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

Medical Management of Colorectal Carcinomas

Current information on the medical treatment of colorectal cancer was reviewed after a search of the literature through Medline. Publications from 1984 to present were surveyed. Appropriate adjuvant therapy increases overall survival and disease-free intervals. The treatment modalities of unresectable or metastatic tumors are disappointing, with at best 40% of patients experiencing short-lasting responses. Whenever possible, patients with advanced colorectal cancer should be enrolled in clinical trials.

Increasing Doses of 5-Fluorouracil and High-Dose Folinic ACID in the Treatment of Metastatic Colorectal Cancer

AIMS AND BACKGROUND

Combined 5-fluorouracil (5FU) and folinic acid (FA) is the first-line treatment of metastatic colorectal cancer. The aims of this study were to individualize the dose of 5FU in a weekly schedule in which the maximum tolerated dose of 5FU is administered to each patient, and to evaluate the impact of increasing 5FU doses on response and survival.

METHODS

Thirty-two patients (30 evaluable for response) with metastatic colorectal cancer were treated with weekly intravenous doses of FA 150 mg/m2 and a fast infusion of 5FU, at an initial dose of 600 mg/m2 which was increased by 60 mg/m2 every week until the appearance of a side effect, in order to determine the maximum tolerated dose for the patient.

RESULTS

We obtained 11 objective responses (36.7%, median survival 22 months) and 15 disease stabilizations (50%, median survival 15 months); there were four cases of progressive disease (13.3%, median survival 4 months). The overall survival was 15 months. Twenty-eight patients (87.5%) tolerated 5FU doses of 720 mg/m2 or more.

CONCLUSIONS

Weekly 5FU with high-dose FA modulation can be individualized by dose escalation. A 5FU dose of 720 mg/m2 per week seems to be critical, as higher doses are no more effective and lead to severe side effects. This schedule gives good results in terms of response, even though the complete response rate remains low.

Leucovorin Enhances the Anti-cancer Effect of Bortezomib in Colorectal Cancer Cells

Colorectal cancer is a major cancer type worldwide. 5-fluorouracil, often given with leucovorin, is the most commonly used drug in colorectal cancer chemotherapy, yet development of drug resistance to 5-fluorouracil in colorectal cancer cells is the primary cause of chemotherapy failure. Most patients receiving intravenous 5-fluorouracil develop side effects. Leucovorin, due to its vitamin-like profile, has few side-effects. Drug repurposing is the application of approved drugs to treat new indications. In this study, we performed a novel drug-repurposing screening to identify Food and Drug Administration-approved chemotherapeutic compounds possessing synergistic activity with leucovorin against colorectal cancer cells. We found that the combination of bortezomib and leucovorin enhanced caspase activation and increased apoptosis in colorectal cancer cells better than either agent alone. Further, the synergistic induction of apoptosis and inhibition of tumor growth were also observed in mouse colorectal cancer xenografts. These data support leucovorin enhances the anti-cancer effect of bortezomib and present this novel combinatorial treatment against colorectal cancer.

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.

Population pharmacokinetics of 5-fluorouracil in colorectal cancer patients

Aims. The pharmacokinetics of 5-fluorouracil (5-FU) after intravenous administration in color- ectal cancer patients were examined using population analysis. The relevant covariates and the extent of inter- and intraindividual variability were evaluated.

Methods. Data from 27 patients with diagnosis of nonmetastatic colorectal adenocarcinoma receiving weekly 5-FU (450 mg/m2), plus levamisol 50 mg/8 hours by oral route for 3 days every 15 days, were pooled with data from 17 patients with diagnosis of metastatic colorectal adenocarcinoma, receiving daily 5-FU (425 mg/m2) and intravenous folinic acid (20 mg/m2) over five consecutive days (daily times five), every four weeks. In both groups 5-FU was administered as a 60-minute infusion and blood samples were collected at 10, 30 and 60 minutes from the end of the infusion, and analysed using a validated high-performance liquid chromatography assay. An open two-compartmental pharmacokinetic model with first-order elimination from central compartment was fitted to the plasma concentration data using nonlinear mixed effect modelling (NONMEM). The potential effect of patient covariates was evaluated using a stepwise method. Model evaluation was performed using bootstrap method.

Results. The pharmacokinetic model was successfully fitted to the data. None of the covariates tested were significantly correlated to the pharmacokinetic parameters. The mean parameters’ estimates (%CV) and the percent coefficient of variation of the central tendency parameters, interindividual (IIV), interoccasion (IOV) and residual variability (s) for the final model were: CL (L/h), 65.3 (13.2); Vc (L), 14.7 (11.8); Vp (L), 334.0 (31.4); Q (L/h), 19.6 (25.5); IIVCL (%), 76.5 (34.6); IIVVc (%), 82.3 (31.0); IIVVp (%), 137.5 (35.1); IIVQ (%), 117.5 (38.5); IOVCL (%), 66.1 (45.3); IOVVc (%), 70.8 (39.5); IOVQ (%), 81.1 (27.8) and s (%), 3.0 (25.4). The bootstrap resampling method confirmed the stability of the final model. The estimates of the central tendency parameters, IIV, IOV and residual variability were essentially equal to those generated with the original dataset (0% to 18% deviation) and the 95% confidence intervals included the mean parameters’ estimates obtained from the former set.

Conclusions. The two-compartmental model accurately described the pharmacokinetics of 5-FU administered by short-term infusion. A population pharmacokinetic approach is a useful tool to integrate the knowledge gathered in the clinical setting. The model developed may help in dose adaptation and will further be used in PK/PD modelling of therapeutic outcomes and adverse events.

Raltitrexed and the treatment of advanced colorectal cancer

Objective. Colorectal cancer is the second largest cause of death from malignant disease in Western countries. Although surgical resection is the preferred treatment in early disease, chemotherapy has an important role to play both as an adjunct to surgery and in the palliation of advanced disease. For many years 5-fluorouracil (5-FU) has been the only cyto toxic drug with significant activity in this condition and, recently, considerable effort has been directed toward enhancing its activity and finding better, alternative agents. Recently, raltitrexed (Tomudex; Zeneca Pharmaceuticals), the first of a new class of cytotoxic drugs, the selective, direct, thymidylate synthase inhibitors, received its first regulatory ap proval for the first-line treatment of advanced colo rectal cancer. The purpose of this review is to con sider the efficacy, toxicity, and resource implications of using this new antineoplastic agent, alongside developments that have been made in the more effective use of fluoropyrimidines, and the place of drug treatment in the management of colorectal cancer.

Data Sources. A variety of sources were used, including manual and on-line (Medline and Pharm- line) literature searching. Approved and other drug names were used as primary search terms, linked with colorectal cancer where limitation was required. The medical information department of Zeneca Pharma ceuticals also was used where appropriate.

Study Selection. Particular attention was di rected to randomized clinical trials, but nonrandom ized and preclinical studies were considered where appropriate.

