4500 to 5000 cGy) preoperative radiation as an adjuvant to low anterior resection of 95 cases of adenocarcinoma of the rectum. The treatment was well tolerated without treatment-related mortality and with a low incidence (5.2%) of severe complications. The local recurrence rate was 4.2%, and distant failure rate was 10.5%. At 5 years, the actuarial survival rate was 66% and the disease-free survival rate was 64%. At 10 years, the actuarial survival rate and disease-free survival rate were 52%. The authors concluded that moderately high-dose (4500 to 5000 cGy) neoadjuvant radiation in clinically resectable adenocarcinoma of the rectum in which one segment of the anastomosis was in the preoperative radiation field is a safe, effective adjuvant to low anterior resection and that it offered patients excellent local control, long-term survival, and sphincter preservation. Results could be enhanced by chemotherapy, and the authors urged well-designed prospective randomized multicenter trials to determine the most appropriate drugs, dosage, and sequencing of co-adjuvant preoperative radiation therapy and chemotherapy with surgery.

Does preoperative radiation therapy enhance the probability of local control and survival in high-risk distal rectal cancer?

One hundred forty-eight patients were treated with preoperative radiation therapy and surgery for resectable rectal adenocarcinoma at the University of Florida between 1975 and 1986. All patients had at least 5 years' follow-up; no patient was lost to follow-up. Three treatment protocols were used over the study period: 1975 to 1978, 3500 cGy in 20 fractions; 1979 to 1983, 4000 to 5000 cGy at 180 cGy per fraction; and 1984 to 1986, 3000 cGy in 10 fractions. The change was made to 3000 cGy in 10 fractions to reduce the inconvenience and expense associated with preoperative radiation therapy without sacrificing any improvement in local control or complication rates. There were no significant differences in the rates of local control, absolute survival, cause-specific survival, or complications between the three preoperative radiation therapy protocols. The results were compared for the 132 patients who underwent complete resection after preoperative radiation therapy and a series of 135 patients who underwent a complete resection alone for adenocarcinoma of the rectum at the University of Florida between 1959 and 1976. The results at 5 years, calculated by the product-limit method, for preoperative radiation therapy and surgery compared with surgery alone, respectively, were as follows: for local recurrence-free survival, 96% and 67%; for absolute survival, 66% and 40%; and for cause-specific survival, 77% and 50%. All of these differences are significant (p = 0.0001 or less). A subset of 56 patients with locally advanced lesions, based on tethering or circumferential involvement of the rectal lumen, treated with preoperative radiation therapy and surgery were compared with patients treated with surgery alone for stage B2 and C cancers. There was a significant improvement in local control and survival rates in the group irradiated before operation. There was no apparent increase in the incidence of postoperative complications in the patients irradiated before operation.

The role of intra-operative irradiation in locally advanced primary and recurrent rectal adenocarcinoma

Useful palliation can often be achieved when standard treatment approaches of external beam irradiation and chemotherapy with or without resection are used for locally advanced primary rectal malignancies. Local control and long-term survival are achieved in only 10% to 50% of patients, however, due to the limited irradiation tolerance of surrounding organs and tissues. Encouraging trends exist in separate intra-operative irradiation analyses from Massachusetts General Hospital and Mayo Clinic with regard to improvement in local control and possibly survival of locally advanced rectal lesions, warranting continued evaluation of such approaches. Disease control within the intra-operative and external irradiation field is decreased, however, when the surgeon is unable to accomplish gross total resection. Therefore it seems reasonable to consistently add 5-Fluorouracil with or without Leucovorin during external irradiation and to evaluate the use of dose modifiers, such as sensitizers or hyperthermia, in conjunction with intra-operative irradiation. Since high systemic failure rates exist with both locally advanced primary and recurrent lesions, more effective chemotherapy needs to be evaluated during external irradiation as well as after completion of such. In view of survival advantages with 5-Fluorouracil plus Leucovorin versus 5-Fluorouracil alone for metastatic disease, this regimen is currently being employed. Even with locally recurrent lesions, the aggressive multimodality approaches including intra-operative irradiation have resulted in improved local control, and long-term survival rates of 20% to 25% versus an expected 5% with conventional techniques in historical series.

