Cetuximab monotherapy and cetuximab plus irinotecan in irinotecan-refractory metastatic colorectal cancer

Irinotecan in the treatment of colorectal cancer

Irinotecan, a water-soluble, semisynthetic derivative of camptothecin, is a key component of first- and second-line treatment regimens for metastatic colorectal cancer (CRC). In the first-line treatment of metastatic CRC, the results of two prospective, multicenter phase III trials have shown that the combination of irinotecan with bolus or infusional 5-fluorouracil (5FU)/leucovorin (LV) can significantly prolong survival compared with 5FU/LV alone, with a manageable side effects profile. In addition, irinotecan-based regimens, with or without oxaliplatin, may improve resectability of metastases and further increase patient survival. Studies of irinotecan in the first-line setting in combination with newer agents, such as bevacizumab, have shown impressive overall survival. In the second-line setting, irinotecan has demonstrated efficacy superior to that of best supportive care. Initial studies of irinotecan plus bolus 5FU/LV, and the preliminary results from trials of irinotecan plus infusional 5FU/LV in the adjuvant setting, have been disappointing; however, for the largest trial, the Pan-European Trial in Adjuvant Colon Cancer, results with sufficient follow-up are pending. Irinotecan has an acceptable tolerability profile and is not associated with cumulative toxicities in patients with metastatic CRC; regimens containing irinotecan extend treatment duration and improve survival. New regimens and adjunctive therapies are being explored to reduce the incidence of common complications of irinotecan treatment, such as diarrhea and neutropenia.

Capecitabine and mitomycin C may be an effective treatment option for third-line chemotherapy in advanced colorectal cancer

AIMS AND BACKGROUND

We evaluated the activity in terms of time to progression (TTP) of mitomycin C and capecitabine in patients with advanced colorectal cancer who progressed after 2 lines of chemotherapy.

METHODS

Patients with advanced colorectal cancer undergoing third-line chemotherapy after failure of 5-FU with CPT-11 or oxaliplatin-based chemotherapy regimens were treated with capecitabine and mitomycin C.

RESULTS

Sixty-one patients were enrolled in this study. The median age was 55 years (range, 26-78 years) and the male:female ratio 21:40. We observed partial remissions in 5 patients (8%), stable disease in 25 patients (40%) and progression of disease in 31 patients (52%). Median TTP was 3 months and median survival was 6 months. Global toxicity was mild and entirely acceptable. Grade 3-4 hematological toxicity occurred in 12 patients and grade 3-4 nonhematological toxicity in 5 patients.

CONCLUSIONS

The combination of capecitabine and mitomycin C could represent an effective and manageable treatment option for colorectal cancer patients failing previous chemotherapy regimens.

Systemic treatment of patients who have colorectal cancer and inflammatory bowel disease

Colorectal cancer is the most common malignant complication in patients who have IBD. The disease is difficult to diagnose because there is an overlap in symptoms in patients who have colon cancer and those who have IBD. Much has been learned about the incidence of colorectal cancer in patients who have IBD and its correlation with disease activity, duration, and anatomic location; however, almost no data are available regarding specific therapeutic considerations during adjuvant or palliative chemotherapy for these patients with respect to their underlying disease. Patients who have IBD who develop colorectal cancer are at higher risk for developing severe diarrhea during chemotherapy that may be due to the toxic effects of cytotoxic drugs or a flare of the IBD. Continuous infusional 5-FU alone, in combination with leucovorin, or in combination with oxaliplatin (FOLFOX) seems to be tolerated best. Bolus infusions of 5-FU (Roswell Park or Mayo regimens) and combination therapy of irinotecan with 5-FU should be avoided because of severe diarrhea and the possibility of sepsis. When diarrhea develops or worsens, empiric aminosalicylates may be given. Although it is theoretically possible that anti-EGFR therapies could affect IBD activity adversely, clinical experience with cetuximab in patients who have colorectal cancer has not shown any significant gastrointestinal side effects. Therefore, it seems reasonable to use it in patients who have colorectal cancer and IBD. The administration of bevacizumab has been associated with rare episodes of intestinal perforation; it should be used with great care in patients who have IBD. More studies and an integrative, multidisciplinary approach from oncologists and gastroenterologists are needed to provide optimal care for patients who have IBD during chemotherapy for colorectal cancer

Description and management of cutaneous side effects during cetuximab or erlotinib treatments: A prospective study of 30 patients

BACKGROUND

Drugs such as cetuximab or erlotinib, which inhibit the epidermal growth factor receptor, are increasingly being used in treatment of solid tumors. This has led to the appearance of new secondary effects.

OBJECTIVE

We sought to describe the cutaneous side effects and their management in patients with cancer treated with cetuximab or erlotinib.

METHODS

We clinically examined 30 patients determining type, frequency, treatment, and evolution of side effects.

RESULTS

Most patients presented with a cutaneous reaction consisting of a follicular eruption, typically appearing in seborrheic areas within the first 15 days of treatment. Painful fissures in palms and soles and paronychia were the second most common cutaneous toxicities. We also noticed an alteration in hair growth at several months' follow-up. As these secondary effects responded well to treatment, few patients discontinued the antineoplastic therapy because of cutaneous toxicity.

LIMITATIONS

This was a prospective but uncontrolled study.

CONCLUSION

Although these new targeted therapies have low systemic toxicity because of their high specificity, cutaneous side effects are common and may be serious.

