Sequential methotrexate, 5-fluorouracil (5-FU), and high dose leucovorin versus 5-FU and high dose leucovorin versus 5-FU alone for advanced colorectal cancer. A multi-institutional randomized trial

Concurrent Modulation of 5-Fluorouracil with Methotrexate and L-leucovorin: An Effective and Moderately Toxic Regimen for the Treatment of Advanced Colorectal Carcinoma a Multicenter Phase II Study of the Southern Italy Cooperative Oncology Group

Aims and Background

Methotrexate (MTX) and leucovorin (LV) can enhance the cytotoxicity of 5-fluorouracil (5FU) by modifying its metabolic pathway inside target cells. Some preclinical studies and clinical trials have suggested that the concurrent or sequential double modulation of 5FU by means of MTX and LV may give a higher activity than single biochemical modulations. The purpose of our phase II study was to assess the activity and toxicity of a biweekly regimen including MTX, levo-LV and 5FU in colorectal cancer patients.

Methods

From July 1994 to May 1997, 100 consecutive patients affected by advanced or metastatic colorectal carcinoma were given MTX, 750 mg/m2 iv (2-h infusion) on day 1, and levo-LV, 250 mg/m2 iv (2-h infusion) followed by 5FU, 800 mg/m2 iv bolus on day 2, every two weeks. Patients were treated until complete response or progressive disease was documented, or for a maximum of 16 courses.

Results

Among 97 eligible patients, 5 complete and 25 partial responses were obtained, giving an overall response rate of 31% (95% exact confidence limits, 22-41%). Response rate was significantly higher in patients with a good (ECOG scale 0) than with a poor (ECOG scale 1 or 2) performance status (40% versus 17%, P <0.02). Median time to treatment failure was 27 weeks, median survival time was 63 (95% confidence limits, 54-71) weeks, and 2- and 3-year probability of survival were 34% and 12%, respectively. Performance status was the only pretreatment characteristic significantly affecting the outcome of patients. Indeed, median survival time was 94 weeks for patients with a performance status = 0 and 37 weeks for patients with a performance status ≥ 1 (P < 0.05). Toxicity of the treatment was low and manageable; grade 3 to 4 leukopenia affected 8% of patients, whereas grade 3 diarrhea and mucositis occurred in 5% and 4%, respectively.

Conclusions

The double biochemical modulation of 5FU by MTX and levo-LV is at least as effective as, and probably more effective than, the single modulation by MTX or by LV. It may therefore represent a therapeutic option for the palliative treatment of patients with advanced colorectal carcinoma.

Oxaliplatin plus high-dose folinic acid and 5-fluorouracil i.v. bolus (OXAFAFU) versus irinotecan plus high-dose folinic acid and 5-fluorouracil i.v. bolus (IRIFAFU) in patients with metastatic colorectal carcinoma: a Southern Italy Cooperative Oncology Group phase III trial

PURPOSE

The primary end point of this phase III trial was to compare the response rate (RR) of oxaliplatin (OXA) plus levo-folinic acid (l-FA) and 5-fluorouracil (5-FU) bolus with that of irinotecan (IRI) plus l-FA and 5-FU bolus in advanced colorectal carcinoma.

PATIENTS AND METHODS

Patients with measurable metastatic colorectal carcinoma were randomly allocated to receive: IRI 200 mg/m(2) on day 1, l-FA 250 mg/m(2) intravenously plus 5-FU 850 mg/m(2) on day 2 (IRIFAFU); or OXA 100 mg/m(2) on day 1, l-FA 250 mg/m(2) plus 5-FU 1050 mg/m(2) on day 2 [OXAFAFU high dose (hd)]. Cycles were given every 2 weeks. After a planned interim analysis, OXA was reduced to 85 mg/m(2) and 5-FU to 850 mg/m(2) [OXAFAFU low dose (ld)].

RESULTS

Two hundred and seventy-four patients (IRIFAFU, 135; OXAFAFUhd, 71; OXAFAFUld, 68) were treated. Forty-two confirmed responses were achieved with IRIFAFU, 29 with OXAFAFUhd and 32 with OXAFAFUld. The response rate with OXAFAFU [44%; 95% confidence interval (CI) 35% to 52%] was significantly higher (P=0.029) than that of IRIFAFU (31%; 95% CI 23% to 40%). Occurrence of grade > or =3 neutropenia with OXAFAFUld was similar to that for IRIFAFU (29% versus 31%), while severe diarrhoea was significantly lower (12% versus 24%). Median failure-free survival (7 versus 5.8 months; P=0.046) and overall survival of patients (18.9 versus 15.6 months; P=0.032) were significantly prolonged with OXAFAFU.

