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Biomedical subjects

R Pazdur

Publications and source records attributed to R Pazdur.

At least 55 records · Page 3Linked to original sources
PubMed1999

Novel agents for colorectal cancer.

The compound 5-fluorouracil (5-FU) has been investigated for over four decades; research has focussed on examining various schedules and biochemical modulators in an attempt to improve its therapeutic activity in advanced colorectal cancer. Combination chemotherapy regimens have not been developed because of the lack of other active agents. Recently, several novel agents are under clinical development for advanced colorectal cancer, including irinotecan, oxaliplatin, oral fluoropyrimidines, raltitrexed, monoclonal antibody 17-1A and tumour vaccines. Both irinotecan and oxaliplatin have uniquely different mechanisms of action compared to 5-FU, and have demonstrated activity in patients whose disease has progressed with 5-FU treatment. Recent randomised trials comparing 5-FU plus leucovorin (5-FU/LV) to combinations of either irinotecan or oxaliplatin plus 5-FU/LV have demonstrated that the addition of these novel agents to 5-FU improve response rates (RRs) and time to progression (TTP). The role and acceptance of these combinations need to be defined, but are rapidly being introduced into the adjuvant therapy of colorectal cancer. Oral fluoropyrimidines (UFT plus leucovorin, capecitabine, eniluracil plus oral 5-FU, and S-1) provide the convenience of oral delivery with a marked reduction in febrile neutropenia and mucositis. To gain clinical acceptance, oral fluoropyrimidines must provide not only convenience and toxicity reduction, but also maintenance of survival advantages associated with optimal use of iv. 5-FU/LV regimens. These novel agents discussed herein provide treatment options which may allow for more individualised treatment strategies.

Journal Article↗
PubMed1999

Tegafur/uracil + calcium folinate in colorectal cancer: double modulation of fluorouracil.

The oral chemotherapeutic agent tegafur/uracil (UFT) is the first of a new class of anticancer drugs called dihydropyrimidine dehydrogenase inhibitory fluoropyrimidines. Tegafur/uracil combines uracil with the fluorouracil prodrug tegafur in a 4:1 molar ratio. Uracil competitively inhibits the degradation of fluorouracil, which results in the concentration of fluorouracil remaining at sustained levels in both plasma and tumour. Tegafur/uracil has been commercially available in Japan since 1983 and examined extensively in various tumours. Trials conducted in the US have focused on the combination of tegafur/uracil plus calcium folinate (calcium leucovorin) [ORZEL]. Several phase I and II trials have evaluated the maximum tolerated dose, pharmacokinetics, efficacy, and safety of this combination in the treatment of colorectal cancer. Results have shown that tegafur/uracil at 300 mg/m2/day in divided doses given every 8 hours for 28 days provides prolonged exposure to fluorouracil. Furthermore, tegafur/uracil + calcium folinate is well tolerated, with dose-limiting toxicity manifesting as diarrhoea. Compared with intravenous fluorouracil plus folinic acid (leucovorin) regimens, tegafur/uracil + calcium folinate has similar efficacy with less toxicity and is more convenient because it is an oral regimen. Early studies have also shown potential cost savings because of fewer complications.

Administration, Oral↗
PubMed1999

Oxaliplatin and UFT/oral calcium folinate for advanced colorectal carcinoma.

Oxaliplatin is a unique platinum compound with single-agent activity in both chemotherapy-naïve colorectal cancer patients and patients who progressed on 5-fluorouracil (5-FU). The combination of oxaliplatin and 5-FU has demonstrated preclinical synergy, and recent clinical trials have demonstrated enhanced activity for the combination in the clinical setting as well. UFT (uracil plus tegafur in a 4:1 molar ratio) plus oral calcium folinate (Orzel) is an oral fluoropyrimidine with several potential advantages over intravenous 5-FU and known activity in colorectal cancer. The current trial was designed to evaluate the role of these agents in combination in the treatment of patients with advanced colorectal cancer.

Adenocarcinoma↗
PubMed1999

Preoperative UFT and calcium folinate and radiotherapy in rectal cancer.