Comparing antibody and small-molecule therapies for cancer

The 'magic bullet' concept of specifically targeting cancer cells at the same time as sparing normal tissues is now proven, as several monoclonal antibodies and targeted small-molecule compounds have been approved for cancer treatment. Both antibodies and small-molecule compounds are therefore promising tools for target-protein-based cancer therapy. We discuss and compare the distinctive properties of these two therapeutic strategies so as to provide a better view for the development of new drugs and the future direction of cancer therapy.

Portal triad clamping (TC) or hepatic vascular exclusion (VE) for major liver resection after prolonged neoadjuvant chemotherapy? A case-matched study in 60 patients

BACKGROUND

Prolonged systemic preoperative chemotherapy induces pathologic changes in liver parenchyma. The consequences of vascular occlusion on liver submitted to prolonged preoperative systemic chemotherapy are not known. The aim of this case-matched study was to assess which method of vascular occlusion is most appropriate for major liver resection in patients who have undergone prolonged preoperative systemic chemotherapy.

METHODS

Among 305 patients who had liver resection for colorectal metastases from 1998 to 2003, 28 underwent major liver resections under portal triad clamping after more than 6 cycles of preoperative chemotherapy (TC group). These 28 patients were compared with 32 patients matched for age, sex, ASA status, number of liver metastases, type of liver resection, and type of preoperative chemotherapy, but who had major liver resection under hepatic vascular exclusion after more than 6 cycles of preoperative chemotherapy (VE group).

RESULTS

There was no postoperative mortality. The morbidity rate was 18% after TC and 43% after VE (P = 0.044). Pulmonary complication rate was greater after VE (31% vs 3%, P = 0.017). The transfusion rate was 50% in the TC group and 40% in the VE group (P = 0.482). Postoperative changes of liver function tests were comparable in the two groups except for the prothrombin time, which was more prolonged from day 1 (P = 0.003) to day 5 (P = 0.04) after VE.

CONCLUSION

Vascular occlusion can be used with no mortality and acceptable morbidity for major liver resection after prolonged preoperative chemotherapy. TC should be preferred to VE, permitted by the location of the neoplasm.

New molecular targeted therapies in thyroid cancer

Carcinoma of the thyroid gland is the most common malignancy of the endocrine system. Differentiated tumors are often curable with surgical resection and radioactive iodine. A small percentage of such patients, however, do not undergo remission and need new therapeutic approaches. Both anaplastic and medullary thyroid carcinomas exhibit aggressive behavior and are usually resistant to current therapeutic modalities. Thyroid carcinoma represents a fascinating model and a particularly promising paradigm for targeted therapy because some of the key oncogenic events are activating mutations of genes coding for tyrosine kinases, and these occur early in cancer development. A prototype is the RET proto-oncogene, a receptor tyrosine kinase, which is a key regulator of development and a 'hotspot' for oncogenic mutations. Mutations in the RET proto-oncogene have been identified as causative for papillary carcinoma and familial medullary thyroid carcinoma, making it an attractive target for selective inhibition in these subtypes. ZD 6474 has shown promising activity in preclinical models against RET kinase, and its contemporary inhibition of vascular endothelial growth factor and epidermal growth factor pathways renders it a very attractive drug for clinical trials in thyroid cancer. Activating point mutation of B-RAF can occur early in the development of papillary carcinoma. Moreover, papillary carcinomas with these mutations have more aggressive properties and are diagnosed more often at an advanced stage. Clinical evaluation of B-RAF-targeting drugs is undergoing and trials in thyroid cancer are planned. Agents that restore radioiodine uptake, such as histone deacetylase inhibitors and retinoids, represent another exciting field in new drug development in thyroid cancer.

Emerging therapies for rectal cancer

Preoperative treatment with either short-course radiotherapy or chemo-radiotherapy (CRT) is used routinely in some centres to reduce local recurrence rates in patients with operable rectal cancer prior to optimal surgery. However, there is a need for new treatment strategies to further improve the outcomes of these patients, particularly with regard to survival. Advances in the treatment of metastatic disease, such as the use of combination chemotherapy with oxaliplatin and irinotecan, and the targeted agents bevacizumab and cetuximab, have led to clinical research into alternative radio-sensitizers during CRT and the novel use of neo-adjuvant (preoperative) chemotherapy prior to preoperative CRT and surgery. Whilst these remain experimental, it is likely that these will serve as a platform for developing an expanded range of treatment options so that clinicians will be better able to tailor treatment to the needs of different patients.

Development of antibodies for cancer therapy

Antibody therapies have become an important component in the management of malignant disease. Recombinant technology offers enormous opportunities to tailor antibodies to meet clinical requirements. This includes the reduction of immunogenicity and the development of smaller antibody fragments that can be incorporated into fusion proteins. Antibodies can block tumour growth factors or their receptors, activate immunological attack on the tumour, or be used to deliver payloads such as radioisotopes, cytotoxic drugs or toxins. Pretargeting includes streptavidin/biotin systems and antibody-directed enzyme prodrug therapy (ADEPT). ADEPT uses an antibody-enzyme complex to deliver a prodrug-activating enzyme to tumours for selective prodrug conversion at the tumour site. New antibody targets, refined antibodies, antibody fusion proteins, combination therapies and the use of antibodies as adjuvant therapy are important topics in the development of antibody therapy against cancer.

