Adjuvant postoperative radiotherapy and chemotherapy in rectal carcinoma: a review of the Gastrointestinal Tumor Study Group experience

Adjuvant therapy for resectable rectal adenocarcinoma

The mainstay of treatment for rectal cancer over the past 100 years has been surgical resection. However, for the majority of rectal cancers treated conventionally by resection alone, locoregional recurrence is the major mode of failure. Over the past several decades, significant progress has been made in developing effective adjuvant regimens. In the United States, postoperative chemoradiation is standard treatment for T3 or node-positive patients. However, preoperative radiation with or without chemotherapy decreases local recurrence, increases sphincter preservation, and may improve survival. The purpose of this article is to review the role of adjuvant therapy in resectable rectal cancers and to update the status of ongoing randomized trials.

Preliminary analysis of a randomized clinical trial of adjuvant postoperative RT vs. postoperative RT plus 5-FU and levamisole in patients with TNM stage II-III resectable rectal cancer

OBJECTIVES

Two-hundred eighteen patients with TNM stage II-III resectable rectal cancer, enrolled into a randomized clinical trial, were assessed for efficacy and toxicity of adjuvant postoperative radiation therapy (RT) vs. those of combined RT and chemotherapy (CT), with 5-fluorouracil (5-FU) plus levamisole. End points were overall survival, disease-free survival, the rate of loco-regional recurrence, and treatment-related toxicity.

METHODS

Patients in arm I underwent RT (50 Gy) in daily fractions of 2 Gy, 5 days/week for 5 weeks. Patients in arm II began with 5-FU (450 mg/m(2)/day intravenous bolus, days 1-5) plus levamisole (150 mg/day orally, days 1-3); postoperative RT was delivered during week 2 at the same dosage and schedule as in arm I. The other five cycles of CT (5-FU every 28 days and levamisole every 15 days for the length of 5-FU administration) continued after the end of RT if clinical and hemato-biochemical parameters were normal.

RESULTS

RT was completed or modified in 170 (90%) of 189 evaluable patients undergoing RT (both treatment groups). Only 44 (59%) of 75 evaluable patients of arm II completed or had an adjustment of the CT schedule; the remaining 31 patients (41%) had to stop or never started the CT regimen. Patients undergoing combined RT and CT had more severe toxicity (enteritis, P = 0.03). There was one CT-related death (gastrointestinal bleeding) in this subset. No significant difference was observed in outcome of patients in the two study groups, nor for pattern of recurrence (heterogeneity chi(2) = 4.82; d.f. = 2; P = 0.08).

CONCLUSIONS

These preliminary findings suggest a similar efficacy, coupled with less morbidity, of postoperative RT alone compared with a combined regimen of postoperative RT and CT in patients undergoing radical surgery for stage II-III rectal cancer.

Preoperative chemotherapy and pelvic radiation for tethered or fixed rectal cancer: a phase II dose escalation study

PURPOSE

To study the impact of preoperative radiation dose escalation and postoperative adjuvant chemotherapy on the outcome of tethered and fixed rectal carcinoma.

METHODS AND MATERIALS

We have treated 156 patients with 3 consecutive preoperative chemoradiation protocols with escalating treatment intensity. Schedule 1 consisted of 40 Gy radiation with concurrent 5-fluorouracil (5-FU) infusion and mitomycin C. Schedule 2 used a sandwich design with preoperative (40 Gy) and postoperative (18 Gy) radiation with concomitant 5-FU infusion, leucovorin, and mitomycin C. In schedule 3, the preoperative radiation dose was increased to 50 Gy and adjuvant 5-FU/leucovorin chemotherapy was added following surgery. There were 54, 27, and 75 patients treated in schedules 1, 2, and 3, respectively.

RESULTS

The resectability was 91% for schedule 1 and 100% for both schedules 2 and 3. A dose-response relationship was observed between the radiation dose and the tumor downstaging and local control. The pathological complete response (T0N0M0) rates for schedules 1, 2, and 3 were 4%, 15%, and 25%, respectively. The respective rates of tumor downstaging were 41%, 33%, and 68%, respectively. The 5-year local relapse-free rates were 67% for schedule 1 (40 Gy), 96% for schedule 2 (58 Gy), and 92% for schedule 3 (50 Gy) (p = 0.0011). The addition of postoperative chemotherapy appeared to improve both the survival and the relapse-free survival. The 5-year survival was increased from 52% to 84% (p = 0.0004) and the 5-year progression-free survival was improved from 48% to 74% (p = 0.0008).

CONCLUSION

Preoperative 5-FU infusion, leucovorin, mitomycin C, and 50-Gy pelvic radiation, followed by postoperative bolus 5-FU/leucovorin chemotherapy, appeared to be an effective treatment for tethered/fixed rectal cancers. However, its therapeutic efficacy could only be validated in randomized studies.

Phase II trial of adjuvant radiation and intraperitoneal 5-fluorouracil for locally advanced colon cancer: results with 10-year follow-up

PURPOSE

To determine the toxicity, disease-free survival, and overall survival for patients with Modified Astler-Coller (MAC) B2-3 or C1-3 colon cancer receiving adjuvant radiation and sequential intraperitoneal 5-fluorouracil (5-FU).

METHODS AND MATERIALS

From August 1984 to June 1989, 45 patients were accrued to this Phase II trial and received a 21-week course of intraperitoneal 5-FU (20 mg/kg/d x 5) and external beam radiation. The radiation was delivered to the tumor bed and para-aortic lymph nodes in two split-courses of 22.5 Gy, alternating with the first two cycles of chemotherapy. All patients then received 4 additional cycles of intraperitoneal 5-FU.

RESULTS

The therapy was well tolerated with 4 patients experiencing Grade 3 peritonitis. Four patients developed small bowel obstruction requiring surgery; in each instance, recurrent tumor was found at the time of laparotomy. The median and overall survivals at 10 years were 9.3 months and 53% respectively. Local failures were infrequent, occurring in only 11% of patients treated.

CONCLUSIONS

Sequential intraperitoneal 5-FU and tumor-bed/para-aortic irradiation is tolerable in patients with resected colon cancer. Although the incidence of local and regional relapse appeared to be lower than anticipated, this did not appear to translate into improved survival.

