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PubMed1986

Controlled phase III clinical study of 4-epi-doxorubicin + 5-fluorouracil versus 5-fluorouracil alone in metastatic gastric and rectosigmoid cancer.

The combination of 4-epi doxorubicin (4-epi-DX) and 5-fluorouracil (5-FU) versus 5-FU alone was studied in previously untreated patients with metastatic gastric and rectosigmoid cancer. 5-FU alone was administered at the dose of 12 mg/kg/day i.v. on days 1, 2, 3, 4 and 5 every 3-4 weeks. The combination regimen included 4-epi-DX 40 mg/m2/day i.v., on days 1 and 2 (80 mg/m2/cycle) and 5-FU administered as in the single-agent schedule, but at a somewhat lower dose (10 mg/m2/day i.v. on days 1, 2, 3, 4 and 5). Sixty-two patients with gastric cancer were evaluable, 30 in the 5-FU group and 32 in 4-epi-DX + 5-FU group. The results showed 6 partial remissions out of 30 patients treated with 5-FU alone (response rate 20%) with a median remission duration of 4 months. With 4-epi-DX + 5FU the response rate was 41% (13/32) with 1 complete and 12 partial remissions. The median remission duration was 8 months. The difference in treatment results was statistically significant (p less than 0.05). In rectosigmoid cancer the group on 5-FU included 26 patients who showed a response rate of 19% (5/26). 4-epi-DX + 5-FU resulted in 6 responses (2 complete remissions, 4 partial remissions) out of 27 patients treated (22%). Median remission duration in the 5-FU group was 3 months whereas it was 6 months in the 4-epi-DX + 5-FU group. Toxicity was mild and well tolerated in both treatment modalities. The results of the study in gastric cancer showed a clear-cut superiority of 4-epi-DX + 5-FU over 5-FU alone, while no difference in response rate was observed between the two approaches in rectosigmoid cancer. Nevertheless, rectal localization of primary tumors showed a slightly better response to 4-epi-DX + 5-FU (33 vs. 16%).

Adult↗
PubMed1987

Combination chemotherapy of hepatocellular cancer. Comparison of adriamycin + VM 26 + 5-fluorouracil with mAMSA + VM 26 + 5-fluorouracil.

Forty-seven patients with hepatocellular cancer were treated in a randomised trial comparing adriamycin + VM 26 + 5-Fluorouracil (5-FU) to mAMSA + VM 26 + 5-FU. Thirteen patients had a partial response to treatment (28%) and another 6 (13%) showed disease stabilisation. There were no significant differences in the response rates between the two treatment regimens. Patients who responded to treatment showed significant prolongation of survival (48 weeks) when compared to non-responders (5 weeks).

Adult↗
PubMedDate not supplied

Second-line treatment with high-dose 5-fluorouracil and folinic acid in advanced colorectal cancer refractory to standard-dose 5-fluorouracil treatment.

Results with second-line treatment of advanced colorectal cancer are poor. Preliminary phase I/II results suggest encouraging response rates to high-dose 5-fluorouracil (FU) (2,600 mg/m2) combined with folinic acid (FA) in pretreated patients with advanced colorectal cancer. To determine the significance of weekly high-dose FU/FA in colorectal cancer refractory to weekly standard doses of FU/FA, a phase II study was initiated. 69 patients with metastatic colorectal cancer refractory to first-line weekly standard-dose FU/FA were treated with weekly high-dose FU 2,600 mg/m2 combined with FA 500 mg/m2 as a 2-hour infusion prior to FU application. Pretreatment was highly homogenous and consisted of weekly FU 500 mg/m2 combined with FA 500 mg/m2 or FA 20 mg/m2 or the pure stereoisomer of FA (6S-FA) 250 mg/m2. At the time of disease progression under first-line therapy, patients were transferred to high-dose FU/FA within 4 weeks. Treatment was continued until tumor progression under therapy was documented. Of the 69 evaluable patients, 17 (24.6%) achieved partial response (PR), 42 (60.9%) had no change (NC) and 10 (14.5%) had progressive disease under therapy. The median duration of PR was 7 months, the median time to progression of NC was 4 months. Median survival of all patients was 9 months, of patients with PR, 11.5 months. 33/38 patients with tumor-related pain experienced impressive relief under therapy. Prognostic factors for a beneficial outcome were complete response/PR under first-line therapy, a small number of metastatic sites and a good Karnofsky performance status. Moderate toxicity was observed, and the pattern of toxic events and severity did not differ from standard-dose FU regimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Antimetabolites, Antineoplastic↗
PubMed1996

Sequential methotrexate and 5-fluorouracil as second-line chemotherapy for advanced colorectal cancer patients pretreated with 5-fluorouracil and leucovorin: a GISCAD study.

