A randomized phase II study to compare oxaliplatin plus 5-fluorouracil and leucovorin (FOLFOX4) versus oxaliplatin plus raltitrexed (TOMOX) as first-line chemotherapy for advanced colorectal cancer

Efficacy of hepatic arterial infusion chemotherapy in patients with primary liver cancer with portal vein tumor thrombosis: a comparative analysis of different perfusion chemotherapeutic regimens

BACKGROUND

Portal vein tumor thrombosis (PVTT) commonly occurs in patients with primary liver cancer (PLC). Transarterial chemoembolization (TACE) is a treatment for patients with PLC and PVTT. Some studies have shown that combining TACE therapy with hepatic arterial infusion chemotherapy (HAIC) might improve the survival rate of PLC patients with PVTT. However, few studies have compared the different regimens of PLC with PVTT. We aimed to compare the differences between the oxaliplatin + raltetrexed regimen and FOLFOX regimen.

METHODS

We divided the 248 patients into two groups. There were 60 patients in the oxaliplatin + ratitetrexed group and 74 patients in the FOLFOX group. The primary endpoints were OS and PFS. The secondary endpoints were ORR and adverse events. We used SPSS software, the Kaplan-Meier method, the t test, and the rank sum test to compare the differences between the two groups.

RESULTS

The median OS was 10.82 months in the oxaliplatin + raltitrexed group and 8.67 months in the FOLFOX group. The median PFS time was greater in the oxaliplatin + raltitrexed group (10.0 months) than that in the FOLFOX group (7.1 months). The ORR was greater in the oxaliplatin + raltitrexed group than that in the FOLFOX group (18.3% vs. 13.5%; P = 0.445). The DCR in the oxaliplatin + raltitrexed group was higher than that in the FOLFOX group (70.0% vs. 64.8%; P = 0.529). However, in the subgroup analysis, the difference between them was more significant in the type II PVTT subgroup. The OS was 12.08 months in the oxaliplatin + raltitrexed group and 7.26 months in the FOLFOX group (P = 0.008). The PFS was 11.68 months in the oxaliplatin + raltitrexed group and 6.26 months in the FOLFOX group (P = 0.014). In the right branch of type II PVTT, the OS was 13.54 months in the oxaliplatin + raltitrexed group and 6.89 months in the FOLFOX group (P = 0.015), and the PFS was 13.35 months in the oxaliplatin + raltitrexed group and 6.27 months in the FOLFOX group (P = 0.030). The incidence of adverse reactions was similar between the two groups.

CONCLUSIONS

Compared with the FOLFOX regimen, the oxaliplatin + raltitrexed chemoembolization regimen had longer OS, PFS time and ORR and DCR and it was safe and tolerable.

First-line chemotherapy with raltitrexed in metastatic colorectal cancer: an Association des Gastro-entérologues Oncologues (AGEO) multicentre study

BACKGROUND

In case of contraindication or intolerance to fluoropyrimidines, raltitrexed is a validated alternative in metastatic colorectal cancer (mCRC), associated or not with oxaliplatin. Little is known about the outcomes of raltitrexed combined with irinotecan or targeted therapies.

METHODS

This retrospective multicentre study enroled mCRC patients treated with first-line raltitrexed-based chemotherapy. Treatment-related toxicities were recorded. Progression-free survival (PFS) and overall survival (OS) were calculated from treatment start.

RESULTS

75 patients were treated with raltitrexed alone, TOMOX, or TOMIRI with or without bevacizumab. Grade 3-4 adverse events were seen in 31% of patients, without significant difference between the different treatment schedules. amongst the 36 patients with a history of fluoropyrimidine-induced cardiac toxicity, none developed cardiovascular events on raltitrexed. Median PFS and OS were 10.6 (95% CI 8.2 - 13.1) and 27.4 months (95% CI 24.1-38.1), respectively. Considering the chemotherapy regimen, TOMOX was significantly associated with better PFS and OS compared to TOMIRI and raltitrexed alone.