Association of tumour site and sex with survival benefit from adjuvant chemotherapy in colorectal cancer

BACKGROUND

Adjuvant chemotherapy can improve 5-year survival in Dukes' C colorectal carcinoma. Improved selection of patients who will respond to adjuvant treatments is required. We investigated whether site of tumour origin, sex, and presence of microsatellite instability (MSI) phenotype were associated with a survival benefit from adjuvant chemotherapy.

METHODS

We analysed data for 656 consecutive patients with Dukes' C colorectal carcinoma, with median follow-up of 54 months (range 7-104) and mean age 66.7 years (SD 12.9). We screened tumour samples by PCR for deletions in the BAT-26 mononucleotide repeat to establish MSI status. Details of chemotherapy and survival were obtained by review of hospital and health-department records. Adjuvant chemotherapy (fluorouracil and levamisole) was given with curative intent to 272 (42%) patients.

FINDINGS

Striking survival benefits were seen for patients who had right-sided tumours and who received adjuvant chemotherapy compared with those who did not (48 vs 27% alive at end of study [95% CI 0.25-0.56], p<0.0001), for women (53 vs 33% [0.25-0.56], p<0.0001), and for patients with MSI tumours (90 vs 35% [0.01-0.53], p=0.0007). MSI-positive tumours were slightly more frequent in women than in men (10 vs 7%). Right-sided tumours were more frequently MSI positive than left-sided tumours (20 vs 1%). Men with right-sided tumours benefited from chemotherapy (37 vs 12% [0.24-0.69], p=0.0007) but men with left-sided tumours did not.

INTERPRETATION

The survival benefits seen in patients treated with adjuvant chemotherapy suggest that data from previous trials of adjuvant chemotherapy should be reassessed and the predictive value of MSI status confirmed. Validation of our results will allow better selection of patients for chemotherapy.

Combined modality therapy of rectal cancers

Rectal cancer accounts for about 10% of new cancer cases each year. It strikes men and women at nearly the same rate, generally in the range of 50-80 years of age, with rising incidence with age. Despite simple screening procedures rectal cancer is often advanced when discovered. Current trends in the management of cancer have focused on organ preservation and improved quality of life without compromising the overall survival. During the last decade substantial progress has been made in treatment modalities: new and improved radiation techniques (conformal radiotherapy, altered fractionation, brachytherapy), chemotherapy (protracted infusion, use of radiosensitizers) and development of surgical procedures-enabling safer postoperative irradiation. In patients with advanced/unresectable disease aggressive combined chemoradiation can be added prior to surgery to downstage the tumour and increase the proportion treated with anal-rectal-sparing procedures. Preoperative chemoradiation therapy regimens are as safe and tolerable as the standard postoperative treatment. In this presentation indications for preoperative radiochemotherapy will be discussed in detail, together with treatment-related side effects, prognostic parameters, tumour response and outcome. Different irradiation settings and chemotherapy schedules are described. In patients with primary resectable disease (mainly Dukes C) several prospective randomised trials have shown less local recurrence with postoperative combined modality therapy.

A pilot study of continuous, hyperfractionated, accelerated radiotherapy in rectal adenocarcinoma

This pilot study investigated the feasibility, toxicity and effect of continuous, hyperfractionated, accelerated radiotherapy (CHART) in 19 patients with adenocarcinoma of the rectum who were treated at Mount Vernon Hospital between April 1992 and April 1994. A total dose of 54 Gy was given in 36 fractions over 12 consecutive days; three fractions of 1.5 Gy were employed each day with an interfraction interval of 6 hours. Of these 19 patients, 13 had local pelvic recurrence from rectal carcinoma, four had a primary rectal carcinoma (which was unsuitable for abdominoperineal resection because of patient frailty), and two had large, fixed, unresectable tumours and were given radiotherapy preoperatively to a lower dose of 42 Gy in 28 fractions over 10 days to facilitate surgery. However, none of the 19 patients subsequently underwent surgical resection. Treatment compliance with radiotherapy was 95%. Acute bowel toxicity was assessed by means of a daily bowel chart for 6 weeks and then at 8, 12 and 26 weeks after the completion of radiotherapy. Patients were subsequently scored using the World Health Organization (WHO) grading system. No toxic deaths were observed in this study. There were five grade 3 and one grade 4 toxicities (WHO scale) observed in six patients. There has been minimal acute bladder toxicity in two patients and skin reactions have been surprisingly minimal in all but three patients. Small bowel obstruction and late bowel damage, possibly attributable to radiotherapy, occurred in three patients. Complete pain relief was achieved in recurrent rectal cancer in 100% of patients, at a median of 15 days since commencing radiotherapy (range 7-63 days), and has been maintained for mean and median durations of 19 and 18 months respectively (range 1.5-45 months). Five patients have had a recurrence of pain at 3, 4, 8, 9 and 18 months respectively. All four patients with primary rectal adenocarcinoma achieved a complete response, which has been sustained for 4 months (until death), 54 and 57 months, although one patient relapsed locally at 8 months. In summary, CHART appears to be a feasible treatment for pelvic tumours with regard to toxicity. Patients with pain from a locoregional recurrence achieved rapid complete pain relief, which was sustained for many months.

Pre-operative chemoradiotherapy in locally advanced rectal cancer

BACKGROUND

The aim of the present study was to investigate the effectiveness and toxicity of pre-operative chemoradiation in locally advanced rectal cancer (T3-T4).

METHODS

Forty-seven patients were assessed (38 T3 and nine T4 tumours). Pre-operative pelvic radiotherapy was delivered in four fields, 45 Gy in 25 fractions over 5 weeks. Bolus 5-fluorouracil (5-FU) was delivered 500 mg/m2 on days 1, 2, 3 and days 22, 23, 24. Total mesorectal excision of the rectal tumour either by anterior or abdomino-perineal resection was planned at 4-6 weeks from completion of pre-operative treatment. Response to therapy was assessed by fresh macroscopic measurement of the surgical specimen.

RESULTS

All patients undergoing chemoradiation completed therapy as planned, with no treatment-related interruptions. The regimen had a low acute toxicity profile with an estimated 50% or greater response in 38 out of 47 patients (four patients had complete responses). Forty-three (97%) of 44 patients who underwent surgery were operable. Patients who were operated on between 4 and 7 weeks had a statistically better response then those who were operated on after 7 weeks (P = 0.013; Fisher's exact test). Eight of 10 patients who were considered to be inoperable prior to the treatment underwent total mesorectal excision with negative radial margins. Anastomotic leakage occurred in four patients (9%); one required surgical intervention. Wound infection occurred in three patients (6%); one patient required re-exploration for haemorrhage. Delayed complications occurred in three patients (6%); one requiring surgery for a stomal stricture. After a median follow-up of 20 months, two patients (4%) had developed local recurrence.

