Phase I study of preoperative oral uracil and tegafur plus leucovorin and radiation therapy in rectal cancer

Efficacy and short-term outcomes of preoperative chemoradiotherapy with intermittent oral tegafur-uracil plus leucovorin in Japanese rectal cancer patients: a single center experience retrospective analysis

BACKGROUND

Various types of preoperative chemoradiotherapy (CRT) have been established for rectal cancer; thus, Physicians will need to refine the selection of appropriate preoperative CRT for different patients since there are various treatment regimens. Oral tegafur-uracil (UFT) plus leucovorin (LV) is commonly used to treat rectal cancer in Japan. Oral chemotherapy offers patients many potential advantages. Since 2008, we have been performing preoperative CRT with intermittent oral UFT plus LV in locally advanced rectal cancer patients to prevent postoperative local recurrence. Here, in a retrospective analysis, we evaluated the efficacy and short-term outcomes of preoperative CRT with intermittent oral UFT plus LV.

METHODS

We analyzed data from 62 patients with locally advanced rectal cancer, including 31 patients who underwent preoperative CRT between 2009 and 2013 (the CRT group) and 31 patients who were treated with surgery alone between 2001 and 2008 (the non-CRT group). Clinicopathologically, both groups included patients with rectal cancer at clinical tumor stages III-IV or clinical node stages 0-III. In the CRT group, curative operations were performed ≥8 weeks after CRT. Patients were concomitantly treated with 2 cycles of oral UFT (300 mg/m²/day, days 1-14 and 29-42) plus LV (75 mg/day, days 1-14 and 29-42) and 45 Gy of radiotherapy. Chemotherapy was repeated every 28 days, followed by a 2-week break.

RESULTS

The completion rate of CRT was high at 94% (n = 29/31). The downstaging rate of CRT was 61% (n = 19/31). The pathological complete response rate was 6.5% (n = 2/31). Significant differences were observed in the 3-year local recurrence rate between the two groups (P < 0.05).

CONCLUSIONS

Preoperative CRT with intermittent oral UFT plus LV appears to be a tolerable and effective treatment for Japanese patients with rectal cancer. A further investigation of a diversification of preoperative CRT for Japanese rectal cancer patients is required.

Neoadjuvant chemoradiation therapy using concurrent S-1 and irinotecan in rectal cancer: impact on long-term clinical outcomes and prognostic factors

PURPOSE

To assess the long-term outcomes of patients with rectal cancer who received neoadjuvant chemoradiation therapy (NCRT) with concurrent S-1 and irinotecan (S-1/irinotecan) therapy.

METHODS AND MATERIALS

The study group consisted of 115 patients with clinical stage T3 or T4 rectal cancer. Patients received pelvic radiation therapy (45 Gy) plus concurrent oral S-1/irinotecan. The median follow-up was 60 months.

RESULTS

Grade 3 adverse effects occurred in 7 patients (6%), and the completion rate of NCRT was 87%. All 115 patients (100%) were able to undergo R0 surgical resection. Twenty-eight patients (24%) had a pathological complete response (ypCR). At 60 months, the local recurrence-free survival was 93%, disease-free survival (DFS) was 79%, and overall survival (OS) was 80%. On multivariate analysis with a proportional hazards model, ypN2 was the only independent prognostic factor for DFS (P=.0019) and OS (P=.0064) in the study group as a whole. Multivariate analysis was additionally performed for the subgroup of 106 patients with ypN0/1 disease, who had a DFS rate of 85.3%. Both ypT (P=.0065) and tumor location (P=.003) were independent predictors of DFS. A combination of these factors was very strongly related to high risk of recurrence (P<.0001), which occurred most commonly in the lung.

CONCLUSIONS

NCRT with concurrent S-1/irinotecan produced high response rates and excellent long-term survival, with acceptable adverse effects in patients with rectal cancer. ypN2 is a strong predictor of dismal outcomes, and a combination of ypT and tumor location can identify high-risk patients among those with ypN0/1 disease.

Phase II study of preoperative radiation plus concurrent daily tegafur-uracil (UFT) with leucovorin for locally advanced rectal cancer

Background

Considerable variation in intravenous 5-fluorouracil (5-FU) metabolism can occur due to the wide range of dihydropyrimidine dehydrogenase (DPD) enzyme activity, which can affect both tolerability and efficacy. The oral fluoropyrimidine tegafur-uracil (UFT) is an effective, well-tolerated and convenient alternative to intravenous 5-FU. We undertook this study in patients with locally advanced rectal cancer to evaluate the efficacy and tolerability of UFT with leucovorin (LV) and preoperative radiotherapy and to evaluate the utility and limitations of multicenter staging using pre- and post-chemoradiotherapy ultrasound. We also performed a validated pretherapy assessment of DPD activity and assessed its potential influence on the tolerability of UFT treatment.

Methods

This phase II study assessed preoperative UFT with LV and radiotherapy in 85 patients with locally advanced T3 rectal cancer. Patients with potentially resectable tumors received UFT (300 mg/m/²/day), LV (75 mg/day), and pelvic radiotherapy (1.8 Gy/day, 45 Gy total) 5 days/week for 5 weeks then surgery 4-6 weeks later. The primary endpoints included tumor downstaging and the pathologic complete response (pCR) rate.

Results

Most adverse events were mild to moderate in nature. Preoperative grade 3/4 adverse events included diarrhea (n = 18, 21%) and nausea/vomiting (n = 5, 6%). Two patients heterozygous for dihydropyrimidine dehydrogenase gene (DPYD) experienced early grade 4 neutropenia (variant IVS14+1G > A) and diarrhea (variant 2846A > T). Pretreatment ultrasound TNM staging was compared with postchemoradiotherapy pathology TN staging and a significant shift towards earlier TNM stages was observed (p < 0.001). The overall downstaging rate was 42% for primary tumors and 44% for lymph nodes. The pCR rate was 8%. The sensitivity and specificity of ultrasound for staging was poor. Anal sphincter function was preserved in 55 patients (65%). Overall and recurrence-free survival at 3 years was 86.1% and 66.7%, respectively. Adjuvant chemotherapy was administered to 36 node-positive patients (mean duration 118 days).

Conclusion

Preoperative chemoradiotherapy using UFT with LV plus radiotherapy was well tolerated and effective and represents a convenient alternative to 5-FU-based chemoradiotherapy for the treatment of resectable rectal cancer. Pretreatment detection of DPD deficiency should be performed to avoid severe adverse events.

Pre-operative chemoradiotherapy with UFT and Leucovorin in patients with advanced rectal cancer: a phase II study

PURPOSE

The aim this study was to determine the pathologic complete response (pCR) rate defined as tumor regression grade 1 (TRG1) and toxicity profile of the combination of high-dose pre-operative radiotherapy and simultaneous UFT/leucovorin (LV) in patients with locally advanced rectal cancer.

