Redefining adjuvant chemotherapy in patients with stage III colon cancer: X-ACT trial

The current standard adjuvant chemotherapy for suitable patients with stage III colon cancer is the combination of oxaliplatin and 5-fluorouracil plus folinic acid (5-FU/LV). However, until recently and for many years prior to this, the accepted standard adjuvant chemotherapy was 6-8 months of bolus 5-FU/LV. However, bolus treatment was associated with significant toxicity, namely stomatitis, diarrhea and neutropenia, in addition to multiple hospital visits for drug administration for patients. The X-ACT trial (Xeloda in Adjuvant Colon Cancer Therapy) compared traditional bolus 5-FU/LV (as per the Mayo Clinic regimen) with capecitabine, in the adjuvant treatment of 1987 stage III colon cancer patients. The main safety, efficacy and pharmacoeconomic results have all been published, and the updated 5-year efficacy results have also recently been presented. This trial demonstrated that capecitabine was at least as effective as bolus 5-FU/LV in terms of disease-free and overall survival, with trends towards superiority for both. Moreover, there was much less toxicity associated with capecitabine, apart from hand-foot syndrome which was significantly more prevalent. On the basis of the X-ACT trial, capecitabine was approved by the US FDA, the National Institute for Clinical Excellence and the Scottish Medicines Consortium as monotherapy for the adjuvant treatment of stage III colon cancer.     

Redefining adjuvant chemotherapy in patients with stage III colon cancer: X-ACT trial

The current standard adjuvant chemotherapy for suitable patients with stage III colon cancer is the combination of oxaliplatin and 5-fluorouracil plus folinic acid (5-FU/LV). However, until recently and for many years prior to this, the accepted standard adjuvant chemotherapy was 6–8 months of bolus 5-FU/LV. However, bolus treatment was associated with significant toxicity, namely stomatitis, diarrhea and neutropenia, in addition to multiple hospital visits for drug administration for patients. The X-ACT trial (Xeloda in Adjuvant Colon Cancer Therapy) compared traditional bolus 5-FU/LV (as per the Mayo Clinic regimen) with capecitabine, in the adjuvant treatment of 1987 stage III colon cancer patients. The main safety, efficacy and pharmacoeconomic results have all been published, and the updated 5-year efficacy results have also recently been presented. This trial demonstrated that capecitabine was at least as effective as bolus 5-FU/LV in terms of disease-free and overall survival, with trends towards superiority for both. Moreover, there was much less toxicity associated with capecitabine, apart from hand–foot syndrome which was significantly more prevalent. On the basis of the X-ACT trial, capecitabine was approved by the US FDA, the National Institute for Clinical Excellence and the Scottish Medicines Consortium as monotherapy for the adjuvant treatment of stage III colon cancer.     

Oral capecitabine: bridging the Atlantic divide in colon cancer treatment

5-Fluorouracil (5-FU) plus leucovorin (LV) has been the mainstay of treatment for colorectal cancer (CRC), with infused schedules more widely adopted in Europe and bolus schedules preferred in North America. However, the effective, oral fluoropyrimidine capecitabine is increasingly replacing intravenous (IV) 5-FU/LV on both sides of the Atlantic. Capecitabine generates 5-FU preferentially in tumor and is a well-established, first-line treatment for metastatic CRC. In this setting, capecitabine achieves a superior response rate, at least equivalent time to disease progression (TTP) and overall survival, and favorable safety compared with bolus 5-FU/LV. The benefits of capecitabine have been transfered into the adjuvant setting. Recent data from a large, international, randomized trial (Xeloda Adjuvant Chemotherapy Trial [X-ACT]) confirm that capecitabine (Xeloda, Roche Laboratories, Nutley, NJ) achieves favorable safety versus 5-FU/LV (Mayo Clinic regimen) and is at least as effective as IV 5-FU/LV in the adjuvant treatment of patients with resected stage III colon cancer. Capecitabine is also an effective and well-tolerated combination partner for oxaliplatin (XELOX) and irinotecan (XELIRI), achieving high efficacy with a good safety profile. An extensive phase III clinical trial program is further establishing the potential of the simplified capecitabine combinations to improve outcomes and unify treatment practices in the metastatic and adjuvant settings. New combinations with novel agents such as capecitabine/oxaliplatin plus erlotinib or bevacizumab are currently under investigation. Capecitabine has also shown promising activity and good tolerability in combination with radiotherapy in rectal cancer.     