CONCLUSION

The pre-operative chemoradiation regimen employed had a low acute toxicity profile and all patients completed therapy. The majority of patients considered inoperable prior to receiving this treatment underwent successful excision. Appropriately fractionated pre-operative chemoradiotherapy is a reasonable option in this disease and deserves further evaluation.

Morbidities of adjuvant chemotherapy and radiotherapy for resectable rectal cancer: an overview

PURPOSE

Although adjuvant chemoradiotherapy may improve outcomes after surgery for high-risk rectal cancer, its toxicities are not well documented. This is a review of complications associated with adjuvant therapy in randomized, controlled trials.

METHODS

A MEDLINE and literature search was performed for randomized, controlled trials of adjuvant therapy for rectal cancer. Modalities of adjuvant therapy evaluated included preoperative radiotherapy, preoperative chemoradiotherapy, postoperative radiotherapy, and postoperative chemoradiotherapy. All documented complications were analyzed, including any effect on pelvic floor function and quality of life.

RESULTS

Short-term (acute) complications of preoperative radiotherapy include lethargy, nausea, diarrhea, and skin erythema or desquamation. These acute effects develop to some degree in most patients during treatment but are usually self-limiting. With preoperative radiotherapy the incidence of perineal wound infection increases from 10 to 20 percent. The acute toxicities after postoperative radiotherapy for rectal cancer occur in 4 to 48 percent of cases, and serious toxicities, requiring hospitalization or surgical intervention, occur in 3 to 10 percent of cases. Postoperative radiotherapy is associated with more complications than preoperative radiotherapy. The main problems with postoperative radiotherapy are small-bowel obstruction (5-10 percent), delay in starting radiotherapy caused by delayed wound healing (6 percent) and postoperative fatigue (14 percent), and toxicities precluding completion of adjuvant therapy (49-97 percent). The morbidity and mortality of both preoperative and postoperative radiotherapy are higher in elderly patients and when two-portal rather than three-portal or four-portal radiation technique is used. Meticulous radiation technique is important, and multiple fields of irradiation are mandatory. After combined adjuvant chemotherapy and radiotherapy acute hematologic and gastrointestinal toxic effects are frequent (5-50 percent). Delayed radiation toxicities include radiation enteritis (4 percent), small-bowel obstruction (5 percent), and rectal stricture (5 percent). Pelvic floor function and quality of life have not been well evaluated in randomized, controlled trials.

CONCLUSION

Adjuvant therapy for rectal cancer has considerable adverse effects. Adverse effects on bowel and sphincter function and quality of life have not been defined.

[Late intestinal complications of adjuvant radiotherapy of rectal cancers]

Pre or postoperative pelvic irradiation has demonstrated a definitive efficacy in reducing the local failure rate of rectal cancer treated with surgery alone. However it can induce late small bowel morbidity that could alter the therapeutic ratio. The clinical pictures of radiation enteritis include obstruction and diarrhea/malabsorption. Prognostic factors that increase the risk of late small bowel complications include extended fields out of the pelvis, irradiation dose, inappropriate irradiation technique, and increased small bowel irradiated volumes. The addition of chemotherapy increases acute but not late toxicity. Recommendations concerning the clinical practice are described. Radiotherapy may also alter the residual sphincter function and we recommend to assess correctly these complications.

Adjuvant therapy for resectable rectal and colonic cancer

BACKGROUND

Recurrence of rectal and colonic carcinoma remains substantial despite apparently curative surgery. Adjuvant therapy has been applied to improve prognosis.

METHODS

This review evaluates the use of adjuvant therapy in the management of resectable rectal and colonic carcinoma. It assesses critically the evidence supporting the addition of radiotherapy, chemotherapy, chemoradiotherapy and other treatment modalities to optimal surgery.

RESULTS

In the case of rectal tumours, preoperative is more effective than postoperative radiotherapy; It can significantly reduce the incidence of local tumour recurrence. A number of trials have tended towards showing a survival advantage and a recent large randomized trial has shown a significant improvement in survival in patients with Dukes C tumours. Postoperative chemoradiotherapy is associated with a survival benefit and is standard therapy in the USA, although it is associated with increased toxicity. The effectiveness of preoperative chemoradiotherapy is currently being investigated. Postoperative fluorouracil-containing chemotherapy has resulted in a survival advantage in patients with Dukes C colonic tumours; such therapy may be administered either systemically or intraportally. The evidence of benefit with rectal tumours is more limited. Immunotherapy has been studied to a limited extent and the use of a tumour-directed monoclonal antibody has produced a survival advantage in a single trial.

CONCLUSION

Preoperative radiotherapy and postoperative chemoradiotherapy can produce a survival advantage in patients with Dukes C rectal carcinoma and reduce local recurrence. Postoperative fluorouracil-containing chemotherapy can produce a survival advantage in those with Dukes C colonic cancer. The optimal use and combination of adjuvant therapy remains uncertain.

Pre-operative radiotherapy and chemotherapy for non-resectable rectal cancer

BACKGROUND

The treatment results of combined pre-operative radiotherapy and chemotherapy followed by surgery for patients with initially non-resectable primary rectal cancer were reviewed.

METHODS

Thirteen patients with locally advanced non-resectable rectal cancer were treated with pre-operative irradiation consisting of 50.4-54 Gy plus concomitant 5-fluorouracil (5-FU) delivered during the 1st and 5th weeks of radiotherapy.

RESULTS

Following pre-operative therapy, the resectability rate was 91%, with all but one patient undergoing complete resection. The pathologic complete response rate was 10%. The overall peri-operative and postoperative complication rate was 0.8 complications per patient. There was no postoperative mortality.

CONCLUSIONS

This early experience indicates that high resectability rates are achievable with pre-operative radiotherapy and chemotherapy for non-resectable rectal cancer while maintaining acceptable postoperative morbidity.

Radical surgery and postoperative radiotherapy as combined treatment in rectal cancer. Final results of a phase III study of the European Organization for Research and Treatment of Cancer

BACKGROUND

There is controversy whether adjuvant radiotherapy should be given before or after surgery for locally advanced, resectable rectal cancer. Preoperative radiotherapy substantially reduces local recurrence rates but may increase postoperative complications. In addition, patients found to have early cancers are treated unnecessarily. This study is a randomized trial of postoperative radiotherapy in patients who had a potentially curative resection for locally advanced rectal carcinoma.