CONCLUSIONS

OXAFAFU was more active and less toxic than IRIFAFU, and it should be preferred in the first-line treatment of advanced colorectal cancer patients.

Modulation of fluorouracil by leucovorin in patients with advanced colorectal cancer: an updated meta-analysis

PURPOSE

The modulation of fluorouracil (FU) by folinic acid (leucovorin [LV]) has been shown to be effective in terms of tumor response rate in patients with advanced colorectal cancer, but a meta-analysis of nine trials previously published by our group failed to demonstrate a statistically significant survival difference between FU and FU-LV. We present an update of the meta-analysis, with a longer follow-up and the inclusion of 10 newer trials.

PATIENTS AND METHODS

Analyses are based on individual data from 3,300 patients randomized in 19 trials on an intent-to-treat basis. Two trials had multiple comparisons, leading to a total of 21 pair-wise comparisons. FU doses were similar in both arms in 10 pair-wise comparisons, 15% to 33% higher in the FU-alone arm in six comparisons, and more than 66% higher in five comparisons.

RESULTS

Overall analysis showed a two-fold increase in tumor response rates (11% for FU-LV v 21% for FU-LV v 11% for FU [corrected] alone; odds ratio, 0.53; 95% CI, 0.44 to 0.63; P <.0001) and a small but statistically significant overall survival benefit for FU-LV over FU alone (median survival, 11.7 v 10.5 months, respectively; hazards ratio, 0.90; 95% CI, 0.87 to 0.94; P =.004), which were primarily seen in the first year. We observed a significant interaction between treatment benefit and dose of FU, with tumor response and overall survival advantages of FU-LV over FU-alone being restricted to trials in which a similar dose of FU was prescribed in both arms.

CONCLUSION

This updated analysis demonstrates, on a large data set, that FU-LV improves both response rate and overall survival compared with FU alone and that this benefit is consistent across various prognostic factors.

Phase I trial of sequential raltitrexed followed by bolus 5-fluorouracil in patients with advanced colorectal cancer

Our objective was to determine the maximum tolerated dose (MTD) of sequential raltitrexed (Tomudex) and 5-fluorouracil (5-FU) by bolus administration every 3 weeks in patients with advanced colorectal cancer (aCRC) and appendiceal adenocarcinoma. This phase I dose-escalation study was carried out in three stages: (1) 5-FU fixed at 900 mg/m, raltitrexed escalated from 0.5 to 3.0 mg/m, (2) raltitrexed fixed at 3.0 mg/m, 5-FU escalated from 900 mg/m until dose-limiting toxicity (DLT) and (3) 5-FU fixed at the dose level below DLT, raltitrexed escalated from 3.0 mg/m until MTD. Seventy-one patients with measurable disease were enrolled. No DLTs were observed during stage 1 of treatment. At a fixed dose of raltitrexed 3.0 mg/m, DLT developed when 5-FU was increased to 1350 mg/m (stage 2). When 5-FU was fixed at 1200 mg/m and raltitrexed was increased to 6.0 mg/m (stage 3), DLT was dose limiting. The recommended doses for further study are 5.5 mg/m ralitrexed and 1200 mg/m 5-FU. Of the 69 patients evaluated for efficacy, one had a complete response (8.0 months) and five had partial responses (5.1-11.6 months). Thirty patients had stable disease for 5 or more cycles of therapy (mean time to progression: 3.6 months). Median survival was 11.7 months. We conclude that raltitrexed can be combined with bolus 5-FU, at raltitrexed doses that are higher than the recommended single-agent dose of 3.0 mg/m, with manageable toxicity. This combination shows encouraging activity, and survival appears promising in the pre-treated aCRC patient population. Further clinical trials are warranted.

Addition of either irinotecan or methotrexate to bolus 5-fluorouracil and high-dose folinic acid every 2 weeks in advanced colorectal carcinoma: a randomised study by the Southern Italy Cooperative Oncology Group

PURPOSE

The purpose of this study was to compare the activity and toxicity of the combination of irinotecan (IRI) plus folinic acid (FA)-modulated 5-fluorouracil (5-FU) i.v. bolus with a regimen of double modulation of 5-FU with methotrexate (MTX) and FA in patients with advanced colorectal carcinoma.