Capecitabine

Capecitabine, an oral fluoropyrimidine carbamate, is adopted worldwide. As the treatment for metastatic colorectal cancer, capecitabine showed at least comparable efficacy with a favorable safety profile to bolus 5-FU/LV. In a large phase III trial (Xeloda Adjuvant Chemotherapy Trial: X-ACT), as the adjuvant treatment of patients with resected stage III colon cancer, capecitabine showed at least comparable disease-free survival, overall survival, and relapse-free survival with a favorable safety profile to bolus 5-FU/LV. Additionally, capecitabine-based combination regimens with oxaliplatin or irinotecan are now under evaluation. In phase II studies, capecitabine has shown the promising results in combination therapy. In Japan, capecitabine has been evaluated since 1994. In a recent phase II study, which evaluated the global dose as first-line treatment for metastatic colorectal cancer, the response rate was 35% (95% CI 23.1-48.4). The median time to disease progression was 169 days and the median overall survival was 617 days. Hand-foot syndrome (HFS), a characteristic adverse event of capecitabine, was observed in 73.3% of the patients, but the grade 3/4 was observed in 13.3% of the patients and only one patient discontinued the treatment due to HFS. An immediate approval of capecitabine in Japan is expected.     

Oral capecitabine as an alternative to i.v. 5-fluorouracil-based adjuvant therapy for colon cancer: safety results of a randomized, phase III trial.

BACKGROUND: Oral capecitabine achieves a superior response rate with an improved safety profile compared with bolus 5-fluorouracil-leucovorin (5-FU/LV) as first-line treatment for patients with metastatic colorectal cancer. We report here the results of a large phase III trial investigating adjuvant oral capecitabine compared with 5-FU/LV (Mayo Clinic regimen) in Dukes' C colon cancer. PATIENTS AND METHODS: Patients aged 18-75 years with resected Dukes' C colon carcinoma were randomized to receive 24 weeks of treatment with either oral capecitabine 1250 mg/m(2) twice daily, days 1-14 every 21 days (n = 993), or i.v. bolus 5-FU 425 mg/m(2) with i.v. leucovorin 20 mg/m(2) on days 1-5, repeated every 28 days (n = 974). RESULTS: Patients receiving capecitabine experienced significantly (P <0.001) less diarrhea, stomatitis, nausea/vomiting, alopecia and neutropenia, but more hand-foot syndrome than those receiving 5-FU/LV. Fewer patients receiving capecitabine experienced grade 3 or 4 neutropenia, febrile neutropenia/sepsis and stomatitis (P <0.001), although more experienced grade 3 hand-foot syndrome than those treated with 5-FU/LV (P <0.001). Capecitabine demonstrates a similar, favorable safety profile in patients aged <65 years or > or = 65 years old. CONCLUSIONS: Based on its improved safety profile, capecitabine has the potential to replace 5-FU/LV as standard adjuvant treatment for patients with colon cancer. Efficacy results are expected to be available in Keywords: Adjuvant treatment, capecitabine, chemotherapy, colorectal cancer     

Pharmacoeconomic analysis of adjuvant oral capecitabine vs intravenous 5-FU/LV in Dukes' C colon cancer: the X-ACT trial