Conclusions. Although colorectal cancer is in herently resistant to cytotoxic chemotherapy, such treatment now has an established role as an adjunct to surgery and in the palliation of advanced disease. The optimum 5-FU- based regimen has yet to be estab lished with certainty, although in advanced disease a four-times-weekly, 5-day regimen of 5-FU and low- dose folinic acid is probably the best of those fully evaluated to date. Raltitrexed seems to be as effective as this combination while having definite advantages in terms of toxicity and the resources required for its preparation and administration, although it remains to be seen to what extent these and other resource benefits will be offset by its higher cost and how its efficacy and tolerability will compare with other 5-FU- based regimens in ongoing clinical trials.

Conditioned media from human macrophages of M1 phenotype attenuate the cytotoxic effect of 5‑fluorouracil on the HT‑29 colon cancer cell line

Resistance of tumor cells to chemotherapy, such as 5-fluorouracil (5-FU), is an obstacle for successful treatment of cancer. As a follow-up of a previous study we have investigated the effect of conditioned media (CM) from macrophages of M1 or M2 phenotypes on 5-FU cytotoxicity on the colon cancer cell lines HT-29 and CACO-2. HT-29 cells, but not CACO-2 cells, having been treated with a combination of M1 CM and 5-FU recovered their cell growth to a much larger extent compared to cells having been treated with 5-FU alone when further cultured for 7 days in fresh media. M1 CM treatment of HT-29, but not CACO-2 cells, induced cell cycle arrest in the G₀/G₁ and G₂/M phases. 5-FU treatment induced accumulation of cells in S-phase in both HT-29 and CACO-2 cells. This accumulation of cells in S-phase was attenuated by combined M1 CM and 5-FU treatment in HT-29 cells, but not in CACO-2 cells. The mRNA expression of cell cycle regulatory proteins and 5-FU metabolic enzymes were analyzed in an attempt to find possible mechanisms for the M1 CM induced attenuation of 5-FU cytotoxicity in HT-29. Thymidylate synthetase (TS) and thymidine phosphorylase (TP) were found to be substantially downregulated and upregulated, respectively, in HT-29 cells treated with M1 CM, making them unlikely as mediators of reduced 5-FU cytotoxicity. Among cell cycle regulating proteins, p21 was induced in HT-29 cells, but not in CACO-2 cells, in response to M1 CM treatment. However, small interfering RNA (siRNA) knockdown of p21 had no effect on the M1 CM induced cell cycle arrest seen in HT-29 and neither did it change the growth recovery after combined treatment of HT-29 cells with M1 CM and 5-FU. In conclusion, treatment of HT-29 cells with M1 CM reduces the cytotoxic effect of 5-FU and this is mediated by a M1 CM induced cell cycle arrest in the G₀/G₁ and G₂/M phases. So far, we lack an explanation why this action is absent in the CACO-2 cells. The current findings may be important for optimization of chemotherapy in colon cancer.

5-Fluorouracil pharmacogenomics: still rocking after all these years?

The 5-fluorouracil (5-FU) metabolic pathway is mainly dependent on the activity of several intracellular enzymes. Among them, four in particular; thymidylate synthase, methylenetetrahydrofolate reductase, dihydropyrimidine dehydrogenase and thymidine phosphorylase are considered the key points in determining sensitivity or resistance to this drug. These enzymes are needed to metabolize the drug in its active form (thymidylate phosphorylase) or to drop the concentration of the active drug in the cell (dihydropyrimidine dehydrogenase) or both (thymidylate synthase and methylenetetrahydrofolate reductase). Several different studies have tried to investigate the relationship between the presence of mutations in these enzymes and a reduced/improved activity of treatment based on 5-FU or its derivatives. In this article, we will focus on the often contradictory results of these studies.

MTHFR gene polymorphisms and response to chemotherapy in colorectal cancer: a meta-analysis

AIMS

Pharmacogenetic studies investigating the relationship between MTHFR gene polymorphisms and response to fluorouracil-based chemotherapy in patients with colorectal cancer have produced inconclusive results. In an attempt to interpret these results, a meta-analysis of all eligible studies published up until January 2009 was carried out.

MATERIALS & METHODS

A total of ten studies relating MTHFR C677T and six studies relating MTHFR A1298C to the response to chemotherapy in patients with colorectal cancer were included in the meta-analysis and random effects pooled odds ratios were estimated. The heterogeneity between studies, the sources of potential bias and the consistency of genetic effects across ethnicities were explored. Cumulative and recursive cumulative meta-analyses were also performed.

RESULTS

For both the C677T and A1298C polymorphisms, the main analysis revealed nonsignificant heterogeneity and a lack of association under the allele contrast, the recessive and dominant models. The subgroup analysis by ethnicity did not change this pattern of results. The lack of stability of the relative change of odds ratio in the recursive cumulative meta-analysis for both polymorphisms indicated the need for more evidence to support a definite lack of association. There was no differential magnitude of the effect in large versus small studies.

CONCLUSION

The available evidence indicates that MTHFR C677T and A1298C gene polymorphisms cannot be considered as reliable predictors of response to fluorouracil-based chemotherapy in patients with colorectal cancer.

Target Practice: Figuring Out Which, When, and Why to Use Systemic Therapies for Metastatic Colon Cancer

There have been many recent advances in the field of systemic chemotherapy for metastatic colorectal cancer. Each treatment affects a different target, including thymidylate synthase, topoisomerase, DNA, the epidermal growth factor receptor, and vascular endothelial growth factor. These treatments have been used in multiple combinations, schedules, and as first-line, second-line, and third-line therapies. The current clinical trials reported can help guide the clinician to determine the appropriate timing, combination, and schedule of chemotherapy agents. Although the decision regarding colorectal cancer chemotherapy is now more complicated, our patients have certainly benefited from better response rates and most importantly, longer survival times.

Pharmacogenetics in colorectal cancer: a systematic review

Pharmacological treatment of colorectal cancer has improved survival rates in recent years. Individual genetic variation in genes associated with metabolism and targets of commonly used drugs can be responsible for variability in treatment outcome and toxicity. Diverse study designs have been used and heterogeneous end points evaluated by studies assessing the association of genetic markers with treatment outcome. We conducted this systematic review, including 51 studies, to present a comprehensive overview and draw further conclusions. To facilitate comparison of reported study results, risk estimates for observed genetic variants in 33 key genes are presented using defined reference categories and recalculated risk estimates based on data provided in original publications, where necessary. Overall, evidence indicates associations of the UGT1A1(*) 28 variant genotype with toxicity after irinotecan treatment, mutations in GSTP1-105 with improved treatment outcome and the XPD-751 variant genotype with poor treatment outcome after oxaliplatin treatment, and amplification of the EGFR gene with improved treatment outcome after therapy with monoclonal antibodies. Adequately powered prospective investigations designed specifically for pharmacogenetics are needed.

