Capecitabine in combination with irinotecan (XELIRI), administered as a 2-weekly schedule, as first-line chemotherapy for patients with metastatic colorectal cancer: a phase II study of the Spanish GOTI group

BACKGROUND

Combination chemotherapy is standard treatment for metastatic colorectal cancer (MCRC). The aim of this study was to determine the efficacy and safety of capecitabine+irinotecan (2-weekly schedule), as first-line therapy of MCRC.

METHODS

Patients received irinotecan 175 mg m(-2) on day 1 and oral capecitabine 1000 mg m(-2) twice daily on days 2-8 every 2 weeks. For patients aged > or =65 years, the starting doses of irinotecan and capecitabine were reduced to 140 and 750 mg m(-2), respectively.

RESULTS

A total of 53 patients were enrolled: 29 (55%) were > or =65 years old. In an intention-to-treat analysis, complete response was achieved in three patients for an overall response rate (ORR) of 32%. The disease control rate (ORR + stable disease) was 66% and the median duration of response was 7.3 months. Median time to progression and overall survival were 9.0 and 19.2 months, respectively. Grade 4 neutropenia was reported in one patient: no other grade 4 toxicities were recorded. Grade 3 diarrhoea occurred in 8 (15%) patients and grade 1-2 hand-foot syndrome in 7 (13%) patients.

CONCLUSION

Capecitabine and irinotecan, given every 2 weeks, as first-line treatment of MCRC is an active regimen with a manageable toxicity profile, even in older patients.

Improving disease control in advanced colorectal cancer: Panitumumab and cetuximab

Colorectal cancer remains a major public health concern in Europe and North America. It is responsible for one million new cases and half a million deaths per year worldwide. During the past few years new effective treatments have evolved improving the outcome of patients with this disease. Several alternatives are currently available for advanced colorectal cancer patients including different chemotherapeutic regimens (fluoropyrimidines, irinotecan and oxaliplatin) and targeted therapies such as bevacizumab and cetuximab. Different combinations achieve a median survival of over 2 years. Intense efforts focus on identifying agents targeting growth factor receptors, signal transduction pathways or angiogenesis mediators. One of the last available drugs for the management of advanced colorectal cancer is panitumumab, a well-tolerated and effective anti-EGFR monoclonal antibody approved as a single agent in chemotherapy refractory patients. We discuss the current evidence supporting panitumumab for metastatic colorectal cancer treatment, potential predictive biomarkers and ongoing clinical trials with different combinations including panitumumab.

[Key events from the 4th French-speaking congress on digestive and hepatobiliary surgery: synthesis of the oral communications and report of symposium. December 4-6 2008, Paris]

Are presented in this issue, the main oral communications presented at the 4(th) francophone congress on digestive and hepatobiliary surgery and an overview of the symposium that was dedicated to the metastatic colorectal cancer treatment. Colorectal carcinoma is the second leading cause of cancer in Europe and the third cause of cancer death in the United States. Every year in France, 36,000 new cases are diagnosed, 50% of them with visceral metastases. Among these metastasis patients, 70% exhibit liver metastases exclusively at time of diagnosis. In most patients, liver metastases are non resectable, with exclusive chemotherapy offering poor survival. Surgery is the only curative treatment. Among patients with liver metastases, 10 to 20% are resectable with 40% of them surviving at 5 years. The aim of the chemotherapy intensification schedules is to allow resection in 15 to 30% of initially non resectable metastatic patients and consequently offering some long term survivals. Regarding metastatic colorectal cancer treatment, confrontation between oncologists and surgeons is essential in order to give the opportunity to a significant number of metastatic patients to access to cure.

Treatment for colorectal liver metastases: a review

INTRODUCTION

Over the past decade, the emergence of surgical adjuncts such as portal vein embolization, two-stage hepatectomy, and ablative therapies not only decreases mortality and morbidity after an extended hepatectomy but also broadens the indication for surgical treatment of liver metastasis from colorectal cancer. Combination chemotherapeutic regimens, namely 5-fluorouracil/folinic acid with irinotecan or oxaliplatin, and targeted monochromal antibodies can downsize the tumor burden to the extent that formerly unresectable metastases can sometimes be excised.

DISCUSSION

The 5-year survival rate following liver resection ranges between 25% and 58%. During the 5-fluorouracil/folinic acid with oxaliplatin and 5-fluorouracil/folinic acid with irinotecan treatment period, the patients who were deemed to be resectable should be considered as surgical candidates regardless of the associated adverse predictive factors. The emergence of epidermal growth factor receptor antibody agents, which act effectively in patients with Kras wild-type tumor, fosters treatment individualization.

CONCLUSION

The efficacy of the perioperative chemotherapy on survival benefit for resectable liver metastases has not been justified. However, the timing and indication of surgical treatment paradigm in colorectal liver metastasis, including for synchronous disease and extrahepatic disease, are dramatically changing with the development of chemotherapeutic agents.

How much is life worth: cetuximab, non-small cell lung cancer, and the $440 billion question

The spiraling cost of cancer care, in particular the cost of cancer therapeutics that achieve only marginal benefits, is under increasing scrutiny. Although health-care professionals avoid putting a value on a life, our limited resources require that society address what counts as a benefit, the extent to which cost should factor in deliberations, and who should be involved in these decisions. Professional societies, such as the American Society of Clinical Oncology, government agencies, including the Food and Drug Administration, and insurance companies should be involved. However, no segment of society is better qualified to address these issues than the oncology community. Oncologists must offer clear guidance for the conduct of research, interpretation of results, and prescription of chemotherapies. We review recent drug approvals and clinical trials and comment on their relevance to the issue of the spiraling cost of oncology therapeutics. We suggest some standards that would serve as a starting point for addressing these issues.

