Combined-modality therapy for rectal carcinoma--the time has come

A Pilot Clinical Trial of Surgical Adjuvant Treatment with High-Dose 6S-Leucovorin/5-Fluorouracil and Radiation Therapy for High-Risk Rectal Carcinoma

Aims and background

The study was performed to evaluate the feasibility of combining leucovorin (LV) with 5-fluorouracil (5FU) and radiation therapy as adjuvant treatment for high-risk rectal carcinoma.

Methods

Twenty-five patients with histologically proven adenocarcinoma of the rectum, at high-risk of recurrence after potentially curative resection (T3 NO, T any N1-2; MO), received 5FU (370 mg/m2) and 6S-LV (100 mg/m2) on days 1-5, 4 and 8 weeks after surgery. On treatment day 64, radiotherapy on the pelvis (50 Gy) was initiated. Finally, three further courses of 5FU/LV were given at intervals of 4 weeks beginning 28 days after the completion of radiotherapy.

Results

The treatment was generally well tolerated. We observed only 2 cases of grade III toxicity (diarrhea) during the third cycle of chemotherapy. No severe complications were recorded following the use of radiotherapy. The mean overall 5FU dose intensity was 92%. After a median follow-up of 24 months, 4 patients had relapsed (liver, lung, and pelvis, 2 cases).

Conclusions

The association of LV to 5FU and radiation therapy seems to be feasible, with acceptable toxicity. The advantage of this combination, in terms of recurrence rate and survival with respect to 5FU/radiotherapy alone, will have to be evaluated in randomized trials.

Current evidence does not support routine adjuvant radiotherapy for rectal cancer

BACKGROUND

There is widespread support in the published literature for routine adjuvant radiotherapy for rectal cancer.

METHODS

In the present paper, the current evidence regarding adjuvant radiotherapy is reviewed, particularly the most recent studies of preoperative radiotherapy (usually including patients with Stage I, II and III disease) and postoperative radiotherapy (usually for Stage II and III disease), and meta-analyses. Two questions in particular are addressed: Does radiotherapy improve survival when surgeons are able to achieve low local recurrence rates with surgery alone? Does radiotherapy improve patients' quality of life?

RESULTS

Radiotherapy has only been demonstrated to significantly improve survival in one individual study and one recent meta-analysis. The local recurrence rates in the no-radiotherapy arm of these studies were 27% and 21-36.5%, respectively. In more recent studies, with lower local recurrence rates reflecting modern surgical standards, no survival advantage has been found. It is currently unknown whether radiotherapy improves patients' quality of life. Studies have demonstrated that radiotherapy has acute and long-term detrimental effects on quality of life. While local recurrence can be very debilitating, it can also be asymptomatic, and the overall effect of the local recurrence statistics found in adjuvant therapy studies on quality of life has not been systematically investigated. The most recent studies demonstrate that 17-20 patients need to undergo adjuvant radiotherapy to prevent one local recurrence.

CONCLUSION

Current evidence does not support the widespread advocacy for routine adjuvant radiotherapy as used in the treatment arms of recent trials.

The incidence and clinical consequences of treatment-related bowel injury

OBJECTIVE

To assess the frequency and clinical features of treatment-induced bowel injury in rectal carcinoma patients receiving perioperative external beam radiotherapy (EBRT). The frequency of and factors associated with treatment-induced intestinal injury have previously not been well quantified for rectal cancer patients. Postoperative adjuvant chemoirradiation is recommended for Stage II and III rectal cancers, making such data of significant interest.

METHODS AND MATERIALS

The records of 386 consecutive patients undergoing radiotherapy with or without chemotherapy (CT) for rectal carcinoma between 1981-90 were reviewed. Eight-two patients were excluded for receiving nontherapeutic EBRT or modalities other than EBRT.