CONCLUSIONS

In patients with mCRC not eligible for fluoropyrimidines, first-line raltitrexed-based chemotherapy had an acceptable safety profile. PFS and OS were consistent with usual survival data in mCRC, and significantly better in patients treated with TOMOX, independently of associated targeted therapies.

A prospective phase II study of raltitrexed combined with S-1 as salvage treatment for patients with refractory metastatic colorectal cancer

Aim

A third‐line chemotherapy regimen for metastatic colorectal cancer (mCRC) is not available in China. Studies have shown that raltitrexed or S‐1 has no complete cross‐resistance with fluorouracil (5‐FU). In this phase II study, we prospectively analyzed the efficacy and safety of raltitrexed combined with S‐1 (RS regimen) in the treatment of mCRC after the failure of conventional chemotherapy.

Methods

A total of 105 patients with mCRC with progression following treatment with 5‐FU, oxaliplatin, and irinotecan were enrolled between November 2015 and May 2019. Patients received intravenous infusion of raltitrexed (3 mg/m² from day 1 every 3 weeks) and oral S‐1 (80‐120 mg for 14 days every 3 weeks). Tumor evaluations were performed every two cycles according to the RECIST 1.1 guidelines.

Results

In the intention‐to‐treat patients, the objective response and disease control rates were 7.62% and 48.57%, respectively. The median progression‐free survival and median overall survival were 2.5 and 8.0 months, respectively. Common adverse events included neutropenia, anemia, thrombocytopenia, and nausea, while neutropenia, anemia, thrombocytopenia nausea, diarrhea, skin eruption, and oral ulceration had grade 3 or higher adverse events. Subgroup analysis revealed that primary site or gene mutation status had little influence on the RS regimen efficacy, while the baseline albumin level, 5‐FU administration in second‐line therapy, and number of previous treatment regimens affected the efficacy.

Conclusion

The RS regimen demonstrated favorable effects in patients with mCRC following failure of standard chemotherapy, and could be a new choice for third‐line treatment, and must be verified in future randomized clinical trials (Clinical trial: NCT02618356).

A comparison between raltitrexed plus cisplatin and docetaxel plus cisplatin in concurrent chemoradiation for non-surgical esophageal squamous cell carcinoma

PURPOSE

Chemoradiotherapy (CRT) is considered as a standard treatment for unresectable and inoperable esophageal cancer (EC) patients. However, no consensus has been reached regarding the optimal synchronous chemotherapy regimen and the best combination of radiotherapy and chemotherapy. The aim of this study was to evaluate the efficacy and toxicity of raltitrexed plus cisplatin and docetaxel plus cisplatin to find a safe and effective concurrent chemotherapy schedule.

PATIENTS AND METHODS

Our retrospective study included 151 EC patients treated with raltitrexed and cisplatin (RP) (n=90) or docetaxel and cisplatin (DP) (n=61) from 2011 till 2018. Survival outcomes and treatment related toxicity were analyzed between the two groups.

RESULTS

PFS and OS were 18 and 34 months in the RP group, while 13 and 20 months in the DP group (P=0.118 and P=0.270). The 1-, 2-, 3-year survival rates of the RP group were 71.1, 55.4 and 46.4%. For the DP group, these were 63.9, 44.3 and 37.6%, respectively. Compared with DP group, RP group received a superior CR rate (68.9% versus 52.5%, P=0.041). There was a trend that the total number of toxic reactions in RP group was lower than that in DP group (P=0.058).

CONCLUSIONS

Even RP and DP groups have the similar survival outcomes and toxicity, raltitrexed/cisplatin get a higher complete response rate. Our study suggests that raltitrexed combined with cisplatin is a safe and effective concurrent chemotherapy regimen and it might be used as an alternative for cisplatin/5-FU and cisplatin/docetaxel in CCRT for EC patients.