Methylenetetrahydrofolate reductase (MTHFR) variants and fluorouracil-based treatments in colorectal cancer

5-fluorouracil (5FU)-based treatments remain the main chemotherapy for colorectal cancer. Optimal cytotoxicity of fluoropyrimidines requires elevated CH(2)FH(4) tumoral concentrations, controlled by the methylenetetrahydrofolate reductase (MTHFR) enzyme, which irreversibly converts CH(2)FH(4) into 5-methyltetrahydrofolate. The MTHFR gene is subject to several polymorphisms, of which the 677C>T and 1298A>C SNPs are the two most commonly linked with altered enzyme activity. Since a drop in MTHFR enzymatic activity may theoretically favor an increase in intracellular CH(2)FH(4) concentrations, it can be hypothesized that tumors exhibiting the rare MTHFR variants may be more sensitive to 5FU cytotoxicity. Accordingly, experimental data have shown that rare MTHFR variants in position 677 and 1298 are more sensitive to 5FU. However, results of clinical data do not concord regarding the influence of MTHFR genotype on tumoral CH(2)FH(4) concentration, 5FU responsiveness, patient survival and 5FU-related toxicity. These discrepancies may result from the interpatient variability arising from the individual folate status, as well as from the limited role of fluoropyrimidines in the current chemotherapy regimen administered in colorectal cancer.

Survival benefit in patients after palliative resection vs non-resection colon cancer surgery

AIM: To evaluate survival in patients undergoing palliative resection versus non-resection surgery for primary colorectal cancer in a retrospective analysis.

METHODS: Demographics, TNM status, operating details and survival were reviewed for 67 patients undergoing surgery for incurable colorectal cancer. Palliative resection of the primary tumor was performed in 46 cases in contrast to 21 patients with non-resection of the primary tumor and bypass surgery. Risk factors for postoperative mortality and poor survival were analyzed with univariate and multivariate analyses.

RESULTS: The two groups were comparable in terms of age, gender, preoperative presence of ileus and tumor stage. Multivariate analysis showed that median survival was significantly higher in patients with palliative resection surgery (544 vs 233 d). Differentiation of the tumor and tumor size were additional independent factors that were associated with a significantly poorer survival rate.

CONCLUSION: Palliative resection surgery for primary colorectal cancer is associated with a higher median survival rate. Also, the presence of liver metastasis and tumor size are associated with poor survival. Therefore, resection of the primary tumor should be considered in patients with non-curable colon cancer.

Oxaliplatin/5-FU without leucovorin chemotherapy in metastatic colorectal cancer

PURPOSE

Fluorouracil (5-FU) and leucovorin combination therapy have shown synergistic or additive effect against advanced colorectal cancer, but the frequency of mucositis and diarrhea is increased. Most previous studies have used high dose leucovorin (300 approximately 500 mg/m(2)). However, some studies of oxaliplatin and 5-FU with low-dose or high-dose leucovorin in Korea have shown similar response rates. Therefore, we studied the necessity of leucovorin and evaluated the objective tumor response rates and toxicities of a regimen of oxaliplatin and 5-FU without leucovorin every 2 weeks in metastatic colorectal cancer patients.

MATERIALS AND METHODS

Twenty-four patients with metastatic colorectal cancer were enrolled between January 2002 and March 2003. Patients received 85 mg/m(2) of oxaliplatin on day 1, a bolus 5-FU 400 mg/m(2) on day 1 and a continuous 5-FU infusion at 600 mg/m(2)/ 22 hours days 1 and 2, every 2 weeks.

RESULTS

Of the 24 patients treated, 17 patients received previous 5FU with leucovorin and/or other chemotherapy. Three patients could not be evaluated. Five partial responses were observed with overall response rate of 21% (n=24). Of the previous chemotherapy group (n=17), 4 partial responses were observed with response rate of 24%. Median overall survival was 18 months (range 4 approximately 32 months) and median progression free survival was 4 months (range 2 approximately 6 months). This regimen was well tolerated and only 1 grade 3 anemia was observed.

CONCLUSION

Oxaliplatin/5-FU combination therapy without leucovorin achieved a relatively high response rate even in patients resistant to the previous 5-FU chemotherapy, and toxicity was minimal.

Methylenetetrahydrofolate reductase gene polymorphisms and response to fluorouracil-based treatment in advanced colorectal cancer patients

Methylenetetrahydrofolate reductase (MTHFR) controls intracellular CH2FH4 concentrations (required for optimal fluoropyrimidine efficacy) by irreversibly converting CH2FH4 into 5-methyltetrahydrofolate. MTHFR 677C>T and 1298A>C polymorphisms are linked to altered enzyme activity. Thus, mutated MTHFR tumours should, in theory, be more sensitive to 5-fluorouracil (5FU) than wild-type tumours. MTHFR polymorphisms in position 677 and 1298 were analysed in 98 colorectal cancer patients with unresectable liver metastases (57 men, 41 women, mean age 64 years) receiving 5FU-folinic acid. 677C>T and 1298A>C genotypes were determined simultaneously by melting curve analyses on liver metastases. 677C>T genotype distribution was 46.9% wt/wt, 34.7% wt/mut and 18.4% mut/mut; that of 1298A>C was 52.0% wt/wt, 35.7% wt/mut and 12.3% mut/mut. The response rate was not related to 1298A>C genotype but was significantly linked to 677C>T genotype (response rate: 40%, 21% and 56% in wt/wt, wt/mut and mut/mut, respectively; P = 0.040), with an increased response rate in mut/mut tumours relative to wt/wt (odds ratio = 1.88). Thymidylate synthase activity measured in metastases was a significant predictor of 5FU responsiveness and the addition of the 677C>T genotype improved model prediction. MTHFR 1298A>C polymorphism was significantly linked to specific survival, with homozygous mutated patients having the worst prognosis (P = 0.009, relative risk = 2.48 in mut/mut versus wt/wt). MTHFR 1298A>C genotype remained a significant predictor in a multivariate analysis including metastasis characteristics. The results suggest that MTHFR genotypes are relevant and independent factors of patient outcome in 5FU-based treatment of advanced colorectal cancer.

Randomized crossover trial of intravenous 5-FU versus oral UFT both modulated by leucovorin: a one-centre experience

Although intravenous (IV) 5-fluorouracil (5-FU) and uracil/futraful (UFT) have comparable antitumour efficacy in the treatment of metastatic colorectal cancer (MCC), we wanted to assess which of these two regimens would be preferred by our patients. We randomized 20 previously untreated patients with MCC at our centre to receive oral UFT or bolus IV 5-FU both associated with leucovorin. After the first cycle patients were crossed over to the other arm. Before the third cycle we left patients to choose one of the regimens to continue their treatment until disease progression. Two patients chose 5-FU and 18 chose UFT (P < 0.001). Fewer side effects (50%) and convenience of home treatment (40%) were the main reasons for their choice for the oral regimen. UFT induced less mucositis (P = 0. 02) and diarrhoea (P = 0. 01). We conclude that convenience and lower toxicity may explain the observed preference for oral UFT.

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.

Closed continuous hyperthermic peritoneal perfusion model in mice with peritoneal dissemination of colon 26

An original model of closed continuous hyperthermic peritoneal perfusion (CHPP) in mice is presented and was found to support the efficacy of intraperitoneal hyperthermia. Closed CHPP was performed after intraperitoneal inoculation of transplantable colon 26 cells into a mouse. Colon 26 cells (5 x 10(4)) were injected into 18 mice. The mice were then allocated to six groups of three each and subjected to peritoneal perfusion over time. Peritoneal washings from each mouse were sampled and counted by the cytosmear method. On day 10 after inoculation, colonies of the disseminated tumour were seen on the mesentery by staining with 0.1% methylene blue for 5 min. The number of tumour nodules on the mesentery was counted. The number of washed-out tumour cells decreased the most at 24 h after inoculation, and 76% of the inoculated cells did not wash out during the peritoneal perfusion procedure. CHPP was performed after 24 h when colon 26 cells were injected into the peritoneal cavity because this status may represent micrometastasis. The total number of nodules on the mesentery in the CHPP group was significantly smaller than that in the control (p < 0.02). In conclusion, because this treatment model is similar to the clinical CHPP, the biostaining model might be useful for the evaluation of peritoneal dissemination and it was unique and valuable in demonstrating an effective treatment for the prevention of peritoneal dissemination.