A phase 2 study of cetuximab in combination with docetaxel in chemotherapy-refractory/resistant patients with advanced nonsmall cell lung cancer

BACKGROUND

Cetuximab in combination with docetaxel was examined in chemotherapy-refractory/resistant patients with advanced nonsmall-cell lung cancer (NSCLC) to determine response rate, survival, safety, and pharmacokinetics (PK).

METHODS

Patients had evidence of epidermal growth factor receptor (EGFR) expression (> or =1 +) and tumor progression during or disease recurrence within 3 months after chemotherapy. Cetuximab was administered weekly (400 mg/m(2) initial; 250 mg/m(2) thereafter). Docetaxel was administered every 3 weeks (75 mg/m(2)). A response in 3 of the first 21 patients was required to continue accrual to the target sample size of 50 patients.

RESULTS

Confirmed responses included 1 complete response (1.8%), 10 partial responses (18.2%), and 20 with stable disease (36.4%). The response rate was 20% (95% confidence interval [CI], 10.4% to 33.0%) and median time to disease progression was 104 days. There were no differences in PK parameters of docetaxel alone or with cetuximab. The most common grade 3 of 4 adverse events were leukopenia (27.3%) and acne (21.8%). Four patients (7.3%) discontinued due to allergic reaction. The median overall survival (OS) was 7.5 months with a 1-year survival of 35%.

CONCLUSIONS

Cetuximab in combination with docetaxel was well tolerated. The response rate supports more definitive evaluation of this combination in the second-line setting.

PTEN expression and KRAS mutations on primary tumors and metastases in the prediction of benefit from cetuximab plus irinotecan for patients with metastatic colorectal cancer

PURPOSE

PTEN, AKT, and KRAS are epidermal growth factor receptor (EGFR) downstream regulators. KRAS mutations confer resistance to cetuximab. This retrospective study investigated the role of PTEN loss, AKT phosphorylation, and KRAS mutations on the activity of cetuximab plus irinotecan in patients with metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

A cohort of patients with irinotecan-refractory mCRC who were treated with cetuximab plus irinotecan was tested for PTEN immunoreactivity (ie, immunohistochemistry; IHC), pAKT IHC, and KRAS mutations. Analyses were performed both on primary tumors and on related metastases, and the association among IHC, mutational results, and treatment outcomes was investigated.

RESULTS

One-hundred two patients were eligible. Ninety-six primary tumors, 59 metastases, and 53 paired samples were available. Forty-nine primary tumors (58% of assessable samples) had a preserved PTEN expression (PTEN-positive), whereas 35 (40% of assessable samples) were pAKT-positive. Levels of concordance between primary tumors and metastases were 60%, 68%, and 95% for PTEN, pAKT, and KRAS, respectively. PTEN status on primary tumors and pAKT status both on primary tumors and on metastases did not predict response or progression-free survival (PFS). On metastases, 12 (36%) of 33 patients with PTEN-positive tumors were responders compared with one (5%) of 22 who had PTEN-negative tumors (P = .007). The median PFS of patients with PTEN-positive metastases was 4.7 months compared with 3.3 months for those with PTEN-negative metastases (hazard ratio [HR], 0.49; P = .005). Patients with PTEN-positive metastases and KRAS wild type had longer PFS compared with other patients (5.5 months v 3.8 months; HR, 0.42; P = .001).

CONCLUSION

PTEN loss in metastases may be predictive of resistance to cetuximab plus irinotecan. The combination of PTEN IHC and KRAS mutational analyses could help to identify a subgroup of patients with mCRC who have higher chances of benefiting from EGFR inhibition.

Chemotherapy with targeted agents for the treatment of metastatic colorectal cancer

The introduction of novel agents targeted to specific molecular features of cancer cells promises more options and marked improvements in efficacy for treatment of colon cancer. This overview of clinical studies describes the effects of administering the targeted agents bevacizumab, cetuximab, and panitumumab, also known as monoclonal antibodies, to treat metastatic colorectal cancer (mCRC) patients. All three targeted agents have been approved for use by the U.S. Food and Drug Administration and the European Agency for the Evaluation of Medicinal Products. Bevacizumab has been shown to extend survival when used in combination with irinotecan and 5-fluorouracil-based chemotherapy, and the addition of cetuximab to irinotecan and 5-fluorouracil-based chemotherapy overcomes irinotecan resistance. Cetuximab and panitumumab are both efficacious among refractory mCRC patients with wild-type KRAS tumors. Other targeted agents, for example, the tyrosine kinase inhibitors erlotinib, gefitinib, sunitinib, and vatalanib (PTK787/ZK 222584), are currently in various stages of clinical development.

A phase I, pharmacokinetic and pharmacodynamic study on vorinostat in combination with 5-fluorouracil, leucovorin, and oxaliplatin in patients with refractory colorectal cancer

PURPOSE

We conducted a phase I study to determine the maximum tolerated dose of vorinostat in combination with fixed doses of 5-fluorouracil (FU), leucovorin, and oxaliplatin (FOLFOX).

EXPERIMENTAL DESIGN

Vorinostat was given orally twice daily for 1 week every 2 weeks. FOLFOX was given on days 4 and 5 of vorinostat. The vorinostat starting dose was 100 mg twice daily. Escalation occurred in cohorts of three to six patients. Pharmacokinetics of vorinostat, FU, and oxaliplatin were studied.

RESULTS

Twenty-one patients were enrolled. Thrombocytopenia, neutropenia, gastrointestinal toxicities, and fatigue increased in frequency and severity at higher dose levels of vorinostat. Two of 4 evaluable patients at dose level 4 (vorinostat 400 mg orally twice daily) developed dose-limiting fatigue. One of 10 evaluable patients at dose level 3 (vorinostat 300 mg orally twice daily) had dose-limiting fatigue, anorexia, and dehydration. There were significant relationships between vorinostat dose and the area under the curve on days 1 and 5 (Pearson, < 0.001). The vorinostat area under the curve increased (P = 0.005) and clearance decreased (P = 0.003) on day 5 compared with day 1. The median C(max) of FU at each dose level increased significantly with increasing doses of vorinostat, suggesting a pharmacokinetic interaction between FU and vorinostat. Vorinostat-induced thymidylate synthase (TS) modulation was not consistent; only two of six patients had a decrease in intratumoral TS expression by reverse transcription-PCR.

