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Purpose: Primary unresectable and locally advanced recurrent rectal cancer presents a significant clinical challenge. Local failure rates are high in both situations. Under such circumstances, there is a significant need to safely deliver tumoricidal doses of radiation in an attempt to improve local control. For this reason, we have incorporated a new approach utilizing high dose rate intraoperative radiation therapy (HDR-IORT)., Methods and Materials: Between 11/92-12/96, a total of 112 patients were explored, of which 68 patients were treated with HDR-IORT, and 66 are evaluable. The majority of the 44 patients were excluded for unresectable disease or for distant metastases which eluded preoperative imaging. There were 22 patients with primary unresectable disease, and 46 patients who presented with recurrent disease. The histology was adenocarcinoma in 64 patients, and squamous cell carcinoma in four patients. In general, the patients with primary unresectable disease received preoperative chemotherapy with 5-fluorouracil (5-FU) and leucovorin, and external beam irradiation to 4500-5040 cGy, followed by surgical resection and HDR-IORT (1000-2000 cGy). In general, the patients with recurrent disease were treated with surgical resection and HDR-IORT (1000-2000 cGy) alone. All surgical procedures were done in a dedicated operating room in the brachytherapy suite, so that HDR-IORT could be delivered using the Harrison-Anderson-Mick (HAM) applicator. The median follow-up is 17.5 months (1-48 mo)., Results: In primary cases, the actuarial 2-year local control is 81%. For patients with negative margins, the local control was 92% vs. 38% for those with positive margins (p = 0.002). The 2-year actuarial disease-free survival was 69%; 77% for patients with negative margins vs. 38% for patients with positive margins (p = 0.03). For patients with recurrent disease, the 2-year actuarial local control rate was 63%. For patients with negative margins, it was 82%, while it was 19% for those with positive margins (p = 0.02). The disease-free survival was 47% (71% for negative margins and 0% for positive margins) (p = 0.04). Prospective data gathering indicated that significant complications occurred in approximately 38% of patients and were multifactorial in nature, and manageable to complete recovery., Conclusion: HDR-IORT using our technique is versatile, safe, and effective. The local control rates for primary disease compare quite well with other published series, especially for patients with negative margins. For patients with recurrent disease, locoregional control and survival are especially encouraging in patients with negative resection margins. Further follow-up is needed to see whether these encouraging data will continue.

Purpose: We report the local control and survival of two Phase I dose escalation trials of combined preoperative 5-fluorouracil (5-FU), low-dose leucovorin (LV), and radiation therapy followed by postoperative LV/5-FU for the treatment of patients with locally advanced and unresectable rectal cancer., Methods and Materials: A total of 36 patients (30 primary and 6 recurrent) received two monthly cycles of LV/5-FU (bolus daily x 5). Radiation therapy (50.40 Gy) began on day 1 in the 25 patients who received concurrent treatment and on day 8 in the 11 patients who received sequential treatment. Postoperatively, patients received a median of four monthly cycles of LV/5-FU., Results: The resectability rate with negative margins was 97%. The complete response rate was 11% pathologic and 14% clinical for a total of 25%. The 4-year actuarial disease-free survival was 67% and the overall survival was 76%. The crude local failure rate was 14% and the 4-year actuarial local failure rate was 30%. Crude local failure was lower in the four patients who had a pathologic complete response (0%) compared with those who either did not have a pathologic complete response (16%) or who had a clinical complete response (20%)., Conclusion: Our preliminary data with the low-dose LV regimen reveal encouraging downstaging, local control, and survival rates. Additional follow-up is needed to determine the 5-year results. The benefit of downstaging on local control is greatest in patients who achieve a pathologic complete response.