RESULTS

Symptomatic acute treatment-related enteritis (within 30 days of EBRT +/- CT) was diagnosed in 13 patients, 3 of whom developed chronic bowel injury. Chronic treatment-related enteritis was identified in 18 patients and reoperation was required in 17 (5% of the 304 patients with complete follow-up). Chronic proctitis was documented in 38 patients, including 3 patients with small bowel injury. The probability of developing treatment-induced bowel injury at 5 years following treatment was 19%. Variables associated with an increased risk of bowel injury using multivariate analysis were transanal excision (p = 0.002), escalating radiation dose (p = 0.005), and increasing age (p = 0.01). Twenty of the affected patients required operative treatment, and 2 deaths resulted from treatment-induced enteritis.

CONCLUSION

Patients with rectal carcinoma treated with EBRT +/- CT have the risk of developing treatment-induced bowel injury. The pelvic radiation dose should be limited to < or = 5040 cGy unless small bowel can be displaced. Reperitonealization of the pelvis, or other surgical methods of excluding the small intestine should be used whenever possible.

Postoperative adjuvant radiotherapy and 5-fluorouracil chemotherapy for rectal carcinoma

Postoperative combined modality therapy with radiotherapy and 5-fluorouracil (5FU) chemotherapy is an effective adjuvant approach that reduces locoregional and distant metastatic disease in patients with high-risk rectal carcinoma. However, this approach results in a treatment regimen of at least 6 months' duration. The present prospective study investigates the integration of radiotherapy and 5FU chemotherapy in a protocol designed to minimize toxicity and reduce the overall treatment time. A total of 40 patients with TNM stage II or III disease received postoperative radiotherapy at four fractions per week with weekly 5FU bolus injections delivered on the fifth non-radiotherapy day. Patients also received systemic chemotherapy with leucovorin both before and after pelvic irradiation, with the total treatment duration extending for only 18 weeks. Patients were able to complete radiotherapy in 90% of cases, while the delivery of full-dose chemotherapy was achievable in the vast majority. The incidence of haematologic and gastrointestinal toxicities requiring the cessation of treatment was acceptable. With a median follow-up of 20.9 months among surviving patients, the estimated progression-free and overall survival at 2 years were 71% and 79%, respectively.

Independently predictive prognostic variables after resection for colorectal carcinoma

BACKGROUND

Clinical variables such as surgical morbidity, comorbidity and follow-up have been claimed to influence ultimate survival in patients who have resection for colorectal cancer. It is unclear whether the effect of clinical covariates is confounding or independent. We have attempted to build a comprehensive model, which is capable of testing the dependence and importance of prognostic factors.

METHODS

A consecutive series of patients admitted between 1970 and 1988 and followed until 1992 had data recorded about presentation, pathology, hospitalization, aftercare and long-term outcome. The patients were also divided into two approximately equal groups that were cared for by one and seven surgeons, respectively. Clinical and pathological covariates were built into a Cox (multivariate) proportional hazard model of crude survival. This was achieved with the SPSS advanced statistical package version 6.1. Comparison between groups was then performed of clinical and pathological factors and subsequent cancer management.

RESULTS

There were 207 patients whose average age was 75 years, median survival was 43 months and operative mortality was 4%. The Cox model was robust. Covariates that had independent survival effects were pathological stage (P = 0.0000), grade (P = 0.014), age (P = 0.018), heart disease (P = 0.001), and group (P = 0.0008). Some of the dependent variables were symptoms, type of surgery, complications and length of stay. The groups, however, were well matched for age, stage, substage and comorbidity. Furthermore there were no substantial differences in mortality, complications or follow-up frequency. There was a significant survival difference (P = 0.0003) between groups, which was restricted to patients who were in clinicopathological stages B and C. Within stages B and C there was a significant (P = 0.008) survival difference between patients who were or were not treated for recurrent disease. Diagnosis of recurrence was pursued more aggressively (P < 0.01), and decisions to treat recurrent disease were made more frequently in group 1 (P = 0.0002).

CONCLUSIONS

Pathology, comorbidity and management of recurrence all have a significant independent effect upon crude survival after colorectal carcinoma resection.