CONCLUSIONS

The maximum tolerated dose of vorinostat in combination with FOLFOX is 300 mg orally twice daily x 1 week every 2 weeks. Alternative vorinostat dosing schedules may be needed for optimal down-regulation of TS expression.

Bevacizumab: a safe and effective treatment in a patient with advanced colorectal cancer and repeated removal of metastases

Bevacizumab has been shown to be effective combined with chemotherapy for first-line treatment of advanced colorectal cancer, but little information is available about its efficacy and safety in patients who may be candidates for surgery at any time during the disease. The case history of a female patient with colorectal cancer, undergoing surgery for liver metastases and bilateral surgery for lung metastases at different time-points during her disease, is reported. Perioperative bevacizumab administration caused no complications either associated with surgery, in the early postoperative period, or in the subsequent months.

Cetuximab in combination with irinotecan/5-fluorouracil/folinic acid (FOLFIRI) in the initial treatment of metastatic colorectal cancer: a multicentre two-part phase I/II study

Background

This study was designed to investigate the efficacy and safety of the epidermal growth factor receptor (EGFR) inhibitor cetuximab combined with irinotecan, folinic acid (FA) and two different doses of infusional 5-fluorouracil (5-FU) in the first-line treatment of EGFR-detectable metastatic colorectal cancer.

Methods

The 5-FU dose was selected on the basis of dose-limiting toxicities (DLTs) during part I of the study. Patients received cetuximab (400 mg/m² initial dose and 250 mg/m²/week thereafter) and every 2 weeks irinotecan (180 mg/m²), FA (400 mg/m²) and 5-FU (either low dose [LD], 300 mg/m² bolus plus 2,000 mg/m² 46-hour infusion, n = 7; or, high-dose [HD], 400 mg/m² bolus plus 2,400 mg/m²; n = 45).

Results

Only two DLTs occurred in the HD group, and HD 5-FU was selected for use in part II. Apart from rash, commonly observed grade 3/4 adverse events such as leucopenia, diarrhoea, vomiting and asthenia occurred within the expected range for FOLFIRI. Among 52 patients, the overall response rate was 48%. Median progression-free survival (PFS) was 8.6 months (counting all reported progressions) and the median overall survival was 22.4 months. Treatment facilitated the resection of initially unresectable metastases in fourteen patients (27%): of these, 10 patients (71%) had no residual tumour after surgery, and these resections hindered the estimation of PFS.

Conclusion

The combination of cetuximab and FOLFIRI was active and well tolerated in this setting. Initially unresectable metastases became resectable in one-quarter of patients, with a high number of complete resections, and these promising results formed the basis for the investigation of FOLFIRI with and without cetuximab in the phase III CRYSTAL trial.

Shifting to first-line regimen after previous failure of irinotecan and oxaliplatin containing chemotherapies in unresectable metastatic colorectal cancer: a retrospective study of case analysis

PURPOSE

Conventional use of FOLFIRI-FOLFOX or the reverse sequence is the optional regimen in metastatic unresectable colorectal cancer (CRC). We present our experience in chemotherapy (C/T) shifting to first-line regimen after previous failure of irinotecan and oxaliplatin containing regimens.

MATERIALS AND METHODS

A total of 48 patients with metastatic unresectable CRC were examined retrospectively. All the patients had both failure of a first-line C/T and a second-line C/T. Of these patients, 13 patients received C/T shifting to first-line regimen. Data were collected retrospectively.

RESULTS

Rate of disease control of 38.4% was achieved (five in 13 patients). In the positive disease control group, metastatic sites were all extra-hepatic (five patients). In the negative disease control group, hepatic metastatic rate was 62.5% (five in eight patients, P=0.044).

CONCLUSIONS

Even after previous failure of irinotecan and oxaliplatin containing C/T, we observe positive disease control response and survival benefit in selected patients with C/T shifting to the first-line regimen especially in extra-hepatic metastasis. The preliminary results are proposed to gain insight into the need for further investigations and large-scale studies.

Anti-epidermal growth factor receptor monoclonal antibodies in cancer treatment

Although the prognosis of cancer remains poor recent advances in the diagnostic methods, new approaches in surgical procedures and the development of new therapeutic agents have had a significant impact in the outcome of cancer patients. A better understanding of the molecular pathways that characterize cell growth, apoptosis, angiogenesis and invasion has provided novel targets in cancer therapy. The epidermal growth factor receptor (EGFR) mediated signal transduction has been one of the most studied pathways in carcinogenesis. The phosphorylation of EGFR activates multiple biological processes including apoptosis, differentiation, cellular proliferation, motility, invasion, adhesion, DNA repair and survival. Several therapies have been developed to inactivate the EGFR pathway including monoclonal antibodies against the extracellular domain of EGFR. In this review, the authors examine the development of monoclonal antibodies against EGFR and the effects of this blockage in cell cycle, as well as the most important trials with these monoclonal antibodies in several tumor types.

Treatment of patients with colorectal cancer: emphasis on liver metastases

The treatment of colorectal liver metastases has progressed considerably in recent years. Coordinated multidisciplinary management of patients on clinical trials has resulted in 5-year survival rates exceeding 50%, and for certain patients cure is now a realistic goal. For all patients, the approval of six new drugs has contributed to an increase in median survival from 6 months to over 20 months. Recent molecular discoveries promise an era of tailored therapy in which only patients known to benefit will be treated, an approach that will enable more efficient use of the already stretched resources. Clinical trials continue to investigate different combinations and methods of administering approved therapies, but if the progress of the past decade is to be replicated it is imperative that we embrace innovative treatment strategies and novel trial designs. In this review, we highlight the developments that have improved survival for patients with colorectal liver metastases and discuss the many issues that challenge further progress.

