Adjuvant postoperative radiotherapy in carcinoma of the rectum and rectosigmoid

Current status of locally advanced rectal cancer therapy and future prospects

Rectal cancer treatment has been evolving ever since the beginning of the 20th century. Surgery was originally the only available method regardless of the extent of tumor invasion or nodal involvement status. Total mesorectal excision was established as the standard procedure in the early 1990s. Advances in the utilization of radiation for rectal cancer led to the addition of radiotherapy (RT) combined with chemotherapy to the postoperative treatment algorithm. The promising results of the Swedish short-course preoperative RT set the basis for a number of large randomized trials investigating the efficacy of neoadjuvant RT or chemoradiotherapy (CRT) for advanced rectal cancer. Both short-course RT and long-course preoperative CRT compared favorably to adjuvant treatment and became the standard of choice for patients with extramural invasion or lymph node involvement. Recently, the focus of clinical research has been shifted towards total neoadjuvant therapy (TNT), delivering the whole course of RT and chemotherapy before surgery, and showing good tolerance and encouraging efficacy. Although targeted therapies haven't displayed a benefit in the neoadjuvant setting, preliminary evidence suggests impressive efficacy of immunotherapy in rectal carcinomas with mismatch-repair deficiency. In this review, we provide an in-depth critical overview of all significant randomized trials that have shaped the current treatment guidelines for locally advanced rectal cancer and discuss future trends for the treatment of this common malignancy.

Postoperative hypofractionated-accelerated radiotherapy (HypoAR) for locally advanced rectal cancer

BACKGROUND

despite the advances in preoperative hypofractionated-accelerated radiotherapy for patients with locally advanced rectal cancer, postoperative radiotherapy delivered with standard fractionation (46-50 Gy in 5 weeks) remains a standard adjuvant schedule. The role of hypofractionated-accelerated radiotherapy in a postoperative setting remains largely unexplored.

METHODS

eighty-eight patients with rectal cancer infiltrating the rectal wall and/or having metastasis to the perirectal lymph nodes were treated with surgery followed by adjuvant chemotherapy and, subsequently, with hypofractionated-accelerated radiotherapy. Ten fractions of 3.4 Gy were delivered to the pelvis for 10 consecutive fractions, within 12 days. The follow-up of patients alive at the time of analysis ranges from 12-120 months (median 48).

RESULTS

mild abdominal discomfort and diarrhoea were frequent, but medical medication was demanded in 14/88 (15.9%) of patients. The incidence of late toxicities was low; 4/88 (3.5%) patients complained for intermittent intestinal urgency. Locoregional recurrence occurred in 8/88 patients (9%). The 5-year locoregional relapse-free survival was achieved in 89.7% of patients, and this dropped to 84% in node-positive patients (P = 0.45). The 5-year disease-specific overall survival was 72.4%. Nodal involvement showed a trend to negatively affect prognosis (5-year overall survival 68.2 vs. 79.6%; P = 0.23).

CONCLUSION

postoperative hypofractionated-accelerated radiotherapy has minimal early and late toxicity. The locoregional control and disease-specific survival rates are similar to the expected from conventional postoperative chemoradiotherapy. The 2.5-fold decrease of radiotherapy treatment time, reduction of waiting lists and the lower overall cost of radiotherapy are additional benefits associated with hypofractionated-accelerated radiotherapy.

Postoperative Adjuvant Chemoradiotherapy for Rectal Cancer: Analysis of Acute and Chronic Toxicity

Aims and background

The aim of the study was to evaluate acute and chronic toxicity of combined postoperative standard radiation therapy to the pelvis and 5-fluorouracil plus levamisole in resectable rectal cancer.

Methods

Between July 1990 and September 1993, 58 patients with histologically confirmed adenocarcinoma of the rectum entered the prospective study. The schedule consisted of 5-fluorouracil, 450 mg/m2 i.v. for 5 days, and from day 28 5-fluorouracil, 450 mg/m2 i.v. weekly for 24 weeks, plus levamisole given orally at the dose of 150 mg every day for 3 days every 2 weeks for 6 months; radiotherapy (180 cGy/day) 5 days a week for a total dose of 45 Gy was administered from day 28.

Results

After the first cycle of chemotherapy (before radiotherapy), overall toxicity was mild. During chemoradiotherapy, dose-limiting toxicity was grade 3 diarrhea and proctitis, for which the combined treatment was interrupted for more than 7 cumulative days in 28 patients. During the 24 weeks of weekly 5-fluorouracil (after radiotherapy), no severe toxicity was reported. Three-year survival and progression-free survival were 65% and 50–55%, respectively.

Conclusions

Although adjuvant chemoradiotherapy is usually feasible, in our study toxicity was severe in a substantial proportion of patients, probably due to the schedule applied. We are evaluating the feasibility and toxicity of a combined treatment which includes 5-fluorouracil in continuous chronomodulated infusion during radiotherapy.

Revised TN categorization for colon cancer based on national survival outcomes data

PURPOSE

The sixth edition of American Joint Committee on Cancer (AJCC) Cancer Staging Manual for colon cancer subdivided stage II into IIA (T3N0) and IIB (T4N0) and stage III into IIIA (T1-2N1M0), IIIB (T3-4N1M0), and IIIC (anyTN2M0). Subsequent analyses supported revised substaging of stage III because of improved survival for T1-2N2 versus T3-4N2 and T4N1 survival was more similar to T3-4N2 than to T3N1. The AJCC Hindgut Taskforce sought population-based validation that depth of invasion and nodal status interact to affect survival.

PATIENTS AND METHODS

Surveillance, Epidemiology, and End Results (SEER) population-based data from January 1992 to December 2004 for 109,953 colon cancer patients were compared with National Cancer Data Base (NCDB) data on 134,206 patients. T4N0 cancers were stratified by tumors that perforate visceral peritoneum (T4a) versus tumors that invade or are adherent to adjacent organs or structures (T4b). N1 and N2 were stratified by number of involved positive lymph nodes (N+): N1a/N1b (1 v 2-3), N2a/N2b (4 to 6 v > or = 7). Five-year observed and relative survival data were obtained for each TN category.

RESULTS

SEER rectal cancer analyses confirm that T1-2N2 cancers have better prognosis than T3-4N2,T4bN1 have similar prognosis to T4N2, T1-2N1 have similar prognosis to T2N0/T3N0, and T1-2N2ahave similar prognosis to T2N0/T3N0 (T1N2a) or T4aN0 (T2N2a). Prognosis for T4a lesions is betterthan T4b by N category. The number of positive nodes affects prognosis.

CONCLUSION

This SEER population-based colon cancer analysis is highly consistent with rectal cancer pooled analysis and SEER rectal cancer analyses, supporting the shift of T1-2N2 lesions from IIIC to IIIA/IIIB, shifting T4bN1 from IIIB to IIIC, subdividing T4/N1/N2, and revising substaging of stages II/III. Survival outcomes by TN category for colon and rectal cancer are strikingly similar.