MATERIALS/METHODS

Eligibility included biopsy proven rectal adenocarcinoma; T3-T4 N0-N2; performance status < 2 (ECOG) and adequate blood, hepatic and renal function. Treatment consisted of radiotherapy 54 Gy at 1.8 Gy/day and UFT 300 mg/m(2)/day and LV 60 mg/day, given simultaneously daily for 6 weeks. Surgery was performed within 4-6 weeks period after chemoradiotherapy. Patients who did not achieve TGR1 were to receive 4 cycles of adjuvant UFT/LV on days 1-28, every 5 weeks.

RESULTS

Sixty-eight patients were included. All but one received full dose of radiation and 62 had the total planned pre-operative UFT/LV dose. Grade 3 toxicities were diarrhea 7% and proctitis 3%. Complete resection was achieved in 62 patients (91%). Tumor regression grade 1 (TRG1) was seen in 11 patients (16%). Forty-eight patients received adjuvant UFT/LV. Grade 3 toxicity during adjuvant UFT/LV included diarrhea 12%, asthenia 4%, neutropenia 2%, and hand-foot syndrome 2%. The 3-year disease-free survival was 71%.

CONCLUSIONS

Simultaneous high-dose pre-operative localized radiation therapy concurrent with UFT/LV is feasible and has a low toxicity profile. This schedule is highly effective and merits further investigation.

UFT (tegafur-uracil) in rectal cancer

BACKGROUND

Major achievements in the treatment of localised rectal cancer include the development of total mesorectal excision and the perioperative administration of radiotherapy in combination with continuous infusion (CI) 5-fluorouracil (5-FU). This multimodal approach has resulted in extended survival and lower local relapse rates, with the potential for sphincter-preserving procedures. However, CI 5-FU is inconvenient for patients and is costly. Oral fluoropyrimidines like UFT (tegafur-uracil) offer a number of advantages over 5-FU.

METHODS

We undertook a review of published articles and abstracts relating to clinical studies of UFT in the treatment of locally advanced rectal cancer (LARC). Pre- and postoperative studies carried out in patients with newly diagnosed or recurrent disease were included.

RESULTS

The combination of UFT and radiotherapy was effective and well tolerated in the preoperative setting, while adjuvant UFT improved survival and reduced distant relapse compared with surgery alone. The efficacy of UFT appears comparable with that of 5-FU and capecitabine and its side-effect profile is favourable.

CONCLUSION

Clinical experience to date suggests that UFT is a valuable treatment option for the perioperative treatment of LARC. Further improvements in patient outcomes may result from the combination of UFT with targeted agents.

Preliminary results of phase I trial of oral uracil/tegafur (UFT), leucovorin plus irinotecan and radiation therapy for patients with locally recurrent rectal cancer

BACKGROUND

Surgical attempts for locally recurrent rectal cancer often fail due to local re-recurrence and distant metastasis. Preoperative chemoradiation may enhance better local control and survival. The aim of this study was to assess the safety of oral uracil and tegafur (UFT) plus leucovorin (LV), and irinotecan combined with radiation and determine the maximum-tolerated dose (MTD) and dose limiting toxicity (DLT) of the triple drug regimen.

PATIENTS AND METHODS

Patients with locally recurrent rectal cancer received escalating doses of irinotecan on days 1, 8, 15, and 22 (starting at 30 mg/m2, with 10 mg increments between consecutive cohorts) and fixed doses of UFT (300 mg/m2) plus LV (75 mg/day) on days 3 to 7, 10 to 14, 17 to 21, and 24 to 28. Radiation was given 5 days per week totaling 40 to 50 Gy (2Gy/day).

RESULTS

Six patients were treated at the starting dose, and 2 received the full scheduled chemoradiotherapy. The other 4 patients had grade 3 diarrhea and diarrhea was the DLT. One patient had partial response and he had subsequently radical surgical resection. Median progression free survival for local recurrence was 320 days.

CONCLUSION

Irinotecan plus UFT/LV with concomitant radiotherapy in patients with locally recurrent rectal cancer was not feasible due to diarrhea in this setting. Modification of the treatment is needed.

Preoperative tegafur suppositories for resectable rectal cancer: phase II trial

PURPOSE

Preoperative radiochemotherapy for rectal cancer causes a high rate of moderate-to-severe toxicities and is associated with only moderate survival benefits. A simpler, safer, and more convenient treatment would be preferable. Preoperative tegafur suppositories (1,500 mg/day) for at least 14 days were piloted.

METHODS

A total of 129 patients with resectable rectal cancer were enrolled. The primary end points were pathologic response, adverse events, rate of sphincter-sparing surgery, recurrence, and survival.

RESULTS

The total dose of tegafur ranged from 21 to 78 (mean, 32) g. The anal sphincter was preserved in 60.5 percent with microscopic no residual tumor (R0). The overall morbidity rate was 32 percent. Wound infection occurred in 13.2 percent of cases and anastomotic leakage in 9 percent of cases. Pathologic responses were observed in 70 percent of patients, with a complete necrosis occurring in 3.9 percent, two-thirds or more necrosis in 6.2 percent, one-third or more but less than two-thirds necrosis in 18.6 percent, and less than one-third necrosis in 41.9 percent. The mean total dose that patients showing complete or two-thirds or more necrosis received was 42.8 +/- 6.4 g (P = 0.01) compared with 31.6 +/- 1.2 g administered to patients showing less than two-thirds necrosis. Adverse events were observed in 15.6 percent of patients overall, and Grade III or IV events were observed in 2.3 percent of patients. During a median follow-up of 48 months, distant metastasis occurred in 14.7 percent of patients and local recurrence occurred in 6.2 percent of patients. The four-year, disease-free and overall survival rates were 67.6 and 80.1 percent, respectively.

CONCLUSIONS

Preoperative tegafur suppositories are associated with low toxicity and may lead to anal sphincter-sparing surgery with acceptable postoperative complications and favorable local and distal control.

Phase II Trial of Preoperative Chemoradiation With a Hyperfractionated Radiation Boost in Locally Advanced Rectal Cancer

PURPOSE

The purpose of this phase II study was to prospectively determine the efficacy of preoperative chemoradiation with a hyperfractionated (Hfx) RT boost to 61.8 Gy in locally advanced rectal cancer.

METHODS

Eligibility stipulated that the primary lesion had to be either T4; or T3 and >4 cm or 40% of the bowel circumference. Radiation (RT) consisted of 45 Gy to the pelvis (1.8 Gy per fraction) followed by 1.2 Gy twice daily (to the gross tumor volume) to a total RT dose of 61.8 Gy. There was 5-FU infused at 1 g/m2/24 hours for 4 days during the 1st and 6th weeks of RT (concurrent with the Hfx boost). Surgical resection was planned 4 to 6 weeks later. Adjuvant chemotherapy (bolus 5-FU/leucovorin) was scheduled for 4 cycles at 28-day intervals.