Radiotherapy treatment for isolated loco-regional recurrence of rectosigmoid cancer following definitive surgery: Peter MacCallum Cancer Institute experience, 1981-1990

PURPOSE

To assess the success of external beam radiation treatment in the management of loco-regional recurrence of rectosigmoid cancer.

METHODS AND MATERIALS

A retrospective analysis of 135 patients with locally recurrent rectosigmoid cancer presenting to Peter MacCallum Cancer Institute between January 1981 and December 1990 was undertaken. Patients were treated with three different dose ranges of radiotherapy: 50-60 Gy ("Radical" group), 45 Gy ("High-dose palliative" group), and <45 Gy ("Low-dose palliative" group). Symptomatic response rates and overall survival for each group were determined.

RESULTS

Symptomatic response rates of 85, 81, and 56% were achieved in the radical, high-dose palliative, and low-dose palliative groups, respectively. Estimated median survival times were 17.9, 14.8, and 9.1 months for the radical, high-dose palliative, and low-dose palliative groups, respectively.

Fluorouracil and high-dose leucovorin with radiotherapy as adjuvant therapy for rectal cancer. Results of a phase II study

The purpose of this phase II study was to evaluate the efficacy and toxicity of fluorouracil and high-dose leucovorin (5-FU/LV) with pelvic irradiation as adjuvant therapy for patients with macroscopical resected rectal or recto-sigmoid cancer. Following surgery for stages II-III primary (52) or recurrent rectal cancer (4), 56 patients received 8 cycles of 5-FU/LV and pelvic irradiation. 5-FU doses were 200 mgr/m2 for cycles 2-3 and 300 mgr/m2 for cycles 1 and 4-8. LV doses remained fixed at 200 mgr/m2. Pelvic radiation was started in the third week, between the first and second cycle. The total dose was 50.4 Gy. No severe complications had been recorded. The incidence of grade 3 diarrhea was 19%. Three patients presented leukopenia grade 3 (5%). In 44 patients (78%) the planned treatment could be administered. The median follow-up was 40 months (range 22-66). Seven patients had a local relapse (13%) and 6 developed distant metastasis (10%). The 3-year disease-free survival was 72% and the overall survival was 76%. These preliminary results show that combined post-operative 5-FU/LV and pelvic radiotherapy are well tolerated and present a reasonable local control and survival rates. This adjuvant treatment should be evaluated in randomized trials.

Combined preoperative irradiation and direct postoperative 5-fluorouracil without negative effects on early anastomotic healing in the rat colon

BACKGROUND AND PURPOSE

Preoperative irradiation with direct postoperative chemotherapy could benefit patients undergoing surgery for colorectal cancer. This study was designed to examine, in an experimental model, if such treatment is feasible without detrimental effects on early anastomotic healing.

MATERIAL AND METHODS

A colonic segment was irradiated (25 Gy) in 3 groups (n = 10 each) of male Wistar rats. After 5 days, a colonic resection was performed with anastomotic construction; only the distal limb consisted of irradiated bowel. Postoperatively, animals received daily intraperitoneal 5-fluorouracil (5-FU, group I/CH: 17.5 mg/kg; group I/CL: 12.5 mg/kg) or saline (group I). Three additional groups were treated similarly, but with sham-irradiation: CH, CL and C, respectively. All rats were killed 7 days postoperatively. Parameters measured were: weight, serum albumin and protein, and anastomotic bursting pressure, breaking strength and hydroxyproline content.

RESULTS

Body weight was diminished significantly in rats receiving chemotherapy. Serum albumin and protein was significantly lower in irradiated groups. At sacrifice, 40% of I/CH rats had functional rectal stenosis. The average bursting pressure (P = 0.0005) and the average breaking strength (P = 0.012) were only reduced significantly in the CH group. The anastomotic hydroxyproline content was significantly higher in the I/CH and I/CL groups vs. the control group.

