Biochemical modulation of fluorouracil with leucovorin: confirmatory evidence of improved therapeutic efficacy in advanced colorectal cancer

Application of Metabolic Reprogramming to Cancer Imaging and Diagnosis

Cellular metabolism governs the signaling that supports physiological mechanisms and homeostasis in an individual, including neuronal transmission, wound healing, and circadian clock manipulation. Various factors have been linked to abnormal metabolic reprogramming, including gene mutations, epigenetic modifications, altered protein epitopes, and their involvement in the development of disease, including cancer. The presence of multiple distinct hallmarks and the resulting cellular reprogramming process have gradually revealed that these metabolism-related molecules may be able to be used to track or prevent the progression of cancer. Consequently, translational medicines have been developed using metabolic substrates, precursors, and other products depending on their biochemical mechanism of action. It is important to note that these metabolic analogs can also be used for imaging and therapeutic purposes in addition to competing for metabolic functions. In particular, due to their isotopic labeling, these compounds may also be used to localize and visualize tumor cells after uptake. In this review, the current development status, applicability, and limitations of compounds targeting metabolic reprogramming are described, as well as the imaging platforms that are most suitable for each compound and the types of cancer to which they are most appropriate.

Efficacy and safety of high-dose vs low-dose leucovorin in patients with colorectal cancer: systematic review and meta-analysis

AIM

The clinical benefits of a combination of leucovorin and fluorouracil have been established in the treatment of colorectal cancer. Due to a leucovorin shortage in 2008, many institutions revised their protocols to reduce the dose of leucovorin. After the shortage was resolved, some hospitals still maintained their modified protocols. Thus, we conducted a systematic review to evaluate the efficacy and safety of low- vs high-dose leucovorin in the treatment of colorectal cancer.

METHOD

The PubMed, Embase and Cochrane databases were searched for studies published before May 2019. The meta-analysis was performed to estimate the pooled effect sizes by using a random effect model. The primary outcomes were median survival time and tumour response rate. Secondary outcomes were haematological and nonhaematological toxicities.

RESULTS

Eight randomized controlled trials and four retrospective studies were reviewed. The pooled median survival time was similar between the two dose levels (standard mean difference -0.06, 95% CI -0.19 to 0.08). The pooled tumour response rate was comparatively higher in the high-dose leucovorin regimen (OR 0.81; 95% CI 0.55-1.18). No statistically significant difference was found between the haematological and nonhaematological toxicities of the two groups. However, there were fewer diarrhoea events in the low-dose leucovorin regimen.

CONCLUSION

Low-dose leucovorin regimens seemed feasible approaches for colorectal cancer treatment when the shortage happened, because both regimens manifested comparable outcomes in survival time and tumour response rate.

Differential Survival Benefits of 5-Fluorouracil-Based Adjuvant Chemotherapy for Patients With Microsatellite-Stable Stage III Colorectal Cancer According to the Tumor Budding Status: A Retrospective Analysis

BACKGROUND

Recent research has established tumor budding as a prognostic factor and a possible histomorphologic reflection of epithelial-mesenchymal transition in colorectal cancer, highlighting the ability of cancer cells exhibiting epithelial-mesenchymal transition to resist chemotherapy.

OBJECTIVE

This study aimed to investigate the clinical benefits of adjuvant chemotherapy according to the tumor budding status in microsatellite-stable stage III colorectal cancer.

DESIGN

This was a retrospective study of 2 cohorts.

SETTINGS

The study was conducted at the National Defense Medical College in Japan.

PATIENTS

We reviewed 2 data sets of patients with microsatellite-stable stage III colorectal cancer with curatively intended surgery (R0) from 1999 to 2005 (first cohort; n = 203) and 2006 to 2012 (second cohort; n = 346). In both cohorts, 128 and 203 patients received 5-fluorouracil-based adjuvant chemotherapy and 75 and 143 patients did not.

MAIN OUTCOME MEASURES

We assessed the benefits of adjuvant chemotherapy according to the grades of tumor budding based on the cancer-specific survival.

RESULTS

In low-budding tumors, the chemotherapy group exhibited better cancer-specific survival than the surgery-alone group (first cohort, 93.1% vs 65.5%, p = 0.001; second cohort, 94.0% vs 76.0%, p < 0.0001). Conversely, the prognostic difference between the chemotherapy and surgery-alone groups was statistically insignificant in high-budding tumors (first cohort, 59.7% vs 52.4%, p = 0.57; second cohort, 83.1% vs 75.6%, p = 0.19). The multivariate analysis corroborated the benefits of adjuvant chemotherapy in low-budding tumors (first cohort, p = 0.002, HR = 0.28; second cohort, p < 0.0001, HR = 0.23) but not in high-budding tumors.

LIMITATIONS

Postoperative adjuvant chemotherapy and treatments for recurrence were not homogeneous, and the patient backgrounds differed between the chemotherapy and surgery alone groups.

CONCLUSIONS

The high-budding group demonstrated resistance to 5-fluorouracil-based chemotherapy, whereas the low-budding group exhibited significant survival benefits from adjuvant chemotherapy in stage III colorectal cancer. See Video Abstract at http://links.lww.com/DCR/B14. BENEFICIOS DE SUPERVIVENCIA DIFERENCIAL DE LA QUIMIOTERAPIA ADYUVANTE BASADA EN 5-FLUOROURACILO PARA PACIENTES CON CÁNCER COLORRECTAL EN ESTADIO III ESTABLE CON MICROSATÉLITE SEGÚN EL ESTADO DE BROTACIÓN DEL TUMOR: UN ANÁLISIS RETROSPECTIVO:: Investigaciones recientes han establecido la aparición de tumores como un factor pronóstico y una posible reflexión histomorfológica de la transición epitelial-mesenquimatosa en el cáncer colorrectal, destacando la capacidad de las células cancerosas que presentan una transición epitelio-mesenquimática para resistir la quimioterapia.El objetivo de este estudio es investigar los beneficios clínicos de la quimioterapia adyuvante según el estado de brotación del tumor en el cáncer colorrectal en estadio III estable con microsatélite.Este fue un estudio retrospectivo de dos cohortes.El estudio se realizó en la Escuela de Medicina de la Defensa Nacional de Japón.Revisamos dos conjuntos de datos de pacientes con cáncer colorrectal en estadio III estable con microsatélite con cirugía de intención curativa (R0) de 1999 a 2005 (primera cohorte; n = 203) y 2006 a 2012 (segunda cohorte; n = 346). En ambas cohortes, 128 y 203 pacientes recibieron quimioterapia adyuvante basada en 5-fluorouracilo y 75 y 143 pacientes no, respectivamente.Evaluamos los beneficios de la quimioterapia adyuvante de acuerdo con los grados de brotación del tumor en función de la supervivencia específica del cáncer.n los tumores con brotes bajos, el grupo de quimioterapia mostró una mejor supervivencia específica al cáncer que el grupo con cirugía sola (primera cohorte, 93.1% vs. 65.5%, p = 0.001; segunda cohorte, 94.0% vs. 76.0%, p < 0.0001). A la inversa, la diferencia pronóstica entre los grupos de quimioterapia y cirugía sola fue estadísticamente insignificante en los tumores de brotes elevados (primera cohorte, 59.7% vs. 52.4%, p = 0.57; segunda cohorte, 83.1% vs. 75.6%, p = 0.19). El análisis multivariado corroboró los beneficios de la quimioterapia adyuvante en los tumores de brotes bajos (primera cohorte, p = 0,002, índice de riesgo: 0,28; segundo cohorte, p <0,0001, índice de riesgo: 0,23) pero no en los tumores de alto brote.a quimioterapia adyuvante postoperatoria y los tratamientos para la recurrencia no fueron homogéneos, y los antecedentes de los pacientes difirieron entre los grupos de quimioterapia y cirugía sola.El grupo de alto brote demostró resistencia a la quimioterapia basada en 5-fluorouracilo, mientras que el grupo de bajo brote mostró beneficios significativos de supervivencia de la quimioterapia adyuvante en el cáncer colorrectal en estadio III. Vea el Resumen del Video en http://links.lww.com/DCR/B14.