PATIENTS AND METHODS

Two-hundred and thirty-four patients were enrolled: 118 patients received IRI 200 mg/m2 (90-min i.v. infusion) on day 1, followed by levo-FA 250 mg/m2 (2-h i.v. infusion) and 5-FU 850 mg/m2 (i.v. bolus) on day 2 (IRIFAFU), and 116 patients received MTX 750 mg/m2 (2-h i.v. infusion) on day 1, followed by levo-FA 250 mg/m2 (2-h i.v. infusion) and FU 800 mg/m2 (i.v. bolus) on day 2 (MTXFAFU). Both cycles were repeated every 2 weeks until progression or to a maximum of 16 cycles. Response rate (RR) was the main end point of the study; responses were assessed every four cycles and confirmed after 2 additional months of treatment.

RESULTS

RR was significantly greater with IRIFAFU (36%) than with MTXFAFU (20%) (P <0.001). Multivariate analysis showed that IRIFAFU was significantly associated with a greater activity (P = 0.028). Median progression-free survival was longer with IRIFAFU than with MTXFAFU (7.2 months compared with 4.8 months; P = 0.048). Median survival time (MST) did not differ between the two arms (14.7 months compared with 14.8 months, respectively). Patients not receiving second-line chemotherapy, however, lived longer when treated in the first-line with IRIFAFU (MST 11.9 months compared with 6.4 months; P = 0.038). IRIFAFU caused a significantly greater occurrence of grade 3 or 4 neutropenia (40% compared with 9%; P = 0.001) and diarrhoea (13% compared with 4%; P = 0.024), but a significantly lower incidence of stomatitis (3% compared with 12%; P = 0.007), than the comparative regimen.

CONCLUSIONS

IRIFAFU appeared comparable in terms of activity and toxicity with other weekly or biweekly bolus or infusional combination regimens. IRIFAFU, however, seems easier to administer, because it does not require infusional catheter or pump devices, and it is less expensive. It may represent a new option for treating advanced colorectal carcinoma.

Biweekly irinotecan or raltitrexed plus 6S-leucovorin and bolus 5-fluorouracil in advanced colorectal carcinoma: a Southern Italy Cooperative Oncology Group phase II-III randomized trial

PURPOSE

The aim of this randomised trial was to evaluate the activity and toxicity of a biweekly regimen including 6S-leucovorin-modulated 5-fluorouracil (LFA-5-FU), combined with either irinotecan (CPT-11 + LFA 5-FU) or raltitrexed (Tomudex) (TOM + LFA-5-FU), in advanced colorectal cancer patients, and to make a preliminary comparison of both these experimental regimens with a biweekly administration of LFA-5-FU modulated by methotrexate (MTX + LFA-5-FU).

PATIENTS AND METHODS

One hundred fifty-nine patients with advanced colorectal carcinoma previously untreated for the metastatic disease (34 of them previously exposed to adjuvant 5-FU) were randomly allocated to receive: CPT-11, 200 mg/m2 i.v. on day 1, followed on day 2 by LFA, 250 mg/m2 i.v. infusion and 5-FU, 850 mg/m2 s i.v. bolus (arm A); TOM, 3 mg/m2 i.v. on day 1, followed on day 2 by LFA, 250 mg/m2 i.v. infusion and 5-FU, 1050 mg/m2 i.v. bolus (arm B); or MTX, 750 mg/m2 i.v. on day 1, followed on day 2 by LFA, 250 mg/m2 i.v. infusion and 5-FU, 800 mg/m2 i.v. bolus (arm C). Courses were repeated every two weeks in all arms of the trial. Response rate (RR) was evaluated after every four courses. The sample size was defined to have an 80% power to detect a 35% RR for each experimental treatment, and to show a difference of at least 4% in RR with the standard treatment if the true difference is 15% or more.

RESULTS

The RRs were: 34% (95% confidence interval (95%, CI): 21%-48%) in arm A, including 3 complete responses (CRs) and 15 partial responses (PRs), 24% (95% CI: 14%-38%) in arm B, including 2 CRs and 11 PRs, and 24% (95% CI: 14%-38%), with 2 CRs and 11 PRs, in arm C. After a median follow-up time of 62 (range 18-108) weeks, the median time to progression was 38, 25, and 27 weeks for arm A, B, and C, respectively. With 94 patients still alive, the one-year probability of survival was 61%, 54%, and 59%, respectively. WHO grade 3 or 4 neutropenia and diarrhoea affected 46% and 16%, respectively, of patients treated with CPT-11 + LFA 5-FU. Median relative dose intensity over eight cycles (DI8) was 78% for CPT-11 and 82% for 5-FU. Severe toxicities of TOM + LFA-5-FU were neutropenia (16%) and diarrhoea (16%), but median relative DI8 was 93% for TOM, and 82% for 5-FU.