Oral capecitabine (Xeloda) is an effective drug with favourable safety in adjuvant and metastatic colorectal cancer. Oxaliplatin-based therapy is becoming standard for Dukes' C colon cancer in patients suitable for combination therapy, but is not yet approved by the UK National Institute for Health and Clinical Excellence (NICE) in the adjuvant setting. Adjuvant capecitabine is at least as effective as 5-fluorouracil/leucovorin (5-FU/LV), with significant superiority in relapse-free survival and a trend towards improved disease-free and overall survival. We assessed the cost-effectiveness of adjuvant capecitabine from payer (UK National Health Service (NHS)) and societal perspectives. We used clinical trial data and published sources to estimate incremental direct and societal costs and gains in quality-adjusted life months (QALMs). Acquisition costs were higher for capecitabine than 5-FU/LV, but higher 5-FU/LV administration costs resulted in 57% lower chemotherapy costs for capecitabine. Capecitabine vs 5-FU/LV-associated adverse events required fewer medications and hospitalisations (cost savings pound3653). Societal costs, including patient travel/time costs, were reduced by >75% with capecitabine vs 5-FU/LV (cost savings pound1318), with lifetime gain in QALMs of 9 months. Medical resource utilisation is significantly decreased with capecitabine vs 5-FU/LV, with cost savings to the NHS and society. Capecitabine is also projected to increase life expectancy vs 5-FU/LV. Cost savings and better outcomes make capecitabine a preferred adjuvant therapy for Dukes' C colon cancer. This pharmacoeconomic analysis strongly supports replacing 5-FU/LV with capecitabine in the adjuvant treatment of colon cancer in the UK.     

Comparison of oral capecitabine versus intravenous fluorouracil plus leucovorin as first-line treatment in 605 patients with metastatic colorectal cancer: results of a randomized phase III study.

PURPOSE: To compare the response rate, efficacy parameters, and toxicity profile of oral capecitabine with bolus intravenous (IV) fluorouracil plus leucovorin (5-FU/LV) as first-line treatment in patients with metastatic colorectal cancer. PATIENTS AND METHODS: We prospectively randomized 605 patients to treatment with oral capecitabine for 14 days every 3 weeks or 5-FU/LV by rapid IV injection daily for 5 days in 4-week cycles. RESULTS: The overall objective tumor response rate among all randomized patients was significantly higher in the capecitabine group (24.8%) than in the 5-FU/LV group (15.5%; P =.005). In the capecitabine and 5-FU/LV groups, median times to disease progression were 4.3 and 4.7 months (log-rank P =.72), median times to treatment failure were 4.1 and 3.1 months (P =.19), and median overall survival times were 12.5 and 13.3 months (P =.974), respectively. Capecitabine, compared with bolus 5-FU/LV treatment, produced a significantly lower incidence (P <.0002) of diarrhea, stomatitis, nausea, and alopecia. Patients treated with capecitabine also displayed lower incidences of grade 3/4 stomatitis and grade 3/4 neutropenia (P <.0001) leading to significantly less neutropenic fever/sepsis. Grade 3 hand-foot syndrome (P <.00001) and grade 3/4 hyperbilirubinemia were the only toxicities more frequently associated with capecitabine than with 5-FU/LV treatment. CONCLUSION: Oral capecitabine was more active than 5-FU/LV in the induction of objective tumor responses. Time to disease progression and survival were at least equivalent for capecitabine compared with the 5-FU/LV arm. Capecitabine also demonstrated clinically meaningful benefits over bolus 5-FU/LV in terms of tolerability.     