RESULTS

There were 22 patients, ages 22 to 81 years (median, 64) enrolled in the study. Of the 20 patients evaluable for response, 10 (50%) had evidence of clinical downstaging and 5 patients (25%) had > or =90% fibrosis in the resected specimen. With a median f/u of 40 months (7-158), the 4 years actuarial rate for all patients (n = 22) of OS was 64%, of DFS 62%, and of LC 84%. 3/21 patients (14%) had positive margins, all of whom developed a local failure (P < 0.001).

CONCLUSION

This regimen of high dose preoperative chemoRT with a Hfx RT boost (to 61.8 Gy) in patients with bulky, locally advanced rectal cancer results in clinical downstaging in half of the patients with significant fibrosis in the operative specimen.

Tegafur and 5-fluorouracil pelvic tissue concentrations in rectal cancer patients receiving preoperative chemoradiation

BACKGROUND AND PURPOSE

To investigate the presence of 5-Fluorouracil (5-FU) in pelvic tissue after oral administration of tegafur. To measure tegafur and 5-FU concentrations in normal rectal mucosa, perirectal fat and residual tumor in rectal cancer patients receiving preoperative chemoradiation. To correlate drug concentrations with cancer downstaging effects.

PATIENTS AND METHODS

Three tissue samples taken from 16 surgical specimens after recto-sigmoid resection were analyzed. Tegafur and 5-FU concentrations were measured using high-performance liquid chromatography. 16 patients with locally advanced rectal cancer were treated with preoperative pelvic irradiation (45-50 Gy) sensitized with oral tegafur (400 mg for every 8 hours daily). Seven patients received a precharge dose of tegafur (400 mg oral every 8 hours) 24 hours before surgery.

RESULTS

In 8 of the 9 patients who did not receive a precharge dose, detectable levels of tegafur were observed in fat tissue, normal mucosa and tumor, but detectable 5-FU levels were only observed in one patient. Mean concentrations (ranges) for tegafur in fat, normal mucosa and tumor in patients without the precharge dose were 72.19 (12.1-205.6), 179.53 (11.30-727.7) and 252.35 (27.9-874.6) ng/g, respectively; mean concentrations for 5-FU in the same samples were 0.95, 1.92 and 2.68 ng/g (1 patient), respectively. In patients receiving a tegafur precharge, both tegafur and 5-FU were present in all tissue samples with the exception of 2 fat samples, in which drug concentrations were undetectable. 5-FU levels were higher in tumor than other sites, with a median value of 68.24 ng/g (range 3.8-283.05 ng/g). Tegafur levels were also higher in tumor samples than other sites (mean 3446.53 ng/g, range 1044.5-7847.0 ng/g), except in 2 patients who had higher levels of tegafur in normal mucosa.

CONCLUSIONS

Tegafur and 5-FU are not always present in pelvic tissues 5 to 6 weeks after oral administration of tegafur. Both drugs were present in the tissues analyzed, in relevant concentrations, 24 hours after oral administration of tegafur. The data obtained suggest a tendency (not significant) toward a correlation between levels of 5-FU present in the residual tumor and cancer downstaging.

Preoperative versus postoperative treatment for locally advanced rectal carcinoma

EPIDEMIOLOGY

Overall mortality of rectal cancer at 5 years is approximately 40%. This cancer is commonly diagnosed at an early stage, but because of local relapse and/or metastatic disease, only half of radically resected patients can be considered disease free.

COMMON TREATMENT

The value of adding radiotherapy to surgery in the treatment of patients with resectable rectal cancer has been assessed in trials using either preoperative or postoperative irradiation.

IMPROVEMENTS IN TREATMENT

Preoperative radiotherapy and complete resection are established modalities for Stage II and III rectal cancer whilst data reporting improvement of survival by preoperative chemoradiotherapy are still not available. At present, the improved results reported by Phase II trials in terms of local control, sphincter saving and tumor regression grade make neoadjuvant treatment the 'standard' therapy only in North America and some other countries, but the concept of preoperative combined modality treatment is not supported globally.

Neoadjuvant chemotherapy prior to preoperative chemoradiation or radiation in rectal cancer: should we be more cautious?

Neoadjuvant chemotherapy (NACT) is a term originally used to describe the administration of chemotherapy preoperatively before surgery. The original rationale for administering NACT or so-called induction chemotherapy to shrink or downstage a locally advanced tumour, and thereby facilitate more effective local treatment with surgery or radiotherapy, has been extended with the introduction of more effective combinations of chemotherapy to include reducing the risks of metastatic disease. It seems logical that survival could be lengthened, or organ preservation rates increased in resectable tumours by NACT. In rectal cancer NACT is being increasingly used in locally advanced and nonmetastatic unresectable tumours. Randomised studies in advanced colorectal cancer show high response rates to combination cytotoxic therapy. This evidence of efficacy coupled with the introduction of novel molecular targeted therapies (such as Bevacizumab and Cetuximab), and long waiting times for radiotherapy have rekindled an interest in delivering NACT in locally advanced rectal cancer. In contrast, this enthusiasm is currently waning in other sites such as head and neck and nasopharynx cancer where traditionally NACT has been used. So, is NACT in rectal cancer a real advance or just history repeating itself? In this review, we aimed to explore the advantages and disadvantages of the separate approaches of neoadjuvant, concurrent and consolidation chemotherapy in locally advanced rectal cancer, drawing on theoretical principles, preclinical studies and clinical experience both in rectal cancer and other disease sites. Neoadjuvant chemotherapy may improve outcome in terms of disease-free or overall survival in selected groups in some disease sites, but this strategy has not been shown to be associated with better outcomes than postoperative adjuvant chemotherapy. In particular, there is insufficient data in rectal cancer. The evidence for benefit is strongest when NACT is administered before surgical resection. In contrast, the data in favour of NACT before radiation or chemoradiation (CRT) is inconclusive, despite the suggestion that response to induction chemotherapy can predict response to subsequent radiotherapy. The observation that spectacular responses to chemotherapy before radical radiotherapy did not result in improved survival, was noted 25 years ago. However, multiple trials in head and neck cancer, nasopharyngeal cancer, non-small-cell lung cancer, small-cell lung cancer and cervical cancer do not support the routine use of NACT either as an alternative, or as additional benefit to CRT. The addition of NACT does not appear to enhance local control over concurrent CRT or radiotherapy alone. Neoadjuvant chemotherapy before CRT or radiation should be used with caution, and only in the context of clinical trials. The evidence base suggests that concurrent CRT with early positioning of radiotherapy appears the best option for patients with locally advanced rectal cancer and in all disease sites where radiation is the primary local therapy.

