Phase III study of bolus versus infusion fluorouracil with or without cisplatin in advanced colorectal cancer

TGF-β in correlation with tumor progression, immunosuppression and targeted therapy in colorectal cancer

Colorectal cancer (CRC) is a complex malignancy responsible for the second-highest cancer deaths worldwide. TGF-β maintains normal cellular homeostasis by inhibiting the cell cycle and inducing apoptosis, but its elevated level is correlated with colorectal cancer progression, as TGF-β is a master regulator of the epithelial-to-mesenchymal transition, a critical step of metastasis. Tumors, including CRC, use elevated TGF-β levels to avoid immune surveillance by modulating immune cell differentiation, proliferation, and effector function. Presently, the treatment of advanced CRC is mainly based on chemotherapy, with multiple adverse effects. Thus, there is a need to develop alternate tactics because CRC continue to be mostly resistant to the present therapeutic regimen. TGF-β blockade has emerged as a promising therapeutic target in cancer therapy. Blocking TGF-β with phytochemicals and other molecules, such as antisense oligonucleotides, monoclonal antibodies, and bifunctional traps, alone or in combination, may be a safer and more effective way to treat CRC. Furthermore, combination immunotherapy comprising TGF-β blockers and immune checkpoint inhibitors is gaining popularity because both molecules work synergistically to suppress the immune system. Here, we summarize the current understanding of TGF-β as a therapeutic target for managing CRC and its context-dependent tumor-promoting or tumor-suppressing nature.

Delayed Coronary Vasospasm in a Patient with Metastatic Gastric Cancer Receiving FOLFOX Therapy

A 40-year-old man with stage IV gastric adenocarcinoma was found to have coronary artery vasospasm in the setting of recent 5-fluorouracil administration.

Prediction of exposure-driven myelotoxicity of continuous infusion 5-fluorouracil by a semi-physiological pharmacokinetic-pharmacodynamic model in gastrointestinal cancer patients

Purpose

To describe 5-fluorouracil (5FU) pharmacokinetics, myelotoxicity and respective covariates using a simultaneous nonlinear mixed effect modelling approach.

Methods

Thirty patients with gastrointestinal cancer received 5FU 650 or 1000 mg/m²/day as 5-day continuous venous infusion (14 of whom also received cisplatin 20 mg/m²/day). 5FU and 5-fluoro-5,6-dihydrouracil (5FUH2) plasma concentrations were described by a pharmacokinetic model using NONMEM. Absolute leukocyte counts were described by a semi-mechanistic myelosuppression model. Covariate relationships were evaluated to explain the possible sources of variability in 5FU pharmacokinetics and pharmacodynamics.

Results

Total clearance of 5FU correlated with body surface area (BSA). Population estimate for total clearance was 249 L/h. Clearances of 5FU and 5FUH2 fractionally changed by 77%/m² difference from the median BSA. 5FU central and peripheral volumes of distribution were 5.56 L and 28.5 L, respectively. Estimated 5FUH2 clearance and volume of distribution were 121 L/h and 96.7 L, respectively. Baseline leukocyte count of 6.86 × 10⁹/L, as well as mean leukocyte transit time of 281 h accounting for time delay between proliferating and circulating cells, was estimated. The relationship between 5FU plasma concentrations and absolute leukocyte count was found to be linear. A higher degree of myelosuppression was attributed to combination therapy (slope = 2.82 L/mg) with cisplatin as compared to 5FU monotherapy (slope = 1.17 L/mg).

Conclusions

BSA should be taken into account for predicting 5FU exposure. Myelosuppression was influenced by 5FU exposure and concomitant administration of cisplatin.

Electronic supplementary material

The online version of this article (10.1007/s00280-019-04028-5) contains supplementary material, which is available to authorized users.

Continuum of care strategy in metastatic colorectal cancer: a review

Treatment of human metastatic colorectal cancer (mCRC) has changed remarkably in the past two decades. The use of novel therapies and more complex treatment strategies have contributed to progressively increase the median life expectancy of patients up to approximately 30 months. Although traditional cytotoxic chemotherapy and newer targeted therapy are now available for use in treating patients with mCRC, the optimal treatment strategy remains unknown. In recent years, there has been a treatment paradigm shift for mCRC patients with the emergence of the concept of ‘continuum of care’ as the optimal palliative therapy strategy. It is based on the concept whereby patients are exposed throughout the course of their disease to different active drugs; the therapy is personalized according to the need for rapid response, the burden of disease and molecular subtype status, such as RAS, BRAF, MMR and HER2. Drugs are often reintroduced if they demonstrated activity in a previous line of therapy, and most importantly, maintenance chemotherapy and/or intermittent therapy are considered. This review details available data for the use of the continuum of care strategy in mCRC, in which the strategy has provided significant clinical benefit in clinical studies. As our understanding advances, optimal treatment strategy for the patients with mCRC should still be individualized.

Irinotecan: a new treatment in metastatic colorectal cancer

Objective. Historically, outcomes of metastatic colorectal cancer therapy have been disappointing, with fluorouracil (5-FU) producing response rates of no more than 15%. The addition of leucovorin increases response rates; however, survival rates are largely unaffected. Recently, the topoisomerase I inhibitor, irinotecan, has proved active in metastatic colorectal cancer and is indicated as second-line therapy following disease recurrence or progression after 5-FU-based therapy. More recently, irinotecan plus 5-FU-LV was compared with 5-FU-LV as first line treatment of colorectal cancer, showing impressive results. This article discusses the role of irinotecan, as a single agent and in combination with 5-FU-LV, in the treatment of advanced colorectal cancer.

Data sources. A MEDLINE search was conducted using 5-fluorouracil, irinotecan, leucovorin, and metastatic colorectal cancer as primary search terms. Reference lists, bibliographies of pertinent articles, and abstracts from the American Society of Clinical Oncology and the European Society for Medical Oncology annual meetings were also identified and reviewed. Clinical literature was reviewed and analyzed.

Data synthesis. Results of studies comparing irinotecan with continuos infusion 5-FU or best supportive care suggest that irinotecan is superior to either treatment as second-line therapy of metastatic colorectal cancer. Based on these study results, along with irinotecan's lack of cross-resistance with other chemotherapy agents and mechanism of action that differs from 5-FU, phase III trials evaluating the use of irinotecan in combination with 5-FU-LV as first-line treatment for advanced colorectal cancer were conducted. The results of a pivotal trial evaluating irinotecan plus 5-FU-LV in this setting show superior response rates (RRs), time to tumor progression (TTP), and median survival times (MSTs) when compared with 5-FU-LV alone. This combination represents a major advance in the treatment of metastatic colorectal cancer and should be considered the first-line treatment standard.

Exact one-sided confidence limits for Cohen's kappa as a measurement of agreement

Cohen's kappa coefficient, κ, is a statistical measure of inter-rater agreement or inter-annotator agreement for qualitative items. In this paper, we focus on interval estimation of κ in the case of two raters and binary items. So far, only asymptotic and bootstrap intervals are available for κ due to its complexity. However, there is no guarantee that such intervals will capture κ with the desired nominal level 1- α. In other words, the statistical inferences based on these intervals are not reliable. We apply the Buehler method to obtain exact confidence intervals based on four widely used asymptotic intervals, three Wald-type confidence intervals and one interval constructed from a profile variance. These exact intervals are compared with regard to coverage probability and length for small to medium sample sizes. The exact intervals based on the Garner interval and the Lee and Tu interval are generally recommended for use in practice due to good performance in both coverage probability and length.

Management of advanced colorectal cancer, Part 1

PURPOSE

Important developments in chemotherapy for advanced colorectal cancer over the past 15 years are reviewed, with an emphasis on the most recently published data from clinical trials of newer multidrug regimens, administration techniques, and dosing schedules.

SUMMARY

Eight agents are approved by the Food and Drug Administration (FDA) for use in treating patients with advanced colorectal cancer. Fluorouracil and leucovorin still constitute the foundation of most chemotherapy regimens for this population; combination fluorouracil-leucovorin therapy plus either irinotecan (the FOLFIRI regimen) or oxaliplatin (the FOLFOX regimen) are two firmly established first-line treatments shown to produce similar outcomes. In Phase III trials conducted over the past six to seven years, regimens of capecitabine plus oxaliplatin (CapeOx) were demonstrated to have clinical effectiveness comparable to that of FOLFOX therapy. Response rates of 35-55% and median overall survival of ≥20 months have been documented with some of the newer regimens. Research to define the optimal role of the three monoclonal antibody agents approved by FDA for use in managing advanced colorectal cancer is ongoing; bevacizumab has been shown to confer significant survival benefits when added to certain chemotherapy regimens, and other monoclonal antibodies (cetuximab and panitumumab) also appear to offer significant benefits in select patients as first- or second-line therapies.