CONCLUSIONS

CPT-11 + LFA-5-FU compares favorably in term of activity and toxicity with other combination regimens including CPT-11 and continuous infusional 5-FU. The hypothesis of a RR 15% higher than the MTX + LFA-5-FU treatment can not be ruled out after this interim analysis. The TOM + LFA 5-FU regimen showed a RR and a toxicity profile very close to the MTX + LFA 5-FU combination, and dose not deserve further evaluation in advanced colorectal cancer patients.

Non-surgical treatment for liver metastases

The liver is a common site for developing metastatic disease. Although any malignancy can spread to the liver, the direct passage of blood from the gastrointestinal tract to the liver via the portal circulation results in a high rate of liver metastasis from gastrointestinal tract tumours. Various radiographical tests including computed tomography and magnetic resonance imaging can detect the majority of liver metastases. Surgical resection if feasible is the treatment of choice since it produces a 5-year survival rate of about 30%. However, the majority of the patients relapse after hepatic resection, 50% relapsing in the liver. Systemic chemotherapy produces response rates of 15-30% with a median survival of 10-12 months. It is estimated that 30,000 patients each year in the USA are candidates for regional hepatic therapy. Hepatic arterial chemotherapy, hepatic artery embolization, chemoembolization, cryosurgery, ethanol injection of the tumour and radiation therapy are being investigated as potential treatment options for such patients.

Biomodulation of Fluorouracil in colorectal cancer

5-Fluorouracil (5-FU) remains the agent of choice for the treatment of colorectal cancer. Research has focused on the biomodulation of 5-FU in order to attempt to improve the cytotoxity and therapeutic effectiveness of this drug in the treatment of advanced colorectal cancer. Modulation of 5-FU by methotrexate (MTX), trimetrexate (TMTX), interferon-alpha (IFN-alpha), leucovorin (LV), or N-(phosphonacetyl)-L-asparte acid (PALA) has produced higher response rates than those observed with 5-FU alone. Methotrexate may improve the durability of response to or survival with 5-FU, but with inferior results compared with those in trials of 5-FU and leucovorin. Trimetrexate produces a number of responses, and further phase III trials are in progress to confirm the results of promising phase II trials with this drug. IFN-alpha has shown therapeutic efficiency when combined with 5-FU alone or with 5-FU and leucovorin, but latest studies with these combinations have shown increased toxicity. Initial single-institution phase I trials with 5-FU and PALA reported promising responses, but the latter responses with PALA were not substantiated in randomized multicenter trials. Leucovorin enhances the cytotoxic activity of 5-FU in vitro and in vivo, and several clinical trials have shown improved response rates and possible trends in improved survival when such therapy is compared with the use of 5-FU as a single-agent. More recent randomized trials have focused their attention on determining the optimal dose and schedule with this combination for producing a better clinical response with minimal toxicity. Schedules using infusional 5-FU appear to be the most active regimens when 5-FU is used as a single agent, as demonstrated by recent randomized trials. The Southwest Oncology Group (SWOG) and the Eastern Cooperative Oncology Group (ECOG) have performed separate randomized trials and have shown that the optimal regimens employ infusional 5-FU as a single agent, and that these are the least toxic regimens, perhaps more effective, and associated with a better quality of life. Future studies will focus on infusional regimens involving either short-term, high-dose protracted or long-term, low-dose protracted infusion of 5-FU, since these regimens have shown the most favorable toxicity spectrum and produced the longest survival times. Future research will also focus on the evaluation of various methods of delivery of 5-FU, including oral administration of the drug in combination with compounds that can modify its catabolism.