Protracted infusions of 5-fluorouracil (5-FU) combined with pelvic radiotherapy have been associated with improved survival and decreased local and distant metastases in the adjuvant therapy of rectal cancer. However, this method of 5-FU infusion requires the inconvenience and expense of central venous line placement and care, infusion pumps, and treatment of catheter-related complications. We previously demonstrated that a completely oral therapy with UFT (uracil plus tegafur in a 4:1 molar ratio) plus oral calcium folinate (Orzel) can achieve pharmacokinetic parameters similar to those associated with protracted 5-FU infusions. This trial examines the feasibility of using UFT plus oral calcium folinate both during preoperative pelvic radiation and postoperatively, and shows that patients can be treated safely and effectively with a completely oral chemotherapy program combining UFT plus oral calcium folinate with pelvic radiation therapy.

Adolescent↗
PubMed1999

Oral fluoropoyrimidines.

Protracted intravenous infusions of fluorouracil (5-FU) in the treatment of colorectal cancer have been associated with a reduction in toxicity and enhanced clinical activity compared with bolus 5-FU schedules. However, these protracted infusions require portable infusion pumps and central venous lines, which are associated with complications of venous thrombosis, infection, and line slippage. An effective oral 5-FU formulation could provide a more convenient protracted treatment method with fewer complications. Because of its inconsistent and erratic absorption, the use of oral 5-FU was abandoned decades ago. The inconsistent absorption of oral 5-FU may be attributed to varying levels of dihydropyrimidine dehydrogenase (DPD) in the gastrointestinal tract. Two methods have been used to circumvent 5-FU's metabolism by DPD in the gastrointestinal tract. First, DPD may be inactivated, allowing for reliable, consistent absorption of 5-FU. Second, 5-FU prodrugs can be administered, being absorbed as intact molecules via the gastrointestinal tract and subsequently converted to 5-FU. The oral fluoropyrimidines discussed here are capable of providing prolonged 5-FU exposure with a reduced incidence of toxicity.

Animals↗
PubMed1999

Dihydropyrimidine dehydrogenase inhibitory fluoropyrimidines: a novel class of oral antineoplastic agents.

Protracted intravenous regimens of 5-fluorouracil (5-FU) produce fewer toxic effects and greater response rates than do bolus infusion regimens. An effective oral regimen would allow a protracted course of 5-FU without the need for central venous lines and the associated increase in complications, such as venous thrombosis, infection, and line slippage. Dihydropyrimidine dehydrogenase (DPD) is the primary catabolic enzyme of 5-FU. The varying levels of DPD located in the gastrointestinal tract make the absorption of oral 5-FU and resultant plasma levels erratic. The use of 5-FU pro-drugs and/or DPD inhibitors can overcome this absorption problem and allow for oral dosing of fluoropyrimidines. In Japan, oral fluoropyrimidines have been used for decades and have gained widespread acceptance in the treatment of cancer. More recently, encouraging clinical results have led to the development of a new generation of oral fluoropyrimidines, commonly referred to as DPD inhibitory fluoropyrimidines, that specifically target DPD. Several DPD inhibitory fluoropyrimidines are in advanced stages of clinical development in the United States. As studies have shown so far, DPD inhibitory fluoropyrimidine can prolong exposure to 5-FU, while causing fewer toxic effects, and may have therapeutic advantage over intravenous 5-FU.

Antineoplastic Agents↗
PubMed1998

Phase II study of prolonged infusion of Taxol in patients with metastatic colorectal carcinoma.

PURPOSE: Taxol represents a new class of anticancer agents with activity against a wide variety of solid tumors. In preclinical systems, its cytotoxicity is schedule dependent with prolonged exposure being more effective. We studied a 120-hour infusion schedule of Taxol in patients with metastatic measurable colorectal carcinoma who had had one prior 5-FU-based chemotherapy. METHODS: Patients with measurable metastatic colorectal carcinoma were eligible. Patients had to have normal liver, renal, and bone marrow functions. Written informed consent was obtained from all patients. The starting dose of Taxol was 150 mg/m2 infused over 120-hours in the outpatient setting. Taxol was repeated every 21 days. RESULTS: Fifteen patients were registered. Among 14 evaluable patients, we did not observe any complete or partial response. Major toxicity included myelosuppression and mucositis. There was no treatment-related death. CONCLUSION: Taxol administered by this schedule was found ineffective in patients with metastatic colorectal carcinoma who had previously received one 5-FU-based chemotherapy.

Adult↗
PubMed1998

Pharmacokinetics of recombinant human interferon-alpha 2a combined with 5-fluorouracil in patients with advanced colorectal carcinoma.