Metastatic colorectal cancer

Metastatic colorectal cancer remains a public-health issue on a global scale. With development of a new generation of cytotoxic agents, survival has improved for patients with metastatic disease. How to maximize the benefit of chemotherapy with acceptable toxicity remains incompletely answered. Hepatic resection can provide a significant hope for long term survival, and a subset of patients might benefit from perioperative approaches. More recently, specific molecular processes have been targeted for therapeutic interventions, and encouraging results have been achieved using inhibitors of the Epidermal Growth Factor Receptor and the Vascular Endothelial Growth Factor.

Therapy with immunoglobulin: applications for monoclonal antibodies

The ability of antibodies to recognize specific antigenic targets and trigger responses from the immune system has made them attractive candidates as therapeutic agents. Monoclonal and recombinant technology have made possible the development of a new class of therapeutic and diagnostic agents that combine the exquisite specificity of antibodies with biologic compatibility and protracted half-lives. This technology is just beginning to be explored and considerable evolution may be expected in the next few decades.

Antitumor efficacy of edotecarin as a single agent and in combination with chemotherapy agents in a xenograft model

The novel indolocarbazole edotecarin (J-107088, formerly ED-749) differs from other topoisomerase I inhibitors both pharmacokinetically and pharmacodynamically. In vitro, it is more potent than camptothecins and has a variable cytotoxic activity in 31 different human cancer cell lines. Edotecarin also possesses greater than additive inhibitory effects on cell proliferation when used in combination with other agents tested in vitro against various cancer cell lines. The present in vivo studies were done to extend the in vitro findings to characterize the antitumor effects of edotecarin when used either alone or in combination with other agents (i.e., 5-fluorouracil, irinotecan, cisplatin, oxaliplatin, and SU11248) in the HCT-116 human colon cancer xenograft model. Treatment effects were based on the delay in onset of an exponential growth of tumors in drug-treated versus vehicle control-treated groups. In all studies, edotecarin was active both as a single agent and in combination with other agents. Combination therapy resulted in greater than additive effects, the extent of which depended on the specific dosage regimen. Toxicity in these experiments was minimal. Of all 359 treated mice, the six that died of toxicity were in the high-dose edotecarin/oxaliplatin group. The results suggest that edotecarin may serve as effective chemotherapy of colon cancer when used as a single agent, in combination with standard regimens and other topoisomerase inhibitors or with novel agents, such as the multitargeted tyrosine kinase inhibitor SU11248.

Prevention of irinotecan associated diarrhea by intestinal alkalization. A pilot study in gastrointestinal cancer patients

AIM AND BACKGROUND

Intestinal alkalization could prevent irinotecan associated diarrhea modulating some chemical equilibria between irinotecan metabolites. The aim of this study was to evaluate the efficacy of this procedure in advanced gastrointestinal cancer patients (GICP).

MATERIALS AND METHOD

In this prospective study advanced GICP, receiving irinotecan based chemotherapy regimens, were well trained to add sodium bicarbonate to the water intake in order to accomplish intestinal alkalization.

RESULTS

A total of twenty four advanced GICP were enrolled. Grade III-IV diarrhea has been observed in four patients (16%), some of whom had several risk factors for diarrhea. Only one out of seventeen colorectal cancer patients, receiving the irinotecan combination as first line therapy, had grade III-IV diarrhea. No side effects of the procedure have been appreciated.

CONCLUSIONS

Intestinal alkalization may be effective as a preventive treatment for irinotecan associated diarrhea in chemotherapy regimens used in GICP. This procedure deserves further investigation.

Drug resistance, predictive markers and pharmacogenomics in colorectal cancer

Resistance to chemotherapy limits the effectiveness of current cancer therapies, including those used to treat colorectal cancer, which is the second most common cause of cancer death in Europe and the United States. 5-Fluorouracil-based chemotherapy regimens are the standard treatment for colorectal cancer in both the adjuvant and advanced disease settings. Drug resistance is thought to cause treatment failure in over 90% of patients with metastatic cancer, while drug resistant micrometastic tumour cells may also reduce the impact of adjuvant chemotherapy treatment. The identification of panels of biomarkers that not only identify those patients most likely to benefit from chemotherapy treatment, but also which chemotherapies to use, would be a major advance. In this review, we describe molecular mechanisms of drug resistance that may be relevant to colorectal cancer. We also describe the results of predictive biomarker studies in this disease. Finally, we discuss how pharmacogenomics and other high through-put technologies may impact on the clinical management of colorectal cancer in the future.

Angiogenesis in colorectal cancer: prognostic and therapeutic implications

Angiogenesis is important for tumor growth and metastasis. This account reviews the clinicopathological studies conducted in the field of angiogenesis in colorectal cancer, the methods of assessing vascular-related characteristics in tissue sections and provides a background for the usefulness of antiangiogenic policies along with chemotherapy and radiotherapy. Highly angiogenic colorectal tumors are associated with aggressive histopathological features and poor patients' survival. Similarly, factors stimulating angiogenesis, such as vascular endothelial growth factor (VEGF), thymidine phosphorylase (TP), and others, are commonly related to increased vascular density (VD) and, therefore, to an unfavorable clinical course. Anti-VEGF agents have improved prognosis in patients with metastatic colorectal cancer, when added to standard chemotherapy. It is expected that, in addition to adjuvant chemotherapy and radiotherapy, agents blocking the stimulatory effect of VEGF on endothelial cells would prove beneficial to the patient.