Oxaliplatin plus high-dose leucovorin and 5-fluorouracil (FOLFOX 4) in platinum-resistant and taxane-pretreated ovarian cancer: a phase II study

OBJECTIVE

A prospective phase II study was conducted to evaluate the efficacy and toxicity of oxaliplatin plus 5-fluoruracil (5-FU) and high-dose leucovorin (LV) (FOLFOX-4) in patients with platinum-resistant, taxane-pretreated recurrent ovarian cancer.

PATIENTS AND METHODS

Thirty-eight patients, with a median age of 58 years (range 33-77), were treated with oxaliplatin 85 mg m(-2) as a 2-h infusion on day 1, LV 200 mg m(-2) day(-1) as a 2-h infusion followed by bolus 5-FU 400 mg m(-2) day(-1) and a 22-h infusion of 5-FU 600 mg m(-2) day(-1) for 2 consecutive days. Treatment was repeated every 3 weeks. Patients were evaluated for response every two cycles.

RESULTS

The vast majority of patients had performance status 0 or 1 and 76.3% had > or = 2 metastatic sites. A median number of four cycles per patient (range, 1-8) were administered. Based on an intention-to-treat analysis, 3 patients (7.9%) achieved a complete response (CR) and 8 (21.1%) achieved a partial response (PR), for an overall response rate of 29%. Another 29% of patients had stable disease (SD). The median relapse-free survival was 5.2 months (range 2.5-17), the median time to tumor progression was 4.8 months (range 0.6-19), and the median overall survival was 10.1 months (range 0.2-36). Toxicity was mild to moderate. Grade 3/4 neutropenia and thrombocytopenia occurred in 29% and 21.1% of patients, respectively. Febrile neutropenia was encountered in 3 patients (7.9%), who were successfully treated. Grade 3/4 neurotoxicity developed in 15.8% of patients; neurotoxicity gradually declined after treatment discontinuation. Alopecia, nausea-vomiting, diarrhea, mucositis, and asthenia were not a serious problem. There were no treatment-related deaths.

CONCLUSION

The combination of oxaliplatin and 5-FU/LV (FOLFOX-4) appears to be an effective regimen with a good toxicity profile for the treatment of platinum-resistant, taxane-pretreated ovarian cancer.

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Rectal cancer

Rectal cancer is an important tumour from an epidemiological point of view and represents the benchmark for an optimal use of integrated treatments (surgery, radiotherapy and chemotherapy) in the oncological practice. Performing radio-chemotherapy (best if preoperatively), medical and radiation oncologists are now able to increase survival, to decrease the occurrence of pelvic recurrence and to ameliorate the quality of life of patients. Updated recommendations for the management of these patients are here reported.

Non-curative surgery for colorectal cancer: critical appraisal of outcomes

BACKGROUND AND AIMS

The value of surgery for patients with incurable colorectal cancer is controversial. This study evaluated outcomes in patients undergoing non-curative surgery for colorectal cancer and aimed to identify patients who would benefit from palliative surgery.

PATIENTS AND METHODS

Demographics, tumour characteristics, operating details and outcomes were reviewed for 180 patients undergoing surgery for incurable colorectal cancer; palliative resection was performed in 150 cases. Seventeen patients died in the postoperative period. Risk factors for postoperative mortality and poor survival were analysed with univariate and multivariate analysis.

RESULTS

Multivariate analysis showed that operative mortality was significantly higher in patients with non-resection surgery and in those with ascites. Median survival of patients with resection was significantly longer than in those without resection (30 vs. 17 weeks). Other independent factors that were significantly associated poor survival were the presence of ascites, presence of bilobar liver metastasis and absence of chemotherapy and/or radiation therapy.

CONCLUSION

Non-curative surgery is associated with high mortality in patients without resection and in the presence of ascites. These two factors, together with the presence of bilobar liver metastasis and the absence of chemotherapy and/or radiation therapy, are associated with poor survival. In the presence of these factors the balance between the benefit and risk of surgery should be carefully considered before decision for operative treatment.

Down-regulation of thymidylate synthase expression and its steady-state mRNA by oxaliplatin in colon cancer cells

Recently, evidence has accumulated that weekly 24-h infusion of high-dose 5-fluorouracil (5-FU) with leucovorin (LV, folinic acid) biochemical modulation may improve the response rates compared with the bolus 5-FU regimens in colorectal cancer (CRC). Combining the infusional 5-FU/LV (iFL) regimens with oxaliplatin or irinotecan is widely adopted to further improve treatment efficacy. Either oxaliplatin-iFL or irinotecan-iFL may achieve an overall response rate of more than 50% in the first-line treatment. Intriguingly, in the salvage treatment for metastatic CRC patients who had failed iFL, only oxaliplatin-iFL may achieve a response rate of about 13-25%. In contrast, oxaliplatin alone or irinotecan-iFL had a very low response rate of 5% or less. To test if the oxaliplatin may reverse the iFL-related 5-FU resistance in CRC, we used DLD-1 colon adenocarcinoma cells as the in vitro study model. First, we revealed that oxaliplatin and 5-FU act synergistically on DLD-1 cells by MTT cytotoxicity assay and median drug effect analysis. Second, we treated the DLD-1 cells with serial concentrations of oxaliplatin (0.1-10 microM). Oxaliplatin treatment results in down-regulation of free thymidylate synthase (TS) protein expression by Western blotting. Further, we analyzed the TS mRNA level by reverse transcription and real-time quantitative polymerase chain reaction assay. Oxaliplatin treatment results in down-regulation of the TS mRNA level up to 40% (mean +/- SD of ratio to reference control = 0.60 +/- 0.21, range 0.42-0.84). In this study, our data provide important information explaining the reason why the combination of oxaliplatin and 5-FU results in a better objective response in 5-FU-resistant patients than oxaliplatin alone does. Our data also suggest that TS down-regulation happens at the transcriptional level. TS modulation and down-regulation had, thus, shed light on the useful potential strategy to achieve objective responses in 5-FU-resistant CRC patients.