Phase I trial of Orzel (UFT plus leucovorin), cisplatin, and radiotherapy in the treatment of potentially resectable esophageal cancer

PURPOSE

Fluorinated pyrimidines have been established as radiosensitizers in the combined modality therapy of esophageal cancer. UFT, an oral combination of a 5-fluorouracil pro-drug (uracil) and a dihydropyrimidine dehydrogenase inhibitor (ftorafur), may provide improvement in the ease of administration with equal efficacy. This Phase I study was designed to determine the maximal tolerated dose and dose-limiting toxicity of UFT, leucovorin, and cisplatin when given with radiotherapy in the neoadjuvant treatment of resectable esophageal cancer.

METHODS

Chemotherapy consisted of i.v. cisplatin 80 mg/m(2) (Days 1 and 22) and UFT with leucovorin orally on Days 1-35. UFT was escalated in 50-mg/m(2) increments, starting at 200 mg/m(2)/d. Radiotherapy consisted of 4500 cGy in 25 fractions. Patients underwent resection 4-6 weeks after chemoradiotherapy.

RESULTS

Ten patients with resectable esophageal cancer were enrolled. Of the 7 patients entered at dose level 1, 1 developed a dose-limiting toxicity of nausea. All 3 patients entered at dose level 2 developed dose-limiting toxicity. The maximal tolerated dose for UFT was the starting level, 200 mg/m(2)/d. Of the 10 patients enrolled, 8 underwent esophagectomy and 2 developed progressive disease and did not undergo surgery. The disease of 6 of the 8 patients was downstaged at surgery.

CONCLUSION

The recommended UFT dose for Phase II studies is 200 mg/m(2)/d given orally in two divided doses when given with leucovorin, cisplatin, and radiotherapy.

Neoadjuvant treatment for locally advanced rectal carcinoma

Rectal cancer is one of the most common neoplasms of Western Countries. Overall mortality at 5 years is about 40%. This cancer is commonly diagnosed at a precocious stage, but because of local relapse and/or metastatic disease, only half of radically resected patients can be considered disease free. The value of adding radiotherapy to surgery in the treatment of patients with resectable rectal cancer has been assessed in trials using either preoperative or postoperative irradiation. Preoperative irradiation is more "dose-effective" than postoperative radiotherapy; that is, a higher dose is needed postoperatively to reduce rates of local recurrence to the same extent as preoperative radiation. Nevertheless, preoperative treatment has not been routinely recommended, mainly because it has not been shown to improve overall survival and because in some trials it has been associated with increased postoperative mortality. This paper critically reviews clinical trials of chemoradiotherapy on whether an optimal combination exists for locally advanced rectal cancer. Even if in the latest years, recent advances in surgery have improved the local control of disease, the next steps in rectal cancer care should aim at the improvement of local cure rates and the enhancement of systemic control. New approaches to CT treatment are necessary. Patient enrollment into rigorous and well-conducted clinical trials will generate new information regarding investigational therapies and it will offer improved therapies for patients with this disease.

Pre-operative chemoradiotherapy with oral tegafur-uracil and leucovorin for rectal cancer

BACKGROUND

To evaluate the efficacy and toxicity of pre-operative radiotherapy (RT) combined with oral tegafur-uracil (UFUR) plus leucovorin (LV) in rectal cancer.

PATIENTS

Sixty-five patients with rectal adenocarcinoma (clinical staged T2-4N0-2M0) received pelvic RT of 45 Gy in 20 fractions over 28 days. Concurrent chemotherapy consisted of UFUR (200 mg/m(2)/day) and LV (45 mg/day) on day 1-28. UFUR (250 mg/m(2)/day) and LV were continued on day 36-63. Surgery was performed on day 70.

RESULTS

Sixty-three patients completed the concurrent chemoradiotherapy (CCRT) and 56 received curative or palliative surgery. Among the 52 patients receiving curative resection, downstaging (DS) occurred in 39 (75%), pathological complete response in 13 (25%), and sphincter preservation was achieved in 16 of 29 (55%) with lower-seated tumors. With a median follow-up time of 33 months, local failure developed in 4 (8%) and distant metastases occurred in 7 (14%). The 3-year overall survival was 92% and disease-free survival 76%. For all 65 patients, grade 3-4 diarrhea developed in 6 (9%) and grade 3-4 leucopenia observed in 2 (3%).

CONCLUSIONS

Oral UFUR + LV administered with pre-operative RT are effective in tumor DS, pathological complete response, and sphincter preservation with tolerable toxicity in rectal cancer.

Chemoradiation with raltitrexed (Tomudex) in preoperative treatment of stage II-III resectable rectal cancer: a phase II study

PURPOSE

To evaluate the impact of preoperative chemoradiation with raltitrexed (Tomudex(1)) on tumor response, sphincter preservation, and toxicity in patients with locally advanced rectal cancer.

METHODS AND MATERIALS

Between 1998 and 2002, 54 consecutive patients with Stage T3 or T2N+ resectable rectal carcinoma were treated with preoperative chemoradiation, i.v. bolus of raltitrexed on Days 1, 19, and 38 and concurrent 50 Gy external beam radiotherapy. Surgery was performed 6-8 weeks after the end of chemoradiation.

RESULTS

No patients had Grade 4 acute toxicity. Grade 3 acute toxicity occurred in 16.6% of cases and was hematologic in 6 patients and GI in 2. The overall clinical response rate was 88.8%, with a complete response in 5.5%, partial response in 83.3%, and no change in 9.2%. No patient showed disease progression. All patients underwent surgery. Sphincter saving was obtained in 83.3% of patients. No perioperative mortality occurred, and the perioperative morbidity rate was 5.5%. Of 20 resected patients (37%) who were candidates for abdominoperineal resection at diagnosis (anorectal ring distance < or =30 mm), 13 (65%) underwent a sphincter-saving procedure. At pathologic examination, 13 (24%) of 54 patients had a complete pathologic response (pT0) and 10 (18.5%) had rare isolated residual cancer cells (pT, microscopic foci). Overall, 42.5% had major downstaging. The tumor regression grade (TRG), using Mandard's score system, was also applied and was TRG1 in 13 patients, TRG2 in 11, TRG3 in 20, and TRG4 in 10 patients; no patient had TRG5.

CONCLUSION

The use of raltitrexed in a neoadjuvant chemoradiation schedule promoted high pathologic tumor downstaging and use of a sphincter-saving procedure. The low toxicity profile supports the rationale to explore raltitrexed combined with other drugs with different biologic targets.