METHODS

Following complete excision of a Dukes B or C rectal cancer, 172 patients were randomized to adjuvant radiotherapy (46 Gy 5 days per week in 30-38 days) (84 patients) or controls (88 patients).

RESULTS

After a median follow-up of 85 months, no benefit from postoperative radiotherapy had been observed in disease-free survival (P = 0.81), overall survival (P = 0.52), local recurrence-free interval (P = 0.46) or in the number and sites of recurrence. Acute toxicity following radiotherapy included diarrhoea (20 per cent), cystitis (13 per cent), delayed wound healing (7 per cent), pneumonia (5 per cent) and seizures (1 per cent). Late complications included reoperation for small bowel obstruction (5 per cent), chronic diarrhoea (20 per cent), chronic cystitis (12 per cent) and persistent perineal sinus (9 per cent). In the group who had surgery alone, late morbidity was found in 11 per cent.

CONCLUSION

This trial failed to demonstrate any improvement in overall survival or local control when postoperative irradiation was given following resection of locally advanced rectal carcinoma.

Treatment of colorectal cancer. Current guidelines and future prospects for drug therapy

Colorectal carcinoma is one of the most common cancers in Western countries (yearly incidence rate of 1:3000), and represents, after lung cancer, the second leading cause of deaths due to cancer. During the past decades, knowledge about this carcinoma has considerably increased, but little progress has been made in improvement in patient survival. At least 40% of patients with colorectal cancer will have metastases sometime during the course of their illness. In colon cancer, the first therapeutic approach is surgery, but the important role of adjuvant chemotherapy in these patients, in terms of disease-free survival and overall survival benefit, is now well established. Until today, standard therapy was represented by fluorouracil plus levamisole and/or calcium folinate (folinic acid). Other strategies are represented by monoclonal antibodies (mAb), which improve survival, (with a decrease in mortality by 32%), and by portal vein fluorouracil, alone or in combination with systemic therapy. In rectal cancer, the best results have been obtained with a combination of radiotherapy and chemotherapy. In advanced colorectal cancer, a standard treatment has not yet been established. This disease is usually considered as poorly chemosensitive and for more than 30 years fluorouracil has been the standard drug. Tumour response rates (partial+complete) for patients treated with bolus intravenous fluorouracil are 10 to 15%, with a median survival about 1 year. Many attempts have been made to improve these results. Biochemical modulation of fluorouracil is one of the most interesting strategies developed in the last few years in an attempt to increase the therapeutic index of this compound. Another way has been to administer fluorouracil by continuous infusion. Further innovative compounds such as irinotecan and raltitrexed are now being evaluated in clinical trials. Preliminary data from phase II and III studies have provided encouraging results on the use of these new drugs. In metastatic disease confined to the liver, the possibility of locoregional therapy through implantable pumps should be taken into consideration.

"Sandwich" preoperative and postoperative combined chemotherapy and radiation in tethered and fixed rectal cancer: impact of treatment intensity on local control and survival

PURPOSE

The present "sandwich" preoperative and postoperative chemotherapy and radiation study was undertaken to evaluate the impact of treatment intensity on the local control and survival in tethered or fixed rectal adenocarcinoma (T3, 4 NX M0).

METHODS AND MATERIALS

Between 1990 and 1992, 27 patients were treated with this sandwich protocol. Preoperative therapy consisted of 4 weeks of concurrent radiation (40 Gy) and chemotherapy (mitomycin C on day 1, 5-fluorouracil infusion and leucovorin on days 1-4 and days 15-18, respectively), and one cycle of bolus 5-fluorouracil and leucovorin chemotherapy. After surgery, they received 2 additional weeks of radiation (18 Gy) and 4 days of similar chemotherapy. The outcome was compared to another 54 patients who were treated with our previous preoperative chemoradiation protocol (mitomycin C, 5-fluorouracil infusion and 40 Gy of pelvic RT).

RESULTS

The complete resectability rate was improved from 91% in the preoperative protocol to 100% in the sandwich protocol, and the pathologic complete response rate (T0 N0 M0) was increased from 4 to 15%. There was no local recurrence in the sandwich protocol. The 4-year local failure rate was 23 vs. 0% (p = 0.005). The 4-year distant failure rate was 47 vs. 28% (p = 0.079). The 2-year and 4-year survival were 63 and 41% for the preoperative protocol, vs. 92 and 72% for the sandwich protocol, respectively (p = 0.014). There were more treatment-related Grade 2 diarrhea, but not Grade 3/4 diarrhea in the sandwich protocol. Two patients (7%) in the sandwich protocol developed late gastrointestinal complications.

CONCLUSIONS

More intensive radiation and chemotherapy appeared to improve the resectability, local control, and survival in tethered and fixed rectal cancers. There was a moderate but acceptable increase in the bowel morbidity.

Adjuvant postoperative radiotherapy in rectal cancer: 148 cases treated at Florence University with 8 years median follow-up

BACKGROUND AND PURPOSE

To analyse the outcome, the treatment related side effects, the prognostic significance of clinical parameters in a group of patients with rectal cancer receiving postoperative radiotherapy after radical resection.

MATERIALS AND METHODS

From 1980 to 1990 148 consecutive patients with rectal carcinoma stage B2-B3 or C1-C2-C3 were treated with postoperative radiotherapy after radical surgery. All patients received 50 Gy in 25 sessions in 5 weeks. In 42 a "flash' dose of 5 Gy was also given within 24 h before surgery. Median follow up was 8.1 years.

RESULTS

At 5 years the overall survival was 54%, the determined (cancer specific) survival 61%, the local recurrence-free survival 88%. The influence of stage, histotype, distance from anal margin, type of surgery, number of involved nodes and flash dose were analysed. Overall and determined survival and distant metastasis rate were significantly influenced (P < 0.005) by the pathological stage. Patients with more than 3 involved nodes presented a significantly lower determined survival (P < 0.001) and a higher distant relapse rate (P < 0.005) than those with 3 or less involved nodes. A higher determined survival (P < 0.01) was also found in patients receiving the preoperative "flash'; this group was however unbalanced in respect to the relative number of cases with 3 or less involved nodes. The incidence of major side effects requiring surgery or hospitalization for medical treatment was 35% before 1985 and 12% thereafter. The systematic use of small bowel visualization during simulation and the discontinuation of the flash dose were the main modifications introduced in the second period. As a consequence of the small bowel visualization the size of lateral fields was slightly reduced and some patients were excluded from the treatment.