Phase II multicenter trial of bevacizumab plus fluorouracil and leucovorin in patients with advanced refractory colorectal cancer: an NCI Treatment Referral Center Trial TRC-0301

PURPOSE

To provide bevacizumab (BV) -based therapy to patients with advanced colorectal cancers (CRC) who had exhausted standard chemotherapy options, and to evaluate the response to BV combined with fluorouracil (FU) and leucovorin (LV) in this patient population.

PATIENTS AND METHODS

This was a multicenter, single-arm treatment trial conducted under the National Cancer Institute Treatment Referral Center network nationwide. Patients were treated with BV 5 mg/kg every 2 weeks combined with FU/LV; FU was administered by bolus or continuous infusion. Eligibility criteria included advanced CRC that had progressed after irinotecan- and oxaliplatin-based chemotherapy, Eastern Cooperative Oncology Group performance status 0 to 2, and absence of thromboembolism. The primary end point was objective response rate (RR) in the first 100 assessable patients. All patients received follow-up for toxicity and survival.

RESULTS

Due to rapid accrual, a total of 350 patients were enrolled at 32 participating sites nationwide by October 2003. In the initially planned cohort of 100 assessable patients, the objective RR was 4% (95% CI, 1.1% to 9.9%) by investigators' assessment and 1% (95% CI, 0% to 5.5%) based on independent review; median progression-free survival was 3.5 months and median overall survival was 9.0 months. The safety profile was similar to prior BV trials in CRC. Grade 3 to 4 hemorrhage occurred in 5% of patients, including 3.8% with bleeding in the GI tract. Other adverse events such as hypertension, thrombosis, and bowel perforation were also observed at rates consistent with other studies.

CONCLUSION

For patients with advanced CRC that had progressed after both irinotecan-based and oxaliplatin-based chemotherapy regimens, the combination of BV and FU/LV was associated with rare objective responses.

Are HER1/EGFR interactions with ligand free HER2 related to the effects of HER1-targeted drugs?

This paper is aimed to describe consequences of possible dimerization modes between ligand binding HER1 and ligand free HER2 receptors on cellular membrane. Cells without HER2/neu need high exposure to HER1 ligands for growth stimulation since formation of HER1-ligand:HER1-ligand homodimers depends on the number of both HER1 and ligand molecules and an "all or none" threshold under which cell growth is not stimulated can be expected. Cells with HER2/neu molecules on their surface can react to moderate or even low HER1 ligand exposure through formation of HER2:HER1-ligand dimers, making them more sensitive to growth stimulation by EGF or other ligands without the "all or none" threshold in cell growth stimulation. Formation of some HER2:HER2 homodimers can provide the basal cell growth stimulation despite available ligands to HER1. In tumors, high expression of HER2 can lead to many HER2:HER2 homodimers and increased cell growth that contributes to a poor prognosis. Here presented concept is that some 75 millions of years ago, introduction of HER2/neu with increased sensitivity to low EGFR ligand exposure, might be the cause of increased variability of HER1 expression on normal cells and of the basal EGF secretion from the uninjured tissue. Spontaneous formation of HER2:HER2 homodimers in cells with HER2/neu expression might have substituted the low ligand exposure from uninjured tissue and thus slowly reduce importance of basal secretions of EGFR ligands. Reported variability in HER1 tumor expression and response to HER1-targeted agents, a wide range of EGF concentration in healthy women breasts fluid and the skin rash/tumor response relation to HER1-targeted drugs are discussed as possible examples of individual differences in tissue dependency on HER1 interactions with ligands in normal and cancer tissue.

Perinatal epidermal growth factor receptor blockade prevents peripheral nerve disruption in a mouse model reminiscent of benign world health organization grade I neurofibroma

Benign peripheral nerve tumors called neurofibromas are a major source of morbidity for patients with neurofibromatosis type 1. Some neurofibroma Schwann cells aberrantly express the epidermal growth factor receptor (EGFR). In a mouse model in which the CNPase promoter drives expression of human EGFR in Schwann cells, nerves develop hypertrophy, mast cell accumulation, collagen deposition, disruption of axon-glial interactions, characteristics of neurofibroma and are hypoalgesic. Administration of the EGFR antagonist cetuximab (IMC-C225) for 2 weeks beginning at birth in CNPase-hEGFR mice normalized all pathologies at 3 months of age as evaluated by hotplate testing or histology and by electron microscopy. Mast cell chemoattractants brain-derived neurotrophic factor, monocyte chemoattractant protein-1, and transforming growth factor-beta1, which may account for mast cell accumulation and fibrosis, were reduced by cetuximab. Later treatment was much less effective. A birth to 2-week pulse of cetuximab blocked hEGFR phosphorylation and Schwann cell prolifera-tion in perinatal mutant nerve, so CNPase-hEGFR Schwann cell numbers correlate with the cetuximab effect. A >250-fold enlarged population of EGFR(+)/p75(+) cells was detected in newborn Nf1(+/-) mouse nerves. These results suggest the existence of an EGFR(+) cell enriched in the perinatal period capable of driving complex changes characteristic of neurofibroma formation.