Magnitude of advantage in tumor response contributes to a better correlation between treatment effects on overall survival and progression-free survival: a literature-based meta-analysis of clinical trials in patients with metastatic colorectal cancer

BACKGROUND

Although it is suggested that the endpoints originated from the concept of tumor shrinkage dynamics, such as early tumor shrinkage and depth of response, are strongly associated with overall survival (OS) in patients with metastatic colorectal cancer (mCRC), they are yet to be validated as a single surrogate endpoint of OS by themselves. This study aimed to investigate the impact of advantage in tumor response on the correlation between treatment effects on progression-free survival (PFS) and OS in mCRC patients.

METHODS

Based on an electronic search, we identified randomized controlled trials of first-line therapy for mCRC. The impact of advantage in objective response rate (ORR) on the correlation between treatment effects on PFS and OS was evaluated based on Spearman correlation coefficients (r_s).

RESULTS

Forty-seven trials with a total of 24,018 patients were identified. The hazard ratio for PFS showed a relatively higher correlation with that for OS (r_s = 0.63) when the trials were limited to those that demonstrated a larger difference in ORR, compared to the case for trials that demonstrated a smaller difference (r_s = 0.32). This tendency was also observed in the subgroup analysis stratified by the types of treatment agents (targeted or non-targeted).

CONCLUSIONS

The magnitude of advantage in tumor response was suggested to contribute to a better prediction of OS benefit based on PFS in patients with mCRC. The accuracy of OS estimation in mCRC is expected to be improved by considering the degree of tumor shrinkage in conjunction with PFS.

Efficacy And Safety Of Raltitrexed Plus Oxaliplatin-Based Transarterial Chemoembolization In Patients With Unresectable Hepatocellular Carcinoma

Objective

To evaluate the efficacy and safety of raltitrexed plus oxaliplatin-based transarterial chemoembolization (TACE) in patients with unresectable hepatocellular carcinoma (HCC).

Methods

A total of 123 patients with unresectable HCC were recruited into the prospective cohort study. Raltitrexed plus oxaliplatin-based TACE was performed according to the traditional method at monthly intervals and was repeated for up to 4 cycles if no disease progression or intolerable toxicity occurred. The primary efficacy endpoint was overall survival (OS), and the secondary endpoints were progression-free survival (PFS) and tumor response rate. The Cox proportional-hazards regression model was used to assess the independent prognostic factors of OS. Adverse events were also observed.

Results

The median OS time and PFS were 623 days (95% CI: 461, 785) and 338 days (95% CI: 302, 704), respectively. The disease control rate was 95.5% (118/123). The Cox proportional-hazards regression model indicated that age, ECOG performance status and response to TACE as independent prognostic factors of OS. No treatment-related mortality occurred within 30 days of treatment procedure. The most common complications included postembolization syndrome, liver dysfunction and hematological toxicity. Grade 3 pain, transglutaminase abnormality and thrombocytopenia were observed in 16 (13%), 15 (12.2%) and 3 (2.4%) patients, respectively. No grade 4 adverse events were observed.

Conclusion

Raltitrexed plus oxaliplatin-based TACE led to high tumor response rate and promising PFS and OS, and was considered safe and tolerable in patients with unresectable HCC.

Efficacy and Cardiotoxic Safety Profile of Raltitrexed in Fluoropyrimidines-Pretreated or High-Risk Cardiac Patients With GI Malignancies: Large Single-Center Experience

BACKGROUND

Gastrointestinal (GI) cancer patients may not be considered for therapy with fluoropyrimidines (FPs) because of previous cardiovascular (CV) toxicity or preexisting risk factors; such patients may benefit from raltitrexed-based therapy.

PATIENTS AND METHODS

Patient, tumor, and treatment characteristics, as well as clinical outcomes of all consecutively treated patients with raltitrexed at the Royal Marsden Hospital between October 1998 and July 2011 were examined. GI cancer patients who developed CV toxicity as a result of FPs and those with significant CV risk factors receiving raltitrexed were included in this analysis.