[What are the new therapeutic strategies in metastatic colorectal cancer including biotherapies?]

Colorectal cancer remains one of the major causes of cancer death. Recent identification of new molecular targets led to the development of novel agents directed against growth factor receptors or key factors of angiogenesis. Recent phase III trials demonstrated a significant clinical benefit with bevacizumab, a VEGF inhibitor, and with EGFR-inhibitors, namely cetuximab and panitumumab. In this article we review the diverse treatment options combining cytotoxic and targeted therapies available for patients with metastatic colorectal cancer.

Updates in Gastrointestinal Oncology - insights from the 2008 44th annual meeting of the American Society of Clinical Oncology

We have reviewed the pivotal presentations rcelated to colorectal cancer (CRC) and other gastrointestinal malignancies from 2008 annual meeting of the American Society of Clinical Oncology (ASCO). We have discussed the scientific findings and the impact on practice guidelines and ongoing clinical trials. The report on KRAS status in patients with metastatic CRC receiving epidermal growth factor receptor (EGFR) targeted antibody treatment has led to a change in National Comprehensive Cancer Network guideline that recommends only patients with wild-type KRAS tumor should receive this treatment. The results of double biologics (bevacizumab and anti-EGFR antibody) plus chemotherapy as first-line treatment in patients with metastatic CRC has shown a worse outcome than bevacizumab-based regimen. Microsatellite Instability has again been confirmed to be an important predictor in patients with stage II colon cancer receiving adjuvant treatment. Adjuvant gemcitabine therapy for pancreatic cancer was investigated by the CONKO-001 study; this resulted in superior survival as compared with observation and can be regarded as an acceptable option, without the addition of radiotherapy. The addition of bevacizumab to gemcitabine and erlotinib was not supior to gemcitabine and erlotinib for advanced disease. Second-line therapy for advanced pancreatic cancer with 5-fluorouracil and oxaliplatin resulted in a survival benefit. Irinotecan plus cisplatin and paclitaxel plus cisplatin result in similar survival when combined with radiotherapy for esophageal cancer. The novel fluoropyrimidine S1 appears to be active in gastric cancer, as a single agent or as combination therapy. Adjuvant intraperitoneal mitomycin-C may decrease the incidence of peritoneal recurrence of gastric cancer. Sorafenib is an effective agent in Asian patients with hepatocellular carcinoma secondary to hepatitis B; its utility in child's B cirrhosis remains to be proven. Sunitinib is also an active agent in hepatocellular carcinoma, and may represent an alterative to sorafenib for advanced disease. These and other important presentations from the 2008 ASCO annual meeting are discussed in this article.

A Markov model assessing the effectiveness and cost-effectiveness of FOLFOX compared with FOLFIRI for the initial treatment of metastatic colorectal cancer

OBJECTIVE

To analyze the efficacy and cost-effectiveness of FOLFOX compared with FOLFIRI for patients with metastatic colorectal cancer.

METHOD

We developed a Markov decision model using a hypothetical cohort of patients with metastatic colorectal cancer to compare beginning chemotherapy with FOLFOX or FOLFIRI. Probabilities of toxicities, including neutropenia, diarrhea, and neuropathy, were based on published literature for FOLFOX and FOLFIRI. Costs for physician and hospital services unadjusted for geographic location were estimated using Centers for Medicare and Medicaid services reimbursement data. Drug costs were estimated using Medicare B reimbursement and the Federal Supply Schedule. Health outcomes were measured in quality-adjusted life years (QALYs). Univariate and probabilistic sensitivity analyses were performed to address uncertainty in the model parameters.

RESULTS

The FOLFOX strategy provided 1.003 QALYs at a cost of $29,865, whereas FOLFIRI provided 0.921 QALYs at a cost of $24,551. The incremental cost-effectiveness ratio for FOLFOX treatment was $65,170/QALY. In 10,000 probabilistic Monte Carlo simulations, FOLFOX was cost-effective in 48.59% of trials using a $50,000/QALY threshold. The most influential variables in univariate sensitivity analysis were the expected years of survival associated with each chemotherapy regimen.

CONCLUSIONS

FOLFOX and FOLFIRI are similar in terms of costs and benefits. The slight QALY benefits associated with FOLFOX are within the range of $100,000/QALY, an accepted threshold in oncology.

Clinical use of anti-epidermal growth factor receptor monoclonal antibodies in metastatic colorectal cancer

Abstract Cetuximab and panitumumab, monoclonal antibodies used to target the epidermal growth factor receptor (EGFR), were recently approved by the United States Food and Drug Administration for use as single agents or in combination with other chemotherapy drugs in the treatment of metastatic colorectal cancer. The anti-EGFR monoclonal antibodies, either as single agents or in combination with chemotherapy, have demonstrated clinical activity in this setting. When combined with standard cytotoxic chemotherapy or other targeted agents (e.g., bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody), anti-EGFR monoclonal antibodies have been well tolerated and produced minimal toxicities. However, cetuximab and panitumumab appear to benefit only select patients. Predictive markers of efficacy, including EGFR overexpression, development of skin rash, and the absence of a K-ras mutation, have been evaluated in clinical studies to identify patients likely to respond to anti-EGFR monoclonal antibody therapy. This review discusses recent clinical studies of anti-EGFR monoclonal antibodies in the treatment of metastatic colorectal cancer, predictive markers of their efficacy, and common toxicities associated with their use.