The biochemical modulation of 5-fluorouracil (5-FU) by means of methotrexate (MTX) and 6-S leucovorin (LV) seems mainly directed at two different intracellular targets, supporting the hypothesis of possible non-cross resistance between these two methods of 5-FU potentiation. Thirty-one patients, all previously treated with 5-FU and LV for advanced colorectal cancer (ACC), were treated with MTX = 200 mg/m2 iv day 1 and 5-FU 600 mg/m2 day 2 with 6-S LV 10 mg/m2 po q 6 h X 6 starting 24 h after MTX, repeated every 2 weeks. Of 30 evaluable patients, 2 Partial Remissions (PR) were achieved (Response Rate = 6.6%; 95% Confidence Interval 0%-14%). Eight patients had disease stabilization (SD). The overall median survival was 5 months (range 1-11). No WHO grade III-IV toxicities were reported. Despite the good tolerability, this combination of MTX, 5-FU and LV rescue has minimal activity in ACC after the failure of 5FU+LV-based chemotherapy.

Adult↗
PubMed2006

A prospective randomized study of irinotecan (CPT-11), leucovorin (LV) and 5-fluorouracil (5FU) versus leucovorin and 5-fluorouracil in patients with advanced colorectal carcinoma.

The purpose of this study was to compare the activity and toxicity of an irinotecan (CPT-11), leucovorin (LV) and 5-fluorouracil (5FU) combination with a standard regimen of 5FU and LV, in patients with advanced colorectal carcinoma. One hundred and sixty patients were randomized; 80 patients (group A) received LV 20 mg/m(2) bolus i.v. and 5FU 425 mg/m(2) bolus i.v. on days 1-5, every 28 days; 80 patients (group B) received CPT-11 80 mg/m(2) (30-90 min i.v. infusion), followed by LV 20 mg/m(2) bolus i.v. and 5FU 425 mg/m(2) bolus i.v. on days 1, 8, 15, 22, 29, and 36, every 8 weeks. The overall response rate was 30% and 47.5% in groups A and B respectively. Progression-free survival was significantly higher in the triple-drug combination arm (median 7.5 vs. 4.5 months; p= 0. 0335). However, overall survival did not differ significantly between the two arms (15 months vs. 14 months for the groups B and A respectively; p=0.3531). The main grade 3 adverse events were diarrhea (19%, in group A vs. 35% in group B; p=0.032) and mucositis (2% vs. 14%; p=0.017). The regimen containing irinotecan showed activity in advanced colorectal cancer. The overall safety data confirm this combination as a well-tolerated treatment.

Adult↗
PubMed1985

Treatment of locally unresectable cancer of the stomach and pancreas: a randomized comparison of 5-fluorouracil alone with radiation plus concurrent and maintenance 5-fluorouracil--an Eastern Cooperative Oncology Group study.

One hundred ninety-one patients with pathologically confirmed, locally unresectable adenocarcinoma of the stomach (57 patients) and pancreas (91 patients), were randomly allocated to therapy with 5-fluorouracil (5-FU) alone, 600 mg/m2 intravenously (IV) once weekly, or radiation therapy, 4,000 rad, plus adjuvant 5-FU, 600 mg/m2 IV, the first three days of radiotherapy, then follow-up maintenance 5-FU, 600 mg/m2, weekly. Forty-three patients (22%) could not be analyzed because of ineligibility or cancellation, thus 148 patients were evaluable. The median survival time was similar for both treatment programs and for both types of primary carcinoma, and was as follows: gastric primary carcinoma, 5-FU, 9.3 months; 5-FU plus radiotherapy, 8.2 months; pancreatic primary carcinoma, 5-FU, 8.2 months; 5-FU plus radiotherapy, 8.3 months. Substantially more toxicity was experienced by patients treated with the combined modality arm than by those patients receiving 5-FU alone. Severe or worse toxicity experienced by patients with gastric primary carcinoma treated by 5-FU was 19%, and the combined modality arm was 31%. The toxicity experienced by patients with pancreatic primary carcinoma treated with 5-FU was 27%, and the combined modality arm was 51%. Significant prognostic variables included: weight loss in stomach-cancer patients; and performance status, degree of anaplasia, and reduced appetite in pancreas-cancer patients.