CONCLUSION

Over the past 15 years, a shift toward multiagent treatment strategies including a variety of chemotherapy agents and monoclonal antibodies has yielded improved rates of response and prolonged survival among patients with advanced colorectal cancer. The CapeOx, FOLFOX, and FOLFIRI regimens are currently among the most widely used first-line treatments.

Preferences of patients with advanced colorectal cancer for treatment with oral or intravenous chemotherapy

BACKGROUND

In recent years, patient-reported outcomes such as health-related quality of life have become important areas of clinician focus in general cancer management. Patients' preferences for, and/or satisfaction with, oral versus intravenous (IV) chemotherapy schedules may have a major impact on such outcomes.

OBJECTIVE

To evaluate preferences for oral or IV chemotherapy in patients with advanced colorectal cancer.

METHODS

A multicenter, randomized, crossover trial was conducted in 12 hospitals in Southern Italy, in which 22 patients with advanced colorectal cancer received one cycle of oral capecitabine ± irinotecan or oxaliplatin, followed by one cycle of an IV de Gramont or similar regimen (arm A), or the same regimens in reverse order (arm B). Patients were aged 50-70 years and 21% had a higher level of education (graduate or similar). Patients received oral capecitabine 3500 mg/m/day for 7 days (± irinotecan 180 mg/m or oxaliplatin 85 mg/m on day 1 only), followed by an IV de Gramont regimen ± irinotecan (FOLFIRI) or oxaliplatin (FOLFOX); or the two schedules administered in reverse order.The main outcome measure was patients' preferences for oral versus IV chemotherapy, as determined by a pre- and post-treatment therapy preference questionnaire (TPQ).

RESULTS

Before treatment, 75% of patients preferred oral therapy. Characteristics that patients considered to be important were that treatment should not interfere with daily activities (100% of patients) and should not cause fatigue (95%), diarrhea (76%), or painful mouth ulcers (76%); other factors considered important were the risk of infection and nausea (90%), and that treatment could be administered at home (65%). After receiving both chemotherapy schedules, only 45% of patients preferred oral therapy, while 55% preferred IV therapy. Among the latter, the most important characteristics influencing treatment choice were less nausea (66%), fewer mood effects (65%), the safety of hospital IV treatment (62%), less interference with family relationships (55%), less vomiting (55%), less interference with daily activities (50%), and less diarrhea (50%). Although the order in which patients received therapy did not influence treatment preference, significantly fewer patients with a lower rather than higher educational level preferred oral therapy (47% vs 80%; chi-square test = 9.9; p = 0.002).

CONCLUSION

These results suggest that there may be a correlation between educational level and the preference of patients with advanced colorectal cancer for oral or IV chemotherapy.

Multicenter retrospective study of 132 patients with unresectable small bowel adenocarcinoma treated with chemotherapy

BACKGROUND

No standard chemotherapy regimen has been established for unresectable or recurrent small bowel adenocarcinoma (SBA).

METHODS

Clinical courses of 132 patients with unresectable or recurrent SBA who received chemotherapy at 41 institutions in Japan were reviewed retrospectively. Patients were classified into five groups according to first-line chemotherapy regimens: fluoropyrimidine monotherapy (group A), fluoropyrimidine-cisplatin (group B), fluoropyrimidine-oxaliplatin (group C), fluoropyrimidine-irinotecan (group D), and other regimens (group E).

RESULTS

The number of patients in each group was as follows: groups A, 60 patients; group B, 17 patients; group C, 22 patients; group D, 11 patients; and group E, 22 patients. Median progression-free survival (PFS) times were as follows: group A, 5.4 months; group B, 3.8 months; group C, 8.2 months; group D, 5.6 months; and group E, 3.4 months. Median overall survival (OS) times were as follows: group A, 13.9 months; group B, 12.6 months; group C, 22.2 months; group D, 9.4 months; and group D, 8.1 months. Patients in group C achieved significantly longer PFS times and substantially (but not significantly) longer OS times than patients in group A. After adjusting for clinical background characteristics, fluoropyrimidine-oxaliplatin therapy was a significant positive prognostic factor for PFS and OS times.

CONCLUSION

The results suggest that fluoropyrimidine-oxaliplatin combination therapy is the most promising first-line chemotherapy regimen for unresectable or recurrent SBA.

Pharmacokinetic properties and antitumor efficacy of the 5-fluorouracil loaded PEG-hydrogel

Background

We have studied the in vitro and in vivo utility of polyethylene glycol (PEG)-hydrogels for the development of an anticancer drug 5-fluorouracil (5-FU) delivery system.

Methods

A 5-FU-loaded PEG-hydrogel was implanted subcutaneously to evaluate the drug retention time and the anticancer effect. For the pharmacokinetic study, two groups of male rats were administered either an aqueous solution of 5-FU (control group)/or a 5-FU-loaded PEG-hydrogel (treated group) at a dose of 100 mg/kg. For the pharmacodynamic study, a human non-small-cell lung adenocarcinoma (NSCLC) cell line, A549 was inoculated to male nude mice with a cell density of 3 × 10⁶. Once tumors start growing, the mice were injected with 5-FU/or 5-FU-loaded PEG-hydrogel once a week for 4 weeks. The growth of the tumors was monitored by measuring the tumor volume and calculating the tumor inhibition rate (IR) over the duration of the study.

Results

In the pharmacokinetic study, the 5-FU-loaded PEG-hydrogel gave a mean residence time (MRT) of 8.0 h and the elimination half-life of 0.9 h; these values were 14- and 6-fold, respectively, longer than those for the free solution of 5-FU (p < 0.05). In the pharmacodynamic study, A549 tumor growth was significantly inhibited in the 5-FU-loaded PEG-hydrogel group in comparison to the untreated group beginning on Day 14 (p < 0.05-0.01). Moreover, the 5-FU-loaded PEG-hydrogel group had a significantly enhanced tumor IR (p < 0.05) compared to the free 5-FU drug treatment group.

Conclusion

We suggest that 5-FU-loaded PEG-hydrogels could provide a useful tool for the development of an anticancer drug delivery system.

Oxaliplatin Added to Simplified Bimonthly Low-Dose Leucovorin and 5-FU for Pretreated Advanced Colorectal Cancer Is Effective and Not Affected by Different Previous 5-FU Regimens

This phase II study examined bimonthly oxaliplatin (85 mg/m2) added to a continuous infusion of fluorouracil (3000 mg/m2 for 46 h following a 400 mg/m2 bolus), with leucovorin (LV) (150 mg/m2) administrated in a simplified way to patients with metastatic colorectal cancers (CRC) refractory or resistant to 5-fluorouracil (5-FU). Sixty patients were registered. Of the 52 evaluable patients, 3 (5.8%) achieved a complete response (CR) and 18 (34.6%) achieved a partial response (PR). The overall response rate (CR + PR) was 40.4% (95% confidence interval [CI]: 26.6%-54.2%) for evaluable patients and 35% (95% CI: 22.6%-47.4%) by intention to treat. The median progression-free survival (PFS) was 5.2 months, and the median survival was 14.2 months. No significant differences were seen in response rates and PFS of patient groups pretreated either with high-dose 5-FU/LV by continuous infusion or with intravenous 5-FU/LV by a weekly bolus. From the 421 cycles analyzed, dose-limiting toxicities included cumulative sensory neuropathy and leukopenia, accounting for 11.6% and 10.0%, National Cancer Institute-Common Toxicity Criteria grade 3/4 toxicities per patient, respectively. Two (3.3%) patients experienced hepatic encephalopathy related to high-dose 5-FU. With necessary caution, this regimen was effective for 5-FU-pretreated CRC, regardless of ethnic differences, and it had the advantage of LV being administrated at a low dose in a simplified way.