Phase II study and biomarker analysis of cetuximab combined with modified FOLFOX6 in advanced gastric cancer

This prospective study was conducted with the Korean Cancer Study Group to evaluate the efficacy and safety of cetuximab combined with modified FOLFOX6 (mFOLFOX6) as first-line treatment in recurrent or metastatic gastric cancer and to identify potential predictive biomarkers. Patients received cetuximab 400 mg m(-2) at week 1 and 250 mg m(-2) weekly thereafter until disease progression. Oxaliplatin (100 mg m(-2)) and leucovorin (100 mg m(-2)) were administered as a 2-h infusion followed by a 46-h continuous infusion of 5-fluorouracil (2400 mg m(-2)) every 2 weeks for a maximum of 12 cycles. Biomarkers potentially associated with efficacy were analysed. Among 38 evaluable patients, confirmed response rate (RR) was 50.0% (95% CI 34.1-65.9). Median time-to-progression (TTP) was 5.5 months (95% CI 4.5-6.5) and overall survival (OS) 9.9 months. Eleven patients having tumour EGFR expression by immunohistochemistry with low serum EGF and TGF-alpha levels showed a 100% RR compared to 37.0% in the remaining 27 patients (P<0.001). Moreover, ligand level increased when disease progressed in seven out of eight patients with EGFR expression and low baseline ligand level. No patient exhibited EGFR amplification or K-ras mutations. Gastric cancer patients with EGFR expression and low ligand levels had better outcomes with cetuximab/mFOLFOX6 treatment.

Toxicity associated with combination oxaliplatin plus fluoropyrimidine with or without cetuximab in the MRC COIN trial experience

We present the preliminary toxicity data from the MRC COIN trial, a phase III randomised controlled trial of first-line therapy in advanced colorectal cancer, with particular reference to the addition of cetuximab to an oxaliplatin-fluoropyrimidine combination. A total of 804 patients were randomised between March 2005 and July 2006 from 78 centres throughout the United Kingdom. Patients were allocated to oxaliplatin plus fluoropyrimidine chemotherapy with or without the addition of weekly cetuximab. The choice of fluoropyrimidine (either 5-fluorouracil (5FU) or capecitabine) was decided by the treating physician and patient before randomisation. Toxicity data were collected from all patients. Two hundred and three patients received 5FU plus oxaliplatin (OxMdG, 25%), 333 oxaliplatin+capecitabine (Xelox, 41%), 102 received OxMdG+cetuximab (OxMdG+C, 13%) and 166 Xelox+cetuximab (21%). Percent grade 3/4 toxicities included diarrhoea 6, 15, 13 and 25%, nausea/vomiting 3, 7, 7 and 14% for OxMdG, Xelox, OxMdG+C and Xelox+C, respectively. Sixty-day all-cause mortality was 6, 5, 5 and 7%. Statistically significant differences were evident for patients receiving Xelox+cetuximab vs Xelox alone: diarrhoea relative risk (RR) 1.69 (1.17, 2.43, P=0.005) and nausea/vomiting RR 2.01 (1.16, 3.47, P=0.012). The excess toxicity observed in the oxaliplatin-, capecitabine-, cetuximab-treated patients led the trial management group to conclude that a capecitabine dose adjustment was required to maintain safety levels when using this regimen.

[Antiangiogenic therapy for gastrointestinal tumors]

Angiogenesis plays a major role in the pathogenesis of many disorders. Vascular endothelial growth factor has been shown to be the key regulator of normal and pathological angiogenesis. Increased expression of VEGF has been associated with tumor neovascularization, metastasis and proliferation of cancer cells. Bevacizumab, a monoclonal antibody against VEGF, has shown promising preclinical and clinical activity against different types of cancer, particularly in combination with chemotherapy. There is an increasing evidence that bevacizumab has a disease-modifying effect in metastatic colorectal carcinoma (CRC), and also in advanced hepatocellular carcinoma. Further investigation is needed to evaluate the role of antiangiogenic therapeutic strategies in other gastrointestinal malignancies. This review summarizes recent knowledge about antiangiogenic therapy for gastrointestinal cancers.

Efficacy of oxaliplatin plus capecitabine or infusional fluorouracil/leucovorin in patients with metastatic colorectal cancer: a pooled analysis of randomized trials

PURPOSE

Six randomized phase II and III trials have investigated the role of oxaliplatin (OX) in combination with capecitabine (CAP) or infusional fluorouracil (FU) in metastatic colorectal cancer. This meta-analysis compared the efficacy of CAP/OX compared with infusional FU/OX.

PATIENTS AND METHODS

This analysis compared all published CAP/OX versus infusional FU/OX regimens. A total of 3,494 patients (FU, n = 1,737; CAP, n = 1,757) were analyzed for response rate (RR), progression-free (PFS), overall survival (OS), and toxicity.

RESULTS

The fixed-effect pooled estimate for RR showed higher RR for FU-based regimens (Odds ratio [OR] = 0.85; 95% CI, 0.74 to 0.97; P = .02) whereas the analysis of chemotherapy-only trials, excluding the bevacizumab containing NO16966 and TREE 2 trials, led to an OR of 0.74 (95% CI, 0.60 to 0.92; P = .007). However, for PFS (hazard ratio [HR] = 1.04; 95% CI, 0.96 to 1.12; P = .17) and OS (HR = 1.04; 95% CI, 0.95 to 1.12; P = .41) all models suggested similar outcome within the range of noninferiority. Grade 3/4 toxicities (thrombocytopenia-HR = 2.07, 95% CI, 1.42 to 3.03; P < .0002; diarrhea-HR = 1.34; 95% CI, 1.08 to 1.66; P < .0009; and grade 2/3 hand-foot-syndrome [HFS]-HR = 3.54; 95% CI, 2.07 to 6.05; P < .00001) were less prominent with FU-based regimens whereas neutropenia (HR = 0.15; 95% CI, 0.11 to 0.19; P < .00001) was lower in the CAP regimens.