Purpose: To determine if preoperative radiation therapy allows sphincter preservation in the treatment of rectal cancer., Methods and Materials: Thirty patients with the diagnosis of invasive, resectable, primary adenocarcinoma of the rectum limited to the pelvis were enrolled on a Phase I/II trial of preoperative radiation therapy plus low anterior resection/coloanal anastomosis. By preoperative assessment, all patients had invasive tumors (2: T2 28:T3) involving the distal half of the rectum and required an abdominoperineal resection. The median tumor size was 4 cm (range: 1.5-6 cm) and the median distance from the anal verge was 4 cm (range: 3-7 cm). The whole pelvis received 46.8 Gy followed by a 3.60 Gy boost to the primary tumor bed. The median follow-up was 43 months (range: 6-82 months)., Results: Of the 29 patients who underwent resection, 3 (10%) had a complete pathologic response and 24 (83%) were able to successfully undergo a low anterior resection/colonanal anastomosis. The incidence of local failure was crude: 17% and 4-year actuarial: 23%. The 4-year actuarial survival was 75%. One patient developed a partial disruption of the anastomosis and two developed rectal stenosis. Analysis of sphincter function using a previously published scale was performed at the time of last follow-up in 22 of the 24 patients who underwent a low anterior resection/coloanal anastomosis. Function was good or excellent in 77%. The median number of bowel movements/day was two (range: 1-6)., Conclusions: This technique may be an alternative to an abdominoperineal resection in selected patients. Continued follow-up is needed to determine if this approach ultimately has similar local control and survival rates as an abdominoperineal resection.

Purpose: We performed a Phase I trial to determine the maximum tolerated dose of combined pre-operative radiation (5040 cGy) and 2 cycles (bolus daily x 5) of 5-FU and low dose LV (20 mg/m2), followed by surgery and 10 cycles of post-operative LV/5-FU in patients with unresectable primary or recurrent rectal cancer., Methods and Materials: Twelve patients were entered. The initial dose of 5-FU was 325 mg/m2. 5-FU was to be escalated while the LV remained constant at 20 mg/m2. Chemotherapy began on day 1 and radiation on day 8. The post-operative chemotherapy, was not dose escalated; 5-FU: 425 mg/m2 and LV: 20 mg/m2. The median follow-up was 14 months (7-16 months)., Results: Following pre-operative therapy, the resectability rate with negative margins was 91% and the pathologic complete response rate was 9%. For the combined modality segment (preoperative) the incidence of any grade 3+ toxicity was diarrhea: 17%, dysuria: 8%, mucositis: 8%, and erythema: 8%. The median nadir counts were WBC: 3.1, HGB: 8.8, and PLT: 153,000. The maximum tolerated dose of 5-FU for pre-operative combined LV/5-FU/RT was 325 mg/m2 with no escalation possible. Therefore, the recommended dose was less than 325 mg/m2., Conclusions: Since adequate doses of 5-FU to treat systemic disease could not be delivered until at least 3 months (cycle 3) following the start of therapy, we do not recommend that this 5-FU, low dose LV, and sequential radiation therapy regimen be used as presently designed. However, given the 91% resectability rate we remain encouraged with this approach.

Following surgery for Stages T3-4N0-2M0 primary and recurrent resectable rectal cancer limited to the pelvis, 25 patients have been entered on a Phase I trial of pelvic radiation therapy (RT) [5040 cGy] and 12 cycles of postoperative 5-FU and high dose Leucovorin (LV) chemotherapy. 5-FU was escalated 50 mg/m2 while the LV remained constant at 200 mg/m2. The initial doses of 5-FU were: combined-RT/chemotherapy = 200 mg/m2 and post-RT chemotherapy = 325 mg/m2. The median F/U was 25 months (range: 13-36). Two maximum tolerated doses (MTD's) have been determined, one for combined-RT/chemotherapy and one for post-RT chemotherapy. The MTD for combined-RT/chemotherapy was 250 mg/m2; therefore, the recommended dose of 5-FU is 200 mg/m2. The MTD for post-RT chemotherapy was 375 mg/m2; therefore, the recommended dose of 5-FU is 325 mg/m2. The dose limiting toxicities were diarrhea, tenesmus, frequent bowel movements, dysuria, and myelosuppression. For the nine patients who received 5-FU at the recommended dose level the median low counts were WBC 3.5 (2.2-4.0), HGB 10.3 (9.0-12.3), and PLT (x 1000) 167 (133-280), and the incidence of any grade greater than or equal to 3 toxicity was 22% diarrhea, 17% tenesmus, and 22% frequent bowel movements. The recommended dose of combined-RT/chemotherapy as used in this protocol was relatively well tolerated. However, optimal doses of 5-FU cannot be delivered until the fourth postoperative month. Therefore, despite the encouraging results reported with high dose LV in patients with advanced disease, we do not recommend that high dose LV be used with combined RT and 5-FU in the treatment regimen as presently designed.