Cost-effectiveness analysis of oxaliplatin compared with 5-fluorouracil/leucovorin in adjuvant treatment of stage III colon cancer in the US

BACKGROUND: The MOSAIC trial demonstrated that oxaliplatin/5-fluorouracil/leucovorin (FU/LV) (FOLFOX4) as adjuvant treatment of TNM stage II and III colon cancer significantly improves disease-free survival compared with 5-FU/LV alone. For stage III patients the 4-year disease-free survival (DFS) was 69% in the FOLFOX4 arm vs 61% in the LV5FU2 arm, P = .002). The cost-effectiveness of FOLFOX4 in stage III patients was evaluated from a US Medicare perspective. METHODS: By using individual patient-level data from the MOSAIC trial (median follow-up: 44.2 months), DFS and overall survival (OS) were estimated up to 4 years from randomization. DFS was extrapolated from 4 to 5 years by fitting a Weibull model and subsequent survival was estimated from life tables. OS beyond 4 years was predicted from the extrapolated DFS estimates and observed survival after recurrence. Costs were calculated from trial data and external estimates of resources to manage recurrence. RESULTS: Patients on FOLFOX4 were predicted to gain 2.00 (95% confidence interval [CI]: 0.63, 3.37) years of DFS over those on 5-FU/LV. The predicted life expectancy of stage III patients on FOLFOX4 and 5-FU/LV was 17.61 and 16.26 years, respectively. Mean total lifetime disease-related costs were $56,300 with oxaliplatin and $39,300 with 5-FU/LV. Compared with 5-FU/LV, FOLFOX4 was estimated to cost $20,600 per life-year gained and $22,800 per quality-adjusted life-year (QALY) gained, discounting costs and outcomes at 3% per annum. CONCLUSIONS: FOLFOX4 is likely to be cost-effective compared with 5-FU/LV in the adjuvant treatment of stage III colon cancer. The incremental cost-effectiveness ratio compares favorably with other funded interventions in oncology.     

Future treatment options with capecitabine in solid tumours

The oral fluoropyrimidine, capecitabine is attracting great interest in the context of tumour-selective therapy and rationally designed combination regimens. Agents such as taxanes upregulate thymidine phosphorylase (TP), and there is therefore a clear rationale for their combination with capecitabine. Preclinical studies of capecitabine/taxane combination therapy demonstrated synergistic antitumour activity and phase I studies showed encouraging efficacy. Therefore, a randomised, phase III trial (docetaxel versus docetaxel/capecitabine) has been initiated in anthracycline-refractory metastatic breast cancer patients. Recruitment is complete. In colorectal cancer, capecitabine/oxaliplatin combination therapy is promising and a phase I, dose-finding trial has been conducted in patients with refractory metastatic solid tumours. A similar trial has evaluated capecitabine/irinotecan combination treatment. Capecitabine is also being investigated as adjuvant therapy for colorectal and breast cancers. The primary objective of the ongoing X-ACT trial in almost 2000 Dukes' C colon cancer patients is to demonstrate at least equivalent disease-free survival between capecitabine and the Mayo Clinic regimen. In addition, the CALGB is planning a randomised, phase III trial of capecitabine versus doxorubicin/cyclophosphamide or cyclophosphamide/methotrexate/5-fluorouracil (CMF) as adjuvant treatment in high-risk, node-negative breast cancer patients aged >65 years.     

Capecitabine versus 5-fluorouracil/folinic acid as adjuvant therapy for stage III colon cancer: final results from the X-ACT trial with analysis by age and preliminary evidence of a pharmacodynamic marker of efficacy

BackgroundThis multicenter randomized trial compared oral capecitabine with bolus i.v. 5-fluorouracil (5-FU)/folinic acid (FA) as adjuvant therapy for stage III colon cancer.Patients and methodsPatients were assigned to 24 weeks of capecitabine 1250 mg/m² twice daily on days 1–14 every 3 weeks or 5-FU/FA (Mayo Clinic regimen). The primary end point was disease-free survival (DFS).ResultsThe intent-to-treat population received capecitabine (n = 1004) or 5-FU/FA (n = 983). With a median follow-up of 6.9 years, capecitabine was at least equivalent to 5-FU/FA in terms of DFS [hazard ratio (HR) = 0.88; 95% confidence interval (CI) 0.77–1.01] and overall survival (OS) (HR = 0.86; 95% CI 0.74–1.01); the 95% CI upper limits were significantly less than the predefined noninferiority margins of 1.20 (P < 0.0001) and 1.14 (P < 0.001), respectively. This pattern was maintained in all subgroups, including patients aged ≥70 years. Preplanned multivariate analyses showed that capecitabine had statistically significant beneficial effects on DFS (P = 0.021) and OS (P = 0.020) versus 5-FU/FA. A post hoc analysis suggested that the occurrence of hand–foot syndrome may be associated with better outcomes in capecitabine recipients.ConclusionOral capecitabine is an effective alternative to bolus 5-FU/FA as adjuvant treatment of patients with stage III colon cancer with efficacy benefits maintained at 5 years and in older patients.     

