A new approach to adjuvant radiotherapy in rectal cancer

Adjuvant Postoperative Radiotherapy in Locally Advanced Rectal and Rectosigmoidal Cancer

A pelvic recurrence is the cause of death in about 1/3 of radically operated patients for rectal and rectosigmoidal cancer without clinical evidence of distant metastases. Preoperative and postoperative radiotherapy are largely used to reduce the incidence of locoregional relapses and to improve disease-free and overall survival and quality of life. Benefits from radiotherapy have been widely demonstrated, and adjuvant postoperative radiotherapy is at present strongly recommended. Twenty-one patients with locally advanced (stage B2, B3, C) rectal (11 cases) and rectosigmoidal cancer (10 cases) were treated with postoperative radiotherapy at the National Cancer Institute of Milan from 1975 to 1978. The pelvis received a median dose of 4500 rad (range, 4000–5200 rad) in 5 to 7 weeks through AP, PA opposed fields; 6 patients received a boost of 1000 rad on the perineum. Median follow-up after surgery is 83 months (range, 24–63 months). Only 1 case (« 5%) had a pelvic recurrence, at the perineum. The expected recurrence rate after surgery alone is 40 %, and our favorable results after postoperative radiotherapy are comparable with recent data from other institutions. Radiotherapy side effects were moderate and transient; no late damages to small bowel were observed.

Late complications after a combined pre and postoperative (sandwich) radiotherapy for rectal cancer

BACKGROUND AND PURPOSE

The purpose of this study was to analyse the treatment related side effects, the outcome and the prognostic significance of clinical parameters in two groups of patients with rectal cancer receiving either preoperative or pre and postoperative radiotherapy after radical resection. The authors of this study were not involved in the radiation treatments.

PATIENTS AND METHODS

From 1986 to 1990, 63 patients received a combined pre and postoperative (sandwich) radiotherapy. Preoperative irradiation was given in four fractions of 5 Gy each applied within 2 or 3 days. Postoperative irradiation consisted mostly of 15 x 2 Gy (31 patients) but the range was 20-40 Gy. The results were compared with those on 73 patients who only received preoperative radiotherapy in the same time period. The distribution of prognostic factors was not very different between treatment groups. Out of 63 patients in the sandwich group, 22 received concurrent chemotherapy and 18 also received radiotherapy to the liver. Radical surgery usually followed on the day after the last preoperative radiotherapy session. Median follow-up of survivors was 6 years.

RESULTS

Local tumour control was 88% after 5 years and 84% after 8 years in the sandwich group, and 90 and 85%, respectively, in the preoperative radiotherapy group. Thus, tumour control was similar for the two radiotherapy regimens applied. However, the percentage of patients suffering from one or more complications after 5 years was 84% in the sandwich and 17% in the preoperative radiotherapy group. The incidence of severe late complications (grade > or = 3) was recorded as a function of time after start of treatment. In the sandwich group the actuarial rates of late complications at 5 years (and the median time to diagnosis) were 53% (27 months) for anorectum, 43% (37 months) for bladder, 28% (51 months) for bone, 19% (36 months) for dermis, 47% (48 months) for ileum, 41% (32 months) for lymphatic and soft tissue, and 44% (53 months) for ureters.

CONCLUSIONS

Severe late reactions did not occur within a certain period of time, but continued to appear for at least 10 years after radiotherapy. Sandwich therapy, as given in this series, did not appear to give a greater tumour control than preoperative radiotherapy alone, whereas the rate of complications was drastically enhanced. Thus, the rationale of a sandwich therapy with a long time interval between surgery and postoperative irradiation appears questionable.

Postoperative adjuvant radiotherapy for adenocarcinoma of the rectum and rectosigmoid