A total of 22 patients with the diagnosis of invasive, resectable, primary adenocarcinoma of the rectum limited to the pelvis were enrolled on a Phase I/II trial of pre-operative radiation therapy+low anterior resection/coloanal anastomosis. By pre-operative assessment, all patients had invasive tumors involving the distal half of the rectum and required an abdominoperineal resection. The median tumor size was 4 cm (1.5-6 cm) and the median distance from the anal verge was 4 cm (3-7 cm). The whole pelvis received 4680 cGy followed by a 360 cGy boost to the primary tumor bed. The median follow-up was 29 months (10-60 months). Of the 21 patients who underwent resection, 10% had a complete pathologic response and 90% were able to successfully undergo a low anterior resection/coloanal anastomosis. The incidence of local failure as a component of failure was crude: 23% and 4-year actuarial: 32%. The 4-year actuarial survival was 61%. No patients experienced Grade 3 or 4 toxicity while receiving radiation therapy, and 6% developed a partial disruption of the anastomosis. Of the patients who underwent a low anterior resection/coloanal anastomosis, 89% had a good or excellent functional result. This technique may be an alternative to an abdominoperineal resection in selected patients. Further follow-up is needed in order to determine if this approach ultimately has similar local control and survival rates as an abdominoperineal resection.

The standard approach to patients with unresectable rectal cancer is pre-op radiation therapy followed by surgery. To determine the impact of RT on local failure and survival, we present an analysis of our preliminary results of this approach in patients with unresectable rectal cancer. A total of 22 patients were analyzed (9 primary, 13 recurrent). The median follow-up was 22 months. There were two groups of patients. Group 1 included 12 patients with unresectable tumors in whom surgery was planned following pre-operative radiation therapy. Group 2 included 10 patients in whom no surgery was planned following radiation therapy due to extensive pelvic bone destruction. The whole pelvis received 4680 cGy followed by a boost of 360-1440 cGy. Six underwent brachytherapy. For the total patient group, the 3-year actuarial survival was 52% (Group 1: 91% vs Group 2: 30%). Patterns of failure as a component of failure were: local failure (or local progression): 50%, abdominal: 23%, and distant: 9%. The dose of pelvic radiation had no significant impact on the local failure rate (5040 cGy: 55% vs greater than 5700 cGy:45%). None of the seven patients with negative margins developed local failure compared with 73% of those with positive margins. The complete resection rate in Group 1 patients was 58%, and all are alive without local failure. Further follow-up will be needed to determine the ultimate local failure and survival rates.

From 1981 to 1986, 28 patients (27 evaluable) were treated with intraluminal brachytherapy (ILBT) using a remote afterloading technique for persistent or recurrent anal, rectal and rectosigmoid cancers. Eighty-nine percent underwent previous surgery for colorectal cancer. Seventy-seven percent of the patients received external beam irradiation (ERT) as a part of the present treatment. Intraluminal brachytherapy was given with a 2 cm diameter cylinder and the dose per fraction ranged from 440 cGy to 840 cGy at 0.5 cm from the surface of the cylinder. Follow-up ranged from 1 to 74 months with a median of 12 months. Patients were divided into two groups. Group I consisted of 15 patients receiving elective ILBT; Group II: 13 patients with recurrent disease. Seventy-one percent of the patients in Group I and 39% of the patients in Group II achieved local control. The majority of patients tolerated treatment well with only transient reactions. However, three patients (11%) developed grade 3 (G3) complications requiring surgical intervention. Eight patients developed moderate complications--grade 2 (G2)--requiring only conservative treatment. This study has identified several factors which appear to influence the risk of developing complications with this combined treatment, using remote afterloading apparatus, among which are technique of previous external beam irradiation, treatment length, anatomical location, intraluminal brachytherapy fractionation, and total cumulative dose (ERT + ILBT). This experience suggests that intraluminal brachytherapy appears to be an acceptable form of treatment, as a boost to external beam radiation therapy, in the management of rectal and colorectal cancers.

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.