Role of pre-operative irradiation for anal preservation in cancer of the low rectum

Since 1979, 157 patients with T2, T3, or T4 cancer of the lower rectum have been treated by a short course of irradiation, 30 Gy within 12 days by cobalt 60 using 120 degrees arc rotation on a sacral field, followed by a 2-month rest before surgery. The operative specimens were tumor-free in 13% of patients, Dukes' A in 40% of patients, Dukes' B in 22% of patients, and Dukes' C in 25% of patients. Three (1.9%) patients died postoperatively. At 3 years (107 patients) and 5 years (74 patients) the rates of death of local failure were 7.5% and 9.5%, respectively. The 3-year and 5-year disease-free survival were 71% and 58%. Since 1983, the surgeons took advantage of the tumor regression to carry out sphincter-saving operation in 67 patients with T2, T3, and T4 tumors of the lower third of the rectum. The proportion of patients treated by restorative surgery instead of abdominoperineal resection has grown significantly during the past 4 years, from 22% to 71%. Diverting colostomy was performed in 10 patients. Anastomotic leakages were observed in 7 patients. Of 31 patients who underwent low anterior resection and were followed 3 to 7 years (mean 4.5 years), 5 patients died of distant metastasis and 3 patients are alive after segmental hepatectomy. One patient had local recurrence which was controlled by abdominoperineal resection. The rate of 3-year disease-free survival was 77%.(ABSTRACT TRUNCATED AT 250 WORDS)

Experience with the biofragmentable anastomotic ring (BAR) in bowel preoperatively irradiated with 6000 rad

Previous studies from the authors' laboratory using the biodegradable anastomotic ring (BAR) have demonstrated the safety of this device in animals irradiated preoperatively with the equivalent of 5000 rad; sutured, stapled, and BAR anastomoses all had leak rates of 10 percent or less in this setting. This study was undertaken to assess the safety of the BAR after irradiation with the equivalent of 6000 rad. Thirteen mongrel dogs underwent preoperative irradiation to the rectum and rectosigmoid, receiving 6000 rad according to the nominal standard dose equation. After a three-week rest period, each dog underwent anterior resection of the rectosigmoid and anastomosis with the BAR. The anastomoses were evaluated for early and late healing and anastomotic leaks. The results were compared with previous data from the authors' laboratory using an identical model. Radiographic leaks were found in 7 of 10 sutured anastomoses, 8 of 10 stapled anastomoses, and 3 of 13 BAR anastomoses (P less than 0.01). Comparative clinical leaks were 5 of 10 for sutured, 5 of 10 for stapled, and 3 of 13 for BAR anastomoses. These data suggest that the BAR may offer added safety to an anastomosis after preoperative irradiation. Whether this effect is due to the atraumatic technique of placing the device, improved blood flow to the anastomotic margins, or other factors, is still underdetermined.

Conservative management of anal and rectal cancer. The role of radiation therapy

The role of irradiation in the management of anal and rectal cancer has changed during the past ten years. In small epidermoid carcinomas of the anal canal (T1 T2) irradiation is in most departments considered the primary treatment, giving a 5-year survival rate of between 60 and 80% with good sphincter preservation. Even in larger tumors, irradiation can still offer some chance of cure without colostomy. Surgery remains the basic treatment of rectal cancer but irradiation is used in association with surgery in many cases. Radiotherapy is of value in the conservative management of cancer of the rectum in three situations; In small polypoid cancers contact x-ray therapy can give local control in about 90%. In cancers of the middle rectum, preoperative external irradiation may increase the chances of restorative surgery and reduce the risk of local relapse. In inoperable patients, external radiotherapy and/or intracavitary irradiation may cure some patients with infiltrating tumors (T2 T3) without colostomy.