Thymidine Metabolism as a Confounding Factor for 3'-Deoxy-3'-18F-Fluorothymidine Uptake After Therapy in a Colorectal Cancer Model

Noninvasive monitoring of tumor therapy response helps in developing personalized treatment strategies. Here, we performed sequential PET and diffusion-weighted MRI to evaluate changes induced by a FOLFOX-like combination chemotherapy in colorectal cancer xenografts, to identify the cellular and molecular determinants of these imaging biomarkers. Methods: Tumor-bearing CD1 nude mice, engrafted with FOLFOX-sensitive Colo205 colorectal cancer xenografts, were treated with FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) weekly. On days 1, 2, 6, 9, and 13 of therapy, tumors were assessed by in vivo imaging and ex vivo analyses. In addition, HCT116 xenografts, which did not respond to the FOLFOX treatment, were imaged on day 1 of therapy. Results: In Colo205 xenografts, FOLFOX induced a profound increase in uptake of the proliferation PET tracer 3'-deoxy-3'-18F-fluorothymidine (18F-FLT) accompanied by increases in markers for proliferation (Ki-67, thymidine kinase 1) and for activated DNA damage response (γH2AX), whereas the effect on cell death was minimal. Because tracer uptake was unaltered in the HCT116 model, these changes appear to be specific for tumor response. Conclusion: We demonstrated that 18F-FLT PET can noninvasively monitor cancer treatment-induced molecular alterations, including thymidine metabolism and DNA damage response. The cellular or imaging changes may not, however, be directly related to therapy response as assessed by volumetric measurements.

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.

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

Aims and Background

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

Methods

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

Results

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

Conclusions

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

“Misura” Project: A Retrospective Survey on the Use of 5fluorouracil in the Treatment of Colorectal Cancer in 24 Italian Clinical Centers

The “Misura” project is a retrospective survey, with the aim to evaluate how 5FU is used in the treatment of colorectal cancer in clinical practice in Italian oncology departments. Twenty-four centers participated. Patients seen in the second half of 1998 with colorectal cancer and treated with 5FU were analyzed. Observed patients were 664, 45.9% of patients presented metastatic disease. Biochemical modulation with folinic acid and bolus 5FU was the most used schedule (59%). The De Gramont (LV 5FU2) regimen, alone or with other cytotoxic drugs, was the second most chosen schedule (14%). The most frequent side effect observed was gastrointestinal toxicity. No hematological toxicity was demonstrated in 68.8% of patients. Cutaneous toxicity occurred in 21.1% of patients. 5FU is widely used independently by the stage of disease. In palliative treatment a variety of schedules were administered by the Italian centers, lacking a standard therapy. There are very few surveys investigating oncology clinical practice. A larger survey on this issue is auspicable.

Pharmacogenetic landscape of DPYD variants in south Asian populations by integration of genome-scale data

AIM

Adverse drug reactions to 5-Fluorouracil(5-FU) is frequent and largely attributable to genetic variations in the DPYD gene, a rate limiting enzyme that clears 5-FU. The study aims at understanding the pharmacogenetic landscape of DPYD variants in south Asian populations.

MATERIALS & METHODS

Systematic analysis of population scale genome wide datasets of over 3000 south Asians was performed. Independent evaluation was performed in a small cohort of patients.

RESULTS

Our analysis revealed significant differences in the the allelic distribution of variants in different ethnicities.

CONCLUSIONS

This is the first and largest genetic map the DPYD variants associated with adverse drug reaction to 5-FU in south Asian population. Our study highlights ethnic differences in allelic frequencies.

Drug delivery of oral anti-cancer fluoropyrimidine agents

INTRODUCTION

Sixty years since its introduction, 5-FU still forms the core of chemotherapy regimens for many types of malignancies. 5-FU is a time-dependent drug but is rapidly degraded in plasma by dihydropyrimidine dehydrogenase (DPD). Although originally developed in an intravenous form, 5-FU oral prodrugs were developed with the goal of improving efficacy and minimizing toxicity as well as to capitalize on the advantages of oral drug administration. The inactive 5-FU prodrug is gradually converted into the active form in the systemic circulation. UFT, S-1, and capecitabine are oral 5-FU prodrugs currently in clinical use. However, the efficacy of 5-FU can be further improved by its combination with DPD inhibitors and biochemical modulators, such as uracil and leucovorin, in addition to modifying administration schedules. Areas covered: We focused on the drug delivery of oral 5-FU prodrugs, their pharmacokinetics, and the development of DPD inhibitors. Since oral 5-FU prodrugs have been formulated into combination drugs, we also discussed the regulatory approval of combination drugs. Expert opinion: Many regimens that include intravenously administered 5-FU can be replaced by oral 5-FU prodrugs. Patients would benefit from development of combination 5-FU oral prodrug formulations and its associated path through the combination drug regulatory approval process.

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.

Capecitabine: a novel, orally administered, tumour-activated treatment for colorectal cancer

Objective. To provide a comprehensive review of the preclinical and clinical pharmacology and toxicology of the fluoropyrimidine, capecitabine, with particular reference to its use in its new indication, advanced colorectal cancer.

Data sources. A MEDLINE search was conducted using the term ‘‘capecitabine’’ for the period 1995 -2001. The reference lists from retrieved articles were reviewed and other relevant papers identified. The abstract books from the annual meetings of the American Society of Clinical and Oncology and the European Society of Medical Oncology were also reviewed.