RESULTS

A total of 247 patients (155 and 92 with CV FP-related CV toxicities and significant CV risk factors, respectively) treated with raltitrexed alone or in combination were examined after a median follow-up of 47.1 months. CV toxicity profiles of patients receiving capecitabine (n = 110) and 5-fluorouracil (n = 45) were largely similar. Of raltitrexed-treated patients, 13 (5%) experienced CV toxicities and 1 (< 0.1%) died as a result of myocardial infarction. The median progression-free survival (PFS) and overall survival (OS) were 36.0 months (95% confidence interval [CI], 26.5-48.6) and 44.3 months (95% CI, 33.1-56.8), respectively. The 5-year survival for early stage GI malignancies (n = 140) was 62.0% (95% CI, 50.1-71.9). Median PFS and OS were not reached in this group (interquartile range = 38.4 months to NR); median PFS and OS for advanced GI malignancies (n = 107) were 18.8 (95% CI, 11.9-25.7) and 23.7 months (95% CI, 17.0-26.9), respectively.

CONCLUSION

A raltitrexed-based regimen is well-tolerated therapy with comparable efficacy to FPs in patients with GI malignancies with significant CV toxicities or risk factors.

Transarterial chemoembolization with raltitrexed-based or floxuridine-based chemotherapy for unresectable colorectal cancer liver metastasis

PURPOSE

To evaluate and compare the efficiency and safety of raltitrexed- or floxuridine (FUDR)-based transarterial chemoembolization (TACE) in patients with unresectable colorectal cancer liver metastasis (CRCLM).

METHODS

We conducted a retrospective analysis of 81 patients with unresectable CRCLM who failed systemic chemotherapy and were treated with TACE in our department from Oct 2014 to Oct 2017. Of these, 61 patients received TACE using raltitrexed, oxaliplatin, and pirarubicin (raltitrexed group), and 20 received TACE using FUDR, oxaliplatin, and pirarubicin (FUDR group). The objective response rate (ORR), disease control rate (DCR), overall survival (OS, from the first TACE), progression-free survival (PFS, from the first TACE), and adverse reactions were evaluated and compared between the two groups, and prognostic factors for OS were analyzed.

RESULTS

The ORRs of the raltitrexed group and FUDR group were 67.2 and 45.0%, respectively (P = 0.076), and the DCRs were 86.9 and 80.0%, respectively (P = 0.452). The median OS (from first TACE) was 14.0 months in the raltitrexed group and 13.0 months in the FUDR group (P = 0.556). The median PFS (from first TACE) was 2.1 months in the raltitrexed group and 2.4 months in the FUDR group (P = 0.878). Univariate and multivariate analyses showed that the primary tumor site, Child-Pugh class, and combination with local ablation (RFA or CRA) were independent significant factors affecting survival. There were no significant differences in adverse reactions between the two groups (P > 0.05), and no treatment-related death occurred in either group.

CONCLUSION

TACE treatment based on raltitrexed or FUDR is an efficient and safe alternative choice for treating unresectable CRCLM.

Cardiotoxicity of 5-fluorouracil and capecitabine in Chinese patients: a prospective study

Background

5-Fluorouracil (5-FU) and capecitabine-associated cardiotoxicity ranging from asymptomatic electrocardiography (ECG) abnormalities to severe myocardial infarction has been reported in a number of studies, but such cardiotoxicity in Chinese patients with malignant diseases has not been investigated to date. In the present study, we aimed to prospectively evaluate the incidence rates and clinical manifestations of 5-FU- and capecitabine-associated cardiotoxicity in cancer patients recruited from multiple centers in China.