Cancer of the rectum--sphincter-saving operation. Stapling techniques

The techniques of restoring intestinal continuity after rectal resection for cancer have evolved throughout this century. For the most part, circular staplers have displaced the other pioneering and innovative techniques that our mentors and predecessors devised to improve the quality of life for our patients. With new technology, so also emerge new problems. Although the future likely will render many of our present techniques obsolete, for example, with refining of tissue adhesives, it is incumbent on us to recognize the limits of our present array of weapons and the limits placed on us by the biology of the tumor. About the latter, this means maintaining intellectual honesty in conducting a good cancer operation; about the former, we have to recognize that most of the pitfalls of stapling are preventable or correctable.

Clinically resectable adenocarcinoma of the rectum treated with preoperative irradiation and surgery

Seventy-four patients with clinically resectable adenocarcinoma of the rectum were treated with preoperative irradiation and surgery at the University of Florida between August 1975 and February 1982. All patients have been followed for at least five years. Between 1975 and 1978, 29 patients received 3500 cGy; thereafter the dose was increased to 4000 to 5000 cGy for the remaining 45 patients. All patients were treated at 180 cGy per fraction. Following preoperative irradiation, 65 of 74 patients (88 percent) underwent complete resection of their lesions. Compared with a series of historical controls treated with surgery alone, the local recurrence rate at five years was 5 of 65 (7.7 percent) vs. 39 of 135 (29 percent) (P = .001), and the five-year absolute survival was 43 of 65 (66 percent) vs. 51 of 135 (38 percent) (P less than .001). The local recurrence rate was 13 percent for patients receiving 3500 cGy and 5 percent for doses of 4000 to 5000 cGy. There was no apparent increased incidence in postoperative complications in the preoperatively irradiated patients.

Evaluation of the biofragmentable anastomotic ring following preoperative irradiation to the rectosigmoid in dogs

An animal study was done to evaluate the safety of a sutureless colorectal anastomosis in irradiated bowel. Forty mongrel dogs received preoperative radiation with 5000 rads and then underwent a low anterior resection and anastomosis using either the EEA-31TM stapling device, a two-layer handsewn technique, or the biofragmentable anastomotic ring (BAR) 31-1.5 mm and BAR 31-2.0 mm devices. The anastomoses were then evaluated for early and late anastomotic healing and leaks. The results show four radiographic (three clinical) leaks (P less than .05) in the BAR 31-1.5 mm group and one radiographic leak in the handsewn group. No leaks were detected in the EEA or BAR 31-2.0 mm groups. Results indicate that all three techniques can be done safely with this dose of radiation, and gap size (1.5 mm vs. 2.0 mm) is of critical importance when performing a BAR anastomosis in irradiated bowel.

The future of external beam irradiation as initial treatment of rectal cancer

Several trials have demonstrated that pre-operative irradiation for rectal cancer decreases significantly the incidence of pelvic recurrence. However, this method is far from being generally accepted. It is now possible to enhance the effectiveness of external beam irradiation and to use it to extend the field of sphincter-saving and conservative procedures. Our protocol consists of a split-course regimen with a short course of cobalt-60 arc rotation (3000 cGy in 12 days). After 2 months rest, the second stage of treatment depends upon the pressure of residual disease and the site of the tumour. It consists of either radical surgery (82 cases) or conservative treatment by intracavitary irradiation in the event of a favourable initial response or in the case of poor risk patients (73 cases). In the radiotherapy-surgical group, the subsequent operative specimens were tumour free in 17 per cent of cases and assigned to Dukes' A category in 32 per cent of cases. Of 91 patients with T2 or T3 tumour involving the lower third of the rectum (followed up for more than 3 years) 72 (84 per cent) had no recurrence. Thirty-three of these patients (46 per cent) underwent a colostomy while 39 (54 per cent) had normal anal function. These results demonstrate the major place that a properly planned external beam irradiation can have in the curative management of cancers of the low rectum.