Ongoing Colorectal Cancer Adjuvant Trials in Japan

In Japan, oral fluoropyrimidines have been used widely as adjuvant therapy for colorectal cancers. The 2009 Japanese guideline recommends uracil-tegafur (UFT) and capecitabine, in addition to 5-fluorouracil (5-FU)/leucovorin (LV), as adjuvant therapy for colorectal cancer. At present, seven studies are being conducted in Japan; all are evaluating the efficacy of oral fluoropyrimidines. The SACURA and Japanese Foundation for Multidisciplinary Treatment of Cancer (JFMC)38-0901 trials are investigating the efficacy of UFT and UFT plus polysaccharide K compared with surgery alone for stage II colorectal cancer. The Japan Clinical Oncology Group (JCOG)-0205 trial is evaluating the equivalence of UFT/LV and infusional 5-FU/LV for the treatment of stage III colorectal cancer. The ACTS-CC trial is evaluating the noninferiority of S-1 compared with UFT/LV, whereas the JFMC35-C1 (ACTS-RC) trial is designed to evaluate the superiority of oral S-1 compared with UFT/LV in stage II and III rectal cancer patients. The JFMC37-0801 and JFMC33-0502 trials are evaluating the optimal duration of adjuvant chemotherapy with either capecitabine or UFT/LV.     

An overview of adjuvant systemic chemotherapy for colon cancer

This article summarizes the progress of adjuvant systemic chemotherapy of colon cancer. The study by Moertel et al that showed that the combination of 5-fluorouracil (5-FU) and levamisole in the adjuvant setting reduced mortality by 33% in stage III colon cancer; 5-FU/leucovorin (LV) became the standard of care in the adjuvant treatment of colon cancer after it showed superiority to 5-FU/levamisole. However, no standard schedule of 5-FU/LV has been established. The fortnightly regimen of bolus 5-FU/LV and continuous infusion 5-FU (LV5FU2) has the same efficacy as and is less toxic than the monthly regimen of bolus 5-FU/LV. Oxaliplatin combined with 5-FU and LV (FOLFOX4) is the first combination to demonstrate significant superiority in 3-year disease-free survival as compared with 5-FU/LV in the adjuvant treatment of colon cancer. Three-year disease-free survival is an excellent predictor of 5-year overall survival and, in future studies, can serve as a reliable endpoint that is associated with reproducible 5-year overall survival. Results of studies testing irinotecan combined with 5-FU and LV are not yet available. Adjuvant chemotherapy for patients with stage II colon cancer is a controversial subject. Because the available data suggest that stage II patients benefit from adjuvant chemotherapy, although to a lesser extent than patients with stage III disease, all patients with stage III and high-risk stage II disease should be offered adjuvant treatment with the new standard of care, FOLFOX4. Future studies in adjuvant therapy for colon cancer will explore oxaliplatin and 5-FU with or without antiangiogenesis or anti-epidermal growth factor agents.     