CONCLUSIONS

Value of postoperative radiotherapy to decrease the incidence of local recurrence was confirmed in this retrospective study; the incidence of side effects was however considerable and did not support the addition of chemotherapy as advised by the NIH consensus meeting. Our policy was therefore moved to preoperative irradiation whose combination with chemotherapy was recently reported to be better tolerated and highly effective.

Locally advanced rectal cancer: resection and intraoperative radiotherapy using the flab method combined with preoperative or postoperative radiochemotherapy

PURPOSE

Surgery often fails to achieve local control in advanced rectal cancer. Additional measures are necessary to prevent local recurrence. The aim of this study was to evaluate intraoperative radiation therapy (IORT) (flab technique) combined with preoperative or postoperative radiochemotherapy.

PATIENTS/METHODS

IORT is performed using a flexible flab containing hollow plastic tubes that are connected to a multichannel afterloading device with a 370 Gbq-192-Ir source. Patients receive an intraoperative dose of 15 Gy. Target volumes were measured in a cadaver experiment. From 1989 to 1993, 38 patients were included in this study. Nineteen patients were staged as T3 tumors by preoperative endosonography (Group I) and 19 as T4 tumors (Group II). Patients in Group I underwent resection (abdominoperineal resection (APR), 16; anterior resection, 3) and IORT, followed by postoperative radiochemotherapy (50 Gy/5-fluorouracil), whereas patients in Group II received preoperative radiochemotherapy (40 Gy/5-fluorouracil) followed by resection (APR, 18; anterior resection, 1) and IORT. Mean follow-up was 25.5 months.

RESULTS

Operative radicality in Group I was RO (13), R1 (3), and R2 (3), and in Group II it was RO (14), R1 (3), R2 (2). R2 resections were attributable to preoperative undetected distant metastases. Perioperative mortality was 0 percent in Group I and 10.5 percent (n = 2) in Group II. Postoperative morbidity was 53 percent (n = 10) in Group I and 84 percent (n = 16) in Group II with delayed sacral wound healing being the predominant problem. Stenosis of the ureter occurred in two patients (Group II). Late or persistent therapy-related complications were seen in two patients in Group I and in six patients in Group II. Local recurrence developed in three patients in Group I (15.8 percent) and in two patients in Group II (10.5 percent). Survival data do not reach statistical significance between the two groups because of small numbers but show a favorable trend for the preoperative radiochemotherapy group. When compared with a matched historical control group of patients receiving resection only, adjuvant/neoadjuvant radiotherapy with resection/IORT improves survival significantly.

CONCLUSION

The flab method is a simple but especially practical technique for IORT in the pelvis. Adjuvant/neoadjuvant therapy combined with resection/IORT is associated with high morbidity but acceptable mortality. Preliminary survival data are encouraging and call for a controlled prospective randomized trial.

The current role of radiotherapy in colorectal cancer

During the last two decades, radiotherapy has become an integral part of the multidisciplinary approach in the treatment of patients with colorectal cancer. Currently, radiotherapy is seen mainly as an adjuvant therapy, sometimes in combination with chemotherapy, in a pre- or postoperative setting. Adjuvant radiotherapy alone leads to a significant reduction of local recurrence rates, but an impact on survival is seen only in subset analyses. Combined modality treatment can reduce local recurrence rates even further, and can also reduce the rate of distant relapses and increase survival. The acute toxicity of combined modality is considerably higher. Local radiation can also be use as a component of organ conserving local treatment for selected early lesions. Radiotherapy has been an important palliative treatment modality, diminishing symptoms in cases of inoperable primary rectal cancers or pelvic recurrences. The timing of radiation, surgery and chemotherapy has been under evaluation for years. For patients with locally advanced primary or recurrent malignancies (unresectable due to fixation), the preferred sequence is pre-operative irradiation with or without chemotherapy, followed by surgical resection. For mobile resectable lesions, sequencing issues are being tested in phase III randomised trials.

The rationale to switch from postoperative hyperfractionated accelerated radiotherapy to preoperative hyperfractionated accelerated radiotherapy in rectal cancer

PURPOSE

To demonstrate the feasibility of preoperative Hyperfractionated Accelerated RadioTherapy (preop-HART) in rectal cancer and to explain the rationales to switch from postoperative HART to preoperative HART.

METHODS AND MATERIALS

Fifty-two consecutive patients were introduced in successive Phase I trials since 1989. In trial 89-01, postoperative HART (48 Gy in 3 weeks) was applied in 20 patients. In nine patients with locally advanced rectal cancer, considered unresectable by the surgeon, 32 Gy in 2 weeks was applied prior to surgery (trial 89-02). Since 1991, 41.6 Gy in 2.5 weeks has been applied preoperatively to 23 patients with T3-T4 any N rectal cancer immediately followed by surgery (trial 91-01). All patients were irradiated at the department of radiation-oncology with a four-field box technique (1.6 Gy twice a day and with at least a 6-h interval between fractions). The minimal accelerating potential was 6 MV. Acute toxicity was scored according to the World Health Organization (WHO for skin and small bowel) and the Radiation Therapy Oncology Group criteria (RTOG for bladder). This was done weekly during treatment and every 3 months thereafter. Small bowel volume was estimated by a modified "Gallagher's" method.

RESULTS

Acute toxicity was acceptable both in postoperative and preoperative setup. The mean acute toxicity was significantly lower in trial 91-01 compared to 89-01. This difference was due to the smaller amount of small bowel in irradiation field and lower total dose in trial 91-01. Moreover, there was a significantly reduced delay between surgery and radiotherapy favoring trial 91-01 (median delay 4 days compared to 46 days in trial 89-01). Nearly all patients in trial 89-02 and 91-01 underwent surgery (31 out of 32; 97%). Resection margins were negative in 29 out of 32. Hospitalization duration in trial 91-01 was not significantly different from trial 89-01 (19 vs. 21 days, respectively).

CONCLUSIONS

Hyperfractionated accelerated radiotherapy immediately followed by surgery is feasible as far as acute toxicity is concerned. Preoperative HART is favored by a significantly lower acute toxicity related, in part, to a smaller amount of irradiated small bowel, and a shorter duration of the delay between radiotherapy and surgery. Moreover, the hospital stay after preoperative HART is not significantly increased.