Toxic effects and their management: daily clinical challenges in the treatment of colorectal cancer

Among the many chemotherapeutic options for metastatic colorectal cancer, none has shown clear superiority in efficacy. All pharmacologic agents in current use have been associated with adverse events. Frequently reported adverse events associated with the chemotherapeutic agents oxaliplatin, irinotecan, 5-fluorouracil, and capecitabine include acute and chronic neuropathy, hypersensitivity reactions, diarrhea, neutropenia, and hand-foot syndrome. Although biologic agents are seemingly less toxic, toxic effects can also arise with their use; antiangiogenic agents result in hypertension, and EGFR inhibitors can cause severe hypersensitivity, paronychial infections, and more commonly, dermatologic rash. Furthermore, a correlation has been reported for the efficacy of anti-EGFR agents and development of rash. Data indicate that elderly patients with colorectal cancer who have adequate function and performance status, who may previously have been dissuaded from pursuing active therapy solely on the basis of age, should receive the same treatment as younger patients. To enhance the survival of patients with metastatic colorectal cancer, many therapies are administered. Recognition of treatment-emergent toxic effects will, therefore, aid the design and implementation of management strategies that minimize treatment interruption and/or discontinuation, and enhance quality of life for patients.

Vascular complications of selected cancer therapies

Over the past decade, therapies for several previously untreatable types of cancer have emerged or have improved; thus, more focus has been given to long-term complications of cancer therapy. The most commonly known cardiac toxicities of cancer therapy are cardiac dysfunction or congestive heart failure. Vascular complications--such as ischemia, myocardial infarction, venous or arterial thrombosis, and newly developed or worsened hypertension--are also relatively common following cancer treatment, particularly in patients with advanced-stage cancer. Experimental studies have suggested a number of potential mechanisms that might account for vascular complications of cancer therapies, which include dysfunction or damage of endothelial cells, increased platelet aggregation, and modulation of nitric oxide levels. This Review describes the vascular complications of treatment with 5-fluorouracil, bevacizumab, and several new tyrosine kinase inhibitors, with special emphasis on thrombotic complications and hypertension.

Can inhibiting dihydropyrimidine dehydrogenase limit hand-foot syndrome caused by fluoropyrimidines?

Hand-foot syndrome (HFS) is a cutaneous adverse event that occurs in some patients treated with fluoropyrimidines. Although it is not life threatening, HFS can severely disrupt the daily lives of patients. HFS appears more frequently with 5-fluorouracil (5-FU) delivered by continuous infusion or with the 5-FU oral derivative capecitabine than with bolus 5-FU therapy. HFS is a leading cause of treatment interruption, dosage reduction, or, even, therapy discontinuation for patients on a capecitabine regimen. Interestingly, addition of a dihydropyrimidine dehydrogenase (DPD) inhibitor, such as uracil, 5-chloro-2,4-dihydroxypyridine, or eniluracil, to the fluoropyrimidine treatment regimen significantly diminishes the incidence of HFS. DPD inhibitors were initially combined with fluoropyrimidines to increase the efficacy of the drugs by impairing the DPD-mediated catabolism of 5-FU. However, with the accumulating findings from clinical trials that show the benefits of DPD inhibition on decreasing the risk of HFS, consideration should be given to changing the recommendations for the treatment of cancer patients with fluoropyrimidines to include DPD inhibitor components as standard therapy.

Surrogate end points for median overall survival in metastatic colorectal cancer: literature-based analysis from 39 randomized controlled trials of first-line chemotherapy

PURPOSE

Our aims were to determine the correlations between progression-free survival (PFS), time to progression (TTP), and response rate (RR) with overall survival (OS) in the first-line treatment of metastatic colorectal cancer (MCRC), and to identify a potential surrogate for OS.

METHODS

Randomized trials of first-line chemotherapy in MCRC were identified, and statistical analyses were undertaken to evaluate the correlations between the end points.

RESULTS

Thirty-nine randomized controlled trials were identified containing a total of 87 treatment arms. Among trials, the nonparametric Spearman rank correlation coefficient (r(s)) between differences (Delta) in surrogate end points (DeltaPFS, DeltaTTP, and DeltaRR) and DeltaOS were 0.74 (95% CI, 0.47 to 0.88), 0.52 (95% CI, 0.004 to 0.81), 0.39 (95% CI, 0.08 to 0.63), respectively. The r(s) for DeltaPFS was not significantly different from the r(s) DeltaTTP (P = .28). Linear regression analysis was performed using hazard ratios for PFS and OS. There was a strong relationship between hazard ratios for PFS and OS; the slope of the regression line was 0.54 +/- 0.10, indicating that a novel therapy producing a 10% risk reduction for PFS will yield an estimated 5.4% +/- 1% risk reduction for OS.

CONCLUSION

In first-line chemotherapy trials for MCRC, improvements in PFS are strongly associated with improvements in OS. In this patient population, PFS may be an appropriate surrogate for OS. As a clinical end point, PFS offers increased statistical power at a given time of analysis and a significant lead time advantage compared with OS.

Combined intra-arterial 5-fluorouracil and subcutaneous interferon-alpha therapy for highly advanced hepatocellular carcinoma

Because of the difficulties of low sensitivity for anticancer agents and giving sufficient dose because of poor liver function, chemotherapy may not play a central role for treatment of hepatocellular carcinoma (HCC) patients, especially those with liver cirrhosis. However, chemotherapy must be one of the important possibilities of multimodal treatment for advanced HCC, for which hepatic resection, percutaneous ablation, transcatheter arterial embolization and other general therapies would not be effective or even possible. Also, intra-arterial perfusion chemotherapy is a common therapy for HCC and it is not difficult to maintain; but the effective rate is not sufficient. Recently, the combination therapy of s.c. interferon (IFN)-alpha and intra-arterial 5-fluorouracil (5-FU) showed an outstandingly effective rate for intractable HCC (with portal vein thrombosis). In addition,recent preclinical and clinical studies have revealed that the mechanism of combination therapy may concern direct antitumor effects (through cell-cycle arrest and induction of apoptosis) and indirect actions (through immunocompetent cells and anti-angiogenic effect). For the further advance of HCC treatment and prognosis, this therapy might be a promising treatment modality and is expected to develop. In this review, we summarize recent clinical and preclinical data regarding IFN-alpha and 5-FU combination therapy and discuss the further prospects of this therapy.

Pharmacokinetic and demographic markers of 5-fluorouracil toxicity in 181 patients on adjuvant therapy for colorectal cancer

BACKGROUND

The relationship between 5-fluorouracil (5-FU) pharmacokinetics and toxicity following i.v. bolus administration has not been extensively studied.

PATIENTS AND METHODS

One hundred and eighty-one patients on adjuvant therapy with 5-FU plus leucovorin for colorectal cancer were the study population. 5-FU pharmacokinetics was determined on day 2 of the first, third, and fifth cycles; type and the grade of adverse reactions were recorded on the next cycle.

RESULTS

The 5-FU area under the curve (AUC) measured at the first cycle ranged between 146 and 1236 mg x min/l and was significantly correlated with drug dose, patients' body weight (BW) and gender, females having higher AUCs. These covariates explained only 23% of AUC variability. AUC and age were the only covariates which discriminated between toxic (grade > or =2) and nontoxic cycles (grade <2), with an optimal AUC cut-off value of 596 mg x min/l. Such a correlation was lost during the next cycles following dose reduction because of toxicity in 80 patients.

CONCLUSIONS

A method for calculating the initial 5-FU dose is proposed which takes into account patient BW, gender and a target AUC of 596 mg x min/l. Nevertheless, it appears that a substantial part of 5-FU toxicity is not linked to pharmacokinetic factors and dose adjustments must still be on the basis of careful clinical surveillance.

Phase III trial of fluorouracil-based chemotherapy regimens plus radiotherapy in postoperative adjuvant rectal cancer: GI INT 0144

PURPOSE

Adjuvant chemoradiotherapy after or before resection of high-risk rectal cancer improves overall survival (OS) and pelvic control. We studied three postoperative fluorouracil (FU) radiochemotherapy regimens.