Adjuvant therapy for colon cancer 2005: new options in the twenty-first century

The most effective current regimen for adjuvant treatment of surgically resected stage III colon cancer is the FOLFOX regimen of oxaliplatin, 5-FU and LV for 12 weeks, with a proportional risk reduction of 45% compared with approximately 36% for 5-FU/LV regimens. Infusion regimens of 5-FU with and without LV have been shown to confer equivalent benefit to bolus regimens in reducing the risk of cancer recurrence, but with lesser toxicity profiles. Oral 5-FU prodrug regimens have similarly shown equivalent benefit to bolus regimens, and toxicity comparable to infusional regimens, but with the added convenience over 5-FU infusion therapy. The addition of irinotecan to 5-FU and LV regimens has not demonstrated an advantage compared with 5-FU/LV treatments in the adjuvant setting.     

Cost-effectiveness of oxaliplatin and capecitabine in the adjuvant treatment of stage III colon cancer

For many years, the standard treatment for stage III colon cancer has been surgical resection followed by 5-fluorouracil in combination with folinic acid (5-FU/LV). Ongoing clinical trial evidence suggests that capecitabine and oxaliplatin (in combination with 5-FU/LV) may improve disease-free survival and overall survival when compared against 5-FU/LV alone in the adjuvant setting. This study evaluates the cost-effectiveness profiles of these two regimens in comparison to standard chemotherapy, using evidence from two international randomised controlled trials. Survival modelling techniques were employed to extrapolate survival curves from the two trials in order to estimate the long-term benefits of alternative treatment options over the remaining lifetime of patients. The health economic analysis suggests that capecitabine is expected to produce greater health gains at a lower cost than 5-FU/LV. Oxaliplatin in combination with 5-FU/LV is estimated to cost pounds 2970 per additional QALY gained when compared to 5-FU/LV alone. Future research should attempt to elucidate uncertainties concerning the optimal roles of capecitabine and/or oxaliplatin in the adjuvant setting in order to achieve the maximum level of clinical benefit.     

Capecitabine (Xeloda) improves medical resource use compared with 5-fluorouracil plus leucovorin in a phase III trial conducted in patients with advanced colorectal carcinoma

Standard therapy for advanced or metastatic colorectal cancer consists of 5-fluorouracil plus leucovorin (5-FU/LV) administered intravenously (i.v.). Capecitabine (Xeloda), an oral fluoropyrimidine carbamate which is preferentially activated by thymidine phosphorylase in tumour cells, mimics continuous 5-FU and is a recently developed alternative to i.v. 5-FU/LV. The choice of oral rather than intravenous treatment may affect medical resource use because the two regimens do not require the same intensity of medical intervention for drug administration, and have different toxicity profiles. Here we examine medical resource use in the first-line treatment of colorectal cancer patients with capecitabine compared with those receiving the Mayo Clinic regimen of 5-FU/LV. In a prospective, randomised phase III clinical trial, 602 patients with advanced or metastatic colorectal cancer recruited from 59 centres worldwide were randomised to treatment with either capecitabine or the Mayo regimen of 5-FU/LV. In addition to clinical efficacy and safety endpoints, data were collected on hospital visits required for drug administration, hospital admissions, and drugs and unscheduled consultations with physicians required for the treatment of adverse events. Capecitabine treatment in comparison to 5-FU/LV in advanced colorectal carcinoma resulted in superior response rates (26.6% versus 17.9%, P=0.013) and improved safety including less stomatitis and myelosuppression. Capecitabine patients required substantially fewer hospital visits for drug administration than 5-FU/LV patients. Medical resource use analysis showed that patients treated with capecitabine spent fewer days in hospital for the management of treatment related adverse events than did patients treated with 5-FU/LV. In addition, capecitabine reduced the requirement for expensive drugs, in particular antimicrobials fluconazole and 5-HT3-antagonists to manage adverse events. As anticipated with an oral home-based therapy patients receiving capecitabine needed more frequent unscheduled home, day care, office and telephone consultations with physicians. In the light of clinical results from the phase III trial demonstrating increased efficacy in terms of response rate, equivalent time to progression (TTP) and survival (OS), and a superior safety profile, the results from this medical resource assessment indicate that capecitabine treatment of colorectal cancer patients results in a substantial resource use saving relative to the Mayo Clinic regimen of 5-FU/LV. This benefit is derived principally from the avoidance of hospital visits for i.v. drug administration, less expensive drug therapy for the treatment of toxic side-effects, and fewer treatment-related hospitalisations required during the course of therapy for adverse drug reactions in comparison to patients treated with 5-FU/LV.     