Matching patients with drugs: triumphs and challenges

The foundations of personalized medicine are built on the premise that laboratory tests can accurately predict the response of individual patients to a particular treatment. Herceptin® and the HercepTest®, which is used to select patients with human epidermal growth factor receptor (HER2)-positive breast cancer, are rightfully the jewels in the crown of this new treatment paradigm. Although over 8 years have past since their joint approval, there remain ongoing concerns about the quality of HER2 testing in community pathology laboratories. The development of predictive epidermal growth factor receptor (EGFR) tests for treatment with Tarceva®, Iressa® and Erbitux® has proven more difficult due to the complex biology of the target. It has also exposed some of the business challenges of co-developing both a drug and a companion diagnostic test. This article describes Genentech’s experience of developing predictive tests for HER2 and EGFR and highlights the need for close collaboration between all parties involved in incorporating predictive diagnostic tests into clinical trials and clinical practice.

New Agents, Combinations, and Opportunities in the Treatment of Advanced and Early-Stage Colon Cancer

There has been a dramatic improvement in outcomes for patients who have colon cancer over recent years. These improvements have come about largely because of the availability of new chemotherapy agents (irinotecan, oxaliplatin and capecitabine) and new biologic agents (bevacizumab and cetuximab). Large, well-designed clinical trials have resulted in the routine use of all of these agents in the treatment of patients who have metastatic disease, and this has led to improved survival for these patients. In earlier stage disease, oxaliplatin/5-FU-based chemotherapy has become a new standard of adjuvant therapy for many patients. Clinical research efforts are investigating the use of biologic agents along with chemotherapy for adjuvant treatment; it is hoped that this will translate into a greater cure rate for these patients.

First-line 5-fluorouracil/folinic acid, oxaliplatin and irinotecan (FOLFOXIRI) does not impair the feasibility and the activity of second line treatments in metastatic colorectal cancer

BACKGROUND

We conducted two phase II trials evaluating the combination of 5-fluorouracil/folinic acid, oxaliplatin and irinotecan (FOLFOXIRI) as first-line treatment in 74 metastatic colorectal cancer patients. Results were very promising with an overall response rate of 71% and 72%, a median PFS of 10.4 and 10.8 months and an overall survival of 26.5 and 28.4 months, respectively. A concern about the use of all three active agents up-front is the possibility that this might limit, after progression, disease control with second-line treatments. Therefore, we conducted the present analysis to evaluate the outcome of second-line treatments in these 74 patients.

METHODS

Among the 71 patients so far progressed 54 (76%) received second line chemotherapy (23: FOLFIRI, 17: FOLFOXIRI, five: 5-FU protracted infusion, three: FOLFOX, three: 5-FU+MMC, two: CPT-11, one: CPT-11+LOHP, one: raltitrexed). Seventeen patients (24%) did not receive second line treatments: 10 because of deterioration of performance status (PS), four because of patient refusal and three because of death. Patients' characteristics at the time of second-line treatment were: M/F 36 of 18 patients, median age 64 yrs (range 44-75), ECOG PS>or=1 21 (39%) patients, multiple sites of disease 33 (61%) patients.

RESULTS

A median of 4.1 months of second-line chemotherapy per patient were administered (range 1-8). Overall response rate (52 out of 54 evaluable patients) was 33% and stable disease were 19 (37%). Median duration of response was 8.1 months. At a median follow up of 15.1 months from the start of salvage chemotherapy median PFS and overall survival were respectively 6.7 and 15.2 months.

CONCLUSIONS

First-line FOLFOXIRI does not impair the possibility to obtain objective responses and delay tumor progression with second line treatments containing the same agents used in first-line.

Multitargeted therapy: Can promiscuity be praised in an era of political correctness?

The rapidly expanding knowledge of the pathogenesis of cancer at the molecular level is providing new targets for drug discovery and development. However, cancer is a complex disease characterized by multiple genetic and molecular alterations affecting cell proliferation, survival, differentiation and invasion among others. Many of these alterations represent potential targets for the development of new anticancer therapeutics. Because of the enormous biological diversity of cancer, it is unlikely that attacking only one of these targets will eliminate a malignant cell. Rather, strategic combination of agents targeted against the most critical of those alterations will be needed. Another approach that is rendering promising clinical results is the use of more unspecific agents that inhibit or modulate several relevant targets simultaneously. A deep biologic understanding of the relative relevance of each target in different cancer types will be key to efficiently direct those drugs to diseases more likely to benefit from its particular modulation profile.

Follikuläre Arzneimittelreaktion auf Cetuximab

Cetuximab belongs to a newly developed group of anti-cancer drugs, which have an inhibitory effect on the epidermal growth factor receptor (EGF-R). EGF-R plays a major role in the homeostasis of the epidermis and epidermal appendages. In addition, EGF-R is expressed on a variety of carcinomas of different origin and is thought to be partly associated with tumor progression. For this reason, inhibition of EGF-R seems a promising anti-cancer therapy, as shown in a few clinical trials. As a side effect of the therapy, a follicular rash often develops in the seborrheic areas; this cutaneous reaction is associated with longer survival. We present a typical case and discuss the important features of the follicular rash occurring after EGF-R inhibition.