One hundred five patients treated with potentially curative surgery and adjuvant postoperative radiotherapy for adenocarcinoma of the rectum and rectosigmoid from 1973 through 1981 were reviewed. Radiation therapy was given with 18-25 MeV X rays in doses of 40-50 Gy in 5 weeks (midline dose) using AP-PA fields in 97 patients. A boost of 6 to 10 Gy was directed to the area of maximum risk by anterior-posterior or perineal fields in 71 patients. Local failure occurred in 15 patients and was documented pathologically in 8 patients, or clinically or radiologically in 7 patients. The local recurrences according to the Modified Astler-Coller staging criteria were: B1: 0% (0/3); B2: 4% (1/24); B3: 31% (4/13); C1: 8% (1/12); C2: 18% (8/45); C3: 20% (1/5). Local failure after adjuvant radiotherapy versus surgery alone was compared. The comparison of local failure of combined treatment versus surgery alone, from our institution, is as follows: B2-4% vs 13%, B3-31% vs 26%, C2-18% vs 30%, and C3-20% vs 49%. Sixty-one patients (58.1%) have been followed for 5 years, with a median of 73 months and a minimum of 24 months. The actuarial 5-year survival (disease-free) for the entire group is 55% and is not statistically different for the groups with negative or positive nodes. Fourteen patients (13%) required surgery for small bowel complications; four others (4%) had symptomatic small bowel obstruction treated with conservative therapy only. Small bowel obstruction occurred in 4 of 16 (25%) treated with radiation fields above L5, whereas those treated below L5 had an 11% incidence. Postoperative adjuvant radiotherapy can increase local tumor control compared to surgery alone. The small bowel complication rate in this series most likely reflects AP-PA treatment technique and can be decreased by the use of multiple fields with maximum shielding of the small intestine.

Local control with pre-operative radiotherapy alone versus "sandwich" radiotherapy for rectal carcinoma

Forty-nine patients with primary adenocarcinoma of the rectum, clinically localized to the pelvis were treated with pre-op radiotherapy (RT) 1500 cGy/5 fx with AP/PA fields, followed by immediate curative resection. Patients staged as Astler-Coller B2, C1, or C2 were considered for post-op RT, 4140 cGy/23 fxs with a 4-field technique. There were 47 evaluable patients in this non-randomized study. Two groups of patients were analyzed, namely pre-op RT only (24 patients) and combined pre- and post-op ("sandwich") RT (23 patients). Two patients with pre-op RT only were considered inevaluable for recurrence because they died NED at 1 and 7 mo. All patients have been followed for greater than 1 year; 77% have been followed for greater than 2 yr. There has been only one local recurrence (LR), surprisingly in a Stage A pre-op RT patient who had no residual tumor in the final operative specimen. In the pre-op group which included 10 B2s, and 1 C2, 1500 cGy in 5 days (equivalent to 1940 cGy by the NSD formulation) was associated with no local recurrence. No distant metastases (DM) have developed in this group. In the "sandwich" RT group, which included 3 B2s, 1 C1, 17 C2s, and 1 D (localized to the pelvis, i.e. ovary), there were no LRs and 7 DMs (1 B2 and 6 C2s). Actuarial survival is 92% in the pre-op RT group at 2 and 3 yr, and 82% in the "sandwich" group at 2 and 3 yr. There have been no serious early or late complications related to RT in our pre-op group. The use of 1500 cGy in 5 days as pre-op RT with immediate surgery may prove, upon longer follow-up, to be sufficient for increasing local control, with minimum morbidity, in patients with B2 disease. Patients with C2 disease are being controlled locally with the "sandwich" regimen, but it is not clear whether pre-op RT alone may be adequate in this group as well. We are now addressing this question in a randomized study.

The sandwich approach: irradiation-surgery-irradiation in rectal cancer. Four years' experience

A sandwich technique of adjuvant radiotherapy was used to treat 47 patients with rectal cancer. Preoperatively, 3000 rads were given for 12 days; 300 rads per day for five days, with a two-day interruption and another five days of 300 rads per day, followed by surgery ten days later. On the basis of the histopathologic findings, 26 patients with Dukes' B2 and C rectal cancer were given 3000 rads postoperatively in the same manner as the preoperative irradiation, starting four weeks after surgery. Patients with Dukes' A and B tumors received no postoperative irradiation. The preoperative radiotherapy was well tolerated by all patients with only minimal side effects. During surgery there was no technical difficulty in removing the tumor en bloc and, in some cases, the macroscopic impression was that the tumor had actually disappeared. In most cases, microscopic examination revealed fibrotic tissue replacing the tumor. In some cases, no cancer tissues were observed. The postoperative course was uneventful, the average length of hospitalization being 14.5 days. We believe that this technique of adjuvant radiotherapy with a moderate dose of irradiation is a logical and well-tolerated approach in the treatment of rectal cancer, and patients who were inoperable before irradiation became resectable after it.