We evaluated the pharmacokinetics of 5-fluorouracil (5-FU) combined with recombinant human interferon (IFN)-alpha 2a in 10 previously untreated patients with advanced colorectal carcinoma. 5-FU was administered as a continuous i.v. infusion, 750 mg/m2/day for 5 days during week 1. One s.c. injection of IFN-alpha 2a, 9 x 10(6) IU, was administered during week 2. Beginning with week 3, a continuous i.v. infusion of 5-FU 750 mg/m2/day for 5 days was administered in combination with IFN-alpha 2a, 9 x 10(6) IU s.c. three times per week. The combination of 5-FU and IFN-alpha 2a was continued every other week until either 3 months after complete remission or tumor progression. No grade 4 toxicity was observed. Granulocytopenia (two patients), leukopenia (one patient), thrombocytopenia (one patient), stomatitis (two patients), fatigue (one patient) and hand-foot syndrome (one patient) were the major (grade 3) toxic reactions encountered. Overall, one complete and six partial responses were noted. The results of the paired t-test showed no statistically significant differences between the means of the two treatments, 5-FU and 5-FU plus IFN-alpha 2a, with respect to the steady-state plasma concentration, area under the concentration-time curve, total body clearance, or steady-state volume of distribution of 5-FU, or the serum concentration of IFN. We conclude that 5-FU and IFN-alpha 2a do not interact pharmacokinetically at the doses and schedules in the regimen studied.

Adult↗
PubMed1998

Prospectively randomized trial of postoperative adjuvant chemotherapy in patients with high-risk colon cancer.

PURPOSE: This study had two major goals: (1) to assess the effectiveness of a regimen of fluorouracil (5-FU) plus levamisole plus leucovorin as postoperative surgical adjuvant therapy for patients with high-risk colon cancer, and (2) to evaluate 6 months versus 12 months of chemotherapy. PATIENTS AND METHODS: Patients with poor-prognosis stage II or III colon cancer were randomly assigned to receive adjuvant chemotherapy with either intensive-course 5-FU and leucovorin combined with levamisole, or a standard regimen of 5-FU plus levamisole. Patients were also randomly assigned to receive either 12 months or 6 months of chemotherapy, which resulted in four treatment groups. RESULTS: Eight hundred ninety-one of 915 patients entered (97.4%) were eligible. The median follow-up duration is 5.1 years for patients still alive. There was a difference among the four treatment groups with respect to patient survival, and a significant duration-by-regimen interaction was observed. Specifically, standard 5-FU plus levamisole was inferior to 5-FU plus leucovorin plus levamisole when treatment was given for 6 months (5-year survival rate, 60% v 70%; P < .01). CONCLUSION: There was no significant improvement in patient survival when chemotherapy was given for 12 months compared with 6 months. When chemotherapy was given for 6 months, standard 5-FU plus levamisole was associated with inferior patient survival compared with intensive-course 5-FU plus leucovorin plus levamisole. These data suggest that 5-FU plus levamisole for 6 months should not be used in clinical practice, whereas 6 months of treatment with 5-FU plus leucovorin plus levamisole is effective.

Adenocarcinoma↗
PubMed1998

Phase II trial of paclitaxel, fluorouracil, and cisplatin in patients with advanced carcinoma of the esophagus.