Recent advances in radiation oncology

Radiotherapy remains an important component of the management of malignant disease. Especially when combined with cytotoxic chemotherapy, limited surgical excision, or both, irradiation has been shown to control disease in the primary site and regional nodes without the need for surgical extirpation as frequently as in past years. New developments in three-dimensional treatment planning and the precise delivery of high-dose radiation promise to increase the benefit of radiation treatment. Finally, molecular studies of the cell's response to radiation and the phenomena of DNA damage and repair are providing explanations for heretofore unexplained radiobiologic observations. Such research is laying the groundwork for targeted manipulation of the cell's response to radiation, which will be tested in the near future.

The use of radiotherapy for patients with low rectal cancer: an overview of the Lyon experience

In France, the late Jean Papillon was responsible for much of the pioneering work in the radiotherapy treatment of patients with rectal cancer. This review is written in tribute to his contribution to, and vast experience in, the conservative management of this common tumour. It describes his protocols with minor modifications currently used at the Centre Hospitalier Lyon-Sud, France. In Lyon, pre-operative adjuvant irradiation is the preferred treatment for patients with T2 and T3 rectal cancer. Initial results suggest that this combined approach significantly improves the likelihood of successful sphincter preservation for patients with carcinoma of the lower third of the rectum. To date, the technique has given good local control with minimal postoperative morbidity and low mortality.

The importance of patient selection for adjunctive postoperative radiation therapy for cancer of the rectum. Patient selection in adjunctive therapy

BACKGROUND

Clinical stage of disease is an important selection criterion for choice of primary treatment and strategies for adjunctive therapy for most cancers. For adenocarcinoma of the rectum, strategies for adjuvant treatment are based primarily on pathologic stage alone, without consideration of presenting clinical factors. This analysis was undertaken to assess the effect of patient selection on results of adjunctive therapy.

METHODS

Three groups of patients with Astler-Coller Stage B2 and C rectal cancer were compared to assess the effect of patient selection factors on outcome of treatment after adjuvant postoperative radiation. Thirty-two patients in Group 1 received only 5 Gy preoperatively; 54 patients in Group 2 received low-dose (5 Gy) preoperative and high-dose (45 Gy) postoperative radiation; and 53 patients in Group 3 received high-dose (45 Gy) postoperative radiation. All patients have a minimum follow-up of 5 years. Whereas Group 1 and Group 2 patients were similar in distribution by clinical tumor characteristics, Group 3 had more patients with poor clinical features: higher median age, more men, and a higher proportion of tumors in the distal rectum. Group 3 also had a slightly higher percentage of C2 tumors compared with the other two groups.

RESULTS

Treatment was well tolerated with minimal side effects. Patients in Group 1 had no long-term complications. Four percent of patients (2 of 54) in Group 2 and 6% of patients (3 of 53) in Group 3 experienced major small bowel complications. The incidence of local recurrence was 34% (11 of 32) in Group 1, 9% (5 of 54) in Group 2, and 21% (11 of 53) in Group 3. The incidence of distant metastasis was 28% (9 of 32), 22% (12 of 54), and 38% (20 of 53), respectively. Absolute 5-year survival rates were 54%, 72%, and 41% in these three groups, respectively.

CONCLUSIONS

Low-dose preoperative adjunctive radiation alone (Group 1) resulted in a high incidence of local recurrence and poor survival compared with patients treated more appropriately with low-dose preoperative plus adjunctive postoperative irradiation (Group 2). In spite of postoperative radiation, patients with clinically unfavorable rectal cancer (Group 3) did worse than carefully selected patients, although both were nominally Stage B2 and C. Careful patient selection before surgery, histopathologic stage of disease postsurgery, and adequate adjunctive therapy are all important factors in obtaining the best results from adjunctive therapy.

Pelvic perfusion in the adjuvant therapy of locally advanced rectal cancer. Feasibility trial and initial clinical experience

PURPOSE

The increased risk of pelvic recurrence in patients with locally advanced rectal cancer seems to justify a more aggressive regional therapeutic approach. In this attempt a feasibility study has been recently activated on hyperthermochemotherapeutic pelvic wash in patients with resectable, locally advanced, cancer of the distal rectum.

METHODS

Two alternative methods of hyperthermochemotherapeutic pelvic wash have been used in sequence. In the first method 3000 ml of warm (45 degrees C) saline solution containing 30 mg of mitomycin C were injected into the pelvis both intraoperatively and in the immediate postoperative period. In the second method a 60-minute perfusion of the pelvic space with 2000 ml of heated (45 degrees C) saline solution with 40 mg of mitomycin C was provided intraoperatively using an extracorporeal circuit.

RESULTS

Four patients submitted to abdominoperineal amputation with pelvic lymph node dissection have been treated following one of the two methods. No complications related to the treatment occurred. Either the first or the second hyperthermochemotherapeutic pelvic wash method showed a high regional pharmacokinetic advantage with a perfusate/blood "AUCs" ratio of 576 and 374, respectively.

CONCLUSIONS

The potential role of hyperthermochemotherapeutic pelvic wash as an additional regional treatment in locally advanced rectal cancer and the differences between the two methods, in our limited experience, are discussed.

Adjuvant intraoperative photodynamic therapy for colorectal carcinoma: a clinical study

The local recurrence rate of colorectal carcinoma after surgery is unacceptable in most series, and adjuvant therapies have made only a small impact on this. There is experimental evidence that adjuvant intraoperative photodynamic therapy (AIOPDT) may be effective. AIOPDT involves systematically photosensitizing the patient preoperatively with a drug (HpD) which relatively localizes to tumour and is activated using visible light. At operation the resected tumour bed is illuminated with a predetermined uniform light energy density to eradicate microscopic tumour deposits left at the lateral resection margin. We have previously investigated technical and biological factors leading to this clinical trial. Seventeen patients have received AIOPDT in a potentially effective dose, and safety and technical matters have been investigated. Cutaneous phototoxicity occurred in 3 patients. Three patients had anastomotic breakdown, none considered attributable to PDT. The intraoperative technique was a practical option. AIOPDT carried a low patient morbidity and should be investigated in prospective clinical trials to determine if local recurrence rates can be decreased.