Extrapelvic colon--areas of failure in a reoperation series: implications for adjuvant therapy

A total of 230 patients had planned single or multiple reoperative procedures following "curative" resection of colorectal cancer at the University of Minnesota. The site of the primary lesion was extrapelvic in 91, and later evidence of cancer was found in 58 patients (64%) at re-operation and/or other follow-up. Eight of the 58 (14%) were converted to disease-free status. Incidence and patterns of failure were correlated with initial operative-pathologic extent of disease (87 of the 91 at risk had initial tumor extension beyond the bowel wall, involved nodes or both) and comparisons were made with the previously analyzed rectal reoperation patients. While a component of local-regional failure was more common with rectal lesions (48/74 at risk, 65%), it was not uncommon with extrapelvic primaries (44/91-48%). The incidence of hematogenous metastasis (DM) was equal, but the pattern of initial DM differed (extrapelvic colon--primarily liver; rectum--liver and lung). Peritoneal seeding was a more common component of failure with the extrapelvic primaries (19/91--21% vs 3/74-4%). Since surgery alone is inadequate treatment for many patients with colon as well as rectal cancer, the rationale of adjuvant radiation and systemic therapy, alone or in combination, is discussed.

Results of adjuvant radiation therapy in cancer of the rectum. Thomas Jefferson University Hospital experience

From 1972 to 1981, 174 patients with cancer of the rectum surgically staged as B2 or C disease, underwent surgical resection of the tumors for cure. Eighty-eight patients received surgery only with no further adjuvant therapy, and the remaining 86 patients were treated with a combination of radiation and surgery. Twenty-nine patients received low-dose preoperative radiation (500 rad in one fraction); 26 patients received postoperative radiation (4500 rad in 5 weeks); and 31 patients received combined low-dose preoperative radiation (500 rad) and postoperative radiation (4500 rad in 5 weeks). This experience was analyzed to determine the patterns of failure and the impact of adjuvant therapy on survival. Patients undergoing surgery alone had a 26% incidence of local failure in the pelvis and a 57% incidence of distant metastasis. Patients receiving low-dose preoperative radiation had a reduction in the rate of distant metastasis (24%), but no effect on local failure (34%). On the other hand, patients receiving postoperative radiation had a reduction in the local failure rate (11%), with no effect on distant metastasis (50%). Patients who received the combined preoperative and postoperative treatment had a reduction in both the local recurrence rate (7%), and the rate of distant metastasis (13%), and these patients also had a substantial improvement in survival over surgery alone. Survival of patients undergoing surgery alone was 34% at 5 years and was not substantially different for patients undergoing low-dose preoperative irradiation (48%), or for patients receiving postoperative irradiation (29%). Survival in patients receiving combined preoperative and postoperative irradiation was substantially better (78%) than the other groups of patients.

Adjuvant postoperative radiotherapy in carcinoma of the rectum and rectosigmoid

Local recurrence occurs in 30% to 50% of rectal cancer patients treated with surgery alone if there is tumor extension beyond the bowel wall alone or in conjunction with nodal involvement. This analysis is of 97 such patients who received postoperative irradiation (XRT) in prospective and standardized fashion at Massachusetts General Hospital (MGH) (4500 rad in 25 fractions to large fields and minimum dose of 5040 rad in 28 fractions within a boost field). Results were compared with a group of 103 previously analyzed patients treated with surgery alone at MGH. A statistically significant decrease in local recurrence was seen in four of the six irradiated subgroups (modified Astler-Coller Stages B2g, B3, C1 + C2m, and C2g) at an interval 3 years from resection. This improvement was achieved with no increase in small bowel complications (4% with XRT versus 5% with surgery alone) in view of efforts at surgical reconstruction and use of multiple-field XRT techniques, bladder distension, etc.

Intraoperative and external beam irradiation with or without resection: Mayo pilot experience

At our institution, intraoperative radiation therapy (IORT) with an electron beam has been administered as a single boost dose of 1,000 to 2,000 cGy (rad) in combination with 4,500 to 5,000 cGy (rad) of fractionated external beam irradiation. From April 1981 to July 1983, 50 patients received such treatment, and results are analyzed in detail in this article. All patients had locally advanced disease (initially unresectable for cure, residual after resection, or recurrent), and the main disease sites were gastrointestinal (pancreatic, colorectal, and biliary tumors) and soft tissue (sarcomas). Disease-free survival to date has been excellent in our colorectal and biliary subsets of patients. Although local progression has not been a major problem in patients with unresectable pancreatic lesions, failures in the liver and peritoneal cavity have been excessive, and treatment strategies have been altered in an attempt to decrease the frequency of such failures. Although both short-term and long-term morbidity are acceptable, pilot trials with use of radiation-dose modifiers are planned to determine whether the therapeutic ratio of local control to associated complications can be improved even further.