Adenocarcinoma↗
PubMed1986

Phase II studies of drug combinations in advanced pancreatic carcinoma: fluorouracil plus doxorubicin plus mitomycin C and two regimens of streptozotocin plus mitomycin C plus fluorouracil. The Gastrointestinal Tumor Study Group.

One hundred thirty-three patients with advanced pancreatic adenocarcinoma and measurable disease were treated with 5-fluorouracil (5-FU) plus doxorubicin plus mitomycin C (FAM), streptozotocin plus mitomycin C plus 5-FU (SMF) in the regimen originally reported, and streptozotocin plus mitomycin C plus 5-FU with 5-FU and streptozotocin administered in five-day courses. Respective response rates for all patients were 13%, 15%, and 14%, and for previously untreated patients, 14%, 14%, and 15%. Median survivals for all previously untreated patients range from 3 months (FAM) to 4 1/2 months (original SMF). Predominant toxic reactions were vomiting, leukopenia, and thrombocytopenia. Without evidence of greater therapeutic benefit, none of these regimens should be used in the routine treatment of advanced pancreatic carcinoma.

Adenocarcinoma↗
PubMed1986

Combination chemotherapy (5-fluorouracil, methyl-CCNU, mitomycin C) versus 5-fluorouracil alone for advanced previously untreated colorectal carcinoma. A phase III study of the Piedmont Oncology Association.

One-hundred thirty eligible patients with advanced colorectal carcinoma who had received no prior chemotherapy were randomized to either methyl-CCNU, 70 mg/m2 orally every 6 weeks on day 1, mitomycin C, 10 mg/m2 intravenously every 6 weeks on day 1, and 5-fluorouracil (5-FU), 400 mg/m2 intravenously weekly--(MMF)--or 5-FU, 600 mg/m2 intravenously weekly (5-FU). One hundred twenty-six patients are evaluable for response. Of 62 patients treated with MMF, one (2%) achieved complete remission, and three (5%) attained partial remission. Of 64 patients treated with 5-FU, two (3%) achieved complete remission, and eight (13%) attained partial remission. The median survival for patients receiving MMF was 9.5 months compared with 10.3 months for patients receiving 5-FU. The survival distributions for the two regimens were not significantly different, either unadjusted or adjusted for pretreatment characteristics. Performance status and lactic dehydrogenase (LDH) were both significantly associated with survival. Patients with liver metastases only and normal liver function tests had a median survival of 19.8 months and a 40% response rate. This randomized phase III trial did not show any therapeutic advantage for MMF compared to 5-FU therapy alone in advanced colorectal cancer. In addition, hematologic toxicity was significantly greater with the combination (MMF) regimen.

Adolescent↗
PubMed1988

A prospective randomized trial of fluorouracil versus fluorouracil plus cisplatin in the treatment of metastatic colorectal cancer: a Hoosier Oncology Group trial.

From May 1984 through December 1986, 141 patients with metastatic adenocarcinoma of the colon or rectum were entered on this Hoosier Oncology Group (HOG) trial evaluating the role of cisplatin in systemic therapy. Patients were stratified by the presence or absence of hepatic metastases and by performance status, and were subsequently randomized to receive fluorouracil (5-FU) (15 mg/kg/wk) alone or the same dose of 5-FU plus cisplatin (60 mg/m2 every 3 weeks). The total duration of treatment was six cycles (18 weeks). In 132 fully evaluable patients the objective response rates were 19% for 5-FU and 22% for 5-FU plus cisplatin. Statistically, the median survival times of 40 and 39 weeks were not significantly different (P = .62). However, the median duration of remission (MDR) was superior (P = .05) for 5-FU alone. This study fails to confirm clinically significant synergy of 5-FU plus cisplatin in the treatment of metastatic colorectal cancer.