Revised tumor and node categorization for rectal cancer based on surveillance, epidemiology, and end results and rectal pooled analysis outcomes

PURPOSE

The sixth edition of the American Joint Committee on Cancer (AJCC) rectal cancer staging subdivided stage II into IIA (T3N0) and IIB (T4N0) and stage III into IIIA (T1-2N1M0), IIIB (T3-4N1M0), and IIIC (anyTN2M0). Subsequent analyses supported revised substaging of stage III as a result of improved survival with T1-2N2 versus T3-4N2 and survival of T4N1 more similar to T3-4N2 than T3N1. The AJCC Hindgut Taskforce sought population-based validation that depth of invasion interacts with nodal status to affect survival.

METHODS

Surveillance, Epidemiology, and End Results (SEER) population-based data from January 1992 to December 2004 for 35,829 patients with rectal cancer were compared with rectal pooled analysis data (3,791 patients). T4N0 cancers were stratified by tumors that perforate visceral peritoneum (T4a) versus tumors that invade or are adherent to adjacent organs or structures (T4b). N1 and N2 were stratified by number of positive nodes as follows: N1a/N1b (one v two to three nodes) and N2a/N2b (four to six v > or = seven nodes). Five-year observed and relative survival rates were obtained for each TN category.

RESULTS

SEER rectal cancer analyses confirm that T1-2N2 cancers have better prognosis than T3-4N2, T4bN1 have similar prognosis to T4N2, T1-2N1 have similar prognosis to T2N0/T3N0, and T1-2N2a have similar prognosis to T2N0/T3N0 (T1N2a) or T4aN0 (T2N2a). Prognosis for T4a lesions is better than T4b by N category. The number of positive nodes affects prognosis.

CONCLUSION

This SEER population-based rectal cancer analysis validates the rectal pooled analyses and supports the shift of T1-2N2 lesions from IIIC to IIIA or IIIB and T4bN1 from IIIB to IIIC. SEER outcomes support subdividing T4, N1, and N2 and revised substaging of stages II and III. Survival by TN category suggests a complex biologic interaction between depth of invasion and nodal status.

Impact of T and N stage and treatment on survival and relapse in adjuvant rectal cancer: a pooled analysis

PURPOSE

To determine survival and relapse rates by T and N stage and treatment method in five randomized phase III North American rectal adjuvant studies.

PATIENTS AND METHODS

Data were pooled from 3,791 eligible patients enrolled onto North Central Cancer Treatment Group (NCCTG) 79-47-51, NCCTG 86-47-51, US Gastrointestinal Intergroup 0114, National Surgical Adjuvant Breast and Bowel Project (NSABP) R01, and NSABP R02. Surgery alone (S) was the treatment arm in 179 patients. The remaining patients received adjuvant treatment as follows: irradiation (RT) alone (n = 281), RT + fluorouracil (FU) +/- semustine bolus chemotherapy (CT; n = 779), RT + protracted venous infusion CT (n = 325), RT + FU +/- leucovorin or levamisole bolus CT (n = 1,695), or CT alone (n = 532). Five-year follow-up was available in 94% of surviving patients, and 8-year follow-up, in 62%.

RESULTS

Overall (OS) and disease-free survival were dependent on TN stage, NT stage, and treatment method. Even among N2 patients, T substage influenced 5-year OS (T1-2, 67%; T3, 44%; T4, 37%; P <.001). Three risk groups of patients were defined: (1) intermediate (T1-2/N1, T3/N0), (2) moderately high (T1-2/N2, T3/N1, T4/N0), and (3) high (T3/N2, T4/N1, T4/N2). For intermediate-risk patients, those receiving S plus CT had 5-year OS rates of 85% (T1-2/N1) and 84% (T3/N0), which was similar to results with S plus RT plus CT (T1-2/N1, 78% to 83%; T3/N0, 74% to 80%). For moderately high-risk lesions, 5-year OS ranged from 43% to 70% with S plus CT, and 44% to 80% with S plus RT plus CT. For high-risk lesions, 5-year OS ranged from 25% to 45% with S plus CT, and 29% to 57% with S plus RT plus CT.

CONCLUSION

Different treatment strategies may be indicated for intermediate-risk versus moderately high- or high-risk patients based on differential survival rates and rates of relapse. Use of trimodality treatment for all patients with intermediate-risk lesions may be excessive, since S plus CT resulted in 5-year OS of approximately 85%; however, 5-year disease-free survival rates with S plus CT were 78% (T1-2/N1) and 69%(T3/N0), indicating room for improvement.

Postoperative Radiochemotherapy in Rectal Cancer Comparison of two Combination Schemes: Alternating versus Concomitant

Aims and background

To compare the results on disease control and toxicity of two different schedules of adjuvant combined treatment in advanced rectal cancer.

Methods

From January 1995 to September 1998, 127 patients with stage B2-C rectal cancer were treated with postoperative chemotherapy and radiotherapy with two different schemes: three cycles of 5-fluorouracil and leucovorin followed by pelvic radiotherapy and three weeks after radiation therapy was completed, another three cycles of chemotherapy were administered (alternating arm), or two cycles of 5-fluorouracil and leucovorin followed by concurrent radiochemotherapy and three weeks after ending another two cycles of 5-fluorouracil and leucovorin were administered (concomitant arm).

Results

Grade 3 acute toxicity was more frequent in the concomitant schedule group (33% vs 13%, P = 0.014). In the alternating schedule group, the acute adverse effects were observed after an average radiation dose of 28.4 Gy and in the concomitant schedule group after an average dose of 22.7 Gy (P = 0.012). In the arm of concomitant treatment, 37.8% of patients had to interrupt the irradiation for severe toxicity compared to 10.4% in the arm of alternating treatment (P = 0.001). There was no difference in the rate of late toxicity. The actuarial overall survival rates at 3 and 5 years were, respectively, 68.8% and 56.6% in the alternating arm and 75.5% and 61.8% in the concomitant arm (P = 0.4599). There were no differences between the two arms in the 5-year actuarial rates of overall recurrence (47% vs 51.3%, P= 0.722), local recurrence (34.6% vs 35.7%, P = 0.935) or distant recurrence (32.7% vs 31.8%, P = 0.983).

Conclusions

For patients with B2-C rectal cancer, postoperative treatment with an alternating scheme of chemoradiotherapy is as effective as a concomitant scheme in control of the disease. The concomitant scheme had a higher incidence, earlier appearance and higher severity of intestinal acute toxicity than the alternating scheme, with a lower completion rate of chemoradiotherapy but without any influence on late toxicity incidence.