Uracil/Tegafur Plus Cisplatin with Concurrent Radiotherapy for Locally Advanced Non-Small-Cell Lung Cancer

PURPOSE

To evaluate the efficacy and toxicity of a novel combination treatment using concurrent radiotherapy with cisplatin plus UFT, which is comprised of uracil and tegafur, in locally advanced non-small cell lung cancer (NSCLC) patients.

EXPERIMENTAL DESIGN

In this Phase II trial, patients with unresectable stage III NSCLC were treated with the oral administration of UFT (400 mg/m(2)/d tegafur) on days 1-14 and days 29-42 whereas 80 mg/m(2) cisplatin was administered i.v. on days 8 and 36. Radiotherapy, with a total dose of 60 Gy, was delivered in 30 fractions from day 1.

RESULTS

Seventy patients were enrolled and eligible, as follows: 57 males/13 females; mean age 61 ranging from 36 to 74; performance status 0/1:45/25; stage IIIA/IIIB, 14/56. A complete response was observed in two patients and a partial response in 54 patients, and the overall response rate was 81% (95% confidence interval; 70-89%). The median survival, the 1- and 2-year survival rates were 16.5 months, 67% and 33%, respectively. Grade 3/4 leukopenia occurred in 14%/1% of the patients. Grades 3 non-hematological toxicities were only reported in three patients with nausea, two with esophagitis and one with pneumonitis whereas no grade 4 non-hematological toxicity was observed.

CONCLUSIONS

UFT plus cisplatin with concurrent radiotherapy is considered to be a feasible and effective treatment for locally advanced NSCLC patients. Additional study of this concurrent chemoradiotherapy is warranted.

Preoperative uracil, tegafur, and concomitant radiotherapy in operable rectal cancer: a phase II multicenter study with 3 years' follow-Up

PURPOSE

To assess tolerance and efficacy of preoperative treatment with uracil/tegafur and radiotherapy (RT) followed by surgery and postoperative flurouracil (FU)/leucovorin (LV) in patients with rectal cancer.

PATIENTS AND METHODS

Patients (n = 94) with potentially resectable tumors, ultrasound at stages T2N+ (n = 4), T3 (n = 77), T4 (n = 13) were treated with UFT (400 mg/m2/d, 5 days a week for 5 weeks) and concomitant RT to the pelvis (45 Gy; 1.8 Gy/d over 5 weeks). Patients underwent surgery 5 to 6 weeks later followed by four cycles of FU/LV. Primary end points included downstaging, pathologic responses, and sphincter-preserving surgery. Secondary end points were recurrence-free survival and overall survival.

RESULTS

All patients received the full RT dose. Fifteen patients (16%) needed UFT dose reduction. Preoperative G3+ toxicities included diarrhea (14%), leukopenia (1%), thrombocytopenia (1%), and nausea (4%). The downstaging rate was 54%, pathologic complete response (pCR) was 9% and, in an additional 23%, there were only residual microscopic foci. When cellular viability criteria were taken into account, the pCR was 15%. From 43 patients with abdominoperineal resection indication, 11 (25%) had sphincter-preserving surgery performed. Postoperative scheduled chemotherapy dose was not administered to 24% of patients because of G3+ toxicity (diarrhea, 8%; mucositis, 9%; and leukopenia, 7%). Patients with downstaging had significantly higher survival and recurrence-free survival rates than those without. At 3 years, actuarial patterns of failure were pelvic, 5% and distant, 11%. OS was 75%.

CONCLUSION

UFT combined with RT is safe and effective. In resectable rectal cancer, if preoperative treatment is considered, this approach can be an option.

Four Decades of Continuing Innovation With Fluorouracil: Current and Future Approaches to Fluorouracil Chemoradiation Therapy

Purpose

Chemoradiotherapy, the combination of external radiation therapy and concurrent chemotherapy, has been the basis for the oncologic management of many patients since its development in the 1960s. Fluorouracil (FU) chemoradiotherapy has demonstrated success in several organ sites with multiple dosing schedules that now guide the selection of oral analogs of FU to provide new chemoradiotherapy options.

Methods

This article reviews the metabolism and pharmacology of FU and the advantages of administration of FU by continuous infusion or bolus. The potential role and impact of the oral fluorouracil prodrugs UFT, S-1, BOF-A2, and capecitabine as replacements for intravenous administration are discussed. The results of recent chemoradiotherapy studies with FU from 2000 to 2003 are summarized in rectal, head and neck, esophageal, gastric, pancreatic, biliary, anal, and cervical cancers.

Results

Chemoradiotherapy with FU has the potential to widen the therapeutic window by minimizing normal tissue toxicity while maintaining effective tumor toxicity. Overall, FU chemoradiotherapy maximizes local control and, for some tumor sites (such as head and neck, pancreatic, biliary, cervical, esophageal, and gastric cancers), improves survival rates. Moreover, FU chemoradiotherapy results in improved organ preservation with excellent functional outcome in several anatomic sites including head and neck cancer, anal, and rectal cancer, with improved sphincter preservation.

Conclusion

FU chemoradiotherapy continues to play an important role in the management of many cancer sites. During the last four decades, optimal dosing schedules have produced a therapeutic gain. The introduction of oral prodrug analogs will likely further improve the results of FU therapy in several organ systems, such as the rectum, head and neck, and esophagus.

A Phase I trial of preoperative eniluracil plus 5-fluorouracil and radiation for locally advanced or unresectable adenocarcinoma of the rectum and colon

PURPOSE

Eniluracil, an effective inactivator of dihydropyrimidine dehydrogenase, allows for oral dosing of 5-fluorouracil (5-FU), which avoids the morbidity of continuous infusion 5-FU. We addressed the safety of oral eniluracil and 5-FU combined with preoperative radiotherapy and determined the recommended Phase II dose and dose-limiting toxicity in patients with locally advanced rectal and colon cancer.

METHODS AND MATERIALS

Patients with TNM Stage II or III rectal cancer and residual or recurrent colon cancer received eniluracil (starting at 6.0 mg/m(2) every 12 h) and 5-FU (starting at 0.6 mg/m(2) every 12 h). Eniluracil and 5-FU were given with a 5-week course of preoperative radiotherapy of 4500 cGy, with a possible 540-cGy boost. Surgery was performed approximately 4 weeks after completion of chemoradiotherapy.

RESULTS

Twenty-two patients were enrolled; 1 patient was withdrawn owing to noncompliance. Chemotherapy was completed in all patients; radiotherapy was completed in 20 patients. The recommended Phase II dose of eniluracil and 5-FU was 8 mg/m(2) every 12 h and 0.8 mg/m(2) every 12 h, respectively. Diarrhea was the dose-limiting toxicity. Eleven of the 17 patients with primary rectal cancer underwent a sphincter-sparing procedure. One patient had a pathologic complete response.

CONCLUSION

Preoperative chemoradiotherapy with oral eniluracil and 5-FU is feasible and well tolerated. Additional investigation is warranted.