PATIENTS AND METHODS

After resection of T3-4, N0, M0 or T1-4, N1, 2M0 rectal adenocarcinoma, 1,917 patients were randomly assigned to arm 1, with bolus FU in two 5-day cycles every 28 days before and after radiotherapy (XRT) plus FU via protracted venous infusion (PVI) 225 mg/m2/d during XRT; arm 2 (PVI-only arm), with PVI 42 days before and 56 days after XRT + PVI; or arm 3 (bolus-only arm), with bolus FU + leucovorin (LV) in two 5-day cycles before and after XRT, plus bolus FU + LV (levamisole was administered each cycle before and after XRT). Patients were stratified by operation type, T and N stage, and time from surgery.

RESULTS

Median follow-up was 5.7 years. Lethal toxicity was less than 1%, with grade 3 to 4 hematologic toxicity in 49% to 55% of the bolus arms versus 4% in the PVI arm. No disease-free survival (DFS) or OS difference was detected (3-year DFS, 67% to 69% and 3-year OS, 81% to 83% in all arms). Locoregional failure (LRF) at first relapse was 8% in arm 1, 4.6% in arm 2, and 7% in arm 3. LRF in T1-2, N1-2, and T3, N0-2 primaries who received low anterior resection (those most suitable for primary resection) was 5% in arm 1, 3% in arm 2, and 5% in arm 3.

CONCLUSION

All arms provide similar relapse-free survival and OS, with different toxicity profiles and central catheter requirements. LRF with postoperative therapy is low, justifying initial resection for T1-2, N0-2 and T3, and N0-2 anterior resection candidates.

Should continuous infusion 5-fluorouracil become the standard of care in the USA as it is in Europe?

The mechanism of action of 5-fluorouracil (5-FU) and its pharmacologic behavior are influenced by its mode of administration. Several clinical studies have been conducted with the purpose of evaluating the difference between the continuous (CI 5-FU) and the bolus infusion of 5-FU (BI 5-FU). We focus our review on the studies relevant to the treatment of colorectal cancer, both in the adjuvant and metastatic setting. While individual trials fail to show a survival benefit for CI 5-FU, a meta-analyses of 7 trials shows an improvement in overall survival (OS) over BI 5-FU in metastatic colorectal cancer treatment. All trials in the same setting reveal a different toxicity profile for CI 5-FU that is generally more favorable than BI 5-FU. In the adjuvant setting, CI 5-FU allows the duration of therapy to be shortened by half without compromising the efficacy. CI 5-FU is the regimen of choice when given concurrently with radiation. When given in combination with other cytotoxic agents, CI 5-FU seems to be associated with less toxicity and potentially higher efficacy. Oral fluoropyrimidines, especially capecitabine, appear to behave in similar manner to CI 5-FU and may offer a convenient alternative to the usage of infusion pumps and indwelling catheters. While clinical trials are ongoing to compare capecitabine to CI 5-FU, we believe that CI 5-FU should be offered to patients in the United States given its favorable toxicity profile and higher efficacy in several settings.

Population analysis of the pharmacokinetics and the haematological toxicity of the fluorouracil-epirubicin-cyclophosphamide regimen in breast cancer patients

PURPOSE

The aims of the study were (a) to characterise the pharmacokinetics (PK), including inter-individual variability (IIV) and inter-occasion variability (IOV) as well as covariate relationships and (b) to characterise the relationship between the PK and the haematological toxicity of the component drugs of the fluorouracil (5-FU)-epirubicin (EPI)-cyclophosphamide (CP) regimen in breast cancer patients.

PATIENTS AND METHODS

Data from 140 breast cancer patients, either within one of different studies or in routine clinical management, were included in the analyses. The patients were all treated with the fluorouracil-epirubicin-cyclophosphamide (FEC) regimen every third week for 3-12 courses, either in standard doses, i.e. 600/60/600 mg/m(2) of 5-FU, EPI and CP, respectively, or according to a dose escalation/reduction protocol (tailored dosing). PK data were available from 84 of the patients, whereas time-courses of haematological toxicity were available from 87 patients. The data analysis was carried out using mixed effects models within the NONMEM program.

RESULTS

The PK of 5-FU, EPI and 4-hydroxy-cyclophosphamide (4-OHCP), the active metabolite of CP, were described with a one-compartment model with saturable elimination, a three-compartment linear model and a two-compartment linear model, respectively. No clinical significant correlation was found between PK across drugs. The unexplained variability in clearance was found to be less within patients, between courses (inter-occasion variability, IOV) than between patients (inter-individual variability, IIV) for EPI and 5-FU. For 4-OHCP, however, the IIV diminished by approximately 45% when significant covariates were included and the final population model predicts an IIV that is equal to IOV. Significant covariates for elimination capacity parameters were serum albumin (5-FU, EPI and 4-OHCP), creatinine clearance (5-FU), bilirubin (EPI) and body surface area (BSA) (4-OHCP). Elimination capacity of 5-FU and EPI was not related to BSA and for none of the studied drugs did body weight explain the PK variability. The time-course of haematological toxicity after treatment was well described by a semi-physiological model that assumes additive haematological toxicity between CP and EPI with negligible contribution from 5-FU. The influence of G-CSF could be incorporated into the model in a mechanistic manner as shortening the maturation time to 43% of the normal duration and increasing the mitotic activity to 269% of normal activity.

CONCLUSIONS

The models presented describe the dose-concentration-toxicity relationships for the FEC therapy and may provide a basis for implementation and comparison of different individualisation strategies based on covariates, therapeutic drug monitoring and/or pharmacodynamic (PD) feedback. The PD model extends on previous semi-mechanistic models in that it also takes G-CSF administration into account.

Influence of chemotherapeutic agents and cytokines on the expression of 5-fluorouracil-associated enzymes in human colon cancer cell lines

BACKGROUND

Several studies have demonstrated that intratumoral expression of catabolizing and anabolizing enzymes for 5-fluorouracil (5-FU) is important in the response of cancers to 5-FU-based chemotherapy. We investigated the influence of other chemotherapeutic agents or cytokines, which are often administered for enhancing the efficacy of 5-FU, on the tumoral expression of 5-FU-associated enzymes, i.e., dihydropyrimidine dehydrogenase (DPD), thymidylate synthase (TS), orotate phosphoribosyl transferase (OPRT), and thymidine phosphorylase (TP).

METHODS

Human colon cancer cell lines (HT-29, Caco-2, and DLD-1) were incubated with 5-FU and with 5-FU combined with cisplatin, camptothecin, paclitaxel, mitomycin C, interferon, or TNF-related apoptosis-inducing ligand. mRNA expression of 5-FU-associated enzymes was assessed by real-time PCR. Activity of each enzyme and intracellular 5-FU accumulation after incubation with such agents were also evaluated.

RESULTS

Each agent had a synergistic effect on the cytotoxicity of 5-FU. All chemotherapeutic agents other than cytokines induced marked alteration of the mRNA expression profile of 5-FU-associated enzymes; depression of DPD, elevation of TS, and slight suppression of OPRT and TP. In accordance with mRNA expression, enzyme activity of DPD was significantly depressed by such agents. Furthermore, although 5-FU itself increased DPD mRNA expression, a mechanism considered to be related to the acquisition of 5-FU resistance, the addition of cisplatin or camptothecin significantly inhibited the 5-FU-induced elevation of DPD.

CONCLUSIONS

5-FU-associated enzymes in colon cancer cells were greatly influenced by various chemotherapeutic agents; in particular, DPD expression was depressed. These results appear important in planning chemotherapy and also in understanding the development of adverse effects of 5-FU.

A randomised cross-over trial comparing patient preference for oral capecitabine and 5-fluorouracil/leucovorin regimens in patients with advanced colorectal cancer

BACKGROUND

Traditionally, metastatic colorectal cancer (MCRC) has been treated with intravenous (i.v.) 5-fluorouracil/leucovorin (5-FU/LV). The tumour-activated, oral fluoropyrimidine capecitabine demonstrates superior activity and favourable safety compared with the Mayo regimen, while potentially avoiding the complications and inconvenience associated with i.v. regimens.

PATIENTS AND METHODS

Ninety-seven patients with previously untreated advanced/MCRC were randomised to receive capecitabine followed by i.v. 5-FU/LV [Mayo Clinic, in-patient de Gramont (IPdG) or out-patient modified de Gramont (OPdG) regimens], or i.v. 5-FU/LV followed by capecitabine.