CONCLUSION

The combination of CAP and OX resulted in lower RR, but this did not affect PFS and OS, which were similar in both treatment arms. The toxicity analysis showed the characteristic toxicity of each of the different FU schedules, with thrombocytopenia and HFS consistently more prominent in the CAP regimens.

Open-label phase I trial of vandetanib in combination with mFOLFOX6 in patients with advanced colorectal cancer

BACKGROUND

Vandetanib (ZACTIMA) is a once-daily oral inhibitor of vascular endothelial growth factor, epidermal growth factor and RET receptor tyrosine kinases. The safety and tolerability of vandetanib plus mFOLFOX6 was investigated in patients with advanced colorectal cancer (CRC).

METHODS

Patients eligible for first- or second-line chemotherapy received once-daily oral doses of vandetanib (100 or 300 mg) plus 14-day treatment cycles of mFOLFOX6.

RESULTS

Seventeen patients received vandetanib 100 mg (n = 9) or 300 mg (n = 8) plus mFOLFOX6. The protocol definition of a tolerable dose (vandetanib-related dose-limiting toxicity [DLT] in less than two patients) was met in both dose cohorts, with one DLT of diarrhoea reported in each. Overall, the most common adverse events were diarrhoea, nausea and lethargy (all n = 11). There was no pharmacokinetic interaction between vandetanib and mFOLFOX6. Preliminary efficacy results included one complete response and three confirmed partial responses.

CONCLUSIONS

In patients with advanced CRC, once-daily vandetanib (100 or 300 mg) with mFOLFOX6 was generally well tolerated.

A phase II study of gefitinib, 5-fluorouracil, leucovorin, and oxaliplatin in previously untreated patients with metastatic colorectal cancer

PURPOSE

We investigated the gefitinib, 5-fluorouracil (5-FU), leucovorin and oxaliplatin (IFOX) regimen as first-line therapy in patients with metastatic colorectal cancer.

EXPERIMENTAL DESIGN

Eligible patients had stage IV colorectal adenocarcinoma, and had not received prior chemotherapy for metastatic disease. Each cycle consisted of 14 days. Cycle 1 consisted of oxaliplatin, leucovorin, and 5-FU (FOLFOX-4). All subsequent cycles consisted of FOLFOX-4 with gefitinib at 500 mg orally daily throughout the 14-day cycle.

RESULTS

Forty-five patients were enrolled and were assessable for toxicity. Forty-three patients were assessable for response. Thirty-one of the 43 patients (72%) had either a complete or partial response by the Response Evaluation Criteria in Solid Tumors. Median overall survival was 20.5 months. Median time to progression was 9.3 months. Commonly encountered grade 3 or 4 toxicities included diarrhea in 67% of patients and neutropenia in 60%. Grade 2 acneiform skin rash typical of gefitinib occurred in 60% of patients.

CONCLUSIONS

IFOX is an active first-line regimen in patients with metastatic colorectal adenocarcinoma, showing higher response rates but also increased toxicities compared with FOLFOX-4 alone in a similar patient population.

Innovations in chemotherapy for metastatic colorectal cancer: an update of recent clinical trials

It has been estimated that cancer of the colon and rectum (CRC) would be diagnosed in 153,760 men and women in the U.S. alone in 2007. Approximately one in five patients has metastatic CRC (mCRC) at diagnosis, which, at best, is associated with a 5-year survival rate of just 10.3%. Oxaliplatin- and irinotecan-based combination regimens are standard first-line therapies for mCRC. Recent studies suggest that survival outcomes can possibly be further improved by adding biologic agents to chemotherapy. Novel treatment strategies are being investigated to optimize the opportunity for patients to receive and benefit from the increasing number of available active agents and to further improve the efficacy, safety, and tolerability of multiagent therapy. These include switching therapy before progression, maintenance therapy, and chemotherapy-free intervals. Recent innovations in chemotherapy for mCRC are reviewed, with a focus on emerging data that may significantly improve both survival and quality of life for patients with CRC in the future.

From the podium to the patient: bringing the 2008 ASCO meeting to the clinic

Around 4,800 abstracts on preclinical and clinical research in different oncology areas were presented and discussed by oncology clinicians and scientists at the 44th American Society of Clinical Oncology meeting, the largest international forum in the field. As expected, the meeting provided valuable insights into future developments as well as enlightening clinicians regarding current controversies. This manuscript is an opinion-based review of the studies presented at the meeting, focusing on findings from randomized phase III trials and translational researches that, in the authors' opinion, are most likely to modify clinical practice or help scientists in designing future translational and clinical studies.

Neurosurgical management and postoperative whole-brain radiotherapy for colorectal cancer patients with symptomatic brain metastases

BACKGROUND

New systemic treatments for advanced colorectal cancer have conferred a survival advantage, allowing patients to reach a median survival of almost 2 years. Due to this remarkable life extension, the incidence of brain metastases, though still low, is progressively increasing over time. There is little reported data on the optimal strategy to manage brain lesions from colorectal cancer.

METHODS

To explore the role of an aggressive approach to colorectal cancer brain metastases, we retrospectively collected and analyzed data from 30 patients who underwent neurosurgical resection + whole-brain radiotherapy between March 1998 and December 2006. Univariate (logrank) and multivariate (Cox's model) analyses were used to identify prognostic factors.

RESULTS

Median age at the time of surgery was 66 years, median ECOG PS was 1, most patients (87%) had concomitant lung and/or liver metastases. Median number of previous chemotherapies was two, with half of the patients being exposed both to oxaliplatin and irinotecan. A median of 27 Gy of radiotherapy were administered to 16 patients after resection. At the time of the analysis, 29 out of 30 patients had died, with a median survival time after brain metastasectomy of 167 days (8-682). Only one patient died within a month from surgery. Median survival was significantly longer in patients who received postsurgical radiotherapy (7.6 vs. 4.7 months, P = 0.014).