Methods

Among the 527 patients who completed the study, 196 received 5-FU-based chemotherapy and 331 received capecitabine-based chemotherapy as either first-line or adjuvant therapy. Adverse events were reported during the treatment and up to 28 days of follow-up. Outcome measures included ECG, myocardial enzymes, cardiac troponin, brain natriuretic peptide and echocardiography. Univariate analysis and logistic regression were performed for subgroup analysis and identification of significant independent variables that are associated with cardiotoxicity of both agents.

Results

In total, 161 of 527 patients (30.6%) experienced cardiotoxicity. The incidence rate of cardiotoxicity was 33.8% (112/331) in the capecitabine group, which was significantly higher than the rate of 25% (49/196) in the 5-FU group (P = 0.0042). 110/527 patients (20.9%) suffered arrhythmia, 105/527 (19.9%) developed ischemic changes, while only 20/527 patients (3.8%) presented heart failure and 6/527 patients (1.1%) had myocardial infarction. Pre-existing cardiac disease, hypertension, capecitabine-based chemotherapy and duration of treatment were identified as significant risk factors associated with cardiotoxicity. The odds ratio were 15.7 (prior history of cardiac disease versus no history), 1.86 (capecitabine versus 5-FU), 1.06 (5–8 versus 1–4 chemotherapy cycles) and 1.58 (hypertension versus no hypertension), respectively.

Conclusions

Cardiotoxicity induced by fluoropyrimidines in the Chinese population may be underestimated in clinical practice. Close monitoring of patients is recommended, especially for those patients at high risk for cardiotoxicity. Possible risk factors are duration of treatment, capecitabine-based chemotherapy, pre-existing cardiac diseases and hypertension.

Trial registration This study was initiated on January 22, 2014 and has been retrospectively registered with the registration number ChiCTR1800015434

The Role of Fluoropirimidines in Gastrointestinal Tumours: from the Bench to the Bed

PURPOSE

Gastrointestinal tumours are one of the most common types of cancer. Therapeutic options include surgery, radiotherapy, local ablation techniques, targeted agents, and chemotherapy. Fluoroprimidines are one of the most active drug families in digestive tumours and remains the cornerstone of the most commonly used chemotherapy schemes.

METHODS

We review the molecular basis of thymidylate synthase inhibition and the mechanisms of action of 5-fluorouracil, next generation oral fluoropyrimidines (capecitabine, tegafur and the latest S-1 and TAS-102) and antifolates.

RESULTS

In addition, mechanisms and biomarkers of resistance and toxicity are explored. Finally, new fluoropyrimidines development and clinical trials ongoing in digestive tumours are reviewed.

CONCLUSIONS

Further research is necessary to avoid resistance mechanisms, improve clinical outcomes and continue reducing toxicities. Until new drugs become available, the optimization of current therapies should be a priority.

Network meta-analysis of the efficacy of first-line chemotherapy regimens in patients with advanced colorectal cancer

This network meta-analysis compared the short-term and long-term efficacies of first-line chemotherapy regimens in patients with advanced colorectal cancer (CRC). The 10 regimens included folinic acid + 5-fluorouracil + oxaliplatin (FOLFOX), folinic acid + 5-fluorouracil + irinotecan (FOLFIRI), folinic acid + 5-fluorouracil + gemcitabine (FFG), folinic acid + 5-fluorouracil + trimetrexate (FFT), folinic acid + 5-fluorouracil (FF), irinotecan + oxaliplatin (IROX), raltitrexed + oxaliplatin (TOMOX), folinic acid + tegafur-uracil (FTU), raltitrexed, and capecitabine. Electronic searches were performed in the Cochrane Library, PubMed and Embase databases from inception to June 2017. Network meta-analysis combined direct and indirect evidence to obtain odds ratios (ORs) and surface under the cumulative ranking curves (SUCRA) of different chemotherapy regimens for advanced CRC. Fourteen randomized controlled trails (RCTs) covering 4,383 patients with advanced CRC were included. The results revealed that FOLFOX, FOLFIRI, IROX, and TOMOX all showed higher overall response rates (ORRs) than FF or raltitrexed. Compared with raltitrexed, the aforementioned four regimens also had higher 1-year progression-free survival (PFS) rates. In addition, FOLFOX and FOLFIRI exhibited higher disease control rates (DCRs) and 1-year PFS rates than FF or raltitrexed. Cluster analysis revealed that FOLFOX, FOLFIRI, and TOMOX had better short-term and long-term efficacies. These findings suggest FOLFOX, FOLFIRI, and TOMOX are superior to other regimens for advanced CRC. These three regimens are therefore recommended for clinical treatment of advanced CRC.