RESULTS

Before treatment, of those patients for whom a preference was recorded, almost all (95%) preferred oral treatment (consistent across all treatment groups) and the majority retained this preference after treatment (64% overall; 86%, 63% and 50% in the Mayo, IPdG and OPdG groups, respectively). Following treatment, the principal reasons for oral treatment preference were increased convenience, home-based administration and tablet formulation. Treatment satisfaction was significantly higher with capecitabine compared with Mayo (P<0.05) and with OPdG compared with capecitabine (P<0.05). Quality of life (QoL) was largely constant across the regimens, although it appeared better with OPdG than capecitabine (P<0.05). Grade 3/4 adverse events were uncommon in all arms.

CONCLUSIONS

This study confirmed that the majority of patients with MCRC prefer oral to i.v. therapy, although the OPdG regimen appears to be the most popular i.v. option. Capecitabine clearly represents an effective, well-tolerated oral alternative to i.v. 5-FU/LV.

Results of a Phase II Open-Label Study of Capecitabine in Combination with Irinotecan as First-Line Treatment for Metastatic Colorectal Cancer

BACKGROUND

Between July 2001 and September 2002, 49 eligible patients were enrolled in an open-label phase II study to assess the efficacy and safety of first-line treatment with capecitabine/irinotecan in metastatic colorectal cancer.

PATIENTS AND METHODS

Patients received capecitabine (1000 mg/m2 twice daily) on days 1-14 and irinotecan (240 mg/m2) on day 1 of a 21-day cycle. Patients enrolled had a median age of 64.5 years, and 6% of patients had an Eastern Cooperative Oncology Group performance status of 2. Fifty-seven percent of patients were male.

RESULTS

Forty-two patients were evaluable for response. There was 1 complete response (2%), 18 partial responses (43%), 20 cases of stable disease (48%), and 3 cases of disease progression (7%), for an overall response rate of 45% (95% CI, 30%-60%). The median duration of response was 5.7 months (range, 2.5-II.3 months). Median survival was 13.4 months (range, 1.2-28.8 months) and median progression-free survival was 6.2 months (range, 1.2-17.5 months). At 1 year, the estimated survival rate was 54% and the estimated progression-free survival rate was II%. The median number of cycles received was 6 (range, 1-18 cycles), and most patients (80%) required a dose modification because of diarrhea, nausea, and/or neutropenia. Grade 1/2 hand-foot syndrome occurred in 8 patients (16%). Grade 3/4 toxicities experienced by > or = 5% of patients included diarrhea (20%), neutropenia (12%), dehydration (10%), nausea (10%), anemia (6%), fatigue (6%), pain (6%), and vomiting (6%).

CONCLUSIONS

First-line capecitabine/ irinotecan is an active combination for the treatment of metastatic colorectal cancer and feasible for use in the community-based setting. Despite significant toxicity with the regimen, the treatment was manageable with dose reduction or delay and should be investigated in phase III trials.

Phase III Southwest Oncology Group 9415/Intergroup 0153 randomized trial of fluorouracil, leucovorin, and levamisole versus fluorouracil continuous infusion and levamisole for adjuvant treatment of stage III and high-risk stage II colon cancer

PURPOSE

Modest toxicity and possibly enhanced activity makes continuous-infusion fluorouracil (FU) an attractive alternative to FU plus leucovorin (FU/LV) for the adjuvant treatment of colorectal cancer. Intergroup trial 0153 (Southwest Oncology Group trial 9415) was developed to compare the efficacy of continuous-infusion FU (CIFU) plus levamisole to FU/LV plus levamisole in the adjuvant treatment of high-risk Dukes' B2 and C1 or C2 colon cancer.

PATIENTS AND METHODS

After surgery, patients were randomly assigned to CIFU 250 mg/m(2)/d for 56 days every 9 weeks for three cycles or FU 425 mg/m(2) and LV 20 mg/m(2) daily for 5 days every 28 to 35 days for six cycles. All patients received levamisole 50 mg tid for 3 days every other week. The primary end point was overall survival (OS).

RESULTS

The study closed in December 1999 after an interim analysis demonstrated little likelihood of CIFU showing superiority to FU/LV within the stipulated hazard ratio. A total of 1,135 patients were registered. At least one grade 4 toxicity occurred in 39% of patients receiving FU/LV and 5% of patients receiving CIFU. However, almost twice as many patients receiving CIFU discontinued therapy early compared with those receiving FU/LV. The 5-year OS is 70% (95% CI, 66% to 74%) for FU/LV and 69% (95% CI, 64% to 73%) for CIFU. The corresponding 5-year disease-free survival (DFS) is 61% (95% CI, 56% to 65%) and 63% (95% CI, 59% to 68%), respectively. For all patients, 5-year OS is 83%, 74%, and 55%; 5-year DFS is 78%, 67%, and 47% for N0, N1, and N2-3, respectively.

CONCLUSION

CIFU had less severe toxicity but did not improve DFS or OS in comparison with bolus FU/LV.

Colon cancer

Colon cancer is one of the leading tumours in the world and is considered among the big killers, together with lung, prostate and breast cancer. In the recent years very important advances occurred in the field of treatment of this frequent disease: adjuvant chemotherapy was demonstrated to be effective, chiefly in stage III patients, and surgery was optimized in order to achieve the best results with a low morbidity. Several new target-oriented drugs are under evaluation and some of them (cetuximab and bevacizumab) have already exhibited a good activity/efficacy, mainly in combination with chemotherapy. The development of updated recommendations for the best management of these patients is crucial in order to obtain the best results, not only in clinical research but also in everyday practice. This report summarizes the most important achievements in this field and provides the readers useful suggestions for their professional practice.

Neoadjuvant chemoradiation with tegafur in cancer of the pancreas: initial analysis of clinical tolerance and outcome

The early institutional experience in the neoadjuvant treatment of potentially resectable pancreatic carcinoma using oral Tegafur as radioenhancing agent is analyzed. Fifteen patients (10 male and 5 female, mean age of 61 years) were treated over a 30-month period. Tegafur dose was 1,200 mg/d along the external radiotherapy period (45-55 consecutive days). Preoperative radiotherapy achieved a total dose of 45 to 50 Gy (1.8 Gy/d). Intraoperative electron boost (10-15 Gy) was delivered at the time of surgery. Hematologic tolerance showed a significant decrease of neutrophil and platelet counts from the outset to the end of the neoadjuvant period (p = 0.001 and p = 0.004, respectively). Five grade III vomiting episodes (33%) were also registered. In 9 patients (60%), surgical resection was performed after chemoradiation. Three complete pathologic responses (pT0 specimens) were identified; in seven cases, the resection achieved tumor-free surgical margins of the specimen. With a median follow-up of 21 months, median survival time was 17 months, with actuarial rates of 45% at 1 year and 24% at 3 years. Median survival for the resected patients was 23 months, and for the unresected patients median survival was 8 months (p = 0.02). The overall median survival in completely resected patients was 28 months, with a 71% survival rate at 1 and 3 years. It is concluded that the treatment scheme described is feasible and acceptably tolerated. The use of oral Tegafur seems to induce results similar to those of other therapeutic protocols using intravenous radioenhancing chemotherapy.

Phase III study of mitomycin-C with protracted venous infusion or circadian-timed infusion of 5-fluorouracil in advanced colorectal carcinoma

The combination of protracted venous infusion (PVI) fluorouracil (5-FU) and mitomycin-C has previously been shown to be superior to PVI 5-FU alone in terms of response rate and failure-free survival. This study explores the effect of dose intensification by circadian timing of 5-FU in this combination on response, toxicity, and survival. Patients with advanced colorectal carcinoma were randomized to receive PVI 5-FU 300 mg/m2 daily or circadian-timed infusion (CTI) of 5-FU, beginning at 600 mg/m2 and subsequently reduced to 450 mg/m2, delivered as a flat-rate infusion from 10:15 PM to 9:45 AM. Both groups received mitomycin-C at a dose of 7 mg/m2 given every 6 weeks. From April 1996 to August 1998, 320 patients were randomized, including 263 with metastatic disease and 21 with circumferential margin involvement. The overall response rate for the PVI 5-FU group was 38%, compared with 30.3% for the CTI group (P = 0.176). There was no statistically significant difference in terms of failure-free survival (8.0 months vs. 9.9 months; P = 0.131) or overall survival (15.8 months vs. 16.3 months; P = 0.275) between the treatment groups. There were no differences in global quality of life. Grade 3/4 diarrhea occurred significantly more frequently with CTI 5-FU (6.5% vs. 19.8%; P < 0.001); a nonsignificant trend toward increased incidences of grade 3/4 infection and palmar plantar erythema were observed with CTI 5-FU. This study confirms the high response rate and overall survival figures for the combination of PVI 5-FU and mitomycin-C in colorectal cancer. However, dose intensification of 5-FU using a circadian-timed, flat-rate infusion did not lead to improved response or survival.