Rectal cancer: preoperative versus postoperative irradiation as a component of adjuvant treatment

The search for improved disease control and survival for resectable but high-risk rectal cancers has led to studies that combine all 3 modalities. For surgically resected, high-risk rectal cancers, postoperative chemoradiation has been shown to improve both disease control (local and distant) and survival (disease free and overall) and was recommended as standard adjuvant treatment at the 1990 National Institute of Health Colorectal Cancer Consensus Conference. Three randomized studies showed improved overall survival (OS) and local control for patients treated with postoperative irradiation and chemotherapy when compared with surgery alone or surgery plus irradiation control arms. These include 2 US trials, Gastrointestinal Tumor Study Group and Mayo/North Central Cancer Treatment Group (NCCTG) and a Norway trial. Although most preoperative external beam radiation trials show reductions in local relapse with the addition of preoperative EBRT to resection, only the large Swedish trial of approximately 1,100 patients showed a survival improvement when compared with a surgery alone control arm for resectable primary rectal cancers. In a recent pooled analysis of 3 postoperative adjuvant rectal cancer trials (NCCTG 794751, NCCTG 864751, and GI Intergroup 0114) survival and disease relapse were dependent on both TN and NT stage of disease (N substage within T stage and T substage within N stage). Even among N2 patients (4 or more positive nodes), T substage influenced 5-year OS (T1-2, 69%; T3, 48%; and T4, 38%; P <.001). Ongoing randomized trials are being conducted for patients with high-risk, resectable primary rectal cancers. The intent is to help define optimal combinations of postoperative chemoradiation (US GI Intergroup), to test sequencing issues of preoperative versus postoperative chemoradiation (Germany trial), and to determine if concurrent and maintenance 5-FU and leucovorin add to the benefits found with preoperative irradiation (European Organization for Research and Treatment of Cancer). For subsequent trials, it may be preferable to perform separate studies, or a planned statistical analysis, for different risk groups of patients (low, intermediate, moderately high, and high), as defined in the rectal cancer pooled analysis.

Impact of T and N substage on survival and disease relapse in adjuvant rectal cancer: a pooled analysis

PURPOSE

To determine the rates of survival and disease control by TNM and MAC stage in three randomized North American rectal adjuvant studies.

MATERIALS AND METHODS

Data were merged from 2551 eligible patients on NCCTG 79-47-51 (n = 200), NCCTG 86-47-51 (n = 656), and INT 114 (n = 1695). All patients received postoperative radiation, and 96% were randomized to receive concomitant and maintenance chemotherapy. Five-year follow-up was available in 94% of patients and 7-yr follow-up in 84%. Kaplan-Meier curves were used to estimate the distribution of overall survival (OS) and disease-free survival (DFS), and p values were derived using the log-rank test. Time to local and distant relapse was estimated using cumulative incidence methodology. Analyses were adjusted for treatment effect using Cox proportional hazards models.

RESULTS

OS and DFS were dependent on both TN stage and NT stage (N substage within T stage and T substage within N stage). Even among N2 patients (4 or more LN+), T stage influenced 5-yr OS (T1-2, 69%; T3, 48%; T4, 38%). Three risk groups of patients were defined: (1) intermediate: T3N0, T1-2N1; (2) moderately high: T4N0, T1-2N2, T3N1; and (3) high: T3N2, T4N1, T4N2. For Group 1, 5-yr OS was 74% and 81%, and 5-yr DFS was 66% and 74%. For Group 2, 5-yr OS ranged from 61% to 69%, and for Group 3, OS ranged from 33% to 48%. Cumulative incidence rates of local relapse and distant metastases revealed similar differences by TN and NT stage, as seen in the survival analyses.

CONCLUSION

Patients with a single high-risk factor of either extension beyond the rectal wall (T3N0) or nodal involvement (T1-2N1) have improved OS, DFS, and disease control when compared to those with both high risk factors. Different treatment strategies may be indicated for intermediate- (T3N0, T1-2N1) vs. moderately high or high-risk patients in view of differential survival and rates of relapse. For future trial design, it may be preferable to perform separate studies, or a planned statistical analysis, for the "intermediate-risk" vs. the "moderately high" or "high-risk" subsets of patients.

Hyperthermia for rectal cancer

BACKGROUND

In order to improve the clinical results of rectal cancer, hyperthermia has been prescribed in combination with chemotherapy and radiotherapy. The techniques of hyperthermia and their clinical applications to rectal cancer were reviewed.

METHODS

The development of heating devices has been intensively investigated, including external heating devices, intraluminal heating devices, circulation of warmed saline solution, and whole body hyperthermia.

RESULTS

Nonrandomized and randomized trials for rectal cancer have demonstrated an improved local response with the combined use of hyperthermia and conventional treatments. A preoperative therapy with hyperthermia increased resectability and decreased local recurrence, resulting in the improvement of the postoperative prognosis. There were no major postoperative complications related to the preoperative treatment. A lower incidence of local recurrence was observed in groups that underwent intra- or postoperative hyperthermia treatment, as compared with control groups. In cases with unresectable or local recurrent rectal cancer, hyperthermia achieved a local tumor regression and prolonged pain relief.

CONCLUSIONS

These clinical data suggest that hyperthermia combined with radiation or chemotherapy demonstrates great promise for the treatment of patients with carcinoma of the rectum.

Postoperative pelvic radiotherapy with or without elective irradiation of para-aortic nodes and liver in rectal cancer patients. A controlled clinical trial of the EORTC Radiotherapy Group

OBJECTIVE

The purpose of this randomized multicenter study was to assess the impact on disease free and overall survival of low dose irradiation to para-aortic nodes and liver in patients with a locally advanced resected rectal cancer receiving a 50 Gy postoperative pelvic radiotherapy.

PATIENTS AND METHODS

Main inclusion criteria were: a curative resection for a histologically proved carcinoma of the rectum, Gunderson-Sosin stages B2-B3, C1-C3, age <70 years. The patients were randomized between pelvic irradiation (Lim-XRT): 50 Gy in 25 fractions over 5 weeks and extended irradiation (Ext-XRT): same scheme/doses in the pelvis and extended fields on para-aortic nodes and liver, delivering 25 Gy in 19 fractions over 25 days. From 1983 to 1992, 484 patients were enrolled by 18 EORTC institutions and 29 patients were ineligible. The end-points were local and distant relapses, toxicity and survival.

RESULTS

Compliance to treatment: 87.2% in Lim-XRT arm and 71.8% in Ext-XRT arm. Moderate acute hematological and hepatic toxicities were significantly increased in Ext-XRT arm. Among 325 patients at risk, 44 suffered a severe intestinal complication requiring surgery in 29. The 5- and 10-year estimates of disease free survival were respectively 42 and 31% in Lim-XRT arm and 47 and 31% in Ext-XRT arm (ns). The corresponding figures for overall survival were respectively 45 and 40% in Lim-XRT arm and 48 and 37% in Ext-arm (ns). The 10 years estimate of intra-pelvic failures was approximately 30% in both arms. Patients in Ext-arm appeared to have a slight shorter interval free of liver metastases (P=0.047).