Adult↗
PubMed1988

Phase III randomized study of fluorouracil, epirubicin, and cyclophosphamide v fluorouracil, doxorubicin, and cyclophosphamide in advanced breast cancer: an Italian multicentre trial.

From February 1983 to January 1985, 497 patients with advanced breast cancer were randomly allocated to receive either epirubicin or doxorubicin in the following combination chemotherapy regimen: fluorouracil (5-FU) 500 mg/m2 intravenous (IV) on days 1 and 8; epirubicin or doxorubicin 50 mg/m2 IV on day 1; cyclophosphamide 500 mg/m2 IV on day 1 (FEC or FAC). Cycles were repeated every 21 days until progression or to cumulative doses of 700 mg/m2 for epirubicin and 550 mg/m2 for doxorubicin. Dose reductions were applied according to the standard criteria. Activity was evaluated in 443 patients (222 in the FEC arm and 221 in the FAC arm). The two experimental groups were comparable in age, performance status, menopausal status, histology, previous treatments, and site of the disease. The overall response rate (complete response and partial response [CR + PR]) was not significantly different: 53.6% for FEC and 56.5% for FAC. The median time to progression was 273 days for FEC and 314 days for FAC; the median survival time was 591 and 613 days, respectively. Leukopenia, anemia, nausea, and vomiting were significantly lower in patients treated with FEC. As for cardiotoxicity, four cases of congestive heart failure (CHF) were recorded among patients treated with FAC while only one was observed in the FEC group. These results indicate that epirubicin in a combination chemotherapy regimen is as active as doxorubicin and is significantly less toxic.

Adult↗
PubMed1989

Superiority of sequential methotrexate, fluorouracil, and leucovorin to fluorouracil alone in advanced symptomatic colorectal carcinoma: a randomized trial.

A total of 249 patients with advanced, symptomatic colorectal cancer who received no previous cytostatic therapy were randomly allocated to receive either fluorouracil (5-FU), 600 mg/m2, for 2 days or the following regimen: sequential methotrexate, 250 mg/m2, during the first 2 hours and 5-FU, 500 mg/m2, at hours 3 and 23 followed by leucovorin rescue initiated at hour 24 (15 mg x 8) (MFL). Treatment was repeated every 14 days for eight courses and then continued every 3 to 4 weeks. Five patients were unevaluable. In these groups the objective response could be evaluated in 69% and 73%, respectively, of the patients who received at least four treatment courses, whereas other outcomes were assessed in all randomized patients. The sequential MFL treatment was more effective than 5-FU alone, as indicated by the former's clinically and statistically highly significant advantage regarding the objective (complete [CR] plus partial [PR]) response rates (24% v 3%; P less than .001), subjective response rate (45% v 23%; P less than .001), and survival (median, 8.5 v 6 months; P less than .02). If all patients were considered for objective response, the figures were lower, 17% v 2%, but the difference was still statistically significant (P less than .001). All responses had a minimum duration of 4 months. Overall, the toxicity was low and comparable between the groups, but stomatitis and conjunctivitis were more common after sequential treatment. Our data suggest that the experimentally observed synergistic cell kill between methotrexate and 5-FU has clinical relevance and that the sequential MFL regimen is a superior alternative to 5-FU alone in the treatment of patients with advanced symptomatic colorectal cancer.

Adult↗
PubMed1990

Randomized study of continuous infusion fluorouracil versus fluorouracil plus cisplatin in patients with metastatic colorectal cancer.