High-dose preoperative radiation for cancer of the rectum: impact of radiation dose on patterns of failure and survival

PURPOSE

A variety of dose-time schedules are currently used for preoperative radiation therapy of rectal cancer. An analysis of patients treated with high-dose preoperative radiation therapy was undertaken to determine the influence of radiation dose on the patterns of failure, survival, and complications.

METHODS AND MATERIALS

Two hundred seventy-five patients with localized rectal cancer were treated with high-dose preoperative radiation therapy. One hundred fifty-six patients received 45 Gy, +/- 10% (low-dose group). Since 1985, 119 patients with clinically unfavorable cancers (fixed, low-lying, or deeply ulcerated) were given a higher dose, 55 Gy, +/- 10%, using a shrinking field technique (high-dose group). All patients underwent curative resection. Median follow-up was 66 months in the low-dose group and 28 months in the high-dose group. Patterns of failure, survival, and complications were analyzed as a function of radiation dose.

RESULTS

Fourteen percent (38/275) of the total group developed a local recurrence; 20% (31/156) in the low-dose group as compared with 6% (7/119) in the high-dose group. The actuarial local recurrence rate at 5 years was 20% for the low-dose group and 8% for the high-dose group, and approached statistical significance with p = .057. For tethered/fixed tumors the actuarial local recurrence rates at 5 years were 28% and 9%, respectively, with p = .05. Similarly, for low-lying tumors (less than 6 cm from the anorectal junction) the rates were 24% and 9%, respectively, with p = .04. The actuarial rate of distant metastasis was 28% in the low-dose group and 20% in the high-dose group and was not significantly different. Overall actuarial 5-year survival for the total group of patients was 66%. No significant difference in survival was observed between the two groups, despite the higher proportion of unfavorable cancers in the high-dose group. The incidence of complications was 2%, equally distributed between the two groups.

CONCLUSION

High-dose preoperative radiation therapy for rectal cancer results in excellent local control rates. However, in clinically unfavorable cancers a higher dose (55 Gy) of preoperative radiation can be given safely with significantly improved local control. Careful clinical staging is helpful in selectively treating patients with unfavorable tumors to a higher preoperative radiation dose and thus optimizing their outcome.

Adjuvant postoperative accelerated hyperfractionated radiotherapy in rectal cancer: a feasibility study

PURPOSE

To assess the acute toxicity and hence feasibility of postoperative hyperfractionated accelerated radiotherapy in rectal cancer.

METHODS AND MATERIALS

Twenty patients were submitted to accelerated hyperfractionated radiotherapy after resection of rectal cancer. A total dose of 48 Gy was given in 3 weeks. Two fractions of 1.6 Gy were used with a mean interfraction interval of at least 6 hours. The pelvic volume was treated by a four-field box technique using a linear accelerator (6-18 MV). Acute toxicity was assessed once per week. Small bowel and skin toxicity were scored according to the criteria of the World Health Organization. Bladder toxicity was scored according to the criteria of the Radiation Therapy Oncology Group.

RESULTS

All the patients underwent the treatment as planned except one. No patient presented grade 3 or 4 bladder toxicity. There was only one patient who complained from grade 3 skin toxicity at the end of the treatment. Fourteen patients had some degree of intestinal toxicity. This was the most frequently occurring acute side-effect. Only two out of the fourteen patients had intestinal toxicity exceeding grade 2.

CONCLUSION

Hyperfractionated accelerated radiotherapy on a pelvic volume is feasible as far as acute toxicity is concerned.

The clinical rationale for S-phase radiosensitization in human tumors

Nonhypoxic cell radiosensitizers, principally the halogenated pyrimidines and hydroxyurea, have been studied in the laboratory and clinical setting for more than 30 years. Early clinical experience in the 1960s and 1970s with the thymidine analogs 5-bromodeoxyuridine (BUdR) and 5-iododeoxyuridine (IUdR) was disappointing because normal tissue toxicity eliminated any potential for therapeutic gain. Inadequate delivery systems for intravenous and intraarterial infusions also contributed to the decline of this strategy. More recently, laboratory investigations have revealed further information regarding the mechanism of IUdR/BUdR radiosensitization. This knowledge provided a rationale for the sequence and timing of drug and radiation exposure, which could be both effective and tolerable. Advancing technology also provided safer infusion devices, and a resurgence in clinical trials combining IUdR or BUdR and radiation resulted. Current laboratory studies are now providing data on tumor cell kinetics, which is being applied to ongoing clinical trials. Fluoropyrimidines, principally 5-fluorouracil (5-FU), were also used in early clinical trials and unlike IUdR/BUdR were found to have significant activity as single agents against a variety of tumor types. The clinical integration of 5-FU and radiation occurred more slowly, but recent trials have demonstrated a therapeutic gain. Improved rates of local control and survival with combined 5-FU and radiation versus radiation alone have now been demonstrated in patients with rectal, esophageal, and anal carcinomas. However, the mechanism of interaction between the fluoropyrimidines and radiation remains uncertain and continues to be investigated with the hope of improved clinical outcome. As the cellular pathways influenced by the halogenated pyrimidines have been defined, the potential for biochemical modulation of these agents has been recognized. Leucovorin, the most commonly applied modulator, has been shown to enhance the activity of 5-FU in patients with metastatic colorectal carcinoma. These studies serve as an example for current trials that use biochemical modulators of IUdR, BUdR, and 5-FU as radiosensitizers. Hydroxyurea, currently used in the treatment of chronic leukemia, has also been considered a radiosensitizer. As with IUdR/BUdR, the clinical trials have often been inconclusive and interest in this radiosensitizer has waned. A poor understanding of the mechanism of action and tumor cell/normal tissue kinetics may be responsible for the lack of overall success with this strategy. Current investigations of cell kinetics in humans and potential mechanisms of hydroxyurea action could provide information critical to future trials of hydroxyurea radiosensitization.

Preoperative concurrent 5-fluorouracil infusion, mitomycin C and pelvic radiation therapy in tethered and fixed rectal carcinoma

PURPOSE

This is a Phase I/II study of preoperative concurrent radiation and chemotherapy in tethered and fixed rectal carcinoma. This study examined the curative resectability, the acute toxicities during chemo-radiation and the surgical complications.

METHODS AND MATERIALS

Between 1986 and 1990, 46 patients were treated with preoperative pelvic radiation (4000 cGy in 20 fractions in 4 weeks), 5-Fluorouracil infusion (20 mg/m2, days 1-4 and 15-18) and Mitomycin C (8 mg/m2, day 1). This was followed by surgery 6 to 8 weeks later. 30 patients had tethered tumors and 16 patients had fixed tumors.