PURPOSE: We have previously identified paclitaxel as an active single agent in the treatment of esophageal cancer. We performed a phase II trial of paclitaxel in combination with cisplatin and fluorouracil (5-FU), conventionally used chemotherapy for esophageal cancer. The antitumor response, toxicity, and survival of patients treated with the three-drug regimen were evaluated. PATIENTS AND METHODS: Sixty-one patients with advanced, surgically unresectable, or metastatic squamous cell or adenocarcinoma of the esophagus were treated. No prior chemotherapy was allowed. Thirty patients had adenocarcinoma and 31 patients had squamous cell carcinoma. The majority (47 patients; 77%) had metastatic disease and 14 patients (23%) had an unresectable primary or locally recurrent tumor. Patients received paclitaxel 175 mg/m2 by 3-hour infusion day 1; cisplatin 20 mg/m2 daily days 1 through 5, and 5-FU by continuous infusion at a dose of 1,000 mg/m2 daily days 1 through 5. Because of toxicity observed in the first 10 patients treated, the starting dose of 5-FU was subsequently reduced to 750 mg/m2 daily in the remaining patients. A planned attenuation of cisplatin to 15 mg/m2 daily was made after the first three cycles. Granulocyte colony-stimulating factor (G-CSF) was not routinely administered unless the patient had an episode of febrile neutropenia or prolonged grade 4 neutropenia. Treatment was recycled every 28 days. RESULTS: Sixty-one patients completed a median of five cycles, and 60 patients were assessable for response. Major responses were seen in 29 patients (48%; 95% confidence intervals, 35 to 61), which included seven complete responses (12%). Comparable response rates were seen for patients with adenocarcinoma (46%) and those with squamous carcinoma (50%), and for patients with metastatic disease (22 of 46 patients; 48%) and those with locally advanced disease (seven of 14 patients; 50%). A significantly higher complete response rate was observed in patients with squamous carcinoma (20%) compared with those with adenocarcinoma (3%; chi2 P=.04). The median duration of response was 5.7 months (range, 1 to 18.6 months). Median survival was 10.8 months (range, 1.5 to 25 months). Toxicity was severe but manageable with dose attenuation, and included 18% of patients with grade 3 neurologic toxicity. Twenty-eight patients (46%) required a dose attenuation for toxicity, and 42 of 275 treatment cycles (15%) required a dose attenuation. Twenty-nine patients (48%) required hospitalization for toxicity, which included 11 patients for neutropenic fever (18%). There were no treatment-related deaths. CONCLUSION: The combination of paclitaxel, cisplatin, and 5-FU has substantial antitumor activity in metastatic esophageal carcinoma, with a remarkable complete response rate noted in patients with squamous carcinoma. Paclitaxel is an important new agent in the treatment of esophageal carcinoma, and further evaluation of this agent in combination chemotherapy is warranted. Given the toxicity associated with the current regimen, the optimal dose and schedule of paclitaxel in combination chemotherapy remain to be established.

Adenocarcinoma↗
PubMed1998

Phase I trial of uracil-tegafur (UFT) plus oral leucovorin: 28-day schedule.

UFT [Taiho Pharmaceutical Co. Ltd., Tokyo, Japan; (BMS-200604), Bristol-Myers Squibb, Princeton, NJ], a fluorouracil prodrug, is an oral 4:1 molar concentration of uracil plus tegafur. This study examined the dose-limiting toxic effects and maximum tolerated dose of UFT plus leucovorin administered for 28 consecutive days followed by a 7-day rest period. A course of therapy was repeated every 35 days. UFT dose levels examined were 200 mg/m2/day, with planned escalations to 250, 300, 350, and 400 mg/m2/day; the leucovorin dose remained at 150 mg/day. Three patients were initially enrolled at each UFT dose level. The total daily doses of both UFT and leucovorin were divided into three doses administered every 8 hr. Diarrhea became the dose-limiting toxicity at 400 mg/m2/day UFT, with grade 3 diarrhea noted in 2 of the 3 patients receiving that dose. To further define a phase II UFT starting dose, 3 additional patients were entered at the 350 mg/m2 level; 3 of the 6 patients treated at this level developed grade 3 nonhematological toxic effects. No partial or complete responses were observed. The recommended phase II UFT starting dose is 300 mg/m2/day plus 150 mg/day leucovorin. Since neutropenia, significant mucositis, and "hand-foot syndrome" were not observed with UFT plus leucovorin, the toxicity profile of this regimen appears favorable compared with that of intravenous regimens of fluorouracil plus leucovorin. This phase I trial of UFT served as the basis for a phase II trial, current phase III trials, and a national adjuvant therapy trial of UFT for high-risk colon cancer patients.

Administration, Oral↗
PubMed1998

UFT Plus Oral Leucovorin: A New Oral Treatment for Colorectal Cancer.

UFT is an oral antineoplastic agent that combines the 5-fluorouracil (5-FU) prodrug tegafur with uracil in a 1:4 molar ratio. Uracil is added because it competitively inhibits the degradation of 5-FU, resulting in increased plasma and tumor 5-FU concentrations. Although UFT has been available in Japan since 1984, it has only recently been in clinical development in the United States. Beginning in 1991, phase I/II trials of UFT have been conducted in the United States to establish a maximum tolerated dose, evaluate its pharmacokinetics, and assess its efficacy and safety in advanced colorectal cancer. Pharmacokinetic studies demonstrated that UFT 300 mg/m&sup2;/day administered in divided doses every 8 h for 28 days provides an effective oral method of delivering a prolonged exposure to 5-FU. UFT plus oral leucovorin is well tolerated, with diarrhea as the dose-limiting toxicity. Unlike i.v. administered 5-FU, UFT is not associated with significant myelosuppression, mucositis, hand-foot syndrome, or alopecia, and patients have a decreased risk of toxicity-related hospitalization. In a phase II trial in advanced colorectal cancer, UFT plus oral leucovorin produced an objective response rate of 42%, with survival similar to weekly i.v. 5-FU plus leucovorin. The reduced toxicity, efficacy comparable to i.v. 5-FU, and the convenience and cost savings of an orally administered regimen have potential pharmacoeconomic advantages.