Adjuvant radiation therapy for rectal cancer

Since 1976, 104 patients with rectal cancer have been treated with a new approach of combined pre- and postoperative radiation. All patients were given 500 rad preoperative irradiation on the day of or the day before surgery. Surgery in the majority of patients was an abdominal perineal resection. The disease was then staged pathologically according to Astler-Coller's modification of Duke's staging. Patients with early stage cancer (Stages A and B1) were followed with no further therapy. Patients with poor prognostic characteristics (Stages B2, C1, C2) were given postoperative pelvic irradiation (4500 rad in 5 weeks). Twenty-nine patients were found to have Stage A or B1 cancer and were followed with no further therapy. Of these 29 patients, 1 patient developed recurrence and one has died of metastatic disease. The excellent survival of patients with early tumors indicates that minimizing the role of adjuvant therapy in this group has not been detrimental to their survival. Fifteen were found to have liver metastases at laparotomy and had just a colostomy and palliative therapy. Sixty patients had Stage B2 and C disease. Thirty-one received postoperative irradiation as per protocol. Twenty-nine patients did not receive postoperative irradiation for a variety of reasons. Follow-up ranges from 1 to 7 years in these patients. Of the 29 patients with Stage B2 and C disease who should have but did not receive postoperative radiation, 10 patients (34%) have developed a recurrence in the pelvis, and 5 other patients (17%) have developed metastatic disease. Of 31 patients who received postoperative irradiation, only 2 patients (6%) developed a local recurrence and 4 patients (13%) have developed distant metastases. Survival at 3 years was 80% for patients receiving the combined treatment, as compared to 42% for those not receiving the postoperative part of the treatment protocol.

Low-dose preoperative irradiation, surgery, and elective postoperative radiation therapy for resectable rectum and rectosigmoid carcinoma

A regimen of low-dose preoperative radiation therapy (RT), surgery, and elective postoperative RT for resectable carcinomas of the rectum and rectosigmoid is presented. Initial results in a group of 36 patients is discussed. In four patients clinically silent metastatic disease was discovered. Of 16 patients without indications for postoperative RT, only one died with disease. Indications for postoperative irradiation were found in 15 patients and four relapses (26%) subsequently occurred. Since the surgicopathologic stage of the tumor is the best prognostic predictor for rectal cancer, this regimen allows for the delivery of high-dose adjuvant irradiation only to those at high risk of local recurrence. Thus, this combination selects patients likely to benefit from postoperative RT while preserving the advantages of preoperative RT.

Combined modality treatment of gastric cancer

In a series of 46 patients with localized gastric cancer treated at Massachusetts General Hospital, problems with excessive acute or chronic toxicity due to combination treatment with irradiation (XRT) and chemotherapy (CT) were not seen. Forty of the 46 received combined treatment with 2 regimens: 1) Irradiation plus concomitant 3 days of 5-FU followed by maintenance 5-FU or combined drugs--26 patients; 2) In the other 14 patients, the sequence of irradiation and chemotherapy was altered. A single course of combined drug chemotherapy was given prior to irradiation and 5-6 additional courses were administered after completion of XRT (CT-XRT-CT). The drug combination was initially 5-FU-BCNU but this was changed to FAM (5-FU, Adriamycin, Mitomycin C). Irradiation was delivered to tightly contoured portals using shaped blocks to spare as much small bowel, kidney and marrow as possible while giving 4500-5200 rad in 25 to 29 fractions over 5 to 6 weeks. In this series, there were no cases of septicemia or any deaths related to treatment. A 3 year survival rate of about 20% was achieved for the total group of patients and 43% in the group with resection but at high risk for later failure. Our inability to improve these numbers is undoubtedly a result of dose limitations with external beam irradiation combined with a systemic failure problem. When irradiation is combined with surgical resection of all or a majority of tumor, both survival and local control appear to be better than in the unresected patient group. Only 4 of 29 patients (14%) with curative resection, or resection but residual disease, had later evidence of failure within the irradiation field as opposed to 6 of 9 or 66% in the group with unresectable disease.