Thymidylate synthase and methylenetetrahydrofolate reductase gene polymorphisms: relationships with 5-fluorouracil sensitivity

The relationship of thymidylate synthase (TS) and methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms on 5-fluorouracil (FU) sensitivity was tested on 19 human cancer cell lines (head and neck, breast, digestive tract) in the absence and presence of folinic acid (FA) supplementation. Thymidylate synthase polymorphisms in the 5' promoter region (double or triple tandem repeats) and 3' untranslated region (6-bp deletion) were analysed by PCR. The C677T and A1298C MTHFR polymorphisms were determined by melting curve analyses (LightCycler). Thymidylate synthase activity and intracellular concentration of the reduced folate 5-10 methylenetetrahydrofolate (CH(2)FH(4)) were measured (biochemical assays). Thymidylate synthase activity was significantly different according to 5' TS genotype, heterozygous cell lines (2R/3R) exhibiting higher TS activities than homozygous ones (P=0.05). However, whether in the absence or presence of FA, FU sensitivity was not statistically associated with either 5' or 3' TS polymorphism. Basal CH(2)FH(4) cellular concentrations were lowest in C677T homozygous wild-type (wt) (C/C) cell lines. FU sensitivity was not linked to C677T polymorphism. In contrast, there was a marked trend for a greater FU efficacy in mutated A1298C variants (C/C+A/C) as compared to wt homozygous cell lines (A/A) (P=0.055 and 0.085 without and with FA supplementation, respectively). These results suggest for the first time a potential role of A1298C MTHFR polymorphism on fluoropyrimidine sensitivity.

Phase I and pharmacokinetic study of two different schedules of oxaliplatin, irinotecan, Fluorouracil, and leucovorin in patients with solid tumors

PURPOSE

We sought to determine the maximum-tolerated dose (MTD) and evaluate the toxicities and clinical activity of two irinotecan (CPT-11), fluorouracil (FU), leucovorin (LV), and oxaliplatin schedules in patients with advanced solid tumors. Additionally, we investigated the effect of CPT-11 on oxaliplatin pharmacokinetics.

PATIENTS AND METHODS

Thirteen patients (cohort 1) received intravenous CPT-11 (infusion) and FU/LV (bolus) on days 1, 8, 15, and 22 and oxaliplatin (infusion) on days 1 and 15 every 6 weeks for a total 37 courses (median, three courses) at three dose levels. Twenty-two cohort 2 patients received intravenous CPT-11/oxaliplatin (infusion, day 1) and FU/LV (90-minute bolus infusion, days 2 to 5) every 3 weeks for a total of 122 courses (median, four courses) at three dose levels. Pharmacokinetic and neurotoxicity assessments were performed at the cohort 2 MTD.

RESULTS

Dose-limiting toxicity (DLT) seen in both cohorts at the starting dose required dose de-escalation. Cohort 1 DLT included diarrhea and neutropenia. In cohort 2, diarrhea, vomiting, dehydration, neutropenia, febrile neutropenia, and paresthesias were DLTs. Antitumor activity was seen in both cohorts. In cohort 2, the total platinum area under the curve of patients increased 17% in cycle 2 (P =.048), but objective neurotoxicity was not seen.

CONCLUSION

The toxicities resulting from the addition of oxaliplatin to CPT-11/FU/LV are significant but manageable. The MTDs for the weekly schedule are CPT-11 (75 mg/m2), oxaliplatin (50 mg/m2), FU (320 mg/m2), and LV (20 mg/m2); and, for the 3-weekly schedule, the MTDs are CPT-11 (175 mg/m2), oxaliplatin (85 mg/m2), FU (240 mg/m2), and LV (20 mg/m2). Second-cycle platinum accumulation raises the possibility for enhanced cumulative neurotoxicity with CPT-11/oxaliplatin combinations.

Oxaliplatin plus high-dose leucovorin and 5-fluorouracil in pretreated advanced breast cancer: a phase II study

BACKGROUND

The purpose of this study was to evaluate the efficacy and toxicity of oxaliplatin plus 5-fluorouracil (5-FU) and leucovorin (LV) in patients with metastatic breast cancer (MBC) previously treated with anthracyclines and taxanes.

PATIENTS AND METHODS

Fifty anthracycline- and taxane-pretreated MBC patients were treated with oxaliplatin 85 mg/m(2) as a 2-h infusion on day 1, LV 200 mg/m(2)/day as a 2-h infusion followed by bolus 5-FU 400 mg/m(2)/day and a 22-h infusion of 5-FU 600 mg/m(2)/day for 2 consecutive days. Treatment was repeated every 3 weeks. Patients were evaluated for response every two cycles.

RESULTS

The median age was 51 years (range 34-75). Twenty patients (40%) had received three or more chemotherapeutic regimens, 64% had three or four metastatic sites and 78% had visceral metastases. All patients had prior exposure to anthracyclines and taxanes. Based on an intention-to-treat analysis, one patient (2%) achieved a complete response and 16 (32%) a partial response, for a 34% overall response rate. Twenty-one patients (42%) had stable disease and 12 (24%) progressive disease. The median time to tumor progression was 5.3 months (range 0.5-12.8) and the median overall survival was 12.3 months (range 0.5-19.2). Toxicity was mild to moderate. Grade 3/4 neutropenia and thrombocytopenia occurred in 32% and 18%, respectively. Febrile neutropenia was experienced by three patients (6%), who were successfully treated. Grade 3/4 neurotoxicity was reported in 14% of the patients and gradually declined after treatment discontinuation. Cycle delays were reported in 28% of patients and dose reductions in 26%. Alopecia, nausea-vomiting, diarrhea and mucositis were not significant. There were no treatment-related deaths.

CONCLUSION

The combination of oxaliplatin plus 5-FU/LV seems to be an active regimen in patients with MBC and prior exposure to anthracyclines and taxanes with a good safety profile. The incidence of severe toxicity was quite low and the compliance of patients to the treatment was satisfactory. The results obtained with this regimen could be considered encouraging in this heavily pretreated group of breast cancer patients with a high incidence of visceral metastases.

Randomized comparative study of tegafur/uracil and oral leucovorin versus parenteral fluorouracil and leucovorin in patients with previously untreated metastatic colorectal cancer

PURPOSE

This phase III study compared the time to progression (TTP) of an oral regimen of dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine composed of a fixed combination of tegafur and uracil in a 1:4 molar ratio (UFT) and leucovorin (LV) to intravenous (IV) fluorouracil (5-FU) and LV in previously untreated metastatic colorectal carcinoma (CRC) patients. Secondary end points were survival, tumor response, safety, and quality of life.

PATIENTS AND METHODS

Between May 1996 and July 1997, 380 patients were randomized to receive either UFT (300 mg/m(2)/d) and LV (90 mg/d), administered for 28 days every 35 days, or 5-FU (425 mg/m(2)/d) and LV (20 mg/m(2)/d), given IV for 5 days every 35 days.

RESULTS

No statistically significant difference in TTP was observed between treatments. With 320 events assessed, the median TTP was 3.4 months (95% Confidence interval [CI], 2.6 to 3.8) on UFT/LV and 3.3 months (95% CI, 2.5 to 3.7) on 5-FU/LV (P =.591, stratified log-rank test). There were no statistically significant differences in survival, tumor response, duration of response, and time to response. Substantial safety benefits were observed in patients treated with UFT/LV. They experienced significantly less stomatitis/mucositis (P <.001) and myelosuppression, resulting in fewer episodes of febrile neutropenia (P <.001) and less documented infection (P =.04). Concomitant medication usage was significantly greater on 5-FU/LV (P =.010). With respect to quality of life, after correcting for baseline imbalances, there were no significant differences between treatments for any scale, except diarrhea.