One hundred twenty-two chemotherapy-naive patients with histologically confirmed colorectal adenocarcinoma were entered into a randomized trial comparing infusional fluorouracil (FU) versus cisplatin (CDDP) and FU. In both groups, patients received continuous infusion FU 1,000 mg/m2/d for 5 consecutive days every 4 weeks. Patients randomized to CDDP/FU also received CDDP 20 mg/m2 intravenous (IV) bolus on days 1 to 5 of each cycle. Patients were comparable in terms of age, performance status, baseline laboratory values, dominant sites of measurable disease, and percent of liver involvement. The partial response rate was significantly greater in patients who received CDDP/FU versus FU alone (25% v 3%, P = .001). Patients who received CDDP/FU experienced significantly greater toxicity compared with FU alone: grades 3 and 4 hematologic toxicity occurred in 22% and 0% of patients, respectively (P = .0001); grades 2 to 4 nausea and vomiting occurred in 80% and 15% of patients, respectively (P = .0001). There were no significant differences in either the duration of response (median, 6 and 4.7 months for CDDP/FU and FU groups, respectively) or survival (median 10, and 12 months, respectively). Compared with infusional FU alone, CDDP/FU provided a significantly greater partial response rate with increased toxicity, but it did not improve overall survival in patients with advanced colorectal carcinoma. Therefore, the use of CDDP/FU as routine therapy for the treatment of colorectal carcinoma cannot be recommended.

Adult↗
PubMed1990

Prospective randomized comparison of fluorouracil versus fluorouracil and high-dose continuous infusion leucovorin calcium for the treatment of advanced measurable colorectal cancer in patients previously unexposed to chemotherapy.

Seventy-nine patients with advanced, measurable, metastatic colorectal cancer previously unexposed to chemotherapy were randomly assigned to treatment with either fluorouracil (FUra) administered intravenously at a dose of 370 mg/m2/d for 5 days or the combination of FUra in the same dose and schedule with high-dose continuous infusion leucovorin calcium (500 mg/m2/d) beginning 24 hours before the first dose of FUra and continuing for 12 hours after the completion of FUra therapy. Patients whose disease progressed on treatment with FUra alone were, if eligible, crossed over to receive leucovorin and FUra. Three patients on the FUra plus leucovorin arm of the study were excluded from the analysis because they did not meet eligibility requirements. The treatment arms were well balanced for prognostic criteria including performance status, age, prior radiotherapy, distribution of metastatic sites, and on-study carcinoembryonic antigen (CEA), lactic dehydrogenase, and serum albumin. FUra plus leucovorin was superior to FUra alone for response (P = .0019) and for time to progression or death (log-rank, P = .045). Response rates were 16 of 36 (44%) versus five of 40 (13%), and median time to progression or death was 164 versus 120 days in the two arms of the trial, respectively. Overall survival, however, while longer in the FUra and leucovorin arm was not significantly so. An analysis of the toxicities experienced by the patients in the two treatment groups showed that, except for significantly more stomatitis in the leucovorin arm of the study, the side effects experienced by patients treated with either regimen were comparable. These results suggest that the efficacy of FUra in patients with advanced, measurable, metastatic colorectal cancer can be enhanced significantly by administration of a continuous high-dose infusion of leucovorin calcium.

Adenocarcinoma↗
PubMed1992

Randomized comparison of cisplatin plus fluorouracil and carboplatin plus fluorouracil versus methotrexate in advanced squamous-cell carcinoma of the head and neck: a Southwest Oncology Group study.

PURPOSE: The Southwest Oncology Group (SWOG) conducted a randomized comparison of cisplatin plus fluorouracil (5-FU) and carboplatin plus 5-FU versus single-agent methotrexate (MTX) in patients with recurrent and metastatic squamous-cell carcinoma (SCC) of the head and neck. The primary objective was to compare separately the response rates of each combination regimen to standard weekly MTX. PATIENTS AND METHODS: Two hundred seventy-seven patients diagnosed with SCC of the head and neck were randomized to one of three treatments: (1) cisplatin 100 mg/m2 intravenously (IV) on day 1 and 5-FU 1,000 mg/m2 per day for a 96-hour continuous infusion repeated every 21 days; (2) carboplatin 300 mg/m2 IV on day 1 and 5-FU 1,000 mg/m2 per day for a 96-hour continuous infusion repeated every 28 days; and (3) MTX 40 mg/m2 IV given weekly. RESULTS: All three treatment regimens were well tolerated. However, both hematologic and nonhematologic toxicities were significantly greater with cisplatin plus 5-FU compared with MTX (P = .001). Toxicity from carboplatin plus 5-FU was intermediate compared with the other regimens. The complete and partial response rates were 32% for cisplatin plus 5-FU, 21% for carboplatin plus 5-FU, and 10% for MTX. The comparison of cisplatin plus 5-FU to MTX was statistically significant (P less than .001), and the comparison of carboplatin plus 5-FU to MTX was of borderline statistical significance (P = .05). Median response durations and median survival times were similar for all three treatment groups. Logistic regression models showed that only treatment assigned was associated significantly with response (P = .001). Cox proportional hazards models indicated that only performance status was associated significantly with survival (P less than .01). CONCLUSIONS: We conclude that combination chemotherapy resulted in improved response rates but was associated with an increased toxicity and no improvement in overall survival. Therefore, new treatments that may alter the course of disease in recurrent head and neck cancer patients still need to be identified.