Data extraction. The aim of the review was to be comprehensive and descriptive. All studies containing information deemed to be of interest were reviewed by the author, none were excluded on grounds of quality.

Data synthesis. Capecitabine is a prodrug of the widely used cytotoxic agent 5-fluorouracil (5-FU). Unlike 5-FU it is extensively and reliably absorbed after oral administration and does not require folinate (FA) potentiation. Activation of capecitabine is a three-step enzymatic process. The final activating enzyme, thymidine phosphorylase, is found in unusually high concentrations in many solid tumours, resulting in preferential delivery of 5-FU to tumour tissues, including that of colorectal cancers, suggesting therapeutic potential in this malignancy. Large, randomized trials have demonstrated that capecitabine fulfils this potential—compared with the widely used ‘‘Mayo’’ regimen of intravenous 5-FU and folinic acid, oral capecitabine (1250 mg/m2 twice daily) produced a superior response rate and a similar time to disease progression and duration of survival. It was also better tolerated than 5-FU/FA—of seven common fluoropyrimidine-induced toxicities, four were significantly less common with capecitabine. Capecitabine also produced significantly less grade 4 toxicity or toxicity requiring hospitalization, though the hand -foot syndrome that characterizes prolonged, continuous exposure to 5-FU was more common after capecitabine.

Chinese Herbal Medicine and Fluorouracil-Based Chemotherapy for Colorectal Cancer: A Quality-Adjusted Meta-Analysis of Randomized Controlled Trials

Background Chinese herbal medicines reportedly increase efficacy and minimize toxicity of chemotherapy; however, little attention has been paid to how poor study quality can bias outcomes. Methods We systematically searched MEDLINE, TCMLARS, EMBASE, and Cochrane Library for randomized controlled trials of Chinese herbal medicines combined with fluorouracil-based chemotherapy compared with the same chemotherapy alone. We screened for eligibility, extracted data, and pooled data with random-effects meta-analysis. Outcome measures were survival, toxicity, tumor response, performance status, quality of life, and Cochrane Risk of Bias (ROB) criteria to critically evaluate the quality of reporting in the randomized trials included in the meta-analysis. Results We found 36 potentially eligible studies, with only 3 (those with low ROB) qualifying for meta-analysis. Two reported chemotherapy-related diarrhea reduced by 57% (relative risk [RR] = 0.43; 95% CI = 0.19-1.01; I(2) test for variation in RR due to heterogeneity = 0.0%), with nonsignificant results. Two reported white blood cell toxicity reduced by 66% (RR = 0.34; 95% CI = 0.16-0.72; I(2) test for variation in RR due to heterogeneity = 0.0%), with statistically significant results. Stratifying analysis by studies with high versus low ROB, we found substantial overestimation of benefit: Studies with high ROB overestimated by nearly 2-fold reduction of platelet toxicity by Chinese herbal medicines (RR = 0.35, 95% CI = 0.15-0.84 vs RR = 0.65, 95% CI = 0.11-3.92). Studies with high ROB overestimated by nearly 2-fold reduction of vomiting toxicity (RR = 0.45, 95% CI = 0.33-0.61 vs RR = 0.87, 95% CI = 0.48-1.58). And, studies with high ROB overestimated by 21% the reduction in diarrhea toxicity (RR = 0.34, 95% CI = 0.20-0.58 vs RR = 0.43, 95% CI = 0.19-1.01). Studies with high ROB also overestimated by 16% improvement in tumor response (RR = 1.39, 95% CI = 1.18-1.63 vs RR = 1.20; 95% CI = 0.81-1.79). Not accounting for ROB would have exaggerated evidence of benefit and failed to detect nonsignificance of results. Conclusions In the present analysis, involving 36 studies, 2593 patients, 20 outcomes, 36 medical institutions, and 271 named research authors, 92% of the data points were from studies at high ROB. Given the poor quality of the data in studies identified, it cannot be concluded whether combining Chinese herbs with chemotherapy reduces toxicity of chemotherapy.

Reduced pharmacy resource utilization associated with raltitrexed treatment of advanced colorectal cancer

Objective. The pharmacy resources needed for prep aration of the direct, specific thymidylate synthase inhibitor raltitrexed (`Tomudex' ; Zeneca Pharmaceu ticals, Ltd., Macclesfield, UK); the Mayo, Machover, and De Gramont regimens of 5-fluorouracil (5-FU) and calcium leucovorin (LV); and continuous intravenous 5-FU for the treatment of advanced colorectal cancer were compared.

Design. The pharmacy time spent on prepara tion, the disposables used, and associated drug wast age were recorded and costed for a treatment cycle.

Patients. Colorectal cancer patients receiving standard treatment or included in a clinical trial in a large teaching hospital were considered.

Outcome Measures. The pharmacy preparative time, labor, disposable, and drug wastage costs per treatment cycle, prepared extemporaneously and us ing a batch process, were measured.

Results. A cycle of raltitrexed was much quicker to prepare than any other regimen (P < .05). The labor costs were significantly less (£2.87 for ralti trexed compared with £5.24-19.67 for the 5-FU regi mens) particularly with respect to the Machover regimen, which incurred costs seven times those of raltitrexed. The cost of disposables was significantly lower for raltitrexed, with continuously infused 5-FU incurring the greatest cost. As expected for a new treatment assessed within a clinical trial rather than in a routine setting, drug wastage was higher for ralti trexed (P < .05) except when compared with batch- preparation for the Machover regimen.

Conclusions. Raltitrexed was quicker and sim pler to prepare than 5-FU- based regimens for colo rectal cancer. This resulted in lower pharmacy labor and disposable costs, although in this study drug wastage was higher for raltitrexed prepared under clinical trial conditions.

An analysis of drug costs for the management of chemotherapy-related side effects in advanced colorectal cancer

Purpose. To assess whether there is a difference in associated drug costs for the management of chemo therapy-related side effects for patients with advanced colorectal cancer treated with raltitrexed (Tomudex, Zeneca Limited) or 5-FU plus folinic acid (Mayo regimen).

Data Sources. The drugs used for the manage ment of side effects were determined using a UK cohort (n = 62) taken from a large phase III ralti trexed clinical study. This study compared the toler ability and efficacy of raltitrexed vs 5-FU plus low- dose folinic acid and reported a significantly lower incidence of WHO grade 3/4 mucositis and leucope nia with raltitrexed. Drug costs were sourced using the British National Formulary, the Monthly Index of Medical Specialities and the Chemist and Druggist. Drug costs for the management of individual chemo therapy-related side-effects were calculated for both treatment groups and the total mean cost was com pared using the Student t test. Costs associated with the use of drugs for the management of clinically similar side effects, for example, nausea and vomiting were also investigated.