A Phase I Study of Cetuximab/Paclitaxel in Patients with Advanced-Stage Breast Cancer

BACKGROUND

The epidermal growth factor receptor (EGFR) is part of the ErbB family of receptor tyrosine kinases and is known to be variably expressed in breast cancers. Cetuximab is a humanized monoclonal antibody directed against the EGFR that works by blocking the downstream signaling function of this protein and thereby interfering with cancer cell proliferation. Preclinical studies have indicated a synergistic effect for the combination of anti-EGFR therapy plus paclitaxel in breast cancer models.

PATIENTS AND METHODS

Hence, we conducted a dose-escalation phase I trial using cetuximab/paclitaxel in patients with metastatic breast cancer to evaluate the feasibility of this combination. Patients with EGFR-positive metastatic breast cancer treated with <or= 1 previous therapy, excluding taxanes, were eligible. Treatment consisted of weekly cetuximab therapy and every-3-week paclitaxel, with dose escalation of cetuximab until the maximum tolerated dose was reached.

RESULTS

Twelve patients were enrolled to 3 treatment cohorts. Two of 6 patients on the second cohort (cetuximab 100 mg/m2) developed dose-limiting toxicities, presenting as grade 3 rash. The third cohort was amended to allow the same cetuximab dose but to modify the paclitaxel to a weekly schedule. Despite this, 1 of 3 patients in this group also developed grade 3 skin toxicity as a dose-limiting toxicity; thus, the trial was stopped. Ten of the 12 patients were evaluable for response, and of these, 2 patients experienced stable disease, and 8 patients experienced disease progression.

CONCLUSION

Because of prohibitive dermatologic toxicity and disappointing preliminary efficacy, the combination of paclitaxel/cetuximab was not considered promising in this population, although further study of this regimen might be warranted.

Clinical Implications of Our Advancing Knowledge of Colorectal Cancer Genetics: Inherited Syndromes, Prognosis, Prevention, Screening and Therapeutics

Recent genetic advances in our knowledge of colorectal cancer genetics are beginning to pay translational dividends in the management of this common clinical problem. We are now able to accurately screen and counsel individuals at risk of rare inherited cancer syndromes. We have recently introduced two of what are sure to be numerous biologic-based therapies, and have shown that colorectal neoplasia risk can be modestly reduced by various chemopreventative agents. Finally, our advancing knowledge has led to significant inroads into understanding what genetic alterations define prognosis and predict response to specific chemotherapeutic agents, and we are beginning to explore the utility of this knowledge in mass genetic-based clinical screening efforts. Enthusiasm must be tempered, however, by the extraordinary cost that often accompanies relatively modest gains. Finally, although genetic-based therapy often receives the greatest attention, molecular genetics, will likely have the greatest cost-effective impact in primary prevention and early diagnosis.

Surgical adjuvant therapy for colorectal cancer: current approaches and future directions

Colon cancer is the fourth most common cancer worldwide. The role of systemic adjuvant chemotherapy in colorectal cancer patients with lymph node involvement has been established in a large number of clinical trials. However, its role in stage II colorectal cancer is less well established. 5-Fluorouracil has been the mainstay of therapy for the last four decades. With the development of novel chemotherapy and biological agents, we have entered into a new era for the treatment of colorectal cancer. The combination of adjuvant 5-fluorouracil, leucovorin, and oxaliplatin has been shown to significantly improve disease-free survival and is now considered the standard of care for completely resected colon cancer in healthy patients. For rectal cancer patients with locally advanced tumors, neoadjuvant chemoradiation followed by adjuvant chemotherapy after surgery is the mainstay of treatment. The availability of oral chemotherapy agents has helped with the ease of administration and avoidance of indwelling catheters. A number of national clinical trials are under way to determine the role of targeted agents in combination with chemotherapy. The goal is to develop a regimen that would improve survival without excessive toxicity while maintaining quality of life. Patients should be encouraged to participate in clinical trials whenever feasible. Despite the advances, many patients will develop recurrent disease. It is of utmost importance to develop molecular markers that could predict which patients are at high risk for disease recurrence. Clinical trials are under way to address this issue. Thus, it will be advantageous to be able to tailor therapy individually, according to the risk of recurrence.

Targeting the Epidermal Growth Factor Receptor in Colorectal Cancer: Advances and Controversies

Colorectal cancer (CRC) is the second leading cause of cancer death in the western world. Even with the significant improvement in traditional chemotherapy, there remain limitations with this treatment. One of the most promising new targets in the treatment of CRC is the epithelial growth factor receptor (EGFR). Agents that inhibit the EGFR have demonstrated clinical activity as single agents and in combination with chemotherapy and the most promising of these agents is cetuximab, which blocks the binding of EGF and transforming growth factor-alpha (TGF-alpha) to EGFR. Thus, the finding that monoclonal antibodies against EGFR caused a response in patients, and reversed resistance to chemotherapy, was exciting news. However, expression of EGFR did not correlate with clinical benefit. Clearly, the search for markers of response to treatment against EGFR must go on.