CONCLUSION

The oral UFT/LV regimen failed to achieve improved TTP; however, the study confirms significant safety improvements compared with bolus IV 5-FU/LV for the first-line treatment of metastatic CRC.

Thymidylate synthase: a critical target for cancer chemotherapy

Thymidylate synthase (TS) is a key enzyme in the synthesis of 2'-deoxythymidine-5'-monophosphate, an essential precursor for DNA biosynthesis. For this reason, this enzyme is a critical target in cancer chemotherapy. As the first TS inhibitor in clinical use, 5-fluorouracil (5-FU) remains widely used for the treatment of colorectal, pancreatic, breast, head and neck, gastric, and ovarian cancers. The reduced folate, leucovorin, has been shown to enhance the activity of 5-FU in colorectal cancer. However, response rates of the combination remain in the 25%-30% range, and much effort has been focused on designing new, more potent TS inhibitors. Raltitrexed is a folate analogue that is approved as first-line therapy for advanced colorectal cancer in Europe, Australia, Canada, and Japan, although it remains an investigational agent in the United States. Pemetrexed is an antifolate analogue that has shown promising activity in several solid tumor types, including mesothelioma. ZD9331, a highly specific TS inhibitor that dose not require polyglutamation for its activation, has shown activity in patients with refractory ovarian and colorectal cancer. Capecitabine is an oral fluoropyrimidine carbamate that was designed to generate 5-FU preferentially in tumor cells; this agent was recently approved by the US Food and Drug Administration as first-line therapy for patients with advanced colorectal cancer. As the number of TS inhibitors available for general clinical use increases, further research is needed to elucidate the critical molecular and biochemical elements that determine the efficacy and tumor specificity of each compound.

The incidence and cost of hospitalization for 5-FU toxicity among Medicare beneficiaries with metastatic colorectal cancer

OBJECTIVE

To estimate the incidence and associated cost of hospitalizations for toxicities associated with 5-fluorouracil (5-FU) among patients with metastatic colorectal cancer.

METHODS

Using the 1994 Medicare 5% sample, we identified all patients with metastatic colorectal cancer who had undergone colorectal surgery. We then stratified them into those who received 5-FU therapy within 90 days of their surgery (5-FU group) and those who did not receive chemotherapy (no-chemotherapy group); patients who received chemotherapeutic agents other than 5-FU were excluded from the sample. Using techniques of survival analysis, we then compared the incidence and associated cost of all hospital admissions with listed International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic codes (primary or secondary) for conditions possibly related to 5-FU toxicity (e.g., volume depletion, stomatitis, nausea, and vomiting).

RESULTS

A total of 441 patients met all study entry criteria, including 192 who received 5-FU and 249 who did not receive chemotherapy following surgery. Patients in the 5-FU group were younger than those in the no-chemotherapy group (p < .001). Mean (+/- SD) follow-up time was slightly longer in the 5-FU group (137 +/- 96 days vs. 117 +/- 88 days for no chemotherapy). The incidence of toxicity-related hospitalizations at 10.5 months (principally volume depletion, agranulocytosis, gastroenteritis, and nausea and vomiting) was 31% among patients who received 5-FU and 8% among those who did not receive chemotherapy. The cost of inpatient care at 10.5 months was $2716 higher among 5-FU patients.

CONCLUSIONS

Hospitalization for toxicity of Medicare patients with metastatic colorectal cancer receiving 5-FU is frequent and costly.

Monthly 5-days 5-fluorouracil and low-dose leucovorin for adjuvant chemotherapy in colon cancer

We investigated the dose-related effect of the 5-fluorouracil (5-FU)/leucovorin regimen on survival in 139 colon cancer patients with Dukes' B2 and C2 stage disease. Chemotherapy consisted of 400 mg/m(2) of 5-FU and 20 mg/m(2) of leucovorin injected daily for 5 days in every 4 weeks for a maximum of 12 cycles. The total dose of 5-FU administered per body surface area had a significant effect on the 5-year disease-free survival and 5-year overall survival in stage B2 and C2 colon cancer patients (P=0.0018, P=0.0011). Analysis with reference to the median DSDI demonstrated that there was a significant difference in 5-year survival in Dukes' C2 (P=0.0016), but survival was not affected by the dose intensity. Multivariate analysis demonstrated that only the total dose of 5-FU administered per surface area affected the 5-year disease-free survival and 5-year overall survival (P=0.0016, P=0.0007, respectively). It can be concluded that the total dose of 5-FU administered is important in planned dosage schedule of adjuvant chemotherapy in colon cancer.

New therapies, new directions: advances in the systemic treatment of metastatic colorectal cancer

Colorectal cancer is the second leading cause of cancer death and it is clear that patients with metastatic disease have better quality of life and survival when given treatment. Despite four decades of experience of treating patients with fluorouracil, there remains considerable controversy about the optimum dose and scheduling, as well as biomodulation with leucovorin and methotrexate. However, irrespective of the dose and schedule, overall survival times are poor--about 1 year. Disappointingly, oral agents with similar mechanisms to fluorouracil do not improve survival rates in comparison with fluorouracil and leucovorin treatment. Irinotecan and oxaliplatin are newer agents that have improved the response rates for patients with metastatic disease when they are added to flurouracil and leucovorin. The combination of irinotecan, fluorouracil, and leucovorin has also improved overall survival. These are small advances in the fight against colorectal cancer, and further drug development is necessary.

Metastatic liver tumors

The liver is a common site of metastasis from a variety of tumors. In many cases, liver resection for metastatic cancer provides the only chance for a cure and can be performed with less than 5% mortality and acceptable morbidity. The 5-year survival following liver resection for colorectal metastasis is reported in many large series to be 25% to 37%. The data regarding liver resection for other metastatic tumor types are less clear. However, resection for selected tumors, such as neuroendocrine and renal cell, can provide durable palliation and/or cure. We will review important prognostic factors used to guide the selection of patients for resection of metastatic disease and make recommendations for imaging studies and follow-up routines. The role of adjuvant regional and systemic chemotherapy for resectable metastatic disease is also discussed. Methods for ablating unresectable metastatic tumors may prove to be useful adjuncts to current therapies.

A phase II trial of homoharringtonine and caracemide in the treatment of patients with advanced large bowel cancer

Twenty-four previously untreated, ambulatory patients with advanced colorectal carcinoma were treated with either caracemide (11 patients) or homoharringtonine (13 patients). No objective responses were observed in any of the treatment cohorts. Caracemide was well tolerated with the exception of one death due to sepsis. On the homoharringtonine arm one patient died of pulmonary sepsis, one patient experienced grade 4 leukopenia requiring more than 4 weeks of recovery, and an additional patient developed grade 4 renal failure. These severe and unexpected complications caused early termination of accrual to the homoharringtonine arm of the study. These agents have no activity in the treatment of advanced colorectal carcinoma.

Phase III multicenter randomized trial of oxaliplatin added to chronomodulated fluorouracil-leucovorin as first-line treatment of metastatic colorectal cancer

PURPOSE

To study how adding oxaliplatin (l-OHP) to chronomodulated fluorouracil (5-FU)-leucovorin (LV) affected the objective response rate, as first-line treatment of metastatic colorectal cancer.