Results. There was a significant reduction in the mean total drug cost per patient for the management of chemotherapy-related side effects in the raltitrexed group compared to the 5-FU/folinic acid treatment group (£,64.27 vs £139.14; P = .0016). Infection was the most costly individual side effect for both treat ment groups but was lower in the raltitrexed cohort (£25.46 vs £59.93). Drug costs for the management of nausea and vomiting, pain and abdominal pain, and mucositis side effects were also considerably lower in the raltitrexed cohort.

Conclusion. The significantly lower drug cost for the management of chemotherapy-related side effects for the raltitrexed patients in the UK cohort suggests that the lower WHO grade 3/4 toxicity observed with raltitrexed in the phase III study would also be associated with a reduction in drug costs for the management of chemotherapy-related side ef fects.

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.

High- versus low-dose leucovorin in the modified FOLFOX6 regimen for first-line treatment of metastatic colorectal cancer

Background In response to the national leucovorin shortage in 2008, our institution adjusted the modified FOLFOX6 (leucovorin, fluorouracil, and oxaliplatin) protocol to utilize a lower dose of leucovorin (20 mg/m²). This adjustment was based on prospective studies suggesting that lower doses of leucovorin may be equally effective in other fluorouracil containing regimens. This retrospective study evaluates outcomes in metastatic colorectal cancer (mCRC) patients treated with low- (20 mg/m²) vs. high-dose (400 mg/m²) leucovorin in the FOLFOX6 regimen for mCRC. Methods This retrospective analysis included consecutive mCRC patients from 2004 to 2011 if they received at least one cycle of modified FOLFOX6 as first line therapy. Patients who received an initial leucovorin dose other than 20 mg/m² or 400 mg/m² on their first cycle were excluded. Patient characteristics included demographics, metastatic site at initial diagnosis, and treatment history including chemotherapy and surgery. Primary outcome was date of death or last contact. Cox proportional hazards regression analysis and Kaplan-Meier survival curves were utilized to evaluate the effect of leucovorin dose on overall survival. Log-rank tests were used to compare median survival times by dose group. Results Of the 93 mCRC patients who received first line modified FOLFOX6, leucovorin 400 mg/m² was administered to 47 (51%) patients and 20 mg/m² to 46 (49%) patients. There were no differences of baseline characteristics between the groups with exception of primary site of cancer ( p = 0.038). The overall survival time was 22.5 months (95% CI 16.6-29.6). The median survival time in the leucovorin 400 mg/m² group was 23.1 months (95% CI 16.2-35.7) compared to leucovorin 20 mg/m² which was 20.5 months (95% CI 14.2-34.2); p = 0.573. The median survival times in patients with one versus two or more sites with metastasis were statistically different (26.9 vs. 16.2 months, p = 0.009). Metastatic site removal or ablation showed differences in the median survival, 34.2 months (95% CI 20.8-50.9) vs. 16.6 months (95% CI 14.1-23.6) without metastatic disease removal ( p = 0.004). The odds of dying for patients with two metastatic sites was higher compared with the odds of those patients with one site, HR 1.8 (95% CI 1.08-3.0). Patients without metastatic site removal or ablation had higher odds of dying compared to those patients without this procedure, HR 0.47 (95% CI 0.27-0.81). Conclusion In this single center retrospective study, there was no difference in overall survival for mCRC patients treated with first line FOLFOX6 with low- vs. high-dose leucovorin.

A novel antimetabolite: TAS-102 for metastatic colorectal cancer

TAS-102 is a new oral anti-tumor drug, composed of a thymidine-based nucleoside analog (trifluridine: FTD) and a thymidine phosphorylase inhibitor (tipiracil hydrochloride: TPI). TAS-102 has been shown to significantly improve overall survival and progression-free survival in patients with refractory metastatic colorectal cancer (mCRC) in placebo-controlled randomized phase II and III trials. The current review summarizes mechanisms of action, pharmacokinetics/dynamics and preclinical and clinical data of TAS-102 in colorectal cancer. TAS-102 is a new salvage-line treatment option for patients with mCRC. TAS-102 is well tolerated and has great potential in future clinical drug combination therapies.

Effects of the leucovorin shortage: Pilot study investigating cost, efficacy, and toxicity comparison of low fixed-dose versus body surface area-adjusted leucovorin dosing in patients with resectable colon or metastatic colorectal cancer

Purpose As a result of the leucovorin shortage, we switched from BSA-adjusted to low fixed-dose leucovorin in patients with colon cancer receiving fluorouracil-containing therapy. Methods A retrospective, pilot study of adults receiving intravenous leucovorin as part of a fluorouracil-containing treatment was conducted including individuals with stage II or III colon or newly diagnosed metastatic colorectal cancer. One low fixed-dose (leucovorin 50 mg) patient was matched by the investigator to one BSA-adjusted (leucovorin 200-500 mg/m²/dose) patient on disease stage and age. The objectives were to compare cost of alternative dosing strategies as well as efficacy and adverse event rates. Only patients being treated in the first-line metastatic colorectal cancer setting were included in the efficacy analysis. Results Fifty-eight patients were included. Leucovorin cost was reduced by 7- to 14-fold, and we were able to conserve a total of 1580-3400 doses of leucovorin by changing to fixed-dose (estimated from 200 mg/m² or 400 mg/m² dosing strategies, respectively). No statistically significant differences in progression-free survival ( p = 0.254), overall survival ( p = 0.923), or complications resulted. Conclusion Our decision to reduce the dose of leucovorin allowed us to conserve supply and control cost. The small sample size did not allow us to detect differences in efficacy or adverse event rates, and thus a larger study would be required to confirm our findings that efficacy was not compromised nor adverse effects greater.

Impact of the perioperative neutrophil-to-lymphocyte ratio on the long-term survival following an elective resection of colorectal carcinoma

PURPOSES

The present study was designed to evaluate the prognostic value of the perioperative neutrophil-to-lymphocyte ratio (NLR) for the long-term survival in patients with colorectal cancer.

METHODS

This was a retrospective study of 524 patients with histologically proven stage II or III colorectal cancer who underwent curative colorectal resection. We classified patients into a low NLR group or high NLR group base on their NLR values at three time points (before surgery (Pre), on the first postoperative day (POD1), and on the third or fourth postoperative day (POD3)) and evaluated the survival according to the group.

RESULTS

The cancer-specific survival was significantly longer in the groups with a low NLR on POD3. The disease-free survival was significantly longer in the group with a low NLR on Pre. We subsequently allocated a score of 1 to patients with a high NLR at each point and reclassified patients into those with a low perioperative NLR group (score of 0 or 1) and high perioperative NLR group (score of 2 or 3). Both the cancer-specific survival and disease-free survival rates were significantly different between the two perioperative NLR groups. Both univariate and multivariate analyses demonstrated that being in the high perioperative NLR group was an independent risk factor for both the cancer-specific survival and disease-free survival.