Scope and epidemiology of cancer therapy-induced oral and gastrointestinal mucositis

OBJECTIVE

To discuss the scope and epidemiology of cancer therapy-induced mucositis.

DATA SOURCE

Peer-reviewed articles and book chapters.

CONCLUSION

Mucositis is a frequent and costly complication of cancer treatment. The risk of cancer therapy-induced mucositis varies depending on a number of patient- and treatment-related factors.

IMPLICATIONS FOR NURSING PRACTICE

An awareness of the risk factors associated with mucositis will allow nurses to identify cancer patients at greatest risk and incorporate supportive care measures into their management plans.

Semimonthly versus monthly regimen of fluorouracil and leucovorin administered for 24 or 36 weeks as adjuvant therapy in stage II and III colon cancer: results of a randomized trial

PURPOSE

This randomized, 2 x 2 factorial study compared a semimonthly (LVFU2) with a monthly (FULV) regimen of fluorouracil and leucovorin and 24 versus 36 weeks of each regimen as adjuvant treatment of patients with stage II (Dukes' B2) and III (Dukes' C) colon cancer.

PATIENTS AND METHODS

LVFU2 was administered semi-monthly for 2 consecutive days as dl- or l-leucovorin (200 or 100 mg/m2, respectively) as a 2-hour infusion, followed by a 400 mg/m2 FU bolus and 600 mg/m2 of FU as a 22-hour continuous infusion. FULV was administered monthly for 5 consecutive days as a 15-minute infusion of dl- or l-leucovorin, followed by 400 mg/m2 of FU as a 15-minute infusion.

RESULTS

A total of 905 patients were randomly assigned. The median follow-up was 41 months. Disease-free survival was similar between the LVFU2 and FULV groups (127 v 124 events; hazard ratio [HR] = 1.04; P =.74) and between 24 and 36 weeks of therapy (128 v 123 events; HR = 0.94; P =.63). Analysis of overall survival showed a slight excess in the number of deaths in LVFU2 compared with FULV (73 v 59), but this difference was not statistically significant (HR = 1.26; 95% confidence interval, 0.90 to 1.78; P =.18). The most commonly observed grade 3 to 4 toxicities were neutropenia, diarrhea, and mucositis. Toxicities were significantly lower in the LVFU2 group (all toxicities, P <.001).

CONCLUSION

Our data confirm that LVFU2 is less toxic than FULV. At a median follow-up of 41 months, no statistically significant difference could be detected in disease-free or overall survival between the treatment groups or treatment durations.

Angiogenesis and apoptosis

This review assembles the laboratory and clinical evidence that cytotoxic chemotherapy and antiangiogenic therapy are each dependent on endothelial cell apoptosis. During cytotoxic chemotherapy, apoptosis of endothelial cells in the vascular bed of tumors precedes apoptosis of tumor cells, even when the tumor has been made drug resistant. Administration of an angiogenesis inhibitor which is not directly cytotoxic to tumor cells can increase tumor cell apoptosis and inhibit tumor growth by inhibiting endothelial proliferation and migration and/or by inducing endothelial apoptosis. Furthermore, oncogene expression and loss of tumor suppressor gene activity can at once protect tumor cells against apoptosis and increase their angiogenic output. Both of these survival advantages conferred on the tumor can be overcome by antiangiogenic therapy. They can also be overcome by cytotoxic chemotherapy administered on a low dose 'antiangiogenic schedule' which continuously exposes endothelial cells in the tumor bed to the drug. As a result, endothelial apoptosis can be demonstrated to precede tumor cell apoptosis, and tumors regress or are inhibited, whether or not the tumor cells are resistant to the drug, and with little or no host toxicity. In contrast, cytotoxic chemotherapy administered on a 'conventional schedule' of maximal tolerated dose followed by an off-therapy interval, becomes ineffective after drug resistance is acquired. On the basis of these experimental findings, chemotherapy of cancer may possibly be improved-i.e. decreased drug resistance and decreased toxic side-effects-by changing dose and schedule to maximize apoptosis of endothelial cells in the vascular bed of tumors. Further improvement may be achieved by combining angiogenesis inhibitors with 'antiangiogenic chemotherapy'.

Intermittent FLDP: 24-h infusion of 5-FU on days 1, 3 and 5 combined with low-dose cisplatin on days 1-5 for gastric cancer, and its pharmacologic and kinetic rationale

PURPOSE

To improve the therapeutic efficacy and minimize the toxicity of 5-fluorouracil (5-FU), intermittent therapy consisting of alternate 24-h intravenous infusion and based on differences in generation time (T(G)) between normal cells and tumor cells was investigated.

METHODS

Two human gastric cancer cell lines MKN-7 and MKN-74 with T(G) of 35 h and 17 h, respectively, were used in an in vitro cytotoxic assay. The drug exposure schedule consisted of a continuous 144-h exposure and alternate 24-h exposures. In a clinical trial, a total of 23 patients with advanced or recurrent gastric cancer were treated with intermittent therapy consisting of 24-h intravenous infusion with 5-FU 700 mg/m(2) per day on days 1, 3 and 5 in combination with low-dose cisplatin (CDDP) at 3.3 mg/m(2) per day on days 1 to 5. One cycle of the combined chemotherapy lasted for four consecutive weeks, followed by withdrawal over 1-2 weeks. Plasma 5-FU concentrations were measured by high-performance liquid chromatography in 15 patients and dihydropyrimidine dehydrogenase (DPD) activity in peripheral blood mononuclear cells (PBMC) was measured in 13 patients.

RESULTS

The in vitro study revealed no statistically significant difference in cytotoxicity of 5-FU between the two drug exposure schedules in MKN-7 cells. In MKN-74 cells, however, a statistically significant decrease in cytotoxicity was found with the alternate 24-h exposure. In a clinical trial, plasma 5-FU concentrations showed a trapezoidal pattern. There was a significant correlation between DPD activity in PBMC and total body clearance of 5-FU. There were eight partial responders (8/22, 36%). Toxicities were very mild in severity, with no grade 3 or 4 toxicity. In particular, diarrhea and stomatitis were infrequent (one patient), and none of the patients developed thrombocytopenia.

CONCLUSIONS

Toxicities which may be observed in rapidly growing cells such as bone marrow cells and gastrointestinal epithelial cells following continuous intravenous infusion of 5-FU seemed to be reduced by intermittent therapy of 5-FU consisting of alternate 24-h intravenous infusions.

Minimizing long-term tumor burden: the logic for metronomic chemotherapeutic dosing and its antiangiogenic basis

The general utility of the maximum tolerated dose (MTD) paradigm, a strategy aimed at optimizing the chance of total tumor cell eradication, is here questioned. Evidence to date suggests that for many tumors the potential for eradication is in fact remote, with patients consistently demonstrating tumor cell presence subsequent to MTD treatments having eradicative intent. The failure to eradicate is attributed largely to the heterogeneous nature of the tumor. Heterogeneous cell populations demonstrate short-term refractoriness to up-front dose delivery, but "resensitize" as part of dose recovery, showing increased overall susceptibility to a given series of doses when delivered more evenly spaced. It is demonstrated: (1) that the minimization of total tumor burden, rather than complete eradication, may often be the more practical objective; and (2) that regularly spaced, "metronomic" dosing is the best way to achieve it. As a corollary, it is found that the more efficient ability of the tumor endothelial cells to resensitize following dosing predicts a targeting bias towards the endothelial compartment of a tumor when metronomic dosing is employed. This lends theoretical support to recent empirical studies showing that regularly spaced dosing schedules with no extended rest periods act more antiangiogenically, thereby delaying or avoiding the onset of acquired resistance.

Clinical translation of angiogenesis inhibitors

Angiogenesis inhibitors are a new class of drugs, for which the general rules involving conventional chemotherapy might not apply. The successful translation of angiogenesis inhibitors to clinical application depends partly on the transfer of expertise from scientists who are familiar with the biology of angiogenesis to clinicians. What are the most common questions that clinicians ask as they begin to test angiogenesis inhibitors in cancer clinical trials?