PATIENTS AND METHODS

Two hundred patients from 15 institutions in four countries were randomly assigned to receive a 5-day course of chronomodulated 5-FU and LV (700 and 300 mg/m(2)/d, respectively; peak delivery rate at 0400 hours) with or without l-OHP on the first day of each course (125 mg/m(2), as a 6-hour infusion). Each course was repeated every 21 days. Response was assessed by extramural review of computed tomography scans.

RESULTS

Grade 3 to 4 toxicity from 5-FU-LV occurred in </= 5% of the patients (</= 1% of the courses). Grade 3 to 4 diarrhea occurred in 43% of the patients given l-OHP (10% of the courses), and less than 2% of the patients had severe hematotoxicity. Thirteen percent of the patients had moderate functional impairment from peripheral sensory neuropathy. Sixteen percent of the patients receiving 5-FU-LV had an objective response (95% confidence interval [CI], 9% to 24%), compared with 53% of those receiving additional l-OHP (95% CI, 42% to 63%) (P <. 001). The median progression-free survival time was 6.1 months with 5-FU-LV (range, 4.1 to 7.4 months) and 8.7 months (7.4 to 9.2 months) with l-OHP and 5-FU-LV (P =.048). Median survival times were 19.9 and 19.4 months, respectively.

CONCLUSION

By chronomodulating 5-FU-LV, we were able to add l-OHP without compromising dose-intensities. l-OHP significantly improved the antitumor efficacy of this regimen.

Phase I study of 5-fluorouracil administered by protracted venous infusion, leucovorin, and pelvic radiation therapy

BACKGROUND

This study was designed to assess the toxicity of pelvic radiation therapy, 5-fluorouracil (5-FU) administered by protracted venous infusion, and leucovorin.

METHODS

Pelvic radiation therapy consisted of 50.4-54 gray (Gy) administered in 28-30 fractions. Systemic treatment consisted of leucovorin (10 mg daily) administered orally and protracted venous infusion of 5-FU. The initial daily 5-FU dose was 150 mg/m(2). Dose escalations were planned in increments of 25 mg/m(2).

RESULTS

Forty eligible patients were registered, of whom 37 were evaluable for chemoradiotherapy-related toxicity. Grade 3 or 4 toxicity secondary to radiation therapy, protracted venous infusion of 5-FU, and leucovorin occurred in 2 of 17 patients at a daily 5-FU dose of 150 mg/m(2), in 5 of 10 patients at a daily 5-FU dose of 175 mg/m(2), and in 5 of 10 patients at a daily 5-FU dose of 200 mg/m(2). Diarrhea was dose-limiting in 7 of 8 patients with Grade 4 toxicity. Venous thrombosis, a treatment-related complication not directly related to chemotherapy or radiation therapy, occurred in 5 of the 40 patients entered into this study. Four thromboses occurred at the site of a central catheter. No thrombotic complications occurred in the last 7 patients, who were given warfarin orally (1 mg daily) during treatment.

CONCLUSIONS

Toxicity due to radiation therapy, protracted venous infusion of 5-FU, and leucovorin when 5-FU is given daily at a dose of 150 mg/m(2) is similar to that observed in current chemoradiotherapy regimens for patients with rectal carcinoma. This regimen will be considered as a possible investigational treatment arm of a future trial of adjuvant therapy for rectal carcinoma patients.

5-fluorouracil and levofolinic acid with or without recombinant interferon-2b in patients with advanced colorectal carcinoma: a randomized multicenter study with stratification for tumor burden and liver involvement by the Southern Italy Oncology Group

BACKGROUND

The objectives of the current study were: 1) to verify whether the addition of modulating low doses of interferon-2b (IFN) to 5-fluorouracil (5-FU) and levofolinic acid (1-FA) could improve clinical results in patients with advanced colorectal carcinoma; and 2) to evaluate the role of tumor burden and liver involvement as prognostic factors.

METHODS

A total of 204 untreated patients were randomized to receive 1-FA at 100 mg/m2 and 5-FU at 375 mg/m2 for 5 consecutive days with or without IFN every 3 weeks. IFN was given subcutaneously at 3 MU/day for 7 days starting 2 days before chemotherapy administration. Patients were stratified according to the presence or absence of hepatic disease (H+ or H-) and to total tumor burden defined as "low" or "high" using an area of 10 cm2 as the cutoff value. Thus, four patient categories were obtained: Group 1: H+ > or = 10 cm2; Group 2: H+ < 10 cm2; Group 3: H- > or = 10 cm2; and Group 4: H- < 10 cm2.

RESULTS

No differences were observed in the objective response rate (23% for the combination of 1-FA and 5-FU vs. 24% for the 1-FA, 5-FU, and IFN regimen), median duration of response (11 months vs. 10 months), time to progression (5 months in both arms), and median survival (11 months vs. 12 months). A statistically significant improvement in response rate was observed in patients with limited liver involvement versus those with massive involvement independent of the chemotherapy arm (44% vs. 22%; P = 0.02). Overall survival also was improved in patients with limited liver disease (P = 0.0001) and in those without liver involvement (P = 0.004). Multivariate analysis confirmed these data and identified response and female gender as positive prognostic factors. Toxic side effects (mainly diarrhea, mucositis, and fever) were statistically more frequent in the IFN arm.

CONCLUSIONS

The addition of low modulating doses of IFN to the regimen of 5-FU and I-FA failed to increase the response rate and survival of patients with advanced colorectal adenocarcinoma and significantly worsened toxicity. High tumor burden and the presence of liver involvement were confirmed prospectively as poor prognostic factors and should be taken in account in designing future Phase II or comparative trials.

Chemotherapy of Colorectal Cancer

Progress has been made in the adjuvant treatment of colorectal carcinoma. The improvement in survival with the use of adjuvant 5-FU and leucovorin in patients with stage III colon carcinoma has been readily established. However, a survival benefit in stage II patients treated with adjuvant therapy remains unproven. Further evaluation using additional/new prognostic factors may identify a high-risk stage II group that would benefit from adjuvant treatment. Adjuvant chemoradiation has become standard therapy for stage II and III patients with rectal carcinoma. Investigations using preoperative combined-modality therapy are being explored to assess sphincter preservation rates and to evaluate any impact on survival. Radiosensitizing chemotherapeutic agents need to be evaluated in this patient population. Recent advances in metastatic disease have occurred. Frontline therapy remains 5-FU and leucovorin. CPT-11 has demonstrated responses in 5-FU relapsed and refractory patients and is the new standard therapy in these patients. New data recently available also show a survival advantage in patients treated with CPT-11 versus supportive care in 5-FU and leucovorin failures. New agents such as UFT and oxaliplatin have demonstrated activity in colorectal carcinomas and in the future these agents will likely aid in the treatment of this disease.

