C225 antiepidermal growth factor receptor antibody enhances the efficacy of docetaxel chemoradiotherapy

The role of heat shock proteins in metastatic colorectal cancer: A review

Heat shock proteins (HSPs) are a large molecular chaperone family classified by their molecular weights, including HSP27, HSP40, HSP60, HSP70, HSP90, and HSP110. HSPs are likely to have antiapoptotic properties and participate actively in various processes such as tumor cell proliferation, invasion, metastases, and death. In this review, we discuss comprehensively the functions of HSPs associated with the progression of colorectal cancer (CRC) and metastasis and resistance to cancer therapy. Taken together, HSPs have numerous clinical applications as biomarkers for cancer diagnosis and prognosis and potential therapeutic targets for CRC and its related metastases.

Enhanced Anti-Cancer Effect of Folate-Conjugated Olaparib Nanoparticles Combined with Radiotherapy in Cervical Carcinoma

BACKGROUND

Radiotherapy (RT), one of the main treatments for cervical cancer, has tremendous potential for improvement in the efficacy. Poly (ADP-ribose) polymerase (PARP) is a key enzyme in the repair of DNA strand breaks (DSB). Olaparib (Ola) is a PARP inhibitor that is involved in preventing the release of PARP from RT-induced damaged DNA to potentiate the effect of RT. Although the basic mechanism of Ola's radiosensitization is well known, the radiosensitization mechanism of its nanomedicine is still unclear. In addition, the lack of tumor tissue targeting is a major obstacle for the clinical success of Ola.

MATERIALS AND METHODS

In this study, we developed folate-conjugated active targeting olaparib nanoparticles (ATO) and investigated the anti-tumor effect of ATO combined with radiotherapy (RT) in nude mice using cervical cancer xenograft models. We used folate (FA)-conjugated poly (ε-caprolactone)-poly (ethyleneglycol)-poly (e-caprolactone) (PCEC) copolymer to prepare ATO via emulsification/solvent diffusion. Further, we evaluated ATO particle size, potential, encapsulation efficiency, and in vitro release characteristics, and evaluated the shape of ATO via transmission electron microscopy (TEM). We then performed MTT and cell uptake assays to detect cytotoxicity and targeting uptake in vitro. We investigated the anti-tumor properties of ATO in vivo by apoptosis test, 18 F-FDG PET/CT, and immunohistochemical analysis. Finally, the xenografted tumor in nude mice was subjected to RT and/or ATO treatment.

RESULTS

The results confirmed that ATO in combination with RT significantly inhibited tumor growth and prolonged survival time of tumor-bearing mice. This may be related to the inhibition of tumor proliferation and DNA damage repair and induction of cell apoptosis in vivo.

CONCLUSION

The ATO developed in this study may represent a novel formulation for olaparib delivery and have promising potential for treating tumors with an over-expression of folate receptors.

A Phase 2 Trial of Chemoradiation Therapy Using Weekly Docetaxel for High-Risk Postoperative Oral Squamous Cell Carcinoma Patients

PURPOSE

To evaluate the efficacy and safety of postoperative concurrent chemoradiation therapy using weekly docetaxel in patients with high-risk oral squamous cell carcinoma (OSCC).

METHODS AND MATERIALS

This is a prospective single-arm study from a single institute in Shanghai Ninth People's Hospital, Shanghai, China. Patients with locally stage III to IV OSCC who underwent radical surgery with at least 1 high-risk feature were enrolled for the study. High-risk features evaluated included (1) pathologically confirmed positive or close margins in the primary site or extracapsular nodal extension; (2) histologic involvement of ≥2 regional lymph nodes; and (3) locoregional recurrent OSCC (after initial surgery alone) treated with salvage surgery with curative intent. Docetaxel was administered at a dose of 20 mg/m² concurrently with postoperative radiation therapy (total dose 60-66 Gy). The primary outcome was 2-year disease-free survival (DFS). Secondary endpoints included 2-year locoregional progress-free survival, 2-year overall survival (OS), and toxicities.

RESULTS

From March 2016 to February 2018, 91 patients (59 males, 32 females) were recruited. Median age was 59 years (range, 26-70). All patients were included in final analysis. Fifty-eight patients (63.7%) completed the 6 planned cycles of docetaxel, and all patients completed postoperative radiation therapy. With a median follow-up of 24 months, the 2-year DFS and OS were 75.3% (95% confidence interval, 65.7%-84.2%) and 82.4% (95% confidence interval, 73.0%-89.6%), respectively. Patterns of failure were 13 local recurrences, 2 regional lymph nodes recurrences, and 8 distant failures. Seven patients (7.7%) were recorded as having grade 3 oral cavity mucositis. Two patients had grade 3 hypersensitivity reaction. No other grade 3 or higher adverse events, including hematologic toxicities, were observed.

CONCLUSIONS

The addition of low-dose weekly docetaxel with concurrent radiation therapy is a tolerable regimen with favorable DFS and OS in patients with high-risk, resected OSCC.