Journal Article↗
PubMed1998

Irinotecan: toward clinical end points in drug development.

The objective response rate is the initial method to assess the activity of a novel anticancer agent. Response rates may not characterize a new agent's clinical benefit, however, especially if moderate to severe toxicity may be associated with treatment. Clinical end points, such as improvement in survival or relief of disease-related symptoms, provide clinicians with a more rational basis for selecting therapies. Irinotecan (CPT-11 [Camptosar]) was introduced into clinical practice based primarily on its consistent phase II activity (response rates of 13.3% to 21.7% in patients with advanced colorectal cancer refractory to 5-fluorouracil [5-FU]). Two recently presented, randomized, phase III trials have examined irinotecan's impact on clinical end points of survival, quality of life, tolerability, and control of disease-related symptoms in 5-FU-refractory colorectal cancer patients. The first trial prospectively compared irinotecan and best supportive care (BSC) to BSC alone in patients with 5-FU-resistant metastatic colorectal cancer. Irinotecan-treated patients had significantly prolonged survival, improved quality of life, and better control of disease-related symptoms. The second trial compared irinotecan to infusional 5-FU schedules in colorectal cancer patients whose tumors had progressed within 3 months of prior 5-FU. Patients treated with irinotecan lived significantly longer than those given infusional 5-FU and had a comparable quality of life. These randomized trials demonstrate an evolution in our understanding of the clinical utility of irinotecan.

Antimetabolites, Antineoplastic↗
PubMed1998

Comparison of 5-fluorouracil pharmacokinetics in patients receiving continuous 5-fluorouracil infusion and oral uracil plus N1-(2'-tetrahydrofuryl)-5-fluorouracil.

Plasma 5-fluorouracil (5-FU) levels were compared in the same patients after approximately equimolar doses (1.9 mmol/ m2/day) of 5-day continuous i.v. infusion of 5-FU (CIFU) and oral administration of a formulation of two combined pharmacological agents, uracil (U) plus N1-(2'-tetrahydrofuryl)-5-fluorouracil (ftorafur or FT), a prodrug of 5-FU. Ten patients received CIFU for 5 days, then, after a week wash-out period, began the 28-day oral UFT regimen, which was given in three daily divided doses. Following 1 h of CIFU, the plasma 5-FU levels reached a steady state of 0.6+/-0.2 microM (mean+/-SD; day 1), which was maintained for the entire 5-day infusion period (0.6+/-0.1 microM). In contrast, the maximum 5-FU concentrations (Cpmax) generated from oral UFT at 1 h after dose administration on days 1 and 5 were 2.1+/-1.5 microM and 2.3+/-1.9 microM, respectively, which were higher than the steady-state levels during CIFU. These high 5-FU levels disappeared with an apparent elimination half-life (tl/2,beta) of 5.2+/-2.4 h (day 1) and 7.2+/-3.9 h (day 5). On day 1 of both regimens, CIFU patients had significantly larger 5-FU area under the concentration versus time curve (AUC0-8h) values (4.4+/-1.3 microM.h) than the AUC value when they received the UFT regimen (2.6+/-1.7 microM.h; P = 0.02). However, by day 5, there were no significant differences between AUC0-8 h values in patients receiving CIFU and UFT, respectively (4.8+/-1.5 microM.h versus 3.8+/-2.2 microM.h; P = 0.30)]. On day 5, the average concentration of the metabolite 5-FU at steady-state (Css,aver) within dose interval of 8 h (0.48+/-0.28 microM) for the oral UFT treatment is comparable with the Cpss values of 5-FU from CIFU-treated patients. The post-UFT generated 5-FU pharmacokinetic parameters (higher Cp(mx, comparable Css,aver, equal AUC values, and longer apparent t1/2,beta of 5-FU) may make oral UFT a preferred method of delivering this fluoropyrimidine over CIFU. In addition, oral UFT would eliminate the incidence of venous thrombosis and catheter-related infections sometimes seen in patients treated with CIFU. Furthermore, the convenience and decreased cost of oral administration may be preferable for many patients, particularly those receiving 5-FU for palliation.