CONCLUSIONS

Not only the preoperative but also the postoperative NTR is thus considered to be a predictor of the long-time survival in patients with colorectal cancer.

A community-based multicenter trial of pharmacokinetically guided 5-fluorouracil dosing for personalized colorectal cancer therapy

BACKGROUND

Pharmacokinetically guided (PK-guided) versus body surface area-based 5-fluorouracil (5-FU) dosing results in higher response rates and better tolerability. A paucity of data exists on PK-guided 5-FU dosing in the community setting.

PATIENTS AND METHODS

Seventy colorectal cancer patients, from one academic and five community cancer centers, received the mFOLFOX6 regimen (5-FU 2,400 mg/m(2) over 46 hours every 2 weeks) with or without bevacizumab at cycle 1. The 5-FU continuous-infusion dose was adjusted for cycles 2-4 using a PK-guided algorithm to achieve a literature-based target area under the concentration-time curve (AUC). The primary objective was to demonstrate that PK-guided 5-FU dosing improves the ability to achieve a target AUC within four cycles of therapy. The secondary objective was to demonstrate reduced incidence of 5-FU-related toxicities.

RESULTS

At cycles 1 and 4, 27.7% and 46.8% of patients achieved the target AUC (20-25 mg × hour/L), respectively (odds ratio [OR]: 2.20; p = .046). Significantly more patients were within range at cycle 4 compared with a literature rate of 20% (p < .0001). Patients had significantly higher odds of not being underdosed at cycle 4 versus cycle 1 (OR: 2.29; p = .037). The odds of a patient being within range increased by 30% at each subsequent cycle (OR: 1.30; p = .03). Less grade 3/4 mucositis and diarrhea were observed compared with historical data (1.9% vs 16% and 5.6% vs 12%, respectively); however, rates of grade 3/4 neutropenia were similar (33% vs 25%-50%).

CONCLUSION

PK-guided 5-FU dosing resulted in significantly fewer underdosed patients and less gastrointestinal toxicity and allows for the application of personalized colorectal cancer therapy in the community setting.

Phase I pharmacokinetic study of chronomodulated dose-intensified combination of capecitabine and oxaliplatin (XELOX) in metastatic colorectal cancer

PURPOSE

To evaluate the maximum tolerated dose (MTD) and pharmacokinetic profile of a chronomodulated, dose-intensified regimen of capecitabine in combination with oxaliplatin (XELOX) in metastatic colorectal cancer (mCRC).

METHODS

Patients (N = 18) with 0 or 1 line of prior chemotherapy received oxaliplatin 100 mg/m(2) on day 1 from 1400 to 1800 hours with escalating dose levels of capecitabine (2,500, 3,000, 3,500, 4,000, 4,500, and 5,000 mg) once daily taken at 2400 hours on days 1-5. Each cycle lasted 14 days.

RESULTS

The MTD of capecitabine was 4,500 mg. Transaminitis and anemia were the commonest non-hematologic and hematologic toxicities, respectively. Toxicities were generally mild, with only five occurrences of grade 3 toxicity and none of grade 4. There were no dose-limiting toxicities, defined as specific grade 3 or 4 toxicities occurring in the first two cycles of treatment. The objective response rate was 33.3 %, and median overall survival was 16.3 months (95 % CI: 11.2-18.2 months). The maximum plasma concentration (C(max)) and area under plasma concentration-time curve from time 0 to infinity (AUC([0-∞])) of the capecitabine metabolites in our fixed-dosing chronomodulated regimen were comparable to values seen with comparably dose-intense regimens but associated with significantly reduced toxicity.

CONCLUSIONS

Chronomodulated dose-intensified XELOX facilitates delivery of dose-intense treatment in mCRC with a favorable therapeutic index that is promising.

Adverse event profiles of 5-fluorouracil and capecitabine: data mining of the public version of the FDA Adverse Event Reporting System, AERS, and reproducibility of clinical observations

OBJECTIVE

The safety profiles of oral fluoropyrimidines were compared with 5-fluorouracil (5-FU) using adverse event reports (AERs) submitted to the Adverse Event Reporting System, AERS, of the US Food and Drug Administration (FDA).

METHODS

After a revision of arbitrary drug names and the deletion of duplicated submissions, AERs involving 5-FU and oral fluoropyrimidines were analyzed. Standardized official pharmacovigilance tools were used for the quantitative detection of signals, i.e., drug-associated adverse events, including the proportional reporting ratio, the reporting odds ratio, the information component given by a Bayesian confidence propagation neural network, and the empirical Bayes geometric mean.

RESULTS

Based on 22,017,956 co-occurrences, i.e., drug-adverse event pairs, found in 1,644,220 AERs from 2004 to 2009, it was suggested that leukopenia, neutropenia, and thrombocytopenia were more frequently accompanied by the use of 5-FU than capecitabine, whereas diarrhea, nausea, vomiting, and hand-foot syndrome were more frequently associated with capecitabine. The total number of co-occurrences was not large enough to compare tegafur, tegafur-uracil (UFT), tegafur-gimeracil-oteracil potassium (S-1), or doxifluridine to 5-FU.

CONCLUSION

The results obtained herein were consistent with clinical observations, suggesting the usefulness of the FDA's AERS database and data mining methods used, but the number of co-occurrences is an important factor in signal detection.

A Phase II Trial of 5-Fluorouracil, Leucovorin and Mitomycin C in Patients with Advanced Gastric Cancer

Aims and Background

Low-dose leucovorin is a well known potentiator of 5-fluorouracil activity in colorectal cancer but not in gastric cancer. To assess their efficacy on response rate and survival, 5-fluorouracil and low-dose leucovorin were combined with mitomycin C.

Methods

Fifty patients with gastric cancer and metastatic disease, unresectable or relapsed disease were treated with the following regimen every 28 days: mitomycin C, 7 mg/m2 IV bolus on day 1, and leucovorin, 20 mg/m2 IV, followed immediately by 5-fluorouracil, 375 mg/m2 on days 1–5. All had measurable disease and were assessable for toxicity. Prognostic factors were analyzed to examine any association with response rate or overall survival.

Results

Nineteen of the 48 assessable patients (39.6%; 95% confidence interval [CI], 25.8–53.4) responded, including 4 complete responses (8.3%). The median progression-free survival was 108 days (range, 18+ - 146), and the median duration of survival was 338 days (11.3 months; range, 18+ - 903 days). Response rate and overall survival were not significantly associated with CEA level, performance status, age, or primary and metastatic tumor sites. Toxicity associated with the chemotherapy was tolerable, and all patients were treated at the outpatient clinic. Leukopenia and thrombocytopenia WHO grade ≥3 occurred in 5% and 1% of the patients, respectively. Nausea and vomiting were the most frequent adverse effects (29%), all grade 1 or 2.