Assessment of epidermal growth factor receptor (EGFR) expression in primary colorectal carcinomas and their related metastases on tissue sections and tissue microarray

Metastatic colorectal carcinomas (CRC) resistant to chemotherapy may benefit from targeting monoclonal therapy cetuximab when they express the epidermal growth factor receptor (EGFR). Because of its clinical implications, we studied EGFR expression by immunohistochemistry on tissue sections of primary CRC (n=32) and their related metastases (n=53). A tissue microarray (TMA) was generated from the same paraffin blocks to determine whether this technique could be used for EGFR screening in CRC. On tissue sections, 84% of the primary CRC and 94% of the metastases were EGFR-positive. When matched, they showed a concordant EGFR-positive status in 78% of the cases. Moreover, staining intensity and extent of EGFR-positive cells in the primary CRC correlated with those observed in the synchronous metastases. On TMA, 65% of the primary CRC, 66% of the metastases, and 43% of the matched primary CRC metastases were EGFR-positive. There was no concordant EGFR status between the primary and the metastatic sites. A strong discrepancy of EGFR status was noted between TMA and tissue sections. In conclusion, EGFR expression measured in tissue sections from primary CRC and their related metastases was found to be similar and frequent, but it was significantly underestimated by the TMA technique.

A pathologic complete response of rectal cancer to preoperative combined-modality therapy results in improved oncological outcome compared with those who achieve no downstaging on the basis of preoperative endorectal ultrasonography

BACKGROUND

Preoperative combined-modality therapy (CMT) is the preferred treatment for locally advanced rectal cancer (endorectal ultrasonography [ERUS] T3-4, N1, or clinically bulky) and achieves a pathologic complete response (pCR) in 4% to 33% of patients. However, the prognostic significance of pCR remains unclear.

METHODS

A prospectively collected database was queried to identify 200 patients with locally advanced disease treated from 1992 to 2002. The pCR group was defined as having no evidence of viable tumor on pathologic analysis. The no-downstaging group was defined as no difference between the pre-CMT ERUS stage and the pathologic stage. Those achieving some downstaging but not pCR were excluded. Patients were treated with CMT (5040 cGy of radiation and 5-fluorouracil-based chemotherapy) followed by surgery, and 51 (85%) in the pCR group and 129 (92%) in the no-downstaging group (P = .1) received postoperative chemotherapy. Recurrence-free survival (RFS) and overall survival (OS) were determined by using the Kaplan-Meier method.

RESULTS

The median follow-up was 38.6 months (range, 18.2-124.9 months). The pCR (n = 60) and control (n = 140) groups were similar in age (P = .6), sex (P = .4), distance of the tumor from the anal verge (P = .3), pre-CMT ERUS stage (P = .2), and comorbidities (P = .2). The 5-year RFS was 96% and 54% in the pCR and control groups, respectively (P < .00001); the 5-year OS was 90% and 68% (P = .009). Sphincter-preservation rates were higher in the pCR group (P = .01).

CONCLUSIONS

Rectal cancer patients with pCR after preoperative CMT have improved RFS, OS, and sphincter preservation compared with patients without downstaging. Because pCR seems to be associated with better outcome, an understanding of the factors governing the response to CMT should be pursued.

Protein therapeutics: new applications for pharmacogenetics

Pharmacogenetic studies have traditionally focused on genes involved in processes that affect the pharmacokinetics of small-molecule drugs, such as drug metabolism. However, attention is shifting to the effects of genetic variations in drug targets and associated pathway components on drug responses. We describe how these variations are important for understanding differences in responses to the growing number of protein therapeutics that are entering clinical practice. Pharmacogenetic studies of these drugs are surveyed, and issues important to the success of such endeavours are discussed. As novel protein therapeutics are introduced, we anticipate that the use of pharmacogenetics will assume a key role in their development and clinical application.

Analysis of c-ErbB1/epidermal growth factor receptor and c-ErbB2/HER-2 expression in bronchial dysplasia: evaluation of potential targets for chemoprevention of lung cancer

PURPOSE

Lung cancer is preceded by a premalignant phase during which intervention could decrease associated morbidity and mortality. Molecular characterization of factors involved in controlling progression of bronchial dysplasias will provide markers of premalignant change and identify targets for chemoprevention.

EXPERIMENTAL DESIGN

Immunohistochemical analysis of epidermal growth factor receptor (EGFR; c-ErbB1/EGFR), HER-2/neu (c-ErbB2/HER-2), Ki-67, and minichromosome maintenance protein 2 (MCM2) expression in bronchial dysplasia was undertaken to characterize molecular alterations associated with the progression of these lesions in 268 bronchoscopically obtained biopsies from 134 subjects.

RESULTS

Analysis of biopsies with the most severe diagnosis from each subject showed a linear relationship between increasing marker expression and severity of dysplastic change for EGFR (P < 0.001), Ki-67 (P < 0.001), and MCM2 (P = 0.001) but not HER-2 (P = 0.102). Increased expression of either EGFR or HER-2 was associated with increased levels of Ki-67 and MCM2 expression, and combined overexpression of these receptors was associated with the highest levels of proliferation, suggesting a synergistic effect. Finally, the lack of an associated trend toward increased EGFR expression when comparing the worst and best biopsies within each subject indicated a potential field effect in the induction of EGFR expression.

CONCLUSIONS

The results suggest a prominent role for EGFR overexpression in the development and progression of bronchial dysplasia and provide rationale for exploring inhibition of EGFR signaling in lung cancer chemoprevention.

Synergistic antitumor effects of combined epidermal growth factor receptor and vascular endothelial growth factor receptor-2 targeted therapy

PURPOSE

Combination therapies that target the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) pathways, are being actively tested for the treatment of cancer. In evaluating combination strategies, the ideal combination would be one in which the treatments interact in a way that is synergistic with regard to antitumor effects. Here, we have evaluated the interaction between anti-EGFR antibody Erbitux (cetuximab) and anti-VEGFR2 antibody, DC101, in preclinical models of pancreatic (BxPC-3) and colon (GEO) cancer.