Adult↗
PubMed1993

A randomized, double-blind trial of fluorouracil plus placebo versus fluorouracil plus oral leucovorin in patients with metastatic colorectal cancer.

PURPOSE: A prospectively randomized trial was performed to determine whether the combination of fluorouracil (FU) plus leucovorin (FU-LV) administered orally is more effective than equitoxic FU for patients with metastatic colorectal cancer. PATIENTS AND METHODS: A double-blind, placebo-controlled trial design was used to eliminate observer bias. An escalating FU dosing schedule was used to achieve equal toxicity. End points were response, time to treatment failure (TTF), and eight quality-of-life (QL) parameters. A crossover arm allowed FU-treated patients to receive FU-LV combination treatment after treatment failure. RESULTS: Response rate was 32% for FU-LV versus 23% for FU (P = .15). Median TTF was 22 versus 16 weeks (P = .27). Median survival time was 44 versus 54 weeks (P = .26). QL was the same for both treatments, except for days of hospitalization, which was greater for FU-LV (P < .001). Toxicities were similar to those previously reported for FU-LV and FU alone. CONCLUSION: Oral LV-FU produces the same efficacy and toxicity pattern as has been reported for intravenous LV-FU. When FU-LV is compared with equitoxic doses of FU, there is no difference in patient outcome. These results suggest that patients with advanced disease should receive FU at doses adequate to produce toxicity.

Adenocarcinoma↗
PubMed1993

Phase II trial of postoperative adjuvant intraperitoneal cisplatin and fluorouracil and systemic fluorouracil chemotherapy in patients with resected gastric cancer.

PURPOSE: This study was performed to assess the short- and long-term toxicities and the impact on relapse pattern and survival of postoperative intraperitoneal (IP) cisplatin and fluorouracil (FU) plus systemic intravenous (IV) FU as adjuvant therapy for gastric cancer patients who are at high risk for recurrence after potentially curative resection (T2N1-2M0 or T3-4N(any)M0). PATIENTS AND METHODS: Starting 14 to 28 days after potentially curative resection of primary gastric cancers, 35 patients were given IP cisplatin 25 mg/m2 and FU 750 mg daily for 4 days; FU 750 mg/m2 was concurrently given as a continuous 24-hour i.v. infusion. Five cycles of therapy delivered at 1-month intervals were used. RESULTS: After a median follow-up of 24 months, 51% of patients remain alive and free of disease. Sixteen patients have recurred; 13 of 16 had an intraabdominal component, whereas three had extraabdominal failure only. Two major treatment-related toxicities were noted: neutropenia and a late toxicity of peritoneal fibrosis (sclerosing encapsulating peritonitis [SEP]). There was one postoperative death. Eleven patients underwent second laparotomy: five patients had SEP, two patients had bowel obstruction from adhesions unrelated to SEP, and four patients had recurrent cancer. Potential causes of SEP included an alkaline pH of infused FU and cisplatin that possibly led to activation of cisplatin before infusion. CONCLUSION: IP cisplatin and FU and concurrent systemic FU is a tolerable adjuvant therapy in the postoperative setting for patients with resected gastric cancer. The recommended dosage schedule with this technique is cisplatin 25 mg/m2 and FU 750 mg total dose IP with FU 500 mg/m2 as a continuous 24-hour infusion daily for days 1 to 4. SEP as a late toxicity, which was observed in 15% of patients, is treatable by surgical lysis of adhesions.

Adenocarcinoma↗
PubMed1993

Phase I trial of low-dose, prolonged continuous infusion fluorouracil plus interferon-alfa: evidence for enhanced fluorouracil toxicity without pharmacokinetic perturbation.