Multicenter phase III study of uracil/tegafur and oral leucovorin versus fluorouracil and leucovorin in patients with previously untreated metastatic colorectal cancer

PURPOSE

This phase III study was designed to demonstrate equivalence in survival of oral uracil/tegafur (UFT) and oral leucovorin (LV) to conventional intravenous (IV) fluorouracil (5-FU) and LV in previously untreated metastatic colorectal carcinoma. Safety was also compared.

PATIENTS AND METHODS

Eight hundred sixteen patients were randomized to receive either UFT (300 mg/m(2)/d) and LV (75 or 90 mg/d) for 28 days every 35 days or IV bolus 5-FU (425 mg/m(2)/d) and LV (20 mg/m(2)/d) for 5 days every 28 days.

RESULTS

UFT/LV produced survival comparable to the IV 5-FU/LV regimen. Median survival was 12.4 months (95% confidence interval [CI], 11.2 to 13.6 months) with UFT/LV and 13.4 months (95% CI, 11.6 to 15.4 months) with 5-FU/LV (P =.630). The hazard ratio for survival was 0.964 (95.6% CI, 0.826 to 1.125), supporting equivalent survival. The overall response rate did not differ between treatment arms (UFT/LV, 11.7%; 5-FU/LV, 14.5%; P =.232). Median time to progression favored 5-FU/LV (UFT/LV, 3.5 months; 5-FU/LV, 3.8 months; P =.011), but tumor assessment schedules differed between arms. UFT/LV significantly improved safety compared with 5-FU/LV. Diarrhea, nausea and vomiting, and stomatitis and mucositis were significantly less frequent with UFT/LV, as was myelosuppression. Patients treated with UFT/LV had fewer episodes of febrile neutropenia (P <.001) and documented infections (P <.05). Increased bilirubin, without other liver function abnormalities, was observed more often with UFT/LV (P <.001). Concomitant medications were more frequent with 5-FU/LV, including use of antibiotics, growth factors, and antiemetics.

CONCLUSION

UFT/LV provided a safer, more convenient oral alternative to a standard bolus IV 5-FU/LV regimen for metastatic colorectal cancer while producing equivalent survival.

Schedule-selective biochemical modulation of 5-fluorouracil in advanced colorectal cancer--a phase II study

BACKGROUND

5-fluorouracil remains the standard therapy for patients with advanced/metastatic colorectal cancer. Pre-clinical studies have demonstrated the biological modulation of 5-fluorouracil by methotrexate and leucovorin. This phase II study was initiated to determine the activity and toxicity of sequential methotrexate--leucovorin and 5-fluorouracil chemotherapy in patients with advanced colorectal cancer.

METHODS

Ninety-seven patients with metastatic colorectal cancer were enrolled onto the study. Methotrexate--30 mg/m2 was administered every 6 hours for 6 doses followed by a 2 hour infusion of LV--500 mg/m2. Midway through the leucovorin infusion, patients received 5-fluorouracil--600 mg/m2. This constituted a cycle of therapy and was repeated every 2 weeks until progression.

RESULTS

The median age was 64 yrs (34-84) and the Eastern Cooperative Group Oncology performance score was 0 in 37%, 1 in 55% and 2 in 8% of patients. Partial and complete responses were seen in 31% of patients with a median duration of response of 6.4 months. The overall median survival was 13.0 months. The estimated 1-year survival was 53.7%. Grade III and IV toxic effects were modest and included mucositis, nausea and vomiting.

CONCLUSIONS

This phase II study supports previously reported data demonstrating the modest clinical benefit of 5-FU modulation utilizing methotrexate and leucovorin in patients with metastatic colorectal cancer. Ongoing studies evaluating 5-fluorouracil modulation with more novel agents (Irinotecan and/or oxaliplatin) are in progress and may prove encouraging.

Eastern Cooperative Oncology Group phase II trial (E4296) of oral 5-fluorouracil and eniluracil as a 28-day regimen in metastatic colorectal cancer

Coadministration of eniluracil with 5-fluorouracil (5-FU) allows the oral absorption of small doses of 5-FU, resulting in therapeutic plasma levels. A phase II clinical trial of this combination using a continuous dosing schedule was carried out in patients with metastatic colorectal cancer. Fifty-three previously untreated patients and 46 patients who had received one prior regimen for metastatic disease were enrolled. Patients received 10 mg/m2 of eniluracil and 1 mg/m2 of 5-FU twice daily for 28 days, with cycles repeated after a 7-day rest until progression of disease or prohibitive toxicity. Seven of 53 previously untreated patients had an objective tumor response (13.2%): 1 complete response and 6 partial responses. The mean duration of response was 6.3 months. Only 1 of the 45 evaluable patients in the previously treated group had a partial response, with no complete responses. The duration of response was 3 months. The median progression-free survival was 3.4 months for the previously untreated group and 2.5 months for the previously treated group. Median overall survival was 11.1 months for the previously untreated group and 9.0 months for the previously treated group. Hematologic toxicity was infrequent, with 3 patients experiencing grade 3 toxicity. Incidence of grade 3/4 toxicity included 11 patients with diarrhea, 5 with nausea, and 4 with vomiting. Other common toxicities included anemia and stomatitis, but they were generally mild. This regimen is well tolerated and shows activity in previously untreated patients with metastatic colorectal cancer that is similar to that observed with other 5-FU-based regimens. This regimen has not shown to be effective in patients who have had prior chemotherapy.

Phase II study of capecitabine and oxaliplatin in first- and second-line treatment of advanced or metastatic colorectal cancer

PURPOSE

To determine the efficacy and tolerability of combining oxaliplatin with capecitabine in the treatment of advanced nonpretreated and pretreated colorectal cancer.

PATIENTS AND METHODS

Forty-three nonpretreated patients and 26 patients who had experienced one fluoropyrimidine-containing regimen for advanced colorectal cancer were treated with oxaliplatin 130 mg/m(2) on day 1 and capecitabine 1,250 mg/m(2) bid on days 1 to 14 every 3 weeks. Patients with good performance status (World Health Organization grade 0 to 1) were accrued onto two nonrandomized parallel arms of a phase II study.

RESULTS

The objective response rate was 49% (95% confidence interval [CI], 33% to 65%) for nonpretreated and 15% (95% CI, 4% to 35%) for pretreated patients. The main toxicity of this combination was diarrhea, which occurred at grade 3 or 4 in 35% of the nonpretreated and 50% of the pretreated patients. Grade 3 or 4 sensory neuropathy, including laryngopharyngeal dysesthesia, occurred in 16% of patients on both cohorts. Capecitabine dose reductions were necessary in 26% of the nonpretreated and 45% of the pretreated patients in the second treatment cycle. The median overall survival was 17.1 months and 11.5 months, respectively.

CONCLUSION

Combining capecitabine and oxaliplatin yields promising activity in advanced colorectal cancer. The main toxicity is diarrhea, which is manageable with appropriate dose reductions. On the basis of our toxicity experience, we recommend use of capecitabine in combination with oxaliplatin 130 mg/m(2) at an initial dose of 1,250 mg/m(2) bid in nonpretreated patients and at a dose of 1,000 mg/m(2) bid in pretreated patients.

Overexpression of pyrimidine nucleoside phosphorylase enhances the sensitivity to 5'-deoxy-5-fluorouridine in tumour cells in vitro and in vivo

5-Fluorouracil (5-FU) and 5'-deoxy-5-fluorouridine (5'-DFUR), a prodrug of 5-FU, are representative of the chemotherapeutic agents for colorectal adenocarcinomas. Pyrimidine nucleoside phosphorylase (PyNPase) catalyses the conversion of 5'-DFUR to 5-FU, the activated form. Murine adenocarcinoma CT26 cells were transfected with human PyNPase cDNA. The engineered transfectants producing PyNPase augmented the response to 5'-DFUR in vitro and in vivo. Animals were administered by means of intraperitoneal (i.p.) injection, and not orally, in order to obtain a better efficiency of absorption. The tumours of the transfected cells nearly all disappeared, even following treatment with quite a small amount of the anticancer agent. The animals injected with the tranfected cells were protected against subsequent challenge with the parental tumour cell line. These findings demonstrate that PyNPase gene transfection increases the sensitivity to 5'-DFUR, and thereby decreases the toxicity of the agent.