EXPERIMENTAL DESIGN

Analysis of the interaction between cetuximab and DC101 in vivo used a novel method for establishing the upper 95% confidence limits for the combination index (CI) of isobologram analyses, where CI < 1 indicates synergy. Assessment of tumor cell proliferation, apoptosis, VEGF production, and hypoxia, as well as tumor vascularization, was performed to gain insights into the mechanistic basis for synergy between agents targeting different tumor compartments.

RESULTS

Monotherapy ED(50) values for tumor growth inhibition ranged from 1.8 to 2.3 mg/kg and 10.5 to 16.6 mg/kg for cetuximab and DC101, respectively. From the dose response of the combination treatment, it was determined that cetuximab and DC101 are synergistic in the BxPC-3 (CI = 0.1, P < 0.01) and GEO (CI = 0.1, P < 0.01) models. Overlapping effects on the tumor cell and vascular compartments form a basis for the interaction, with VEGF production and hypoxia-inducible factor 1alpha potentially acting as molecular links between EGFR and VEGFR2 inhibition.

CONCLUSIONS

Results show antitumor synergy for combined EGFR and VEGFR2 targeted therapy, supporting the significant therapeutic potential of this combination strategy.

Management of advanced colorectal cancer: state of the art

Colorectal cancer (CRC) caused over 500 000 deaths worldwide in 2002. Recent advances in the treatment of advanced disease include the incorporation of two new cytotoxic agents, irinotecan and oxaliplatin, into first-line regimens. The concept of planned sequential therapy involving three active agents during the course of a patient's treatment is evolving. Coupled with the integrated use of targeted monoclonal antibodies, we can now expect overall survival rates for advanced disease to exceed 20 months. This review considers current treatments and suggests where future progress may occur.

Gemcitabine in combination with EGF-Receptor antibody (Cetuximab) as a treatment of cholangiocarcinoma: a case report

Background

Extensive disease of cholangiocarcinoma (CC) determines the overall outcome and limits curative resection. Despite chemotherapy, which has been introduced to improve the outcome of biliary tract malignancies, the benefit in survival is still marginal.

Case presentation

We report a 69-year-old patient with non-resectable CC showing hepatic metastasis and peritoneal carcinomatosis. Diagnosis was based on computed tomography, mini-laparoscopy and bioptic specimens. Histology revealed an adenocarcinoma of the biliary tract with expression of epithelial growth factor receptor. After informed consent the patient received experimental gemcitabine (1000 mg/m²) every other week and cetuximab (250 mg/m²) weekly for palliative chemotherapy. During the reported follow up (since time of first presentation) 20 cycles of chemotherapy were administered. Relevant chemotherapy-related toxicity was limited on gemcitabine-associated side effects. Predominantly, haematological toxicity (CTC, grade 3) and neutropenic fever (CTC, grade 3) promoted by catheter-related sepsis were observed. Cetuximab caused only mild skin toxicity (CTC, grade 1).

Chemotherapy led to a partial response (> 30% reduction, according to RECIST) of the target lesions and disappearance of the peritoneal carcinomatosis as shown by computed tomography. Partial response occurred after 17 weeks of treatment and remained stable during the entire course of chemotherapy for 9.7 months. In parallel, Ca 19-9 serum levels, which were elevated 5-fold at time of diagnosis, returned to normal after 16 weeks of treatment. The performance status stabilized and intravenous alimentation could be discontinued.

Conclusion

Our experience from one patient with CC suggests, that a combination of cytotoxic chemotherapy together with cetuximab may show promising efficacy in respect to survival and quality of life. Therefore cetuximab, as a component of palliative chemotherapy in biliary tract cancer, needs further evaluation in prospective randomized trials.

Novel targets in gastric and esophageal cancer

Esophageal cancer (EC) and gastric cancer (GC) constitute a major cause of cancer deaths worldwide. Recent improvements in both surgical techniques and adjuvant/neoadjuvant chemotherapy, radiotherapy or both have increased the survival of patients with loco-regional disease. However, most patients with GC or EC have advanced disease either at diagnosis or during the follow-up, and despite recent advances, these patients still do poorly. Understanding of the molecular pathways that characterize cell growth, cell cycle, apoptosis, angiogenesis and invasion has provided novel targets in cancer therapy. In this review we describe the current status of targeted therapies in the treatment of EC and GC, including EGFR inhibitors, antiangiogenic agents, cell cycle inhibitors, apoptosis promoters and matrix metalloproteinases inhibitors. The emerging data from the clinical development of these compounds has provided novel opportunities in the treatment of EC and GC that will probably translate into clinical benefit for patients with these common malignancies.

Neoadjuvant treatment of unresectable liver metastases from colorectal cancer

There has been increasing interest in the use of neoadjuvant treatment for downstaging and downsizing disease in patients with initially unresectable liver metastases from colorectal cancer with a view to potentially curative surgery. This has been increasingly feasible with the more active treatment combinations presently available based on oxaliplatin or irinotecan. This article reviews the evidence supporting the use of this treatment strategy and discusses the implications of advances in treatment in other metastatic disease settings for these patients and the issues of patient selection and prognostic factors.