Hepatic artery infusion with raltitrexed or 5-fluorouracil for colorectal cancer liver metastasis

AIM

To evaluate the efficiency and safety of hepatic artery infusion chemotherapy (HAIC) using raltitrexed or 5-fluorouracil for colorectal cancer (CRC) liver metastasis (CRCLM).

METHODS

A retrospective analysis of patients with unresectable CRCLM who failed systemic chemotherapy and were subsequently treated with HAIC at our institute from May 2013 to April 2015 was performed. A total of 24 patients were treated with 5-fluorouracil, and 18 patients were treated with raltitrexed.

RESULTS

The median survival time (MST) from diagnosis of CRC was 40.8 mo in the oxaliplatin plus raltitrexed (TOMOX) arm and 33.5 mo in the oxaliplatin plus 5-fluorouracil (FOLFOX) arm (P = 0.802). MST from first HAIC was 20.6 mo in the TOMOX arm and 15.4 mo in the FOLFOX arm (P = 0.734). Median progression-free survival (PFS) from first HAIC was 4.9 mo and 6.6 mo, respectively, in the TOMOX arm and FOLFOX arm (P = 0.215). Leukopenia (P = 0.026) was more common in the FOLFOX arm, and hepatic disorder (P = 0.039) was more common in the TOMOX arm. There were no treatment-related deaths in the TOMOX arm and one treatment-related death in the FOLFOX arm. Analysis of prognostic factors indicated that response to HAIC was a significant factor related to survival.

CONCLUSION

No significant difference in survival was observed between the TOMOX and FOLFOX arms. HAIC treatment with either TOMOX or FOLFOX was demonstrated as an efficient and safe alternative choice.

A systematic review of raltitrexed-based first-line chemotherapy in advanced colorectal cancer

Raltitrexed is a thymidylate synthase inhibitor belonging to the antimetabolite class of cytotoxic drugs. It is also effective in colorectal cancer (CRC) both as a single agent and in combination with other drugs, in particular in those patients with cardiologic risk factors or previous cardiotoxicity. The efficacy of first-line raltitrexed-based chemotherapy containing oxaliplatin (TOMOX) and irinotecan (TOMIRI) was investigated in this systematic review. Studies that enrolled advanced CRC patients for first-line therapy with TOMOX/TOMIRI combinations were identified using electronic databases (Pubmed, SCOPUS, Web of Science, EMBASE, and the Cochrane Library). A systematic analysis was carried out using Comprehensive Meta Analysis (version 2.2.064) software to calculate the pooled response rate and 95% confidence limits. The median pooled overall survival and progression-free survival were also calculated. Results for TOMOX and TOMIRI studies were compared using the two-sided Student's t-test. We tested for significant heterogeneity using Cochran's χ-test and I index. Twelve studies published between 2001 and 2012 were eligible for this analysis and a total of 735 patients were enrolled in these studies. The overall response rate was 40% (95% confidence interval 34-46%): 43.9% for TOMOX and 34.1% for TOMIRI arms. The weighted median overall survival and progression-free survival times were 14.6 and 6.7 months, respectively. Neutropenia and liver toxicity were more frequent with TOMOX, whereas neutropenia and diarrhea were more frequent with TOMIRI. However, compared with historical FOLFOX and FOLFIRI trials, raltitrexed-based doublets are associated with less neutropenia and gastrointestinal toxicity and uncommon cardiotoxicity. TOMOX and TOMIRI doublets are active as first-line chemotherapy for advanced CRC and seem useful in particular when the use of 5-fluorouracil is contraindicated for cardiac comorbidity.