CONCLUSION

Low dose irradiation to the para-aortic nodes and liver did not improve survival for patients with resected adenocarcinoma of the rectum.

Dislocation of small bowel volume within box pelvic treatment fields, using new "up down table" device

PURPOSE

To present the impact of a novel minimization device, the up down table (UDT), on the volume of small bowel included within a 4-field pelvic irradiation plan.

METHODS

A polystyrene bowel displacement standard mold was created and added to a customized vacuum cushion (Vac Lok) formed around the abdomen and legs of each patient in the prone position. Two hundred seventy-seven consecutive patients with pelvic malignancies treated with the UDT device were compared with 1 historic series (68 cases) treated at our division. Small bowel contrast dyes at the time of simulation were used in all patients.

RESULTS

The average volume of small bowel within the planning target volume (high-dose volume, calculated with Gallagher method) was 100 cm(3) (median 49 +/- 114) in the series treated with standard box technique and 23 cm(3) (median 0 +/- 64) in the series treated with the UDT (p < 0.001). The average volume of small bowel included in any isodose (any-dose volume) was 505 cm(3) (median 447 +/- 338) and 158 cm(3) (median 69 +/- 207), respectively (p < 0.001). The incidence of G1, G2, and G3 acute enteric toxicity (Radiation Therapy Oncology Group criteria) in the UDT series was 16%, 15%, and 1.5%; in the standard box technique, it was 28%, 25%, and 3%, respectively (p < 0.05). The incidence of acute enteric toxicity directly correlated with the irradiated small bowel volume. In the UDT series, the 5-year actuarial incidence of G3 chronic enteric toxicity was 1.8%. The setup procedures, analyzed in 18 cases, revealed no systematic errors and a standard deviation equal to +/-5 mm for random errors.

CONCLUSIONS

The UDT technique is comfortable, inexpensive, highly reproducible, and permits an almost full bowel displacement from standard radiotherapy fields.

The role of radiation therapy in the adjuvant treatment of rectal cancer

There have been several advances in the treatment of rectal cancer in the past 20 years. The recognition that surgical therapy alone leads to a local failure rate of 15 to 50% in stages II and III has led to the use of adjuvant radiation therapy. Multiple prospective, randomized trials conducted by multi-institutional cooperative groups have resulted in the use of adjuvant combined modality therapy using radiation therapy and 5-fluorouracil chemotherapy. Some of the trials fine-tuned the sequencing and dose of radiation and chemotherapy to maximize efficacy and minimize toxicity. The advent of accurate endorectal ultrasound and MRI staging has allowed the use of preoperative therapy without the unnecessary treatment of patients with early stage. This has resulted in greater sphincter preservation and fewer complications. The optimal sequencing of adjuvant therapy has yet to be found.

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.

Rectal cancer: changing patterns of referral for radiation therapy 1982-1997

BACKGROUND

The purpose of the present study was to evaluate the changing role of radiation therapy in rectal cancer and to determine the patterns of referral of patients during a 15-year period.

METHODS

From 1982 to 1997, 464 patients with carcinoma of the rectum were referred to the Department of Radiation Oncology, Royal Prince Alfred Hospital: 79% of patients had locoregional disease alone and 21% had distant metastasis. Radiation therapy consisted of irradiation (definitive or palliative) alone to the primary tumour in 9.7% of cases; preoperative radiation in 7.3% of cases: preoperative chemoradiation in 7.5% of patients: postoperative radiation in 15.3% of patients: postoperative chemoradiation in 12.31% of patients: treatment of pelvic recurrence in 23.5% of patients and treatment of metastases in 9.1% of patients. The remainder were treated elsewhere (1.9%) or not treated (13.4%).

RESULTS

There was an average annual 14% increase in referrals over the accrual period. Recurrent rectal cancer decreased from approximately 30% of referrals during 1982-91 to approximately 10% in 1995-7. The use of postoperative adjuvant radiation reached a peak of 50% in 1993. The use of preoperative radiation increased suddenly in 1994 from < 10% to a sustained rate of approximately 30% of referrals. The use of chemoradiation commenced in 1990 for postoperative adjuvant treatment and in 1994 for preoperative treatment. The median survival time from initial diagnosis was 35 months, with 2- and 5-year survival rates of 62 and 28%, respectively. Survivals at 5 years for patients treated with preoperative and postoperative radiation (with or without chemotherapy) and with recurrent disease were 56, 44 and 21%, respectively.

CONCLUSIONS

The present study illustrates the changing role of radiation therapy in the management of rectal cancer. The increase in referrals over the observation period was due to increased multidisciplinary input into the initial management of these patients, based on reported clinical trials. The steady increase in the use of adjuvant therapy has paralleled a decrease in referrals for treatment of recurrence and reflects current clinical results. The sequencing of adjuvant therapy is changing currently, with greater emphasis on preoperative adjuvant treatment. Currently most adjuvant therapy includes chemotherapy.

[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.

The prognostic significance of p53 expression for survival and local control in rectal carcinoma treated with surgery and postoperative radiotherapy

PURPOSE

To investigate whether p53 immunoreactivity is a prognostic factor for survival and pelvic control in rectal carcinoma treated with surgery and postoperative radiotherapy.

METHODS AND MATERIALS

From 1981 through 1989, 146 patients with rectal carcinoma received postoperative radiotherapy and were followed for at least 5 years or until death. The specimens of 123 of these 146 patients could be retrieved and examined immunohistochemically for p53 expression. The prognostic value for survival and pelvic control of p53 expression and other patient and treatment factors was examined by univariate and multivariate analyses.

RESULTS

p53 expression has no prognostic significance for overall survival in this group of 123 patients. The only prognostic factor for survival in this material is tumor stage (p < 0.01). The actuarial pelvic recurrence rates of p53- and p53+ cases are different in favor of the p53- ones. In the univariate analysis this difference is significant (p = 0.05). However, in the multivariate analysis the influence of p53 expression, additional to stage, becomes nonsignificant (p = 0.10). This indicates that p53 expression is not a strong independent prognostic factor for pelvic recurrence. In the multivariate analysis stage turns out to be the only predictor of pelvic recurrence (p = 0.03). When only recurrences inside the radiation field are considered, there is no difference between p53+ and p53-cases.

CONCLUSION

Based on this material, we have found no convincing evidence that p53 expression is an important predictor of survival or local control in rectal cancer treated with surgery and postoperative radiotherapy. We have found no evidence that possible differences in radiosensitivity between p53+ and p53- tumors have clinical significance for this group of patients.