Phase I study of UFT plus leucovorin with radiotherapy in patients with inextirpable non-rectal gastrointestinal cancer

BACKGROUND AND PURPOSE

Chemoradiotherapy is increasingly used in the primary management of patients with loco-regionally advanced gastrointestinal (GI) cancer. Oral chemotherapy with uracil and tegafur (UFT) plus leucovorin (LV) may represent a convenient way of delivering protracted infusion of fluorouracil. Our goal was to evaluate the safety of UFT plus LV combined with radiation and determine the maximum-tolerated dose (MTD) and a recommended dose for further testing.

PATIENTS AND METHODS

Patients with inextirpable GI cancer received escalating doses of UFT (starting at 300 mg/m(2)/d with 50 mg/m(2)/d increments between consecutive cohorts) and fixed doses of LV (90 mg/d). UFT and LV were given 5 days per week concurrently with radiation to 50 Gy (2 Gy/fraction).

RESULTS

Twenty-five patients were treated, and 22 received the planned treatment. Three patients were withdrawn from treatment, two due to disease-progression and one due to toxicity. The MTD of UFT with radiation was 400 mg/m(2)/d with 90 mg/d of LV. Diarrhoea was the main dose limiting toxicity (DLT). Since some toxicity (3/12 DLTs) was seen in the expanded cohort at the level below, but none (0/9 DLT) at the starting level, the recommended dose chosen for further testing is 300-350 mg/m(2)/d depending upon the size of the target volume.

CONCLUSION

Concomitant chemoradiation with oral UFT plus LV is feasible and well tolerated and should be further investigated since tumour responses were frequently seen.

A Comparative Pharmacology Study Between the Intracolonic and Oral Routes of 5-FU Administration in a Colon Cancer-Bearing Yoshida Sarcoma Rat Model

We prepared a colon cancer-bearing Yoshida sarcoma rat model to examine the dose-response relationship of antitumor activity of intracolonically or orally administered 5-fluorouracil (5-FU; 45, 30, 20, 13, and 8 mg/kg). At doses of > or =20 mg/kg and > or =30 mg/kg, the 5-FU intracolonic and oral administration groups each showed a statistically significant difference in antitumor activity against the control group (P<0.05, Williams' test). A statistically significant dose-response relationship was noted in the two routes of administration, with an ED(50) value of 29 mg/kg. White blood cell count tended to decrease at high doses when 5-FU was administered intracolonically and showed a statistically significant decrease at doses of > or =30 mg/kg when 5-FU was administered orally. Regarding the time-course of body weight, even the 5-FU highest dose (45 mg/kg) intracolonic administration group showed no inhibited body weight increase compared to the control group. However, the 5-FU (> or =20 mg/kg) oral administration groups showed a statistically significant difference in body weight increase against the control group. These facts suggested that the intracolonic administration of 5-FU, while exhibiting more potent antitumor activity than that observed in oral administration, allows an extensive reduction in its toxicities compared to oral administration.

UFT and Oral Leucovorin as Radiation Sensitizers in Rectal and Other Gastrointestinal Malignancies

UFT is the combination of the fluorouracil (5-FU) prodrug tegafur, and the dihydrophyrimidine dehydrogenase inhibitor uracil. UFT and leucovorin have been used in the oral treatment of a variety of malignancies. Given the radiosensitizing properties of UFT, its combination with radiation therapy is a logical step in the development of novel strategies for the treatment of gastrointestinal malignancies. Several phase I and phase II studies, described in this review, have attempted to substitute UFT for 5-FU in chemoradiation strategies for the treatment of patients with esophageal, pancreatic and rectal cancer. The results thus far suggest that this approach has acceptable toxicity and promising efficacy. Given the availability of the novel oral fluorinated pyrimidines and their efficacy in metastatic diseases, it remains to be determined whether 5-FU will eventually be substituted by oral fluorinated pyrimidines in the adjuvant and chemoradiation settings.

Palliative treatment of patients with colorectal cancer

BACKGROUND

Metastatic colorectal cancer has a poor prognosis, and the majority of patients are left with palliative measures. The development seen using palliative chemotherapy is reviewed.

MATERIAL AND METHODS

A systematic approach to the literature-based evidence was aimed at.

RESULTS

The continuous improvements during the past 13-15 years have been documented in several large conclusive trials. At the end of the 1980s, the evidence that chemotherapy should be used at all was very limited, whereas presently most patients can be offered two lines of chemotherapy based upon good scientific evidence. Median survival has gradually improved from below 6 months to above 18 months in some recent trials. Several important issues remain to be solved, such as the best sequence of treatments, what regimens to use in various situations, when to start and when to stop if a response is seen, and whether cure may be possible in a small subset of patients.

CONCLUSIONS

Progress has been rapid in advanced colorectal cancer. This is likely a result of well-designed trials in collaboration between academy and industry, showing a great interest in the disease. Future collaborations may hopefully introduce new treatment concepts, further improving outcome.

Advances in combined radiation therapy for the management of rectal cancer

Significant advances have been made in the use of adjuvant radiation for patients with localized rectal cancer. Recent progress in adjuvant postoperative radiation regimens relates to the integration of systemic therapy into radiation, as well as redefining the techniques and sequences for both modalities. The adjuvant radiation management approach in both North America and Europe has been shifting towards preoperative adjuvant therapy to promote sphincter-preserving surgery and to decrease acute and late toxicity. Although 5-fluorouracil-based chemotherapy in combination with radiation remains the standard adjuvant therapy for rectal cancer, the integration of novel chemotherapeutic agents and biologic modulators remains an active area of investigation.

Overview of preoperative and postoperative therapy for colorectal cancer: the European and United States perspectives

Surgery is the primary modality for cure in patients with localized colorectal cancer. However, despite potential curative surgery, the risk of recurrence is high. In colon cancer, the role of adjuvant chemotherapy with 5-fluorouracil (5-FU) and leucovorin (LV) is now established in stage III disease. The benefit of adjuvant treatment in stage II disease is likely to be small, and studies performed thus far have been generally underpowered to detect what might be a clinically significant effect on survival. Whereas bolus scheduling of 5-FU and LV is favored in North America, infusion of 5-FU/LV is preferred in Europe. Indeed, infused 5-FU/LV may be a safer partner with new drugs such as oxaliplatin and irinotecan. Oral fluoropyrimidines are attractive agents that might one day replace parenteral 5-FU. In rectal cancer, postoperative combined chemoradiation was recommended as standard practice in stages II and III disease. Despite a lack of randomized data demonstrating clinical benefit, preoperative chemoradiation has been increasingly used in patients with T3 disease in North America. However, preoperative radiation therapy is more frequently used in Europe. There are discrepancies in pathologic reporting of circumferential resection margin involvement and lymph node status between the United States and Europe. Standardized reporting with improved preoperative imaging would allow patients with truly early-stage disease to undergo more conservative management and be spared the morbidity and mortality of unnecessary adjuvant or neoadjuvant treatment.