Dilemma of dihydropyrimidine dehydrogenase deficiency in colorectal cancer patients: is Uftoral® the right answer?

SUMMARY 

Fluoropyrimidines (5-fluorouracil, capecitabine, S-1, Uftoral® [UFT; Merck, Germany]) and their derivatives are effective in management of colorectal cancer. DPD deficiency is not routinely tested and is usually diagnosed after a patient has severe/grade IV toxicity secondary to the use of 5-fluorouracil or capecitabine. Once DPD deficiency is diagnosed, there are sparse data on the use of UFT or raltitrexed and there are no comparable outcome data with well-known regimens like infusional 5-fluorouracil, leucovorin oxaliplatin (FOLFOX) and infusional 5-fluorouracil, leucovorin, irinotecan (FOLFIRI). Here we report the first case series from India of DPD deficiency and the use of UFT.

Raltitrexed-based chemotherapy for advanced colorectal cancer

AIMS

To evaluate the efficiency and safety profile of raltitrexed-based chemotherapy in the treatment of advanced colorectal cancer.

METHODS

An electronic search was undertaken to identify randomized controlled trials comparing raltitrexed-based regimen to 5-fluorouracil-based regimen in patients with advanced colorectal cancer. The outcomes included overall survival, overall response rate and toxicities.

RESULTS

This meta-analysis included 11 studies with 4622 patients. Overall, there were no significant differences between the two regimens in terms of overall survival (HR=1.06, 95% CI: 0.96-1.17, P=0.23) or overall response rate (RR=1.09, 95% CI: 0.86-1.38, P=0.47). In subgroup analysis, patients in raltitrexed/oxaliplatin group had significantly higher partial response (RR=1.53, 95% CI: 1.17-2.00, P=0.002), overall response rate (RR=1.42, 95% CI: 1.10-1.82, P=0.006), disease control rate (RR=1.16, 95% CI: 1.04-1.29, P=0.009) and lower progressive disease (RR=0.61, 95% CI: 0.45-0.84, P=0.002) when compared to 5-fluorouracil/leucovorin/oxaliplatin group. Occurrence of severe anemia (RR=2.23, 95% CI: 1.38-3.59, P=0.0001), asthenia (RR=2.29, 95% CI: 1.36-3.84, P=0.002), hepatic disorders (RR=7.51, 95% CI: 1.30-43.56, P=0.02), and nausea/vomit (RR=1.70, 95% CI: 1.03-2.81, P=0.04) were significantly higher with the raltitrexed arm treatment, while frequencies of grade 3/4 alopecia (RR=0.36, 95% CI: 0.26-0.50, P<0.00001) and stomatitis/mucositis (RR=0.14, 95% CI: 0.07-0.31, P<0.00001) were increased in the 5-fluorouracil group.

CONCLUSIONS

Raltitrexed-based chemotherapy regimen leads to an equivalent overall survival and response rates with acceptable toxicities compared to traditional 5-fluorouracil-based regimen in patients with advanced colorectal cancer. Raltitrexed can be a treatment option for these patients when 5-fluorouracil-based regimens are not tolerated or inappropriate.

In vivo biodistribution of platinum-based drugs encapsulated into multi-walled carbon nanotubes