Relevance of tumoral folylpolyglutamate synthetase and reduced folates for optimal 5-fluorouracil efficacy: experimental data

The purpose of this study was to investigate folate-related predictors of 5-fluorouracil (5-FU) cytotoxicity in the presence or absence of l-folinic acid (l-FA). Intracellular concentrations of the reduced folates (tetrahydrofolate + 5,10-methylenetetrahydrofolate) and folylpolyglutamate synthetase (FPGS) activity were determined in 14 human cancer cell lines expressing a spontaneous sensitivity to 5-FU. On these 14 cell lines grown without l-FA supplementation, a significant positive correlation was demonstrated between basal intracellular folate concentration and FPGS activity. 5-FU sensitivity (IC50 range 0.6-25.4 microM) was not related to the basal intracellular folate concentration, whereas, significantly, it was linked to FPGS activity (range 2.5-11.1 pmol/min/mg protein): the higher the FPGS activity, the greater the 5-FU sensitivity. Under l-FA supplementation (0.01-300 microM), intracellular reduced folates increased continuously without evidence of saturation in all cell lines; the pattern of accumulation was independent of the FPGS activity. l-FA enhanced 5-FU cytotoxicity by a factor of 1.9-6.4 in 12 of the 14 cell lines. In the 12 FA-sensitive cell lines, the l-FA concentrations allowing 90% of maximum 5-FU potentiation [l-FA]90 ranged between 0.7 and 107.9 micro M (median 1.9); in contrast, the intracellular concentrations of reduced folates allowing 90% of maximum 5-FU potentiation were much less variable (range 7.6-38.3, median 24.8 pmol/mg protein). In the presence of [l-FA]90, 5-FU sensitivity remained significantly correlated to the basal FPGS activity. In addition, reduced folates were measured in 96 tumoral samples (50 head and neck, 16 colon, 30 liver metastases from colorectal cancer) taken before treatment. Almost all investigated tumours had folate concentrations below the median concentration required for optimal 5-FU potentiation in vitro: median levels (range, pmol/mg protein) were 3.8 (0-17.7) for head and neck, 5.8 (2.3-12.0) for colon and 12.1 (1.7-118.5) for liver metastases. Above all, these data establish the relevance of FPGS activity for predicting the efficacy of 5-FU modulated by FA or not and point to the potential clinical interest of FPGS determination in human tumours.

Critical factors for optimizing the 5-fluorouracil-folinic acid association in cancer chemotherapy

BACKGROUND

The 5-fluorouracil (FU)-folinic acid (FA) association has demonstrated clinical efficacy in colorectal cancer, both in adjuvant and metastatic situations. However, there is no clear consensus about the optimal FU-FA schedule and dose. In addition, it would be of interest to identify FU-FA-responsive tumors.

DESIGN

Our purpose was to review preclinical and clinical data dealing with prediction of FU-FA sensitivity and optimization of FU-FA schedules.

RESULTS

Preclinical studies have highlighted the importance of thymidylate synthase (TS), the cellular target of the FU-FA mechanism of action, for predicting FU sensitivity. It appears that the more sensitive cell lines express the lowest TS activity. Interestingly, the cell lines sensitive to FA supplementation are those more sensitive to FU. The role of TS in FU-FA responsiveness has been clearly demonstrated in patients with colorectal and gastric cancers. Preliminary in vitro and clinical data have shown that the folylpolyglutamate synthetase (FPGS), the enzyme responsible for folate polyglutamylation, is another promising tool for identifying FU-FA-responsive tumors. So far, results of clinical trials do not form a clear consensus regarding the need to administer high FA doses for improving FU-FA treatment. Experimental studies on human cancer cell lines have demonstrated the wide variability among cell lines, ranging from 0.05 to 200 microns, of 1 FA concentrations required for maximal FU potentiation. In addition, pharmacokinetic studies have reported a significant variability of active folates in plasma after administration of standard-dose FA. Altogether, these observations favour high-dose FA administration to achieve high folate concentrations in plasma and thus to counteract the variability of the 1 FA concentrations required. With respect to the choice of FU-FA schedule, it appears from experimental data that increasing the duration of exposure to FA enhances FU-FA cytotoxicity, probably through an increased formation of reduced folate polyglutamate forms. Considering the S-phase specificity of FU cytotoxicity as well as its rapid elimination from plasma, a schedule of prolonged exposure to both FU and FA should be considered preferable.

CONCLUSIONS

Results of the new FU-FA administration schedules such as the one consisting of a 2-hour FA administration followed by a combination of FU bolus and FU infusion, or the chronomodulated FU-FA infusion, open up promising approaches for improving the therapeutic index of FU-FA chemotherapy. Finally, future clinical studies should investigate tumoral parameters pharmacologically linked to FU-FA sensitivity such as pre-treatment TS and FPGS activities. Such tumoral investigations along with FU and FA pharmacokinetic investigations should provide a better understanding of inter-patient variability in response to FU-FA therapy and an optimal management of this chemotherapy regimen.