Theoretical and practical uses of elective systemic (half-body) irradiation after 20 years of experimental designs

This article traces the concept and different uses of systemic (Half-Body) irradiation (HBI) for the last 20 years. It presents both indirect and direct evidence of HBI effectiveness and discusses the various hypothesis that have been advanced to explain its success as a palliative and more recently as an elective therapeutic tool. The article discusses the transition from treating overt to subclinical metastatic disease and recalls the pioneer uses of elective HBI in lung and prostate cancers. Recent uses of elective HBI with a variety of unconventional fractionation schemes are discussed. These include clinical trials (51 patients with lung, esophagus, colorectal, prostate, ovary and endometrial cancers) and animal experiments (1195 C3H mice). An intriguing combination of hyper/hypo fractionated HBI proved to be the less toxic of all the schedules used in animals where mortality data, analyzed by the LQ Model, yielded an alpha/beta ratio of 8.3 Gy, a value generally associated with acutely responding tissue.

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.

Improved surgical results after combining preoperative hyperthermia with chemotherapy and radiotherapy for patients with carcinoma of the rectum

PURPOSE

The aim of this study is to evaluate long-term results of preoperative hyperthermia combined with chemotherapy and irradiation (HCR therapy) in patients with carcinoma of the rectum.

METHODS

Postoperative prognoses were compared among 36 patients with carcinoma of the rectum, who were given preoperative HCR therapy followed by surgery, and 52 patients undergoing surgery alone without any preoperative therapy.

RESULTS

There were significant differences in the prognosis between patients given preoperative HCR therapy plus surgery and those having surgery alone, and five-year survival rates were 91.3 and 64 percent, respectively. Particularly, for patients with tumors invading beyond the muscularis propria and/or with positive lymph node metastasis, a significantly longer survival was obtained with HCR plus surgery than in surgery alone (86.5 vs. 50.9 percent and 92.9 vs. 51.7 percent, respectively). However, no significant differences were observed in the postoperative prognosis for cases with no lymph node metastasis and/or with tumors limited to the muscularis propria between these two groups.

CONCLUSIONS

These data clearly demonstrated the effectiveness of preoperative HCR therapy for improving long-term results of patients with carcinoma of the rectum, especially those demonstrating an advanced stage of disease.

[The locoregional recurrence of rectal carcinoma. A computed tomographic analysis and a target volume concept for adjuvant radiotherapy]

BACKGROUND

In the adjuvant postoperative radiotherapy of rectal carcinoma the knowledge of the predominant areas of recurrences is of major importance for the definition of the target volume. We analysed the pattern and locations of tumor recurrences in the CT scans of 155 patients and correlated the findings with the primary tumor location (above and below the peritoneal duplication) and the operating method (abdominoperineal extirpation, anterior resection. Hartmann procedure).

PATIENTS AND METHOD

Hundred and fifty-five patients with the diagnosis of rectal carcinoma recurrences were treated in our institution between 1980 and 1995. To determine the extension of the recurrent tumor within the pelvic levels (presacral levels S1-S5, precoccygeal, pelvic floor level and perineal level) and the tumor infiltration of pelvic organs and muscles we analysed the pretherapeutic CT images. The lymph node recurrences were classified as: pararectal, presacral, iliac internal, iliac external, iliac communis and para-aortal recurrences.

RESULTS

Sixty-one percent of the patients with rectum extirpation and 66% with anterior resection showed a combined local and nodal recurrence. Isolated lymph node recurrences were rare (4% and 5%) (Tables 2 and 3). The local recurrence was mostly situated in the presacral pelvis, predominantly there was an infiltration of the presacral space at the level of S4, S5 and os coccygis regardless of the operating method and the primary tumor location (Figure 1). The anastomosis was involved in the tumor recurrence in 93% of the anteriorly resected patients (Table 3). In 9 out of 96 patients after rectum extirpation the pelvic region caudal of the tip of the coccyx was the origin of the recurrent tumor (Table 2, Figure 2). Primarily all 9 patients had a deep-seated carcinoma (< 6 cm ab ano). Only 2 patients showed an isolated perineal recurrence after rectum extirpation (Table 2. Figure 2). Two thirds of the deep-seated tumors showed a vaginal involvement (Figures 3 and 4). The incidence of iliac internal and presacral nodal recurrence was 47 to 59% (Figures 3 and 4). The incidence of iliac external lymph node recurrences was 7% after rectum extirpation and 2% after anterior resection/Hartmann procedure.

CONCLUSION

Our data demonstrate that 2/3 of the patients with tumor-bed recurrences also show lymph node recurrences predominantly in the iliac internal and presacral groups. This has to be considered in the definition of the boost target volume. The target volume must also include the dorsal wall of the urogenital organs. A ventral extension of target volume up to iliac external lymph nodes is not necessary.

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.

Preoperative and postoperative radiotherapy in rectal carcinoma

Surgery is the initial treatment of choice for most patients with rectal neoplasms. The objectives are to remove of tumor and drain the primary nodes. In stage I disease the surgical approach is though to be sufficiently effective. However, at least in the case of abdominoperineal resection, this causes considerable morbidity. Therefore, at the present time, there are efforts to reduce the extent of the resection by applying other treatment modalities in stage I disease. After curative resection in stage II/III disease a considerable number of patients suffer from local recurrence or distant metastases. In these patients adjuvant therapy is currently recommended. In locally advanced disease, primary resection is not feasible. Different treatment settings which apply combinations of all treatment modalities are possible. The article reviews the literature and shows future directions.

Pelvic radiation therapy combined with hepatic artery chemotherapy for resected rectal carcinoma with liver metastases

PURPOSE

Patients with hepatic metastases from rectal cancer treated with hepatic artery (HA) chemotherapy have a life expectancy great enough to be at risk for pelvic failure. Therefore, a treatment plan was developed for patients with resected rectal cancer and unresectable hepatic metastases, when the pathologic features of transmural invasion and perirectal lymph node metastases were present. Treatment consisted of concurrent pelvic radiation therapy (RT) and HA 5-fluorouracil (FUra), as systemic levels of FUra are achievable with HA administration, followed by HA fluorodeoxyuridine (FdUrd).

METHODS AND MATERIALS

Fifteen patients were offered combined pelvic RT and HA FUra. Radiation was given to an initial dose of 45 Gy to the pelvis, followed by boost treatment for an additional 5.4-10.8 Gy. Concurrent HA chemotherapy was given using FUra or FUra/leucovorin administered in two cycles of 14 days for each cycle. If HA chemotherapy could not be done, then intravenous FUra was given during RT. Following completion of RT and HA FUra, patients were evaluated for treatment with HA FdUrd.