Novel chemotherapy agents for colorectal cancer: Oral fluoropyrimidines, oxaliplatin, and raltitrexed

Agents now under investigation for treatment of advanced colorectal cancer (CRC) include the oral fluoropyrimidines, oxaliplatin, and raltitrexed. Research efforts directed at finding agents that conveniently and effectively deliver 5-fluorouracil (5-FU) in a protracted fashion have led to the development of several oral fluoropyrimidines. These agents, which include capecitabine; tegafur and uracil plus leucovorin (UFT/LV); eniluracil plus oral 5-FU; and S-1, are convenient and less toxic than intravenous bolus 5-FU. Oxaliplatin has a uniquely different mechanism of action compared with that of 5-FU and has demonstrated activity not only in the first-line treatment setting but also in patients whose disease has progressed during or following 5-FU treatment. In the first-line setting, when oxaliplatin is combined with 5-FU plus LV, response rates and time to disease progression are remarkably improved compared with 5-FU/LV alone. Raltitrexed, a unique thymidylate synthase inhibitor, has undergone extensive phase III evaluation in CRC. The advent of these novel agents has led to development of combined chemotherapy regimens now being introduced into the adjuvant setting.     

Fluoropyrimidine therapy: hyperbilirubinemia as a consequence of hemolysis

Background: Hemolytic anemia has been noted during treatment with a variety of chemotherapeutic agents. We observed mild compensated hemolytic anemia in a patient receiving capecitabine during a randomized, controlled trial of adjuvant therapy. In order to investigate the hypothesis that hemolysis is the underlying cause of the hyperbilirubinemia sometimes observed during capecitabine treatment, we evaluated factors associated with hemolysis in ten patients. Factors were also analyzed in ten patients receiving 5-fluorourocil/leucovorin (5-FU/LV). Methods: Twenty chemotherapy-naïve patients undergoing surgery for Dukes C colon cancer were included in the phase III, X-ACT trial, and randomized to receive 24-week adjuvant treatment with either oral capecitabine (eight cycles of 1,250 mg/m² twice daily for 14 days, followed by a 7-day rest period) (n=10) or 5-FU/LV administered according to the Mayo Clinic regimen (six cycles of LV 20 mg/m² followed by 5-FU 425 mg/m², administered as an i.v. bolus on days 1–5 every 28 days) (n=10). Ten patients randomized in each treatment arm were evaluated. Hemolytic parameters evaluated included bilirubin, lactate dehydrogenase, haptoglobin, and reticulocytes. Results: Seven patients receiving capecitabine and three patients receiving 5-FU/LV experienced grade 1/2 elevations of bilirubin during the 24-week treatment period. In most cases, hyperbilirubinemia was associated with concomitant alterations in other hemolytic parameters. Five episodes of grade 1 compensated hemolytic anemia were reported in four capecitabine-treated patients, all of which were associated with hyperbilirubinemia. Conclusion: Adjuvant treatment with capecitabine or 5-FU/LV in a small sample of patients with Dukes C colon cancer was associated with alterations in hemolytic parameters. These alterations, in particular hyperbilirubinemia, were associated in some patients with low-grade compensated hemolytic anemia. All changes were clinically insignificant, fully reversible, and may represent a fluoropyrimidine class effect. Further studies are indicated to evaluate the incidence and implications of this effect.     