CONCLUSION

High-dose direct postoperative 5-FU leads to reduced anastomotic strength. Although the combination of preoperative irradiation (25 Gy) and direct postoperative high-dose 5-FU does not reduce early anastomotic strength, some stenosis may occur. The combination of preoperative irradiation and low-dose 5-FU has no such effect.

Adjuvant treatment of colon and rectal cancer: impact of chemotherapy, radiotherapy, and immunotherapy on routine postsurgical patient management. Forschungsgruppe Onkologie Gastrointestinaler Tumoren (FOGT)

Colon cancer patients with UICC stage III or T4 N0 M0 stage II should receive postoperative adjuvant therapy, since relapse rates are high and surgical outcome has been improved by adjuvant treatment. The standard treatment is 5-fluourouracil plus levamisole; an alternative option is the combination of 5-fluourouracil and folinic acid. Stage II (T3 N0 M0) colon cancer patients should not receive adjuvant treatment outside of studies. Rectal cancer patients of stage II or III should receive postoperative radiochemotherapy with 45-54.4 Gy and 5-fluourouracil as standard treatment. Patients not eligible for radiotherapy may receive adjuvant chemotherapy only. Studies need to be conducted to improve adjuvant therapy in colorectal cancer. All qualified patients should be treated within these studies requiring sufficient patient numbers, as well as comparable surgical procedures, proper patient selection and stratification criteria, drug and dose intensities. Intraportal infusion may be as effective as systemic adjuvant treatment; the tumor type and stage for which benefit from this kind of treatment is consistently significant needs to be defined, since intraportal infusion of all resectable colorectal cancers is overtreatment. Both surgery and histopathological staging may be improved in some centers, and these require standardization and quality control.

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.

Potential disadvantages of post-operative adjuvant radiotherapy after anterior resection for rectal cancer: a pilot study of sphincter function, rectal capacity and clinical outcome

The aim of this study was to try to gauge the functional effect of post-operative adjuvant radiotherapy after potentially curative anterior resection for carcinoma of the rectum. Anorectal function was studied both in the laboratory and clinically in 59 patients, a median of 12 months (range 6-96) after operation. Nine patients received post-operative radiotherapy and 50 matched patients were treated by surgery alone. Though maximum resting anal pressures and maximum squeeze pressures were similar in the two groups of patients, the length and pressure profile of the anal sphincter were both markedly abnormal after radiotherapy. The capacity and compliance of the neorectum were diminished significantly after radiotherapy (maximum tolerated volume 53 ml vs 110 ml after surgery alone, P = 0.008, compliance 1.5 ml/cm H2O vs 3.7 ml/cm H2O after surgery alone, p = 0.018) and the amount of distension of the neorectum required to produced maximum inhibition of the anal sphincter during the rectoanal inhibitory reflex was also significantly diminished after radiotherapy (P = 0.005). Clinical anorectal function was worse among patients who had received radiotherapy, a greater proportion of whom experienced both urgency of defaecation and varying degrees of incontinence. Major faecal leakage necessitating the use of a pad was recorded in 3 of the 59 patients after radiotherapy (one of whom required a permanent colostomy), but in only 5 of 50 patients after surgery alone.

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.

Impact of combined modality therapy on the treatment of adenocarcinoma of the colon

An emphasis on careful surgical staging of adenocarcinoma of the colon has improved the predictive value of tumor staging systems. As a result of improved staging and carefully conducted randomized clinical trials, adjuvant therapy of locally advanced colon cancer, based on 5-fluorouracil chemotherapy, has been proven to substantially reduce recurrence rates and significantly increase overall survival for selected patients. Improved treatments and schedules are currently being studied in randomized trials and may increase the efficacy of this adjuvant therapy. Radiation therapy has not as yet been integrated into the adjuvant treatment of colon carcinoma. The application of a combined approach of surgery and chemotherapy in selected patients with liver metastases may also improve cure rates and long-term survival. The developing understanding of molecular determinants for the biological behavior of these cancers will increase the opportunities to identify, on the one hand, those patients who will benefit from specific therapies, and, on the other hand, new therapeutic strategies and treatments.