CONCLUSIONS

Neurosurgical management of symptomatic brain metastases from colorectal cancer is feasible, relatively safe, and offers a chance of prolonged survival. Patients who received radiotherapy after resection experienced a better outcome.

K-Ras mutations and treatment outcome in colorectal cancer patients receiving exclusive fluoropyrimidine therapy

PURPOSE

K-Ras mutations predict resistance to anti-epidermal growth factor receptor (EGFR) monoclonal antibodies. Because combinations of anti-EGFR with 5-fluorouracil (5-FU)-based chemotherapy are promising treatments, we analyzed the effect of K-Ras mutations in patients having received exclusive 5-FU therapy.

EXPERIMENTAL DESIGN

This study was conducted on 93 stage IV colorectal cancer patients with unresectable measurable liver metastasis receiving 5-FU-leucovorin (56 men and 37 women; 77 cancer deaths). Liver metastases (n = 93) along with primary tumors (n = 48) were analyzed for K-Ras mutations (codons 12 and 13), p53 mutations (exons 4-9), p53 polymorphism (codon 72), thymidylate synthase (TS) polymorphism (28-bp repeats including G>C mutation), methylenetetrahydrofolate reductase polymorphism (677C>T, 1298A>C), thymidylate synthase (TS) activity, dihydropyrimidine dehydrogenase activity, folylpolyglutamate synthase activity, and p53 protein expression.

RESULTS

Thirty-six of 93 (38.7%) metastases were K-Ras mutated (30 at codon 12 and 6 at codon 13). Mutated primary tumors (16 of 48) matched perfectly with mutated metastases. The additional analyzed tumor markers were not different between K-Ras mutated and wild-type tumors. The objective response rate was 37%: 44.4% in K-Ras mutated versus 32.1% in wild-type K-Ras metastasis (P = 0.27). Low TS activity in metastasis was the only significant predictor of tumor response (P = 0.047). K-Ras status did not influence specific survival.

CONCLUSIONS

The present data indicate a perfect concordance of K-Ras mutations between primary and liver metastasis and suggest that any predictive and/or prognostic value of K-Ras mutations in treatments combining anti-EGFR monoclonal antibodies with 5-FU should be exclusively linked to the anti-EGFR agent.

Novel opportunities for thymidylate metabolism as a therapeutic target

For over 40 years, the fluoropyrimidine 5-fluorouracil (5-FU) has remained the central agent in therapeutic regimens employed in the treatment of colorectal cancer and is frequently combined with the DNA-damaging agents oxaliplatin and irinotecan, increasing response rates and improving overall survival. However, many patients will derive little or no benefit from treatment, highlighting the need to identify novel therapeutic targets to improve the efficacy of current 5-FU-based chemotherapeutic strategies. dUTP nucleotidohydrolase (dUTPase) catalyzes the hydrolysis of dUTP to dUMP and PPi, providing substrate for thymidylate synthase (TS) and DNA synthesis and repair. Although dUTP is a normal intermediate in DNA synthesis, its accumulation and misincorporation into DNA as uracil is lethal. Importantly, uracil misincorporation represents an important mechanism of cytotoxicity induced by the TS-targeted class of chemotherapeutic agents including 5-FU. A growing body of evidence suggests that dUTPase is an important mediator of response to TS-targeted agents. In this article, we present further evidence showing that elevated expression of dUTPase can protect breast cancer cells from the expansion of the intracellular uracil pool, translating to reduced growth inhibition following treatment with 5-FU. We therefore report the implementation of in silico drug development techniques to identify and develop small-molecule inhibitors of dUTPase. As 5-FU and the oral 5-FU prodrug capecitabine remain central agents in the treatment of a variety of malignancies, the clinical utility of a small-molecule inhibitor to dUTPase represents a viable strategy to improve the clinical efficacy of these mainstay chemotherapeutic agents.

Biweekly cetuximab and irinotecan in advanced colorectal cancer patients progressing after at least one previous line of chemotherapy: results of a phase II single institution trial

This is a phase II institutional exploratory trial of biweekly irinotecan and cetuximab administration regimen in metastatic colorectal cancer patients progressing to at least one previous chemotherapy line. A total of 40 patients were treated between November 2005 and November 2007 with irinotecan 180 mg m⁻² and cetuximab 500 mg m⁻² q2w (every 2 weeks), in every 21-day cycles, until unacceptable toxicity or progressive disease. An overall response rate of 22.5% was obtained (two complete and seven partial responses). The disease control rate was 60%. The time to progression was 3.4 months and the overall survival was 8 months. The toxicity compared very favourably to weekly cetuximab combination schedules. Grade 3/4 adverse effects were observed in 12 patients. Overall, our results turn up very similar both in terms of toxicity and efficacy to those obtained by weekly and biweekly administration regimens.

Early distant relapse after optimal local control in locally advanced rectal cancer

We present a case of locally advanced rectal cancer with initial optimal local control after neoadjuvant concurrent chemoradiotherapy followed by surgery; early liver recurrence then occurred and was treated again with curative intent with neoadjuvant combination chemotherapy followed by liver surgery. We reflect on this difficult problem and discuss relevant topics to this case report.

Is there an optimal chemotherapy regimen for the treatment of advanced gastric cancer that will provide a platform for the introduction of new biological agents?