RESULTS

Eleven patients received concurrent HA FUra or FUra/leucovorin and pelvic RT. Of these, six continued to receive HA FdUrd after completion of RT, as five patients were found to have progressive hepatic disease. Four patients could not have therapy as outlined, but did receive pelvic RT with concurrent intravenous FUra (two patients), FUra/leucovorin (one patient), or sequential HA FUra (one patient). There were four pelvic recurrences at 1, 4, 14, and 17 months after RT. One was the first site of progression, two occurred simultaneously with other failure, and one occurred after hepatic progression. The liver was the most frequent site of first progression (alone in seven patients; as a component of progression in four patients). Treatment was well tolerated with three Grade > or = 3 toxicities. The median survival was 14 months.

CONCLUSIONS

These data support the hypothesis that patients with metastatic rectal cancer are also at risk for pelvic recurrence. The frequency of hepatic progression supports continued aggressive therapy directed to this site. As systemic and regional therapy of metastatic rectal cancer improves, we anticipate that more patients will be at risk for a pelvic recurrence, making it increasingly important to explore the role of pelvic radiation therapy despite the presence of metastatic disease.

Adjuvant therapy with chemotherapy and radiation therapy in the management of carcinoma of the pancreatic head

Surgical resection remains the backbone of the curative management of carcinoma of the pancreatic head. The primary cause of recurrence appears to be residual locoregional subclinical disease. Data supporting the use and continued study of adjuvant chemotherapy and radiation therapy are summarized.

Radiation dose-response of human tumors

PURPOSE

The dose of radiation that locally controls human tumors treated electively or for gross disease is rarely well defined. These doses can be useful in understanding the dose requirements of novel therapies featuring inhomogeneous dosimetry and in an adjuvant setting. The goal of this study was to compute the dose of radiation that locally controls 50% (TCD50) of tumors in human subjects.

METHODS AND MATERIALS

Logit regression was used with data collected from single institutions or from combinations of local control data accumulated from several institutions treating the same disease.

RESULTS

90 dose response curves were calculated; 62 of macroscopic tumor therapy, 28 of elective therapy with surgery for primary control. The mean and median TCD50 for gross disease were 50.0 and 51.9 Gy, respectively. The mean and median TCD50 for microscopic disease control were 39.3 and 37.9 Gy, respectively. At the TCD50, an additional dose of 1 Gy controlled an additional 2.5% (median) additional patients with macroscopic disease and 4.2% (median) additional patients with microscopic disease. For both macro- and microscopic disease, an increase of 1% of dose at the TCD50 increased control rates approximately 1% (median) or 2-3% (mean). A predominance of dose response curves had shallow slopes accounting for the discrepancy between mean and median values.

CONCLUSION

Doses to control microscopic disease are approximately 12 Gy less than that required to control macroscopic disease, and are about 79% of the dose required to control macroscopic disease. The percentage increase in cures expected for a 1% increase in dose is similar for macroscopic microscopic disease, with a median value of approximately 1%/% and a mean of approximately 2.7%/%.

Treatment of local recurrences of rectal carcinoma

From 1978-1992, 159 patients were treated for local recurrences of rectal carcinoma. They could be subdivided into three groups according to the type of primary treatment given; 82 patients underwent primary surgery without irradiation, 37 patients had preoperative and 40 patients postoperative radiotherapy. The localizations of the recurrences and the curative and palliative potentials of surgery and radiotherapy in the treatment of local recurrences were studied. There was no difference in the localisation of the recurrences in the three groups. Median time between initial surgery and recurrence was also almost the same in the three groups and 75% of the recurrences appeared within 2 years. Twenty percent of the patients in the primary surgery alone group, compared with 49% and 38% in the preoperative and postoperative irradiation groups, respectively, had distant metastases at the time of the diagnosis of local recurrence. The predominant symptom from the local recurrence was pain and, after treatment of the recurrence, pain relief was registered in 63%. In 66%, 16% and 22%, respectively, of the patients in the three groups, the intention of the treatment was curative, with either radiotherapy alone, radiotherapy combined with surgery or surgery alone. The 5-years-survival after recurrence was 6% in the primary surgery alone group and 0% in the other 2 groups. Of the 69 patients treated with a curative intention, 32% were locally symptom-free at death or the last follow-up. Our conclusion is that a local recurrence must be avoided due to the morbidity associated with local failure and the potentially low likelihood of curative treatment of a local recurrence.

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.

Evaluation of preoperative radiation therapy in operable colorectal cancer

MATERIALS AND METHODS

Patients with operable colorectal cancer in the ascending colon, descending colon, and rectum were randomized to 500 cGy before definitive surgery. Patients with stage A and B1 lesions received no further treatment. All patients with stage B2, B3, C1, C2, and C3 received a minimum of 4500 cGy postoperatively.

RESULTS

Three hundred fifty-three patients were registered for the study. Three hundred one patients were available for analyses. Follow-up was a minimum of 5 years on all study patients. The majority of patients had rectal cancer. Complications of treatment were acceptable. Two hundred thirty-one patients had stage B2, B3, C1, C2, or C3 tumors. Estimated 5-year rates for no preoperative therapy versus preoperative therapy were as follows: local recurrence 29% versus 26%; metastasis 41% versus 43%; and survival 54% versus 54%. No statistical benefit was observed for preoperative treatment.

CONCLUSIONS

In a prospective randomized trial designed to test the value of low-dose preoperative irradiation followed by surgery and postoperative irradiation, the authors were unable to observe any benefit to low-dose preoperative therapy in patients with unfavorable stages.

The long-term effect of adjuvant postoperative chemoradiotherapy for rectal carcinoma on bowel function

OBJECTIVE

The authors assessed the long-term effect of postoperative chemoradiotherapy on bowel function.

SUMMARY BACKGROUND DATA

Adjuvant postoperative radiation therapy, often combined with chemotherapy, is being used increasingly often for rectal carcinoma. However, the long-term effect of this treatment on bowel function has not been investigated.

METHODS

The records were reviewed of all patients undergoing anterior resection for rectal carcinoma 2 to 5 years previously. During this period, patients with Astler-Coller stage B2 or C tumors generally were given postoperative radiation therapy with chemotherapy, whereas those with earlier stage tumors were not. To minimize possible confounding factors that may have been more common in the group receiving chemoradiotherapy and that may affect bowel function, extensive exclusion criteria were used, such as invasion of contiguous organs, local or distant metastases, use of a dysfunctioning stoma, and anastomotic or pelvic complications. One hundred remaining patients were suitable for inclusion in the study and participated in a telephone questionnaire; 41 patients had postoperative chemoradiotherapy, and 59 did not.