Conclusions

Combination chemotherapy of 5-fluorouracil plus leucovorin with mitomycin C is effective for the treatment of advanced gastric cancer and is well tolerated.

Colon cancer survival with herbal medicine and vitamins combined with standard therapy in a whole-systems approach: ten-year follow-up data analyzed with marginal structural models and propensity score methods

Although localized colon cancer is often successfully treated with surgery, advanced disease requires aggressive systemic therapy that has lower effectiveness. Approximately 30% to 75% of patients with colon cancer use complementary and alternative medicine (CAM), but there is limited formal evidence of survival efficacy. In a consecutive case series with 10-year follow-up of all colon cancer patients (n = 193) presenting at a San Francisco Bay-Area center for Chinese medicine (Pine Street Clinic, San Anselmo, CA), the authors compared survival in patients choosing short-term treatment lasting the duration of chemotherapy/radiotherapy with those continuing long-term. To put these data into the context of treatment responses seen in conventional medical practice, they also compared survival with Pan-Asian medicine + vitamins (PAM+V) with that of concurrent external controls from Kaiser Permanente Northern California and California Cancer Registries. Kaplan-Meier, traditional Cox regression, and more modern methods were used for causal inference-namely, propensity score and marginal structural models (MSMs), which have not been used before in studies of cancer survival and Chinese herbal medicine. PAM+V combined with conventional therapy, compared with conventional therapy alone, reduced the risk of death in stage I by 95%, stage II by 64%, stage III by 29%, and stage IV by 75%. There was no significant difference between short-term and long-term PAM+V. Combining PAM+V with conventional therapy improved survival, compared with conventional therapy alone, suggesting that prospective trials combining PAM+V with conventional therapy are justified.

Risk factors for oxaliplatin-induced hypersensitivity reactions in Japanese patients with advanced colorectal cancer

OBJECTIVE

Previously, we suggested that oxaliplatin (L-OHP)-related grade 3/4 hypersensitivity reactions occurred immediately after the initiation, but grade 1/2 reactions did not. This study was conducted to clarify the risk factors for L-OHP-related hypersensitivity reactions.

METHODS

Clinical data from 108 Japanese patients with colorectal cancer were analyzed, who were treated with L-OHP-containing regimens, FOLFOX4 and/or mFOLFOX6. The risk factors examined included demographic data, preexisting allergies, laboratory test data, treatment regimen, treatment line of therapy, pretreatment with steroids, total number of cycles and cumulative amount of L-OHP.

RESULTS

The incidence of grade 1/2 and grade 3/4 hypersensitivity reactions were found at 13.0% (14/108) and 9.3% (10/108), respectively. Female (P = 0.037), preexisting allergies (P = 0.004) and lower level of lactate dehydrogenase (P = 0.003) were risk factors for grade 1/2 hypersensitivity reactions, and higher neutrophil count (P = 0.043) and lower monocyte count (P = 0.007) were for grade 3/4 reactions. Total number of cycles were larger in the patients with grade 3/4 reactions than those without reactions (P = 0.049).

CONCLUSIONS

Further extensive examination with a large number of patients is needed to establish a patient management strategy.

Effects of bolus injection of 5-fluorouracil on steady-state plasma concentrations of 5-fluorouracil in Japanese patients with advanced colorectal cancer

OBJECTIVES

The irinotecan (CPT-11) + 5-fluorouracil (5-FU)/leucovorin (LV) + UFT/LV chemotherapy, in which repetitive oral administration of UFT/LV replaces the infusion of 5-FU/LV in the FOLFIRI regimen, has been proposed previously. In this study, five of 10 patients were injected with a bolus of 5-FU and the other were not injected with it in order to examine the effect of omitting it in terms of pharmacokinetics of 5-FU.

METHODS

The treatment consisted of the intravenous infusions of CPT-11 at 100 mg/m(2 )and l-LV at 15 mg/m(2), and the injection of a bolus of 5-FU at 500 mg/m(2) on day 1, and the repetitive oral administration of UFT/LV (300 mg/m(2)/day as tegafur + 75 mg/day of LV) on days 1-5. A total of 13 measurements of the plasma concentrations of uracil, 5-FU and tegafur were made per patient within 48 hr after the start of chemotherapy and the value of area under the concentration-time curve (AUC(0-48)) was evaluated. The plasma concentration was also determined at 2 weeks to assess long-term exposure to 5-FU.

RESULTS

The plasma concentrations of 5-FU at 24 hr after the start of treatment were 27.4 ng/mL and 9.4 ng/mL in the patients with and without the bolus injection, respectively. At 48 hr, they were 31.3 ng/mL and 10.4 ng/mL with the AUC(0-48) values of 22.16 mg h/L and 0.65 mg h/L, respectively. The 5-FU was detected in the plasma at 226 hr after the last administration of UFT/LV for the patients with the bolus injection, but not for those without.

CONCLUSION

A bolus of 5-FU on day 1 provided long-term exposure to 5-FU.

5-fu metabolism in cancer and orally-administrable 5-fu drugs

5-Fluorouracil (5-FU) is a key anticancer drug that for its broad antitumor activity, as well as for its synergism with other anticancer drugs, has been used to treat various types of malignancies. In chemotherapeutic regimens, 5-FU has been combined with oxaliplatin, irinotecan and other drugs as a continuous intravenous infusion. Recent clinical chemotherapy studies have shown that several of the regimens with oral 5-FU drugs are not inferior compared to those involving continuous 5-FU infusion chemotherapy, and it is probable that in some regimens continuous 5-FU infusion can be replaced by oral 5-FU drugs. Historically, both the pharmaceutical industry and academia in Japan have been involved in the development of oral 5-FU drugs, and this review will focus on the current knowledge of 5-FU anabolism and catabolism, and the available information about the various orally-administrable 5-FU drugs, including UFT, S-1 and capecitabine. Clinical studies comparing the efficacy and adverse events of S-1 and capecitabine have been reported, and the accumulated results should be utilized to optimize the treatment of cancer patients. On the other hand, it is essential to elucidate the pharmacokinetic mechanism of each of the newly-developed drugs, to correctly select the drugs for each patient in the clinical setting, and to further develop optimized drug derivatives.