Synthesis and Characterization of Cetuximab-Docetaxel and Panitumumab-Docetaxel Antibody-Drug Conjugates for EGFR-Overexpressing Cancer Therapy

The safety and efficacy of anticancer antibody-drug conjugates (ADCs) depend on the selection of tumor-targeting monoclonal antibody (mAb), linker, and drug, as well as their specific chemical arrangement and linkage chemistry. In this study, we used a heterobifunctional cross-linker to conjugate docetaxel (DX) to cetuximab (CET) or panitumumab (PAN). The resulting ADCs were investigated for their in vitro EGFR-specific cytotoxicity and in vivo anticancer activity. Reaction conditions, such as reducing agent, time, temperature, and alkylation buffer, were optimized to yield potent and stable ADCs with consistent batch-to-batch drug-to-antibody ratios (DARs). ADCs were synthesized with DARs from 0.4 to 3.0, and all retained their EGFR affinity and specificity after modification. ADCs were sensitive to cell surface wildtype EGFR expression, demonstrating more cytotoxicity in EGFR-expressing A431 and MDA-MB-231 cell lines compared to U87MG cells. A431 tumor-bearing mice treated once weekly for four weeks with 100 mg/kg cetuximab-docetaxel ADC (C-SC-DX, DAR 2.5) showed durable anticancer responses and improved overall survival compared to the same treatment regimen with 1 mg/kg DX, 100 mg/kg CET, or a combination 1 mg/kg DX and 100 mg/kg CET. New treatment options are emerging for patients with both wild-type and mutated EGFR-overexpressing cancers, and these studies highlight the potential role of EGFR-targeted ADC therapies as a promising new treatment option.

Postoperative Bio-Chemoradiotherapy Using Cetuximab and Docetaxel in Patients With Cis-Platinum-Intolerant Core High-Risk Head and Neck Cancer: Protocol of a Phase 2 Nonrandomized Clinical Trial

Background

We confirmed the safety of postoperative bio-chemoradiotherapy using cetuximab and docetaxel in a small number of patients with cis-platinum–intolerant core high-risk head and neck cancer.

Objective

To assess treatment efficacy, we planned a phase 2 study of postoperative bio-chemoradiotherapy for patients with cis-platinum–intolerant core high-risk head and neck cancer and will compare the results to those of previously collected radiotherapy data.

Methods

Patients who underwent definitive surgery for oral cavity, laryngeal, oropharyngeal, or hypopharyngeal advanced cancer, whose postoperative pathological results indicated core high risk for recurrence (eg, positive margin in the primary site or extranodal extension) and who were cis-platinum–intolerant, will undergo postoperative bio-chemoradiotherapy. The primary end point is 2-year disease-free survival.

Results

The expected 2-year disease-free survival is set at 55%, and the calculated sample size is 35 patients, according to a statistical analysis based on previous reports.

Conclusions

This treatment method is expected to improve the survival rate of patients with severe head and neck cancer.

Trial Registration

UMIN Clinical Trials Registry UMIN000031835; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ ctr_view.cgi?recptno=R000036355 (Archived by WebCite at http://www.webcitation.org/71fejVjMr)

Skin cancer treatment effectiveness is improved by iontophoresis of EGFR-targeted liposomes containing 5-FU compared with subcutaneous injection

Squamous cell carcinoma (SCC) is a malignant tumor in which epidermal growth factor receptor (EGFR) overexpression is associated with poor prognosis and malignancy. For SCC treatment, cetuximab, an anti-EGFR antibody, is administered in combination with a chemotherapeutic drug for improved efficacy. In this work, an EGFR-targeted immunoliposome loaded with 5-fluorouracil (5- FU) was developed to allow co-administration of the antibody and the chemotherapeutic agent and selective delivery to SCC cells. Topically applied iontophoresis and subcutaneous injections of the 5-FU-loaded immunoliposomes were employed in an SCC xenograft animal model to evaluate the influence of the administration route on therapeutic efficacy. In vitro, cellular uptake of cetuximab-immunoliposomes by EGFR-positive SCC cells was 3.5-fold greater than the uptake of control liposomes. Skin penetration studies showed that iontophoresis of immunoliposomes doubled the 5-FU penetration into the viable epidermis compared with the same treatment with control liposomes. In vivo, subcutaneous injection of immunoliposomes reduced tumor volume by >60% compared with the negative control and approximately 50% compared with the 5-FU solution and control liposome treatments. Interestingly, topical administration via iontophoresis improved tumor reduction by almost 2-fold compared with subcutaneous administration of 5-FU solution and control liposomes but was equally effective for the immunoliposome treatment. However, histological analysis showed that iontophoresis of immunoliposomes was more effective than subcutaneous injection in reducing cell proliferation, resulting in cells with less aggressive characteristics. In conclusion, topical administration of immunoliposomes containing 5-FU using iontophoresis is a promising strategy for SCC treatment.

Prospective, Multicenter, Phase 2 Trial of Induction Chemotherapy Followed by Bio-Chemoradiotherapy for Locally Advanced Recurrent Nasopharyngeal Carcinoma

PURPOSE

To evaluate, in a phase 2 study, whether induction docetaxel, cisplatin, and fluorouracil (TPF) followed by weekly docetaxel and cetuximab in concurrence with intensity modulated radiation therapy can improve the treatment outcome for patients with advanced locally recurrent nasopharyngeal carcinoma (rNPC).