RESULTS

The two groups were well matched for sex, level of anastomosis, and length of follow-up, although the group receiving chemoradiotherapy was slightly younger. The group that had chemoradiotherapy had more bowel movements per day than the group that did not have radiation therapy (median 7 vs. median 2, p < 0.001); the former group had "clustering" of bowel movements more often (42% vs. 3%, p < 0.001), had nighttime movements more often (46% vs. 14%, p < 0.001), had occasional or frequent incontinence more often (39% and 17% vs. 7% and 0%, p < 0.001), wore a pad more often (41% vs. 10%, p < 0.001), and were unable to defer defecation for more than 15 minutes more often (78% vs. 19%, p < 0.001). The group that had chemoradiotherapy also had stool of liquid consistency, used antidiarrheal medications, had perianal skin irritation, were unable to differentiate stool from gas, and needed to defecate again within 30 minutes of a movement significantly more often than the group that did not receive chemoradiotherapy.

CONCLUSION

Adjuvant postoperative chemoradiotherapy for rectal carcinoma has a major long-term detrimental effect on bowel function.

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.

Late complications of postoperative radiation therapy for cancer of the rectum and rectosigmoid

PURPOSE

We retrospectively examined the surgical, medical, radiotherapeutic and technical factors associated with late small bowel and nonsmall bowel morbidity.

METHODS AND MATERIALS

The medical records of 224 patients with cancer of the rectum and rectosigmoid treated mainly with abdominoperineal resection or anterior resection and postoperative radiotherapy at the University of Texas M.D. Anderson Cancer Center from 1973 to 1990 were reviewed. The median dose was 54 Gy (range 34-66 Gy) at 1.8-2 Gy per fraction using various techniques (23 had extended fields to L1 or L2; pelvic fields were treated with anterior-posterior in 85, 83 had a 3-field plan and 33 had a 4-field "box"). A positioning technique that treats patients on an open table-top device was used in 78 patients to move the small intestine out of the pelvis. Bladder distension was used in eight. Forty-seven patients received concomitant 5-fluorouracil. Small bowel series were performed in 122 patients to assess the volume of small bowel inside the pelvis below the conjugate line.

RESULTS

In 29 patients, the median time to the development of small bowel obstruction was 7 months (range 0-69 months); 18 patients required reoperations. The small bowel obstruction rate was 30% in patients treated with daily extended field radiotherapy, 21% in those with a single pelvic field and 9% with multiple pelvic fields. Small bowel obstruction was positively correlated with postsurgical adhesions prior to radiotherapy and absence of reperitonealization at the time of initial surgery (p < 0.05). There was no correlation of small bowel obstruction with a history of hypertension, diabetes, prior surgery, history of abdominal infections, postoperative infections, wound healing, pathologic tumor stage, types of surgical procedures, sites of primary tumor, age, or sex. Patients developing small bowel obstruction had larger amounts of small bowel assessed radiologically below the conjugate line than those without complications. With the open table-top device, the small bowel obstruction rate was 3%. In 47 patients treated with radiation and chemotherapy on the open table-top device, the small bowel obstruction rate was 15%, but these patients had more small bowel inside the pelvis than those without the complication. The median time to the development of nonsmall bowel obstruction in 29 patients was 8 months (range 0-85 months), and the nonsmall bowel obstruction complications were significantly correlated with postoperative infection. Most nonsmall bowel obstruction complications were in the genitourinary tract and occurred in patients who had abdominoperineal resection.

CONCLUSION

The open table-top device, by moving the small bowel out of the treatment field, reduces small bowel obstruction in patients treated with radical surgery and postoperative radiotherapy for cancer of the rectum and rectosigmoid. This technique is facile, reproducible, and does not require patient compliance.

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.

Postoperative local radiotherapy in rectal cancer: treatment results with limited radiation fields

PURPOSE

The purpose of this study is to determine the treatment results and complication rates of postoperative local radiotherapy, with doses per fraction of 2.25 to 2.50 Gy, in patients with rectal carcinoma who have received macroscopically radical surgery.

METHODS AND MATERIALS

A retrospective analysis was done of the records of all consecutive patients (N = 147) with rectal carcinoma Dukes' Stage B or C who have received postoperative local radiotherapy in our institution in the years 1981 through 1989. All patients have been treated on a limited target area covered by only local radiation fields. Locoregional fields covering the whole iliac node chains have not been given. In our treatment protocol doses per fraction were from 2.25 to 2.50 Gy and total doses from 50 to 55 Gy. The minimum follow-up was 24 months; eight patients have been lost to follow-up.

RESULTS

The overall 5-year survival rate for the whole group of patients was 39%. The actuarial 2- and 5-year pelvic recurrence rates were 14% and 22% respectively for Dukes' B patients and 30% and 38% respectively for Dukes' C patients. The difference between the pelvic recurrence rates of Stage B and Stage C patients was statistically significant (p = 0.009). No other factors with prognostic significance for pelvic recurrence were found. The interval between surgery and radiotherapy especially had no influence on pelvic recurrence rates. The 35 pelvic recurrences were classified as follows: 17 in-field, 5 marginal, 1 out-of-field, and 9 peritoneal seeding; in three patients there was not enough information for classification. Of the 32 classified pelvic recurrences, the five marginal recurrences were probably geographical misses, only the one out-of-field recurrences, the five marginal recurrences were probably geographical misses; only the one out-of-field recurrence might have been prevented with locoregional radiotherapy. Serious complications caused by the radiotherapy have occurred in 3% of the patients.

CONCLUSION

We conclude that the results of postoperative local radiotherapy alone are comparable with the published results of locoregional radiation. Even when relatively high doses per fraction are given low complication rates are seen.

Preoperative or postoperative irradiation in adenocarcinoma of the rectum: final treatment results of a randomized trial and an evaluation of late secondary effects

From 1980 to 1985, 471 patients with resectable rectal and rectosigmoid cancer were randomly allocated to receive either preoperative short-term high-dose irradiation (25.5 Gy in one week) for all patients or prolonged postoperative radiotherapy (60 Gy in seven to eight weeks) only for patients with a Dukes B or C lesion. After a minimum follow-up of five years, the local recurrence rate was statistically significantly lower after preoperative than after postoperative radiotherapy (13 percent vs. 22 percent; P = 0.02). No difference in overall survival was noted (P = 0.5). To evaluate possible late side effects on the bowel, urinary bladder, or skin after surgery and additional preoperative or postoperative radiotherapy, all patients included in the randomized trial, together with 58 patients from a preceding pilot study with the same preoperative regimen, were studied in a prolonged follow-up program. The hospital files of all patients were re-examined. Of the patients who were carefully examined, 176 had a survival exceeding five years and 19 had a survival exceeding 10 years. Overall, 7 percent (33/464) either were operated upon or have had a radiologic diagnosis of small bowel obstruction: 14/255 (5 percent) after preoperative irradiation, 14/127 (11 percent) after postoperative irradiation, and 5/82 (6 percent) after surgery alone. The cumulative risk of developing a bowel obstruction was significantly increased after postoperative radiotherapy. Among the 98 patients alive after preoperative irradiation, significant morbidity from the bowel was noted in 11 patients, from the urinary bladder in two, and from the skin in six. In the postoperatively treated group of 34 patients, the bowel, urinary bladder, and skin morbidity were significant in five, two, and five patients, respectively. Corresponding morbidity in 44 nonirradiated patients was seen in five, one, and two patients, respectively. It is concluded that preoperative, short-term, high-dose radiotherapy decreases the local recurrence rate relative to postoperative radiotherapy, with no indications of increased late morbidity after a follow-up of 5 to 10 years.