Oral capecitabine vs intravenous 5-fluorouracil and leucovorin: integrated efficacy data and novel analyses from two large, randomised, phase III trials

This study evaluates the efficacy of capecitabine using data from a large, well-characterised population of patients with metastatic colorectal cancer (mCRC) treated in two identically designed phase III studies. A total of 1207 patients with previously untreated mCRC were randomised to either oral capecitabine (1250 mg m(-2) twice daily, days 1-14 every 21 days; n=603) or intravenous (i.v.) bolus 5-fluorouracil/leucovorin (5-FU/LV; Mayo Clinic regimen; n=604). Capecitabine demonstrated a statistically significant superior response rate compared with 5-FU/LV (26 vs 17%; P<0.0002). Subgroup analysis demonstrated that capecitabine consistently resulted in superior response rates (P<0.05), even in patient subgroups with poor prognostic indicators. The median time to response and duration of response were similar and time to progression (TTP) was equivalent in the two arms (hazard ratio (HR) 0.997, 95% confidence interval (CI) 0.885-1.123, P=0.95; median 4.6 vs 4.7 months with capecitabine and 5-FU/LV, respectively). Multivariate Cox regression analysis identified younger age, liver metastases, multiple metastases and poor Karnofsky Performance Status as independent prognostic indicators for poor TTP. Overall survival was equivalent in the two arms (HR 0.95, 95% CI 0.84-1.06, P=0.48; median 12.9 vs 12.8 months, respectively). Capecitabine results in superior response rate, equivalent TTP and overall survival, an improved safety profile and improved convenience compared with i.v. 5-FU/LV as first-line treatment for MCRC. For patients in whom fluoropyrimidine monotherapy is indicated, capecitabine should be strongly considered. Following encouraging results from phase I and II trials, randomised trials are evaluating capecitabine in combination with irinotecan, oxaliplatin and radiotherapy. Capecitabine is a suitable replacement for i.v. 5-FU as the backbone of colorectal cancer therapy.     

A prospective randomised phase III trial of adjuvant chemotherapy with 5-fluorouracil and leucovorin in patients with stage II colon cancer

The purpose of this trial was to investigate the efficacy of adjuvant chemotherapy with 5-fluorouracil (5-FU) and leucovorin (LV) in stage II colon cancer. Patients with stage II colon cancer were randomised to either adjuvant chemotherapy with 5-FU/LV (100 mg m(-2) LV+450 mg m(-2) 5-FU weekly, weeks 1-6, in 8 weeks cycles x 7) or surveillance only. Five hundred patients were evaluable for analyses. After a median follow-up of 95.6 months, 55 of 252 patients (21.8%) have died in the 5-FU/LV arm and 58 of 248 patients (23.4%) in the surveillance arm. There was no statistically significant difference in overall survival (OS) between the two treatment arms (hazard ratios, HR 0.88, 95% CI 0.61-1.27, P=0.49). The relative risk for tumour relapse was higher for patients on the surveillance arm than for those on the 5-FU/LV arm; however, this difference was not statistically significant (HR 0.69, 95% CI 0.45-1.06, P=0.09). Consequently, disease-free survival (DFS) was not significantly different between the two trial arms. In conclusion, results of this trial demonstrate a trend to a lower risk for relapse in patients treated with adjuvant 5-FU/LV for stage II colon cancer. However, in this study with limited power to detect small differences between the study arms, adjuvant chemotherapy failed to significantly improve DFS and OS.     

FOLFOX and FLOX regimens for the adjuvant treatment of resected stage II and III colon cancer

The MOSAIC trial showed that the use of adjuvant oxaliplatin and an infusional regimen of 5-FU/LV in the treatment of stage II/III colon cancer improved disease-free survival (DFS). The NSABP's C-07 trial evaluated the addition of oxaliplatin to a weekly Roswell Park regimen of bolus 5-FU/LV and found a similar improvement in DFS. The benefit of oxaliplatin appears to be independent of the 5-FU/LV regimen used. This paper reviews the efficacy and toxicities of these two regimens and is meant to serve as a guide for clinical practice.