Globally, gastric cancer is the second most common cause of cancer-related death. The majority of gastric cancer patients will have at presentation or will ultimately develop overt metastatic disease. Meta-analysis has demonstrated not only that systemic chemotherapy can improve survival in patients with advanced disease but also that the best survival results in earlier randomized studies have been achieved with three-drug regimens containing a fluoropyrimidine, an anthracycline, and cisplatin. Although there has been little progress historically in improving median overall survival times beyond the 9-month plateau achievable with the standard epirubicin-cisplatin-infusional 5-fluoropyrimidine (ECF) combination, the availability of newer cytotoxic anticancer agents has provided some measure of optimism that current outcomes can be improved. A number of new triplet and doublet combinations incorporating docetaxel, oxaliplatin, irinotecan, capecitabine, and S-1 have been explored in randomized trials. Although some combinations, such as epirubicin-oxaliplatin-capecitabine, have been shown to be as effective as (or perhaps more effective than) ECF, and although promising early data have been derived for S-1 in combination with cisplatin, a lack of studies in which direct comparisons have been made currently hinders the identification of the optimal regimen in this setting. One factor that might contribute to the lack of clear progress is the absence of consensus on the utility of second-line cytotoxic treatments. It can therefore be concluded that, although there is no first-line regimen that is clearly the most appropriate platform for the investigation of biological agents, there are a number of combinations that have been shown to be effective and therefore good candidates.

EPIC: Phase III Trial of Cetuximab Plus Irinotecan After Fluoropyrimidine and Oxaliplatin Failure in Patients With Metastatic Colorectal Cancer

Purpose

To determine whether adding cetuximab to irinotecan prolongs survival in patients with metastatic colorectal cancer (mCRC) previously treated with fluoropyrimidine and oxaliplatin.

Patients and Methods

This multicenter, open-label, phase III study randomly assigned 1,298 patients with epidermal growth factor receptor–expressing mCRC who had experienced first-line fluoropyrimidine and oxaliplatin treatment failure to cetuximab (400 mg/m2day 1 followed by 250 mg/m2weekly) plus irinotecan (350 mg/m2every 3 weeks) or irinotecan alone. Primary end point was overall survival (OS); secondary end points included progression-free survival (PFS), response rate (RR), and quality of life (QOL).

Results

Median OS was comparable between treatments: 10.7 months (95% CI, 9.6 to 11.3) with cetuximab/irinotecan and 10.0 months (95% CI, 9.1 to 11.3) with irinotecan alone (hazard ratio [HR], 0.975; 95% CI, 0.854 to 1.114; P = .71). This lack of difference may have been due to post-trial therapy: 46.9% of patients assigned to irinotecan eventually received cetuximab (87.2% of those who did, received it with irinotecan). Cetuximab added to irinotecan significantly improved PFS (median, 4.0 v 2.6 months; HR, 0.692; 95% CI, 0.617 to 0.776; P ≤ .0001) and RR (16.4% v 4.2%; P < .0001), and resulted in significantly better scores in the QOL analysis of global health status (P = .047). Cetuximab did not exacerbate toxicity, except for acneform rash, diarrhea, hypomagnesemia, and associated electrolyte imbalances. Neutropenia was the most common severe toxicity across treatment arms.

Conclusion

Cetuximab and irinotecan improved PFS and RR, and resulted in better QOL versus irinotecan alone. OS was similar between study groups, possibly influenced by the large number of patients in the irinotecan arm who received cetuximab and irinotecan poststudy.

Systemic treatment of colorectal cancer

Colorectal cancer is the fourth most common noncutaneous malignancy in the United States and the second most frequent cause of cancer-related death. Over the past 12 years, significant progress has been made in the systemic treatment of this malignant condition. Six new chemotherapeutic agents have been introduced, increasing median overall survival for patients with metastatic colorectal cancer from less than 9 months with no treatment to approximately 24 months. For patients with stage III (lymph node positive) colon cancer, an overall survival benefit for fluorouracil-based chemotherapy has been firmly established, and recent data have shown further efficacy for the inclusion of oxaliplatin in such adjuvant treatment programs. For patients with stage II colon cancer, the use of adjuvant chemotherapy remains controversial, but may be appropriate in a subset of individuals at higher risk for disease recurrence. Ongoing randomized clinical trials are evaluating how best to combine currently available therapies, while smaller studies are evaluating new agents, with the goal of continued progress in prolonging life among patients with metastatic colorectal cancer and increasing cure rates among those with resectable disease.

Cetuximab in combination with weekly 5-fluorouracil/folinic acid and oxaliplatin (FUFOX) in untreated patients with advanced colorectal cancer: a phase Ib/II study of the AIO GI Group

BACKGROUND

This two-part phase Ib/II study investigated the feasibility of administering cetuximab in combination with oxaliplatin and infusional 5-fluorouracil (5-FU)/folinic acid (FA) in a weekly schedule (AIO FUFOX protocol) as first-line treatment in patients with epidermal growth factor receptor-detectable advanced colorectal cancer.

PATIENTS AND METHODS

Cetuximab was administered weekly: 400 mg/m(2) initial dose, then 250 mg/m(2) and FUFOX: oxaliplatin 50 mg/m(2), FA 500 mg/m(2) and 5-FU as a 24-h infusion at either 1500 or 2000 mg/m(2) administered for 4 weeks followed by a 1-week rest (one cycle).

RESULTS

Dose-limiting toxicity (grade 3 diarrhea) occurred in 3 of 14 assessable patients receiving 5-FU at standard 2000 mg/m(2). This dose was administered to a further 25 patients. Cetuximab combined with FUFOX was generally well tolerated with the most common grade 3/4 adverse events being diarrhea (27%) and paresthesia (16%). The confirmed response rate for patients receiving 5-FU at standard 2000 mg/m(2) (N = 41) was 56%, with a median duration of 9.3 months. Median progression-free and overall survival times including all 49 patients were 8.1 (95% confidence interval 6.0-9.7) and 28.2 months, respectively. Cetuximab pharmacokinetics seemed not to be different for combination with FUFOX compared with cetuximab/irinotecan combinations.

CONCLUSION

This protocol is well tolerated and shows promising efficacy supporting further investigation.