Dose response to preoperative irradiation in rectal cancer: implications for local control and complications associated with sphincter sparing surgery and abdominoperineal resection

Sixty patients with locally advanced adenocarcinoma of the rectum have been treated with preoperative high dose pelvic irradiation at the University of Virginia and Rockingham Memorial Hospital. Fifty-six patients showed no evidence of distant metastases at surgery. A dose response was observed with a 67% incidence of local control with 4000 cGy vs. 91% incidence with 5000 cGy. For the 52 patients who received curative surgery, there has been no local failure alone; 6 of these patients have had local plus distant failure and 16 have had distant failure only. Forty-three percent had anterior resection (AR) and 57% had abdominoperineal resections (APR). The major complication rate was 5% and the minor 14%. No increase in complications or decrease in local control was found between APR and AR. Five-year actuarial survival was 64% for lesions limited to the bowel wall, 59% for node negative lesions with disease extending through the wall, and 23% for node positive patients.

Carcinoma of the rectum: current management

In recent years, various approaches have been used to improve survival and the quality of life in patients after surgical treatment of rectal carcinoma. These approaches include earlier detection, sphincter-saving procedures, and adjuvant therapy, intraoperative therapy for locally advanced tumors, and a more aggressive approach for locally recurrent or distal but isolated spread of the disease.

Current issues in the treatment of colorectal cancer

For colorectal cancers that are confined to the bowel wall with uninvolved nodes, surgery alone is curative in most patients, and adjuvant treatment is usually not indicated. A combined modality approach for the initial treatment of many rectal and selected colonic carcinomas is based on data that "radical" operations do not necessarily prevent either local regrowth or distant failures and acceptance of a significant palliative but infrequent curative role for irradiation and chemotherapy when such failures occur. Published data for rectal cancer indicates that local recurrence can be markedly reduced by moderate to high dose pre- and post-operative irradiation +/- chemotherapy. For colon cancer, data from pilot trials suggest that post-operative irradiation may reduce local recurrence by stage when compared with surgery alone analyses, but randomized trials are needed. With locally advanced disease, aggressive treatment combinations appear to increase both local control and survival, but much interaction is required between involved physicians.

Preoperative radiation therapy for clinically resectable adenocarcinoma of the rectum

This is an analysis of 71 patients with clinically resectable adenocarcinoma of the rectum treated with preoperative irradiation and surgery at the University of Florida from July 1975 through December 1981. Seven patients were found to have liver metastasis at surgery; six had a complete resection of their primary rectal lesion and one had an incomplete resection of the rectal tumor. The remaining 64 patients had no evidence of metastasis at the time of surgery and underwent a complete resection of their rectal cancer. In the early years of the trial, the maximum tumor dose consisted of 3000 to 3500 rad in 3.5 to 4 weeks; the dose was subsequently increased to 4500 rad in 5 weeks. Patients were taken to surgery between 2 and 11 weeks (mean, 3.5 weeks) following the completion of radiation therapy. All patients have a minimum follow-up of 3 years and 63% have a minimum follow-up of 5 years. The acute complications of treatment have been acceptable, with only one patient requiring a treatment rest for moist desquamation of the perineum. All patients completed the irradiation course and all were operated on. Pathologic examination of the surgical specimen revealed no tumor in 11%, and the incidence of positive lymph nodes was 19%, which was half the incidence of positive lymph nodes in a series of historical controls treated from 1959 to 1976 with surgery alone. Comparison of patients treated with preoperative irradiation and surgery with those treated with surgery alone revealed that the postoperative complications have been similar in incidence, distribution, and severity. There have been no postoperative deaths. The overall incidence of local-regional recurrence is 5/64 (7.8%), and the combined incidence of local-regional recurrence and/or distant metastasis is 18/64 (28%). The incidence of local-regional recurrence by preoperative dose is 3/23 (13%) for doses of 3000 to 3500 rad and 2/41 (5%) for doses of 4000 to 5000 rad. The 5-year local-regional failure rate is 3/40 (7.5%) for the group irradiated before surgery, and 39/135 (29%) for the historical controls managed by surgery alone (significance level = 0.015). The 5-year determinate disease-free survival is 27/38 (71%) for the patients irradiated before surgery, and 47/114 (41%) for the historical group of patients treated with surgery alone (significance level = 0.008).