Patterns of recurrence in adenocarcinoma of the rectum and rectosigmoid treated with surgery alone: implications in treatment planning with adjuvant radiation therapy

This is an analysis of 140 patients with adenocarcinoma of the rectum and rectosigmoid treated with surgery alone at the University of Florida between May 1959 and April 1976. Patients in the study group had a complete resection, as determined by the surgeon and the pathologist, and no evidence of distant metastasis at the completion of the operation. There is a 5 year minimum follow-up. Local-regional recurrence rates were noted to vary with histologic grade, length of the lesion, and pathologic stage. Approximately 60% of local-regional and distant recurrences were noted by 2 years after treatment, and 92-95% were noted by 5 years. Evaluation of patient status at 5 years revealed that 0% (Stage CIS), 0% (A), 17% (B1), 13% (B2), 17% (C1), and 28% (C2) had developed local-regional recurrence without demonstrable distant metastasis. Complications and crude 5 year survival rates are presented and current treatment modifications discussed.

Combined pre and postoperative radiation for carcinoma of the rectum

Since 1976, a new approach to adjuvant radiation therapy in carcinoma of the rectum has been used at Thomas Jefferson University Hospital. Seventy-eight patients with biopsy-proven invasive carcinoma of the rectum have been treated with low dose preoperative radiation, 500 rad given either on the day of or the day before surgery. Following surgery, the lesions were pathologically staged according to Astler-Coller's Modification of Duke's staging. Patients with good prognostic features (Stage A or B1) were followed with no further treatment while patients with poor prognostic characteristics (Stage B2, C1 and C2) were treated with aggressive postoperative pelvic radiation, 4500 rad delivered in five weeks. All patients entered into this study received the preoperative dose of 500 rad. Fifty-six patients underwent an A-P resection, four patients underwent a low anterior resection and ten patients had a combined abdominal transsacral resection. Eight patients were found to have liver metastasis at laparotomy and underwent a colostomy followed by palliative therapy. Twenty-nine patients were found to have early disease, Stage A or B1, and were given no further therapy. Of 41 patients with Stage B2 or C, 25 patients received the full course of postoperative radiation. Sixteen patients did not receive postoperative radiation for a variety of reasons. Follow-up in these patients ranges from six months to a maximum of 48 months with a median follow-up of 18 months. Sixty-nine of the total group of 78 patients are currently alive. Two patients with early tumor (Stage A or B1) have died of metastasis. One other patient with Stage A carcinoma died of unrelated causes. Two of the 25 patients receiving postoperative radiation developed metastatic disease, but none of the patients developed local recurrence in the pelvis. Six of 16 patients who should have received postoperative radiation, but did not recurred. Four of these six recurrences have been in the pelvis. Both the incidence of failure and the pattern of recurrence between these two groups of patients who did not receive postoperative radiation is suggestive of a better effect in the PR unrelated group. Survival of patients treated with this approach appears to be improved.

Defining the needs for adjuvant therapy of rectal and colonic cancer

Current trials concerned with the adjuvant therapy for large bowel cancer demonstrate for the first time that improvements in survival through the use of adjuvant therapy may be possible in rectal cancer. Similar results in well-designed studies are not evident for colonic cancer. These trials deserve confirmation. In addition, they demonstrate the biologic difference in the behavior of colonic and rectal cancer despite similar requirements in defining curative surgical resection. A comparison of trials unique to individual institutions suggests that the lenient criteria for patient selection and the use of historical control groups make the data from these studies impossible to interpret for extrapolation to wide clinical use. The variations in the survival rates of historical groups, both among different studies and within the same study, suggest that the design of adjuvant therapy programs without concurrent surgically treated control groups will predictably produce a study of limited value, but one that is guaranteed to generate continued controversy. Uniformity of language, staging, and method of reporting is invaluable if individual trials of adjuvant therapy are to become comparable. The development and widespread use of an agreed-upon staging method is an important step in the preparation for further adjuvant trials. The definition of additional prognostic factors (beyond mural penetration and nodal involvement) in rectal cancer and stratification for these additional factors in the design of studies concerning adjuvant therapy in rectal cancer seems to be a target of importance for future studies of adjuvant therapy. Focusing attention on which patients with rectal cancer actually derived a benefit from treatment may assist in the development of a pattern in which surgical goals and radiation goals can achieve better definition in clinical use.