RESULTS

After preoperative chemo-radiation, 41 patients (89%) underwent curative resection. Two patients (4%) had no residual tumor found (T0N0M0). Seven patients (15%) had nodal metastases. Two patients developed grade 3 neutropenia (WBC = 1-2 x 10(9)/L) during chemo-radiation. Five patients had delay in perineal wound healing. One patient had an anastomotic leak. Four patients developed stomal stenosis which required surgical revision. The 2-year actuarial survival was 73%. The 2-year local relapse rate was 16%. Patients with fixed carcinoma had a higher incidence of local failure (38% vs. 10%) and the difference was statistically significant (p = 0.0036). The 2-year distant failure rate was 41%, and the rates were similar for both tethered and fixed carcinomas.

CONCLUSION

Preoperative pelvic radiation, chemotherapy and surgery could achieve a curative resection rate of 89% in tethered and fixed rectal carcinomas. However, distant metastases remained the major cause of failure.

Adjuvant treatment in the curative management of rectal cancer: a critical review of the results of clinical randomised trials

A critical analysis of the results of randomised studies on adjuvant rectal cancer led to a different interpretation than given by the 1990 National Institutes of Health (NIH) conference which concluded that combined postoperative chemotherapy and radiotherapy resulted in increased local control and survival in stage II and III patients. We think there is not as yet indisputable evidence for the use of such combination postoperatively. Furthermore, this approach resulted in increased toxicity and was only consistent with moderate compliance. Conversely, preoperative radiotherapy, which was not even mentioned in the conclusions and recommendations of the NIH consensus conference, definitely increases local control and should now be proposed as standard initial treatment in T3T4 resectable rectal cancer. Moreover, preoperative concomitant chemotherapy is an attractive area for clinical trials.

Postoperative radiotherapy for rectal and rectosigmoid cancer: the impact of total dose on local control

Between 1984 and 1988, 206 patients were treated with pelvic radiotherapy after macroscopically complete surgery for rectal or (recto)sigmoid cancer. Depending on an estimation of the amount of small bowel in the intended treatment volume a total dose was, in general, 45 or 50 Gy. An additional boost of 10 Gy was given to 6 patients because of microscopically involved surgical margins. For tumor stage B a statistically significant trend (p = 0.017) for higher local control with higher total dose was observed comparing patients treated with a total dose of 45 Gy or less, with more than 45 Gy but less than 50 Gy or with a total dose of 50 Gy or more. This finding illustrates the impact of total dose on local control for postoperative radiotherapy for rectal carcinoma.

Conservative management of extensive low-lying rectal carcinomas with transanal local excision and combined preoperative and postoperative radiation therapy. A report of a phase I-II trial

Between 1986 and 1990, 16 patients were enrolled in a prospective Phase I/II study of transanal local excision and combined preoperative and postoperative radiation therapy (RT). All patients had biopsy-proven adenocarcinoma extending to within 6 cm of the anal verge and involvement of at least one third of the rectal circumference with tumor. Five of 16 patients (32%) had T3 tumors, and only two patients had T1 tumors. Patients received a single 500 cGy fraction of RT to the pelvis within 24 hours before surgery and underwent transanal excision followed by postoperative RT (median dose, 5040 cGy). With a median follow-up of 33 months, overall 3-year actuarial survival was 94%. Two patients had isolated local recurrences (both successfully salvaged), and four had distant metastases but maintained local control. The 3-year actuarial rates of continuous freedom from any relapse, continuous local control, and no evidence of disease at last follow-up were 53%, 80%, and 71%, respectively. Only three of 16 patients required colostomy, resulting in a 3-year actuarial colostomy-free rate of 77%. There was a trend toward a higher rate of relapse (P = 0.066) in patients with T3 tumors than those with T1 and T2 tumors. Sphincter-preserving therapy for low-lying rectal carcinomas using local excision and combined preoperative and postoperative RT is feasible, although improved local and adjuvant therapy is needed for patients with T3 lesions.

High dose preoperative irradiation for cancer of the rectum, 1976-1988

Two hundred twenty patients with adenocarcinoma of the rectum have been treated in a program using high dose (greater than 4000 cGy) preoperative irradiation followed by radical surgical resection. The patients were staged on the basis of pretreatment clinical mobility of the cancers. Seventy-four patients had mobile cancers, 49 had partial fixation (tethered), 85 patients had total tumor fixation, and 12 patients had a frozen pelvis (unresectable). Patients were treated with high energy photons using a four field box technique with total doses ranging from 4000 to 6000 cGy. The overall incidence of local recurrence was 15% (32/220). Patients with fixed and unresectable tumors had a higher incidence of local recurrence, 20% (21/97) as compared with patients with mobile and partially fixed tumors, 10% (13/123). Local recurrence by pathological stage of disease was 6% for patients with Stages O, A, B1 versus 20% for patients with Stages B2 and C cancer. Overall 5-year survival of the total group was 67%. The 5-year survival by clinical stages of disease was 87% for mobile tumors, 74% for partially fixed tumors, 70% for fixed tumors, and 22% for the unresectable group. The 5-year survival by pathological stages of disease was 90% for those with Stage O, A, B1 and 71, 75, and 47%, respectively, for Stages B2, C1, and C2 disease.

Randomized trials of adjuvant radiation therapy for rectal carcinoma: a review

An estimated 44,000 cases of rectal carcinoma arise annually in the United States. The traditional management of this disease has been surgery alone, but advances in adjuvant therapy offer potential for improvement of local control, disease-free survival, and survival. In the last two decades, many multicenter randomized trials of adjuvant preoperative and postoperative radiation therapy for rectal carcinoma have been reported. The design and results of these trials are critically reviewed. Results from preoperative trials have been conflicting, reflecting the heterogeneity of the trial designs. Large postoperative adjuvant trials have been reported recently. The combined analysis of local recurrence data from the mature, published trials indicates that radiation therapy results in improved local control (P = 0.02), an important concern in rectal carcinoma as local recurrences present vexing and painful clinical problems often refractory to conventional management. These trials also have shown that radiation therapy can contribute to improved survival in the combined modality setting. Improvements in the clinical outcome of rectal cancer should be possible with appropriate adjuvant therapy. The success of combined modality adjuvant therapy for rectal carcinoma may serve as a model to aid in the design of therapeutic regimens for other solid tumors.