Carbon nanotubes (CNTs) are promising drug delivery systems due to their external functionalizable surface and their hollowed cavity that can encapsulate several bioactive molecules. In this study, the chemotherapeutic drug cisplatin or an inert platinum(IV) complex were entrapped inside functionalized-multi-walled-CNTs and intravenously injected into mice to investigate the influence of CNTs on the biodistribution of Pt-based molecules. The platinum levels in vital organs suggested that functionalized-CNTs did not affect cisplatin distribution, while they significantly enhanced the accumulation of Pt(IV) sample in some tissues (e.g. in the lungs, suggesting their potential application in lung cancer therapy) and reduced both kidney and liver accumulation (thus decreasing eventual nephrotoxicity, a typical side effect of cisplatin). Concurrently, CNTs did not induce any intrinsic abnormal immune response or inflammation, as confirmed by normal cytokine levels and histological evaluations. Therefore, functionalized nanotubes represent an efficient nano-carrier to improve accumulation of Pt species in targeted tissues/organs. From the clinical editor: In this preclinical study functionalized carbon nanotubes are reported to be safe and efficient for targeted delivery of platinum-containing compounds in rodents. Approaches like this may improve the treatment of specific cancers, since platinum based chemotherapies are commonly used, yet limited by toxicity and relatively poor target tissue concentration.

Proteomic analysis of differentially expressed proteins in 5-fluorouracil-treated human breast cancer MCF-7 cells

BACKGROUND

5-Fluorouracil (5-Fu) is a commonly used chemotherapeutic agent in clinical care of breast cancer patients. However, the mechanism of how the 5-Fu works is complex and still largely unknown.

OBJECTIVE

The objective of this study was to understand the mechanism further and explore the new targets of 5-Fu.

METHODS

The differentially expressed proteins induced by 5-Fu in human breast cancer MCF-7 cells were identified by proteomic analysis. Four differentially expressed proteins were validated using Western blot and quantitative real-time reverse-transcription polymerase chain reaction analysis for protein and mRNA levels. The effect of 5-Fu on MCF-7 cells was determined by cell viability assay, transmission electron microscopy and flow cytometry analysis.

RESULTS

5-Fu dose-dependently inhibited cell proliferation with the IC50 value of 98.2 μM. 5-Fu also induced obviously morphological change and apoptosis in MCF-7 cells. Twelve differentially expressed proteins involved in energy metabolism, cytoskeleton, cellular signal transduction and tumor invasion and metastasis were identified.

CONCLUSION

These results may provide a new insight into the molecular mechanism of 5-Fu in therapy of breast cancer.

Targeting thymidylate synthase in colorectal cancer: critical re-evaluation and emerging therapeutic role of raltitrexed

INTRODUCTION

5-fluorouracil continues to be the cornerstone of treatment for colorectal cancer. Although fluoropyrimidines are generally considered as well-tolerated drugs, severe toxicities can be a major clinical problem, and the recommended prolonged infusion of 5-fluorouracil provokes discomfort in patients. Raltitrexed (Tomudex), a quinazoline analogue of folinic acid, is a selective and direct thymidylate synthase (TS) inhibitor with a convenient 3-weekly schedule of administration.

AREAS COVERED

In this review, through critical insight into the mechanism of action and main clinical experiences, the authors suggest the necessity to reconsider raltitrexed as a valuable anticancer drug and as a suitable option for colorectal cancer. The authors highlight its emerging therapeutic role in clinical practice for patients with fluoropyrimidine-induced cardiotoxicity or a significant history of cardiac disease.

EXPERT OPINION

This review discusses if TS could still be a relevant target for colorectal cancer in the era of molecular therapy and if raltitrexed should still be considered a drug with a life-threatening toxicity. Furthermore, this review discusses the principal combination clinical experiences of raltitrexed and its emerging therapeutic role in clinical practice as a suitable option for colorectal cancer patients with fluoropyrimidine-induced cardiotoxicity or a significant history of cardiac disease.

Personalizing colon cancer therapeutics: targeting old and new mechanisms of action

The use of pharmaceuticals for colon cancer treatment has been increasingly personalized, in part due to the development of new molecular tools. In this review, we discuss the old and new colon cancer chemotherapeutics, and the parameters that have been shown to be predictive of efficacy and safety of these chemotherapeutics. In addition, we discuss how alternate pharmaceuticals have been developed in light of a potential lack of response or resistance to a particular chemotherapeutic.