PURPOSE: To determine the maximum-tolerable dose (MTD) of fluorouracil (5-FU) administered as a low-dose, prolonged continuous intravenous infusion (PCI) plus interferon-alfa (IFN-alpha) that would permit treatment for at least 28 consecutive days, and to determine the effect of IFN-alpha on 5-FU pharmacokinetics. PATIENTS AND METHODS: Twenty-six assessable patients with advanced cancer received low-dose PCI 5-FU (150, 200, 250, and 300 mg/m2/d) plus IFN-alpha, 5 x 10(6) IU/m2 administered subcutaneously (SC) at hour 48 of the 5-FU infusion, then thrice weekly thereafter in cohorts of at least three patients. Treatment continued until treatment-limiting toxicity (TLT) developed, such as mucositis, diarrhea, or fatigue. Escalation to the next 5-FU dose level occurred if none of three or zero to two of six patients developed TLT before day 28. Quantitation of plasma 5-FU concentration by high-performance liquid chromatography was performed in 15 patients. Data were standardized using the Cosinor method and compared before and after IFN-alpha administration using the paired t test. RESULTS: The mean number of days of continuous 5-FU therapy for patients receiving 150, 200, 250, and 300 mg/m2/d of 5-FU plus IFN alfa-2a (IFN-alpha 2a) was 75, 54, 37, and 22 days, respectively. The MTD of PCI 5-FU by our criteria that could be combined with IFN-alpha was 250 mg/m2/d. Comparison of the standardized pharmacokinetic data showed no significant effect of IFN-alpha on plasma 5-FU concentration, and no alteration of the normal circadian variation in plasma 5-FU concentration that was evident before IFN-alpha administration. Objective response occurred in patients with adenocarcinoma of the pancreas (n = 3), kidney (n = 2), and lung (n = 1). CONCLUSION: IFN-alpha substantially enhanced the gastrointestinal toxicity of low-dose PCI 5-FU without affecting 5-FU pharmacokinetics, contrary to previous reports using alternative 5-FU schedules in which IFN-alpha-related enhancement of 5-FU toxicity was attributable to reduced 5-FU clearance. Our findings suggest that under certain conditions, mechanisms other than altered 5-FU pharmacokinetics may be responsible for the ability of IFN-alpha to enhance the toxic effects of 5-FU.

Adult↗
PubMed1994

Thymidylate synthase inhibition after administration of fluorouracil with or without leucovorin in colon cancer patients: implications for treatment with fluorouracil.

PURPOSE: To determine the time-dependence of fluorouracil (5FU)-induced thymidylate synthase (TS) inhibition in colon cancer patients, the effect of leucovorin (LV), and the relation to response. PATIENTS AND METHODS: A 5FU injection (500 mg/m2) was given to 47 patients with advanced colorectal cancer; tumor biopsy specimens were obtained 1 to 72 hours after laparotomy. Eleven patients received LV (2-hour infusion of 500 mg/m2) with 5FU midinfusion; biopsies were obtained after 45 hours. TS inhibition was evaluated by comparing the number of total and free 5-fluoro-2'-deoxy-uridine-5'- monophosphate (UMP) (FdUMP) binding sites and the total and residual catalytic activity of TS. RESULTS: The total catalytic TS activity varied from 0 to 621 pmol/h/mg protein and the total number of FdUMP binding sites varied from 0 to 976 fmol/mg protein. The residual catalytic TS activity after 2, 23, and 45 hours was 41%, 65%, and 74% of the total catalytic activity; the number of free FdUMP binding sites was 12%, 27%, and 49% of the total number, respectively. LV enhanced TS inhibition after 45 hours; the residual catalytic activity decreased from 74% to 49%, and the number of free FdUMP binding sites from 49% to 24%. Eleven of 19 patients treated with hepatic arterial infusion of 5FU had a partial response (PR). In the nonresponding patients, total TS activity was significantly higher (P < .05) than in responding patients. A high TS activity with a poor inhibition correlated with no response. CONCLUSION: Residual and total TS activity are predictive for response to 5FU. The findings may be applicable for treatment of patients with advanced disease and TS should be evaluated as a prognostic factor in adjuvant chemotherapy studies.

Adult↗