Clinical experience of capecitabine in metastatic breast cancer

Results from two phase II studies in metastatic breast cancer have shown that the novel, tumour-selective fluoropyrimidine capecitabine provides an effective and well tolerated therapy in patients with metastatic breast cancer failing or resistant to anthracycline and taxane therapy. Response rates of between 20 and 25% have been observed, with median survival of 12.2-12.6 months. In addition, there was an acceptable incidence of adverse events including diarrhoea and hand-foot syndrome, which can be controlled with a dose reduction. Promising results from two further randomised, phase II studies have indicated that capecitabine may also play a role in first- and second-line treatment of metastatic breast cancer. Capecitabine compared favourably with paclitaxel in anthracycline-resistant patients and with intravenous (i.v.) CMF (cyclophosphamide/methotrexate/5-fluorouracil (5-FU)) in post-menopausal women who had received no prior chemotherapy for metastatic disease, with high efficacy and good tolerability. The results of these four phase II studies demonstrate that capecitabine is active and well tolerated in a range of settings for metastatic breast cancer.

Answering patients' needs: oral alternatives to intravenous therapy

Metastatic colorectal cancer has traditionally been treated with i.v. 5-fluorouracil (5-FU), with or without leucovorin (LV). 5-FU is administered as either an i.v. bolus or a protracted infusion. Although schedules using the latter method offer efficacy benefits (objective response rate, time to disease progression), protracted infusion schedules are often associated with medical complications, inconvenience, high costs, and poor quality of life. Issues such as quality of life and convenience have influenced treatment decisions, but the availability of oral fluoropyrimidines represents a new development in this domain. Studies have confirmed that the majority of patients prefer oral to i.v. chemotherapy. Questionnaire-based studies have also demonstrated a preference for home-based rather than hospital-/clinic-based therapy. This preference was one of the driving forces behind the development of the oral fluoropyrimidines capecitabine (Xeloda) and uracil plus tegafur (UFT). Oral agents offer patients a more convenient treatment option that can be administered at home, providing patients with a greater sense of control over their therapy, while avoiding the medical complications and psychological distress associated with venous access. This article highlights some of the problems associated with i.v. therapy and reviews the available data on patient preference, including results of a recent, randomized, phase II study. It also provides a critical evaluation of the efficacy and safety profiles of the only two oral fluoropyrimidines approved for prescription, capecitabine and UFT/LV (UFT/LV not available in Germany and the U.S.), compared with those of two infused, 5-FU-based regimens. Finally, the results of an interactive debate exploring the opinions of approximately 400 oncologists on the issues of oral versus i.v. therapy are presented.

Clinical pharmacokinetics of 5-fluorouracil with consideration of chronopharmacokinetics

Even though 5-fluorouracil (FU) is one of the oldest anticancer drugs, its use in cancer chemotherapy continues to increase. Fluorouracil is a pro-drug that requires intracellular activation to exert its effects. This makes it difficult to associate blood drug concentration with cell toxicity directly, although data from the literature show the existence of such a relationship. The relationship between FU pharmacokinetics and patient response has been explored extensively and reports attest a link between systemic drug exposure and response and survival. This has led to the concept of maximal tolerated exposure, and strategies to achieve this rely on pharmacokinetic follow-up and individual dose adjustment. More than 80% of the administered FU dose is eliminated by catabolism through dihydropyrimidine dehydrogenase (DPD), the rate-limiting enzyme. Dihydropyrimidine dehydrogenase activity is found in most tissues but is highest in the liver. Peripheral blood mononuclear cells (PBMC) are used to monitor clinically DPD activity. A significant, but weak correlation between PBMC and liver DPD activity has been observed. The relationship between PBMC-DPD activity and FU systemic clearance is weak (r2 = 0.10); thus, simply determining PBMC-DPD is not sufficient to predict accurately FU clearance. Population pharmacokinetic analysis identified patient co-variables that influence FU clearance; drug kinetics is significantly reduced by increased age, high serum alkaline phosphatase, length of drug infusion, and low PBMC-DPD. Autoregulation of FU metabolism also is suggested; inhibition of DPD activity was observed after FU administration in both colorectal cancer patients and an animal model. Circadian rhythmicity in DPD activity is suggested from both human and animal investigations. In patients receiving protracted low dose 5-FU infusion, the circadian rhythm in FU plasma concentration peaks at 11:00h and is lowest at 23:00h, on average. The inverse relationship observed between the circadian profile of FU plasma concentration and PBMC-DP activity in these same patients suggests a link between DPD activity and FU pharmacokinetics. The impact of the biological time of drug administration was also studied with short venous infusions; clearance was 70% greater at 13:00h than at 01:00h. Similarly, peak drug concentration occurred in the first half of the night in patients receiving constant rate 5-FU infusion for 2-5d. Several studies describe wide interindividual variation in the timing of the peak and trough of the 24h rhythm in DPD activity. The rational for FU chronomodulated therapy has been the circadian rhythm in host drug tolerance, which is greatest during the night time when the proliferation of normal target tissue is least. A randomized study of chronomodulated FU therapy with maximal delivery rate at 04:00h was shown clearly to be significantly more effective and less toxic than control flat FU therapy. Future research must focus on easy-to-obtain markers of specific rhythms to individualize the chronomodulated FU delivery.

Capecitabine: a novel agent for the treatment of solid tumors

Although 5-fluorouracil (5-FU) has been used to treat breast and colorectal cancers for several decades, bolus 5-FU has disappointing efficacy. Prolonged infusion schedules and biomodulation with leucovorin have resulted in improved response rates, but these have not translated into significant improvements in survival in patients with metastatic disease. Furthermore, prolonged infusion is inconvenient for patients and can result in medical complications. New oral fluoropyrimidines, including capecitabine, are promising alternatives to i.v. 5-FU. Capecitabine generates 5-FU preferentially within tumors through exploitation of the high intratumoral activity of thymidine phosphorylase. The tumor selectivity of capecitabine has been confirmed in a clinical study of colorectal cancer patients. Clinical trials have shown that capecitabine is an effective, well-tolerated treatment for breast and colorectal cancer, with response rates of 20-26% in anthracycline- and taxane-pretreated metastatic breast cancer. As first-line monotherapy, capecitabine produces response rates of 25-27% in metastatic colorectal cancer and 30% in metastatic breast cancer. In all studies to date, capecitabine has been well tolerated, with adverse events typical of infusional 5-FU and manageable with treatment interruption/dose modification. Myelosuppression and alopecia are rare. Capecitabine is also being investigated in other solid tumors (including ovarian, pancreatic and gastric cancers) as adjuvant monotherapy in breast and colorectal cancer, and in combination with other cytotoxic agents. Results of ongoing trials are eagerly awaited.

New options for outpatient chemotherapy--the role of oral fluoropyrimidines

For several decades fluoropyrimidines, especially 5-fluorouracil (5-FU), have played a role in standard chemotherapy regimens for a range of solid tumours, including breast and colorectal cancers. In recent years, schedule modification and biomodulation have achieved improved efficacy and tolerability. However, the complications arising from infused intravenous administration are well-recognized and there is an unmet medical need for oral agents with improved efficacy and tolerability, offering more convenient outpatient therapy. Several oral fluoropyrimidines are in development, including capecitabine, UFT (uracil plus tegafur), S-1 and eniluracil. As yet, only UFT/leucovorin and capecitabine have been evaluated in randomized phase III clinical trials in metastatic colorectal cancer. Both have demonstrated safety benefits and equivalent survival compared with the Mayo Clinic regimen, and capecitabine has demonstrated a significantly superior response rate. Time to disease progression was equivalent to the Mayo Clinic regimen with capecitabine, but inferior with UFT/leucovorin. Capecitabine is also effective in patients with taxoid-pretreated metastatic breast cancer, a population which previously had no established treatment options. Both capecitabine and UFT/leucovorin are being evaluated in combination with irinotecan and oxaliplatin in colorectal cancer, and vinorelbine and docetaxel/paclitaxel in breast cancer. In the future, these more convenient, oral fluoropyrimidines may replace intravenous 5-FU in the treatment of breast and colorectal cancer.