Management of hepatic metastases

Although the liver is the most common site of metastatic disease from a variety of tumor types, isolated hepatic metastases most commonly occur from colorectal cancer and, less frequently, from neuroendocrine tumors, gastrointestinal sarcoma, ocular melanoma, and others. Complete evaluation of the extent of metastatic disease, both intrahepatically and extrahepatically, is important before considering treatment options. Based on a preponderance of uncontrolled studies for hepatic metastatic colorectal carcinoma, surgical resection offers the only potential for cure of selected patients with completely resected disease, with 5-year survival rates of 25% to 46%. Systemic and hepatic arterial infusion chemotherapy may be useful treatment options in patients with unresectable disease and possibly as an adjuvant treatment after liver resection. Other techniques of local tumor ablation, including cryotherapy and radiofrequency ablation, although promising, remain unproved. Management of hepatic metastases from neuroendocrine tumors and other noncolorectal primary tumors should be individualized based on the patient's clinical course, extent of disease, and symptoms.

A prospective randomized study comparing high- and low-dose leucovorin combined with same-dose 5-fluorouracil in advanced colorectal cancer

Although the efficacy of 5-fluorouracil (5-FU) modulated by leucovorin is well established for advanced colorectal cancer, the question of the most effective regimen and optimal dose of leucovorin remains unanswered. This prospective randomized trial compares low-dose (group 1) and high-dose (group 2) leucovorin, combined with the same dose of 5-FU to determine whether high-dose leucovorin was more beneficial than low-dose on overall survival. Inclusion criteria were: unresectable metastatic colorectal carcinoma, with or without evaluable tumor response; a performance status of less than grade 3 (World Health Organization classification); and no previous chemotherapy for metastases. Forty-two patients were randomized in group 1 (leucovorin, 20 mg/m2/day, days 1 through 5) and 41 patients in group 2 (leucovorin, 200 mg/m2/day, days 1-5). All the patients in the two groups received a 1-hour infusion of 400 mg/m2/day 5-FU every 4 weeks. The two groups were matched with no statistically significant differences in gender ratio, site of primary tumor, performance status, and tumor extent. Toxicity in the two regimens was low and not significantly different between the two groups. Overall median survival was 346 days in group 1 and 323 days in group 2 and was not significantly different between the two groups. At 1 year, the test of equivalence was significant (p < 0.01), demonstrating an absence of more than 20% benefit in 1-year survival for the high-dose regimen. The use of high-dose leucovorin combined with 5-FU in the 5-day regimen does not significantly improve overall survival for patients who have metastatic colorectal cancer.

Biomodulation of Fluorouracil in colorectal cancer

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

A review of GERCOD trials of bimonthly leucovorin plus 5-fluorouracil 48-h continuous infusion in advanced colorectal cancer: evolution of a regimen. Groupe d'Etude et de Recherche sur les Cancers de l'Ovaire et Digestifs (GERCOD)

The addition of leucovorin (LV) to 5-fluorouracil (5-FU) in advanced colorectal cancer has shown improved tumour response rates in many trials, but the optimal LV/5-FU regimen has yet to be determined. Seven studies carried out over the last 12 years to evaluate the safety and efficacy of various LV/5-FU regimens are reviewed. The initial bimonthly high-dose LV/5-FU regimen consisted of high-dose LV as a 2-h infusion followed by 5-FU as an intravenous (i.v.) bolus plus a 22-h continuous infusion (CI), repeated for two consecutive days every 2 weeks. A randomised comparison of this bimonthly high-dose LV/5-FU regimen and the NCCTG-Mayo Clinic regimen (LV [20 mg/m2/day] followed by 5-FU bolus [425 mg/m2/day] daily x 5, every 4 weeks) showed that the bimonthly high-dose LV/5-FU regimen was superior to the NCCTG-Mayo Clinic regimen in response rate and progression-free survival, but showed no difference in overall survival. In addition, toxicity was less with the bimonthly high-dose LV/5-FU regimen. These promising results led to a phase II trial of a simplified bimonthly high-dose LV/5-FU regimen consisting of LV (500 mg/m2/day) and a 48-h CI of 5-FU (1.5-2 g/m2/day) which has been administered alone or in combination. In summary, GERCOD-sponsored studies have further demonstrated that high doses of both LV and 5-FU given as a CI can improve response rates still more with acceptable toxicity. Further studies are focused on the effectiveness of combination with oxaliplatin or CPT-11 in metastatic disease and the use of high-dose LV/5-FU regimens for colorectal cancer in the adjuvant setting.

Treatment of colorectal liver metastases by cryotherapy

One hundred fifty-eight procedures were performed on 136 patients with unresectable hepatic metastases using hepatic cryotherapy to ablate the tumors. The median age was 62 years. Patients included 90 males and 46 females. Fifty-eight patients had synchronous metastases, 55 had bilobar lesions, and 90 had precryo chemotherapy. Median preoperative carcinoembryonic antigen (CEA) level was 14.4 ng/dl. The numbers of lesions treated, frozen, and resected were two and one. Median survival of all patients was 30 months. Survival for 39 patients was 37 months. Patients with a CEA level > 100 ng/dl had a statistically worse survival rate than those with a level < 100 ng/dl (P < .001). Twenty patients underwent recryotherapy with median survival of 34 months. Recurrent disease developed in 78% of patients--82% of the patients developed liver recurrence. Complication rates were comparable to liver resection. Operative mortality was 3.7%. Hepatic cryotherapy is effective and safe in treating colorectal hepatic metastases under ultrasound guidance.

Effects of a hybrid recombinant human alpha interferon (A/D) on in vitro cytotoxicity and in vivo localization of monoclonal antibody L6-cytosine deaminase conjugate in a colon cancer model

L6 is an IgG2a murine monoclonal antibody which we have demonstrated binds well to HT29 human colon carcinoma cells by flow cytometry, whole cell ELISA, and mixed hemadsorption. In vitro cytotoxicity studies revealed that the monoclonal antibody L6-cytosine deaminase (L6-CD) immunoconjugate plus the nontoxic prodrug, 5-fluorocytosine (5-FC), is equivalent to 5-fluorouracil (5-FU) in its ability to kill HT29 cells. Human alpha-interferon (A/D) was able to enhance this cytotoxic effect. The I.C.50's revealed that very small amounts of L6-CD are needed for this cytotoxic effect (approximately, 5 pg/ml resulted in 50% viability). The limiting factor was the amount of 5-FC employed with L6-CD (3 microM yielded 50% cell viability). alpha-Interferon (A/D) lowered the requirement of 5-FC to 1 microM to achieve 50% cell lethality. In vivo biodistribution experiments indicated that 1 microgram of L6-CD is nonspecifically taken up by the liver and spleen and cleared rapidly from the blood. Significant localization of L6-CD to HT29 tumors occurred only when 99 micrograms of unlabeled L6-CD was added to 1 microgram of 125I-labeled immunoconjugate injected intravenously. Further augmentation of tumor/blood ratios without reduction in percent injected dose per gram of tumor was possible with the intravenous injection of 100 micrograms of anti-idiotypic monoclonal antibody 13B, 24 hours after L6-CD, which bound unreacted L6-CD and cleared it from the blood. The addition of 100,000 U of alpha-interferon (A/D) given intraperitoneally every day increased the clearance of L6-CD by the liver and spleen, but impaired tumor localization (percent injected dose per gram). These studies demonstrated that in vivo localization of the L6-CD conjugate to HT29 tumors could be optimized by injecting excess L6-CD followed by an equal amount of L6 anti-idiotype mAb 13B, 24 hours after L6-CD.