Phase I dose-escalating study of S-1 in combination with oxaliplatin for patients with advanced and/or metastatic colorectal cancer

The purpose of this study was to determine the optimal dose of oxaliplatin, when combined with a fixed dose of S-1 (40 mg/m twice daily on days 1-14) on a 3-week schedule, for patients with advanced and/or metastatic colorectal cancer. Patients were required to have a histologically proven advanced or metastatic colorectal cancer for which they had received no previous chemotherapy. Oxaliplatin was administered intravenously on day 1 every 3 weeks. Patients were divided into two groups to receive two doses of oxaliplatin - 100 mg/m or 130 mg/m. Ten patients were enrolled in the study between March 2006 and July 2006, and were followed up until 50% of the patients progressed. All patients were evaluated for chemotherapy-related toxicity. The maximum tolerated dose was not reached during the first course. One of six patients experienced grade 3 thrombocytopenia at dose level 2 of oxaliplatin. Nonhematological toxicity was mild and tolerable. During the full course of treatment, complete response was achieved in two of the nine evaluated patients and partial response was achieved in one patient. The remaining six patients achieved stable disease during first two courses of therapy, and four patients remained stable at the time of the last follow-up. The median time to progression-free survival was 8.3 months. When combined with a fixed dose of S-1 80 mg/m, oxaliplatin administered at a dose of 130 mg/m is tolerable and recommended for phase II study.

Pneumatosis cystoides intestinalis after fluorouracil chemotherapy for rectal cancer

Pneumatosis cystoides intestinalis (PCI) is a relatively rare condition characterized by intraluminal gas in the gastrointestinal tract. Several chemotherapeutic agents have been reported to be associated with PCI, although fluorouracil-related PCI is extremely rare. We report a case of a 76-year old man who received adjuvant chemotherapy for rectal cancer with fluorouracil (FU) and leucovorin (LV). After 1 cycle of the treatment, he presented with diarrhea and abdominal pain. Abdominal radiogram revealed the presence of free air under the diaphragm and intramural gas in the intestine. Laparotomy was performed, showing a suspected diagnosis of perforation in the gastrointestinal tract. Intraoperative findings revealed pneumatosis of the intestine without evidence of perforation. He was treated supportively and his symptoms improved. In conclusion, we should consider the possibility of PCI occurring in patients with malignancies during chemotherapy treatment.

Individual fluorouracil dose adjustment based on pharmacokinetic follow-up compared with conventional dosage: results of a multicenter randomized trial of patients with metastatic colorectal cancer

PURPOSE

A phase III, multicenter, randomized study compared conventional dosing of fluorouracil (FU) plus folinic acid with pharmacokinetically guided FU dose adjustment in terms of response, tolerability, and survival.

PATIENTS AND METHODS

Two hundred eight patients with measurable metastatic colorectal cancer were randomly assigned to one of two arms: arm A (104 patients; 96 assessable), in which the FU dose was calculated based on body-surface area; and arm B (104 patients; 90 assessable), in which the FU dose was individually determined using pharmacokinetically guided adjustments. The initial regimen was 1,500 mg/m(2) FU plus 200 mg/m(2) folinic acid infusion during a continuous 8-hour period administered once weekly. FU doses were adjusted weekly in arm B based on a single-point measurement of FU plasma concentrations at steady state until the therapeutic range (targeted area under the curve 20-25 mg x h x L(-1)) previously established in other studies was reached.

RESULTS

An intent-to-treat analysis of the 208 patients showed the objective response rate was 18.3% in arm A and 33.7% in arm B (P = .004). Median overall survival was 16 months in arm A and 22 months in arm B (P = .08). The mean FU dose throughout treatment was 1,500 mg/m(2)/wk in arm A and 1,790 +/- 386 mg/m(2)/wk (range, 900 to 3,300 mg/m(2)/wk) in arm B. Toxic adverse effects were significantly more frequent and severe in arm A compared with arm B (P = .003).

CONCLUSION

Individual FU dose adjustment based on pharmacokinetic monitoring resulted in significantly improved objective response rate, a trend to higher survival rate, and fewer grade 3/4 toxicities. These results support the value of pharmacokinetically guided management of FU dose in the treatment of metastatic colorectal patients.

The influence of fluorouracil outcome parameters on tolerance and efficacy in patients with advanced colorectal cancer

The purpose of this study was to determine simple genetic factors helpful to tailor 5-FU administration and determine strategy in first-line chemotherapy of advanced colorectal cancer. In 76 patients initially treated by 5-FU, thymidylate synthase, dihydropyrimidine dehydrogenase and methylene tetrahydrofolate reductase germinal polymorphisms, dihydrouracil/uracil plasma ratio and 5-FU plasma clearance were investigated and correlated for tolerance (10.5% grade 3 and 4 toxicity) and efficacy (32.9% objective response rate and 20 months median overall survival time). Toxicity was linked to performance status >2 (P=0.004), low UH2/U ratio, 2846 A>T, IVS 14+1G>A for DPD (P=0.031), and homozygoty C/C for MTHFR 1298 A>C (P=0.0018). The overall survival of the patients with a 3R/3R TS genotype associated with C/C for 677 C>T or A/A for 1298 A>C was statistically shorter (log-rank test P=0.0065). Genetic factors permit the tailoring of 5-FU treatment. They should occupy center stage in future clinical trials for specifically designing treatment for patients with a given biologic feature.

Randomized clinical trial of high-dose levamisole combined with 5-fluorouracil and leucovorin as surgical adjuvant therapy for high-risk colon cancer

BACKGROUND

Levamisole combined with 5-fluorouracil (5-FU) was previously shown to significantly reduce tumor relapses and improve patient survival when given postoperatively in patients with resected stage III colon cancer. Laboratory investigations subsequently documented a direct dose-dependent enhancement of 5-FU cytotoxicity with increasing concentrations of levamisole against human cancer cell lines. A clinical trial was designed to test the value of levamisole given at its maximum tolerated dose in combination with 5-FU-based chemotherapy.

PATIENTS AND METHODS

Eight hundred seventy-eight patients who had undergone complete surgical resection of high-risk stage II/III colon cancer were stratified by known prognostic factors and randomized to receive 1 of 2 treatment regimens: standard-dose levamisole combined with 5-FU and leucovorin; or high-dose levamisole combined with the same chemotherapy. Serum neopterin was monitored in a cohort of patients to evaluate immune function.

RESULTS

Severe vomiting and neurologic side effects required reduction in the dose of levamisole that could be safely administered on the high-dose levamisole regimen. There were no significant differences in disease-free survival, overall survival, or levels of serum neopterin between the treatment regimens.

CONCLUSION

It was not possible to improve the efficacy of surgical adjuvant chemotherapy for patients with high-risk colon cancer by giving levamisole at its maximum tolerated dose in combination with 5-FU and leucovorin. High rates of severe gastrointestinal and neurologic side effects were observed with the high-dose levamisole regimen.