Phase I study of oral uracil and Tegafur plus leucovorin and pelvic radiation in patients with recurrent rectal cancer

Continuous 5-fluorouracil (5-FU) infusion during radiation therapy is superior to the application of bolus 5-FU schedules. As an oral therapy, that provides prolonged fluoropyrimidine exposure, uracil and Tegafur (UFT) plus leucovorin (LV) has shown favorable activity with only moderate toxicity in colorectal cancer. The present study was designed to evaluate the safety of UFT+LV combined with pelvic radiation to determine the maximum-tolerated dose (MTD) in recurrent rectal cancer. Patients with recurrent rectal cancer received escalating doses of UFT (starting at 250 mg/m /day with 50 mg/m /day increments between consecutive cohorts) and fixed doses of LV (90 mg). The UFT+LV combination was given 5 days per week simultaneously to a 5-week course of irradiation up to a total dose of 50.4 Gy, 1.8 Gy daily fractions followed by a boost of 5.4 or 9.0 Gy to the gross tumor volume. Nineteen patients were treated and 14 received the full chemotherapy with delivery of all planned radiotherapy. The MTD of UFT was 400 mg/m /day due to the occurrence of dose-limiting diarrhea and emesis. Toxicities were mild and manageable on the lower dose levels. Treatment was feasible mainly on an outpatient base. We conclude that combined chemoradiation with oral UFT+LV is feasible and well tolerated for recurrent rectal cancer patients undergoing pelvic radiation. The safety profile appears comparable to that of i.v. dosing without requiring any i.v. port systems. The recommended doses for further phase II chemoradiation trials are 350 mg/m /day UFT+90 mg LV.

Clinical studies of three oral prodrugs of 5-fluorouracil (capecitabine, UFT, S-1): a review

Although 5-fluorouracil (5-FU) was first introduced in 1957, it remains an essential part of the treatment of a wide range of solid tumors. 5-FU has antitumor activity against epithelial malignancies arising in the gastrointestinal tract and breast as well as the head and neck, with single-agent response rates of only 10%-30%. Although 5-FU is still the most widely prescribed agent for the treatment of colorectal cancer, less than one-third of patients achieve objective responses. Recent research has focused on the biomodulation of 5-FU to improve the cytotoxicity and therapeutic effectiveness of this drug in the treatment of advanced disease. As all the anticancer agents, 5-FU leads to several toxicities. The toxicity profile of 5-FU is schedule dependent. Myelotoxicity is the major toxic effect in patients receiving bolus doses. Hand-foot syndrome (palmar-plantar erythrodysesthesia), stomatitis, and neuro- and cardiotoxicities are associated with continuous infusions. Other adverse effects associated with both bolus-dose and continuous-infusion regimens include nausea and vomiting, diarrhea, alopecia, and dermatitis. All these reasons explain the need for more effective and less toxic fluoropyrimidines. In the first part of this review, we briefly present the metabolic pathways of 5-FU responsible for the efficacy and toxicity of this drug. This knowledge is also necessary to understand the target(s) of biomodulation. The second part is devoted to a review of the literature on three recent prodrugs of 5-FU, i.e., capecitabine, UFT (ftorafur [FTO] plus uracil), and S-1 (FTO plus 5-chloro-2,4-dihydroxypyridine plus potassium oxonate). The pharmacological principles that have influenced the development of these new drugs and our current knowledge of the clinical pharmacology of these new agents, focusing on antitumor activity and toxicity, are presented. The literature was analyzed until March 2002. This review is intended to be as exhaustive as possible since it was conceived as a work tool for readers wanting to go further.

Oral tegafur/uracil

Tegafur is a prodrug of the antineoplastic agent fluorouracil, and is administered in a 1:4 molar ratio with the fluorouracil modulator uracil. Oral tegafur/uracil 300 mg/m(2)/day plus calcium folinate 75 or 90 mg/day for 28 days every 35 days was as effective as intravenous (IV) fluorouracil 425 mg/m(2)/day plus folinic acid 20 mg/m(2)/day for 5 days every 28 or 35 days in the treatment of patients with metastatic colorectal cancer in two large, randomised, nonblind, multicentre trials (n = 816 and 380). Median survival time among patients treated with tegafur/ uracil or fluorouracil was approximately 12 months in both trials. Results from both trials also demonstrated no significant between-group differences in overall response rates among patients treated with oral tegafur/uracil (12 and 11%) or IV fluorouracil (15 and 9%). In elderly patients (aged > or = 70 years) with metastatic colorectal cancer, results from small noncomparative studies showed that treatment with oral tegafur/uracil afforded overall response rates of 12.5 to 29% and was well tolerated. During preoperative treatment with oral tegafur/uracil plus calcium folinate as an adjunct to radiotherapy in patients with stage II or III rectal cancer, the maximum tolerated dosage of tegafur/uracil was 350 mg/m(2)/day (administered 5 days per week for 5 weeks). Among the 15 patients who were followed for 5 to 8 months, three had a complete response to treatment. Treatment with tegafur/uracil was also given postoperatively. The most common adverse events associated with oral tegafur/uracil were anaemia, nausea/vomiting, diarrhoea, thrombocytopenia, mucositis, neutropenia, asthenia, anorexia and abdominal pain. Oral tegafur/uracil was associated with a significantly more favourable tolerability profile than IV fluorouracil in the two large randomised trials. In particular, stomatitis and most adverse haematological events were less frequent.

Neoadjuvant therapy of rectal carcinoma with UFT-leucovorin plus radiotherapy

BACKGROUND

The object of this phase II study was to assess the impact of preoperative external radiation therapy combined with UFT and leucovorin on tumor response, sphincter preservation and tumor control in patients with rectal carcinoma.

PATIENTS AND METHODS

Forty-one patients with resectable extraperitoneal rectal adenocarcinoma received radiation therapy and two courses of chemotherapy. Chemotherapy consisted of a 2-h infusion of 6S-steroisomer of leucovorin (6SLV) 250 mg/m2 on day 1, oral 6SLV 7.5 mg every 12 h on days 2-14, and UFT either 350 or 300 mg/m2 on days 1 to 14 every 28 days. Six additional courses of chemotherapy were given after surgery.

RESULTS

Seven of 16 patients (43%) who received 350 mg/m2/day of UFT had grade 3-4 diarrhea and two other patients (12%) had grade 3-4 dermatitis. The next 25 patients received 300 mg/m2/day of UFT and only 14% of them had grade 3-4 diarrhea. Surgery consisted of low-anterior resection in 26 patients (63%) and abdominal-perineal amputation in 15 (37%). There were six histological complete responses (15%). Downstaging occurred in 25 patients (63%). The overall survival at 3 years was 90% and the pelvic disease-free survival 92%.