Adenocarcinoma↗
PubMed1998

The oral fluorouracil prodrugs.

Discussed herein are selected oral fluorinated pyrimidines that are converted to 5-fluorouracil (5-FU) in vivo to exert antitumor activity. These agents include capecitabine (Xeloda), tegafur-uracil (UFT) plus leucovorin (Orzel), and S-1 (BMS247616). These agents offer the convenience of an orally administered therapy with potentially fewer toxic effects than conventional bolus regimens of 5-FU plus leucovorin. These oral agents provide prolonged 5-FU exposure at lower peak concentrations than observed with bolus intravenous administration of 5-FU and may confer pharmacoeconomic advantages by reducing administration costs and toxicity-related hospitalizations. These regimens also have the potential for improved therapeutic activity by achieving higher 5-FU concentrations in the tumor or by biochemically modulating 5-FU. Phase III trials in patients with advanced colorectal carcinomas are comparing the antitumor activity of these agents with that of intravenous 5-FU plus leucovorin.

Administration, Oral↗
PubMed1998

UFT and leucovorin: a review of its clinical development and therapeutic potential in the oral treatment of cancer.

UFT is an oral antineoplastic drug combining uracil and tegafur in a 4:1 molar ratio. Tegafur acts as a prodrug of 5-fluorouracil (5-FU), being slowly metabolized by cytochrome P450 to 5-FU. Uracil competitively inhibits the metabolism of 5-FU, resulting in increased plasma and tumor 5-FU concentrations. At equimolar doses, higher peak plasma 5-FU concentrations are achieved with UFT plus oral leucovorin with similar systemic 5-FU exposure compared with low-dose continuous 5-FU infusions. The elimination half-life of 5-FU following UFT administration is approximately 7 h compared with 0.2 h with i.v. 5-FU. In phase II studies of UFT plus oral leucovorin for the treatment of advanced colorectal cancer, response rates ranged from 25 to 42%. UFT plus oral leucovorin is well tolerated, with manageable diarrhea being the only dose-limiting toxicity; the regimen is not associated with significant myelosuppression, mucositis, hand-foot syndrome or alopecia. UFT, with or without leucovorin, has also been evaluated alone or in combination with other cytotoxic agents for the treatment of advanced lung, breast and gastric cancers. UFT has also been evaluated as adjuvant therapy for colorectal, breast, gastric, head and neck, and superficial bladder cancers. UFT plus leucovorin offers patients an entirely oral cancer treatment, and appears to provide potential advantages over bolus 5-FU regimens with regard to toxicity and convenience of administration. These benefits should be advantageous in the adjuvant setting, as well as in advanced disease settings in which palliation is an important consideration. Ongoing clinical trials will further define the role of this promising oral treatment regimen.

Administration, Oral↗
PubMed1997

Adjuvant medical therapy for colorectal cancer.

In the mid-1980s, trials of adjuvant therapy for colon cancer in the United States had a "no treatment" arm, which reflected the belief that effective adjuvant chemotherapy did not exist for patients with surgically resected disease at high risk for recurrence. However, with the observation in the early 1990s that postsurgical adjuvant 5-FU plus levamisole reduced tumor recurrence and ultimately increased overall survival in stage III colon cancer, the potential of effective adjuvant chemotherapy was realized. Questions about the duration of adjuvant chemotherapy, the specifics of chemotherapy schedule/drug selection, and its use in stage II colon cancer are beginning to be clarified in large, randomized adjuvant therapy trials. In rectal carcinomas, combined modality postoperative pelvic irradiation plus chemotherapy for stage II and III disease has been shown to reduce both local and systemic recurrences and to prolong survival compared with that in patients treated with local surgery and radiation. Again, large randomized trials are attempting to clarify both the optimal chemotherapeutic agents and schedules to be used and also whether preoperative combined modality therapy can improve the resectability rate, rate of sphincter preservation, and survival. Future trials will examine new agents shown to be effective in advanced disease as well as monoclonal antibodies, such as MoAb 17-1A, that may have selective activity in minimal disease. Improvement in overall survival remains the ultimate endpoint of future adjuvant therapy trials; however, trials will also critically examine toxicity, quality of life, pharmacoeconomics, and genetic and biologic correlates that may help select more appropriate candidates for adjuvant therapies.

Antineoplastic Agents↗