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.

Postoperative adjuvant radiotherapy in Astler-Coller stages B2 and C rectal cancer

Between 1979 and 1983, 127 patients with Stages B2 or C rectal cancer treated with surgery plus postoperative adjuvant radiotherapy (RT group) and 122 patients treated with surgery alone (S group) were compared to evaluate the effect of postoperative radiotherapy on survival and disease recurrence. Each group was stratified into subgroups according to stage and tumor differentiation as follows: Subgroups BW (Stage B2 and well-differentiated tumor), BM (Stage B2 and moderately differentiated tumor), CW (Stage C and well-differentiated tumor), CM (Stage C and moderately differentiated tumor), and P (poorly differentiated tumor). Ninety-five percent of the patients were followed until death or, if alive, to five years after surgery. Postoperative radiotherapy was associated with a reduced five-year survival rate in Subgroup BW (67 vs. 87 percent; P = 0.02). In the remaining subgroups of the RT group, there was a statistically insignificant trend toward a worse survival rate (56 vs. 65 percent, 47 vs. 64 percent, 41 vs. 46 percent, and 50 vs. 36 percent for Subgroups BM, CW, CM, and P, respectively). The local failure rates for the S group and RT group were 10 vs. 23 percent (P = 0.15) in Subgroup BW, 32 vs. 21 percent (P = 0.4) in Subgroup BM, 24 vs. 25 percent (P = 0.6) in Subgroup CW, and 18 vs. 18 percent (P = 0.6) in Subgroup CM, respectively. Eight percent (9/127) had severe or life-threatening radiation-related complications. Postoperative adjuvant radiotherapy alone did not improve the survival of patients with Stages B2 or C rectal cancers. It may have led to worsened survival in the subgroup of patients with well-differentiated Stage B2 rectal cancer.

Pre-operative and post-operative radiotherapy and rectal cancer

The appropriate role for additional radiotherapy in patients with resectable rectal cancer is not yet settled. Irradiation has been considered by surgeons and radiotherapists as superfluous since no effect on survival has been shown. However, numerous trials have demonstrated that peri-operative radiotherapy decreases an often high local recurrence rate while others believe it has a definite place in routine management. Several surgeons have, on the contrary, claimed that a skilled surgeon compared to a less skilled surgeon, will get the same acceptably low local recurrence rates. Since we will probably never have a randomized trial comparing "good" and "bad" surgeons, this argument cannot be settled. A further obstacle arises in the difficulty of persuading surgeons to organize their routine work so that it is performed in an optimal way by those specializing in this field. The question also arises whether radiotherapy should be delivered pre-operatively, postoperatively or as a "sandwich" technique, i.e., both pre-operatively and postoperatively. According to radio-biological considerations and results from reported trials, the best effect on local tumor control has been achieved using pre-operative radiotherapy.

Adjuvant therapy for adenocarcinoma of the rectum

Surgical resection continues to be the primary curative modality for patients with adenocarcinoma of the rectum. However, local tumor recurrence in the pelvis and/or distant metastasis may occur in spite of complete excision of grossly visible malignant disease. Surgical and pathologic staging can identify a subset of surgically treated rectal cancer patients at high risk for tumor relapse and death. Irradiation and chemotherapy have been used as adjuvant therapy in conjunction with surgery as single modalities and in combination for patients with high risk rectal cancer. Evidence from controlled clinical trials indicates a significant decrease in local tumor recurrence, and a significant improvement in disease-free and overall survival with the use of combined postoperative irradiation and chemotherapy in this setting. A current national clinical trial in the United States of America is studying whether irradiation can be combined with new chemotherapy regimens which have shown significant therapeutic benefit as surgical adjuvant therapy for patients with high risk colon cancer (5FU + levamisole) and for patients with metastatic colorectal cancer (5FU + leucovorin) to further improve the efficacy of surgical adjuvant therapy for adenocarcinoma of the rectum.

The value of adjuvant therapy after radical surgery for colorectal cancer

Extensive efforts to improve survival for patients with colorectal cancer using adjuvant treatments in addition to radical surgery have long been tried but without success. Recent data from several controlled trials have, however, shown positive results. The collected information from several trials using different chemotherapy schedules indicate that overall survival is improved. The extent of this improvement is not properly known although several centres have considered it to be sufficiently large to merit routine use in certain stages. Likewise, the collected information from several trials using perioperative radiotherapy indicates that the proportion of local recurrences are reduced by about 50% but without any major influence on survival. Most evidence favours additional radiotherapy before surgery rather than after. If proper dose planning is utilized, sufficiently high doses can be given preoperatively without increasing postoperative mortality.

Pre-operative radiotherapy as adjuvant treatment in rectal cancer

From January, 1975 to December, 1987, 241 patients with rectal cancer underwent pre-operative irradiation and surgical resection. The radiation was delivered with 25 MeV photons, 5 days per week by 2.4 grays fractions up to a total dose of 36 grays. Surgery was curative in 195 patients; 57% had abdomino-perineal resection. Irradiation had to be discontinued in 3 patients and 4 patients subsequently developed severe acute ileitis. Postoperative mortality rate was 2.9%. The most frequent postoperative complications were delayed healing of abdominal wounds (18%) and perineal wounds (14%). Severe late complications occurred in 27 (13%) patients. The incidence of intestinal obstruction was 5%. Follow-up survivors ranged from 18 months to 13 years. Local failure occurred in 24 (12%) of the 195 patients. Local failure rates were 10% for Dukes' A tumors, 11.6% for Dukes' B, and 22.7% for Dukes' C tumors. Five and 10 year actuarial survival rates after curative surgery were 70% and 52%. The Dukes' classification was the only factor that influenced survival.

3-D comparative study of proton vs. x-ray radiation therapy for rectal cancer

To assess the usefulness of proton beams for treatment of patients with rectal cancer, we have performed comparative 3D treatment planning for proton beam and x-ray beam therapy. Three common x-ray techniques (AP-PA, 3-field, and 4-field box), a proton beam only plan, and a proton boost plan were compared. The plan which would have been treated without the aid of the 3D planning system was also simulated. Dose distributions were analyzed and dose-volume histograms computed for the target volumes and critical normal tissues. Analyses of these plans demonstrate that the proton beam techniques reduce the volume of small bowel irradiated. This may allow higher doses to be delivered to the tumor, with a probable increase in local control, or a reduction in normal tissue complications probability. All the plans developed with the 3D planning system treated significantly less bowel than the one planned without it.