CONCLUSIONS

Preoperative therapy with radiotherapy and UFT-6SLV downstaged 63% of tumors and allowed a sphincter-preserving procedure in some patients. Toxicity was moderate. This scheme is convenient because of the oral administration of chemotherapy.

Pathologic downstaging of T3-4Nx rectal cancer after chemoradiation: 5-fluorouracil vs. Tegafur

PURPOSE

To describe downstaging effects in locally advanced rectal cancer induced by 2 fluopirimidine radiosensitizing agents given through different routes in conjunction with preoperative radiotherapy.

METHODS AND MATERIALS

From March 1995 to December 1999, two consecutive groups of patients with cT3-4Nx rectal cancer (94% CT scan, 71% endorectal ultrasound) were treated with either (1) 45-50 Gy (1.8 Gy/day, 25 fractions) and 5-fluorouracil (5-FU) (500-1,000 mg/m2 by 24-h continuous i.v. infusion on Days 1-4 and 21-25) or (2) oral Tegafur (1,200 mg/day on Days 1-35, including weekends). Surgery was performed 4 to 6 weeks after the completion of chemoradiation.

RESULTS

The total T downstaging rate was 46% in the 5-FU group and 53% in the Tegafur group. Subcategories were downstaged by the sensitizing agents (5-FU vs. Tegafur) as follows: pT0-1, 14% vs. 23%; pT2, 32% vs. 32%; pT3, 49% vs. 37%; pT4, 5% vs. 7%; and N(0), 74% vs. 86%. Analysis of residual malignant disease in the specimen discriminated mic/mac subgroups (mic: <20% of microscopic cancer residue), with evident superior downstaging effects in the Tegafur-treated group: pTmic 23% vs. 58% (p = 0.002).

CONCLUSIONS

When administered concurrent with pelvic irradiation, oral Tegafur induced downstaging rates in both T and N categories superior to those induced by intermediate doses of 5-FU by continuous i.v. infusion. In this pilot experience, oral Tegafur reproduced the characteristics of downstaging described previously when full doses of 5-FU have been combined with radiotherapy.

Recent advances in the use of radiosensitizing nucleosides

Chemotherapeutic drugs that perturb nucleotide metabolism have the potential to produce substantial sensitization of tumor cells to radiation treatment. The clinical effectiveness of fluoropyrimidines as radiosensitizers has been proven in multiple randomized trials. The development of oral fluoropyrimidine formulations may allow protracted exposure without the need for indwelling intravenous lines and infusion pumps. These agents may also provide more selective radiosensitization and are likely to be widely incorporated into chemoradiotherapy regimens for patients with gastrointestinal malignancies. Gemcitabine has been well studied in the laboratory, with respect to mechanisms of radiosensitization and strategies that may increase the therapeutic index. Clinical trials based on these studies are now defining the role of this radiosensitizing nucleoside. Issues regarding the use oral fluoropyrimidines and gemcitabine need to be viewed in the context of both local and distant disease control, given the potential systemic activity of these agents.

Chemoradiotherapy for rectal cancer--is there an optimal combination?

PURPOSE

Chemoradiotherapy is increasingly used in the primary management of rectal cancer. A critical review of present knowledge of whether an optimal combination exists was made for each of the major clinical situations.

RESULTS

As preoperative therapy to reduce local recurrence rates in primarily resectable rectal cancers, radiotherapy has almost exclusively been used as single modality, and combined chemoradiotherapy should remain experimental until further evidence is available. This can only be achieved in randomised trials. Postoperatively, a combination of chemotherapy and radiotherapy appears to be more efficient in reducing local failure rates and improving survival than either modality alone, but the literature-based evidence is partly conflicting. As a reference treatment, a combination of continuous infusion 5-fluorouracil (5-FU) and radiotherapy can be advocated based upon one trial. In primarily irresectable cancer, there is some support that chemoradiotherapy may be more efficient than radiotherapy alone in causing tumour regression allowing radical surgery, but the literature is again conflicting. A great number of phase II studies have been performed in these cancers and in those considered to be locally advanced, revealing promising activity and claims of superiority to radiotherapy alone or other schedules. The studies are, however, inconclusive with respect to antitumour activity, and patient selection may be of greater relevance for the results. Chemoradiation has also increasingly been used to facilitate a sphincter-preserving procedure in low-lying cancers. Again, literature is inconclusive as to whether an optimal combination exists, whether it is superior to radiotherapy alone, or if it actually facilitates sphincter preservation at all. Long-term functional outcome is poorly known. Again, 5-FU has been most extensively used, but many other drugs are presently being tested in various combinations.

CONCLUSIONS

An optimal combination of chemoradiotherapy for rectal cancer does not exist. Actually, a critical review of the literature shows that the support for superiority of chemoradiation over radiation alone is weak, or lacking. There is a great need of both more conclusive study designs and a more rational exploration of drug-radiation interactions prior to clinical testing.

Radiation therapy in the management of rectal cancer

Substantial advances have been made in the adjuvant management of patients with resectable rectal cancer. Increasing interest in patient quality of life has promoted the use of radiation therapy to enhance sphincter-preserving surgical approaches as an alternative to the standard abdominoperineal resection. Because of the suggestion of enhanced sphincter preservation with preoperative therapy and the potential advantage of decreased acute morbidity, randomized trials comparing preoperative and postoperative adjuvant combined modality therapy are ongoing. Recent progress in adjuvant postoperative treatment regimens relates to the integration of systemic therapy to radiation, and redefining the techniques for both modalities. The incorporation of improved radiation planning may reduce treatment-related bowel toxicity. The integration of novel chemotherapeutic agents in the adjuvant therapy of rectal cancer remains an active area of investigation.

UFT plus oral leucovorin calcium (Orzel) and radiation in combined modality therapy: a comprehensive review

5-fluorouracil (5-FU) has become the most commonly used drug in combination with radiation therapy. The recent availability of oral formulations of 5-FU in conjunction with the ability to modulate the anabolic and catabolic metabolism of 5-FU with leucovorin and dihydropyrimidine dehydrogenase (DPD) inhibitors, respectively, may provide a substantial improvement in the ease of administration and the efficacy of fluoropyrimidine therapy. Several oral fluoropyrimidines are under investigation. UFT (uracil:tegafur) plus oral leucovorin (Orzel) is the first oral DPD-inhibitory fluoropyrimidine. With daily administration, Orzel achieves similar concentrations of 5-FU obtained with continuous-infusion 5-FU. This paper summarizes the therapeutic rationale for Orzel and reviews the clinical experience with UFT and UFT/LV in combined modality therapy regimens.