Randomised Trial Comparing Three Different Schedules of Infusional 5FU and Raltitrexed Alone as First-Line Therapy in Metastatic Colorectal Cancer

LV5FU2 with high-dose leucovorin (LV), weekly infusional 5-fluorouracil (5FU) (AIO schedule) and raltitrexed have been demonstrated to be active agents in first-line treatment of colorectal cancer. We performed a 4-arm randomised trial to compare (1) a low-dose intravenous bolus of LV (20 mg/m2), followed by an intravenous bolus of 5FU (400 mg/m2), followed by a 22-hour continuous infusion of 5FU (600 mg/m2) on day 1 and day 2/2 weeks (ldLV5FU2 arm), (2) a weekly continuous infusion of high-dose 5FU (2.6 g/m2/week) for 6 weeks followed by a rest week (HD-FU arm) and (3) raltitrexed (Tomudex arm; 3 mg/m2/3 weeks) to standard LV5FU2. From 1997 to 2001, 294 patients were included. The 4 arms were well balanced for sex ratio, age, WHO performance status, the primary tumour site and prior adjuvant chemotherapy. Treatment was stopped due to low accrual. Two toxicity-related deaths were observed in the Tomudex arm. The treatments gave rise to different rates of grade 3-4 neutropenia (3, 4, 11 and 14% of the patients in the LV5FU2, ldLV5FU2, HD-FU and Tomudex arms, respectively, p = 0.028), leucopenia and vomiting. At least one episode of grade 3-4 toxicity was observed in 27, 25, 38 and 47% of the patients in the LV5FU2, ldLV5FU2, HD-FU and Tomudex arms, respectively (p = 0.016). An objective response was observed in 28, 21, 22 and 10% of the patients in the LV5FU2, ldLV5FU2, HD-FU and Tomudex arms, respectively (p = 0.04). Progression-free survival (PFS) of the patients in the Tomudex arm was statistically lower compared to that of patients treated with LV5FU2 or ldLV5FU2 (combined group; p = 0.013, log rank test). In conclusion, Tomudex is more toxic and yields shorter PFS than infusional 5FU. Despite the early closure of the study and the lack of power of the comparison, it seems that ldLV5FU2 could be considered as an active, easier and less expensive option for the treatment of metastatic colorectal cancer compared to classic LV5FU2 or weekly HD-FU.

Irinotecan, oxaliplatin and raltitrexed for the treatment of advanced colorectal cancer

Out of every 17-18 individuals in the US, one develops colorectal cancer (CRC) in their lifetime. Of individuals diagnosed with CRC, > 50% present or develop metastatic disease, which, if untreated, is associated with 6-9 months median survival. Although surgical resection is the primary treatment modality for CRC, chemotherapy is the mainstay of treatment for metastatic or unresectable disease. For nearly three decades, 5-fluorouracil (5-FU) has been the chemotherapy of choice for treatment of CRC. However, the response rates to single 5-FU therapy have been suboptimal with an objective tumour response of 10-20%. Attempts have been made to improve the efficacy of 5-FU by either schedule alteration (protracted infusion versus intravenous push) or biochemical modulation with leucovorin (LV). Continuous infusion induced more tumour regression and prolonged the time-to-disease progression with some significant impact on survival (11.3 versus 12.1 months; p < 0.04). 5-FU/LV resulted in a significant increase in overall response rates and in the prolongation of disease-free survival in the adjuvant setting, although severe toxicities represent a major clinical problem. The last 10 years have seen the addition of several new agents such as irinotecan, oxaliplatin, raltitrexed, bevacizumab and cetuximab. The prognosis has significantly improved with the addition of these agents, with median survivals now > 20 months. This review paper focuses on irinotecan, oxaliplatin and raltitrexed when used alone and in combination.

2006 update of recommendations for the use of white blood cell growth factors: an evidence-based clinical practice guideline

PURPOSE

To update the 2000 American Society of Clinical Oncology guideline on the use of hematopoietic colony-stimulating factors (CSF).

UPDATE METHODOLOGY

The Update Committee completed a review and analysis of pertinent data published from 1999 through September 2005. Guided by the 1996 ASCO clinical outcomes criteria, the Update Committee formulated recommendations based on improvements in survival, quality of life, toxicity reduction and cost-effectiveness.

RECOMMENDATIONS

The 2005 Update Committee agreed unanimously that reduction in febrile neutropenia (FN) is an important clinical outcome that justifies the use of CSFs, regardless of impact on other factors, when the risk of FN is approximately 20% and no other equally effective regimen that does not require CSFs is available. Primary prophylaxis is recommended for the prevention of FN in patients who are at high risk based on age, medical history, disease characteristics, and myelotoxicity of the chemotherapy regimen. CSF use allows a modest to moderate increase in dose-density and/or dose-intensity of chemotherapy regimens. Dose-dense regimens should only be used within an appropriately designed clinical trial or if supported by convincing efficacy data. Prophylactic CSF for patients with diffuse aggressive lymphoma aged 65 years and older treated with curative chemotherapy (CHOP or more aggressive regimens) should be given to reduce the incidence of FN and infections. Current recommendations for the management of patients exposed to lethal doses of total body radiotherapy, but not doses high enough to lead to certain death due to injury to other organs, includes the prompt administration of CSF or pegylated G-CSF.

Combining systemic chemotherapy with chemoembolization in the treatment of unresectable hepatic metastases from colorectal cancer

Treatment of liver metastases from colorectal cancer include surgical resection, radiation, hepatic chemoembolization, immunotherapy and intravenous chemotherapy. Complete surgical resection of liver metastases is feasible only for solitary or unilobar metastasis. Unresectable hepatic metastases of colorectal origin are resistant to radiation and immunotherapy, and the unsatisfactory results of systemic chemotherapy and chemoembolization have led to more aggressive treatment. A new method that combines systemic chemotherapy and chemoembolization is proposed. In this study, data from a total of 40 patients with unresectable hepatic metastasis from colorectal cancer were collected. All of these patients received combined chemoembolization and systemic chemotherapy. Embolization was performed by the selective cannulation of right and left hepatic artery. Equal amounts of a mixture of 10 ml lipiodol, 1,500 mg 5-fluorouracil (5-FU) and 15 mg leucovorin was deployed selectively in equal parts into the main right and left hepatic artery. Two weeks following chemoembolization, patients underwent systemic chemotherapy with 2,600 mg/m2 5-FU continuous infusion for 24 h and received 150 mg leucovorin intravenous bolus. The course of chemotherapy was repeated weekly for 24 weeks. The median follow-up period was 27 months (range 10-36 months). Following the intention-to-treat principle, the objective tumor response rate was 47.5%. The median disease-free interval was 12 months and the median survival time was 16 months. Most of the patients (73%) died of hepatic failure, while the second largest group died of abdominal carcinomatosis. In conclusion, the results of this study are of sufficient interest to justify future randomized trials.