METHODS AND MATERIALS

Thirty-three patients with rNPC (T3-T4, N0-N1, M0) were recruited. Of these, 19 patients (57.6%) had stage rT3 recurrence, and the rest had stage rT4. Eight patients also had rN1 at the time of relapse. Treatment outcomes and safety were evaluated.

RESULTS

Among these 33 patients, 1 died after 1 cycle of TPF, 5 patients withdrew from the study during the induction period because of grade ≥3 toxicities; 27 patients completed the whole course of treatment, but 1 died before any assessment could be made. The median follow-up period was 28.5 months. The progression-free survival and overall survival at 3 years for the whole group were 35.7% and 63.8%, respectively. Among the 26 patients who could be assessed after treatment, the complete response rate was 30.8%, and the locoregional control rate at 3 years was 49.2%. Temporal lobe necrosis (TLN) developed in 8 cases. The rates of grade ≥3 hearing loss, soft tissue necrosis, dysphagia, and trismus were 30.8%, 15.4%, 11.5%, and 19.2%, respectively. Overall, 5 patients died owing to acute (1 after cycle 1 TPF and 1 after completion of bio-chemoradiotherapy) or late (2 epistaxis and 1 TLN) treatment-related complications.

CONCLUSIONS

The proposed salvage treatment regimen for advanced locally recurrent NPC could achieve a better treatment outcome than seen in previous studies. However, poor tolerability of induction TPF and the high rate of TLN limit its applicability outside clinical trials.

Retrospective study of treatment outcomes after postoperative chemoradiotherapy in Japanese oral squamous cell carcinoma patients with risk factors of recurrence

BACKGROUND

The purpose of this study was to investigate the feasibility of postoperative concomitant chemoradiotherapy (CRT) with cisplatin (CDDP), and compare the prognosis in 3 groups-without postoperative therapy (S-only), with radiotherapy (RT) alone (S+RT), and with CRT (S+CRT)-in oral squamous cell carcinoma (OSCC) patients at high risk of recurrence.

METHODS

Clinicopathologic data and treatment modality were investigated. Endpoints evaluated were locoregional control (LRC), relapse-free survival, overall survival (OS), and type of recurrence.

RESULTS

The S+CRT group was associated with a better LRC rate than the S-only (P < .001) and S+RT groups (P = .044). However, there was no significant difference in OS rates between the S+RT and S+CRT groups.

CONCLUSION

The addition of concomitant CDDP to postoperative RT improved LRC. However, there may be no benefit from the addition of concomitant CDDP to postoperative RT for improvement of distant metastasis and OS rates in OSCC patients.

Final Results of a Randomized Phase 2 Trial Investigating the Addition of Cetuximab to Induction Chemotherapy and Accelerated or Hyperfractionated Chemoradiation for Locoregionally Advanced Head and Neck Cancer

PURPOSE

The role of cetuximab in the treatment of locoregionally advanced head and neck squamous cell cancer (LA-HNSCC) remains poorly defined. In this phase 2 randomized study, we investigated the addition of cetuximab to both induction chemotherapy (IC) and hyperfractionated or accelerated chemoradiation.

METHODS AND MATERIALS

Patients with LA-HNSCC were randomized to receive 2 cycles of weekly IC (cetuximab, paclitaxel, carboplatin) and either Cetux-FHX (concurrent cetuximab, 5-fluorouracil, hydroxyurea, and 1.5 Gy twice-daily radiation therapy every other week to 75 Gy) or Cetux-PX (cetuximab, cisplatin, and accelerated radiation therapy with delayed concomitant boost to 72 Gy in 42 fractions). The primary endpoint was progression-free survival (PFS), with superiority compared with historical control achieved if either arm had 2-year PFS ≥70%.

RESULTS

110 patients were randomly assigned to either Cetux-FHX (n=57) or Cetux-PX (n=53). The overall response rate to IC was 91%. Severe toxicity on IC was limited to rash (23% grade ≥3) and myelosuppression (38% grade ≥3 neutropenia). The 2-year rates of PFS for both Cetux-FHX (82.5%) and Cetux-PX (84.9%) were significantly higher than for historical control (P<.001). The 2-year overall survival (OS) was 91.2% for Cetux-FHX and 94.3% for Cetux-PX. With a median follow-up time of 72 months, there were no significant differences in PFS (P=.35) or OS (P=.15) between the treatment arms. The late outcomes for the entire cohort included 5-year PFS, OS, locoregional failure, and distant metastasis rates of 74.1%, 80.3%, 15.7%, and 7.4%, respectively. The 5-year PFS and OS were 84.4% and 91.3%, respectively, among human papillomavirus (HPV)-positive patients and 65.9% and 72.5%, respectively, among HPV-negative patients.

CONCLUSIONS

The addition of cetuximab to IC and chemoradiation was tolerable and produced long-term control of LA-HNSCC, particularly among poor-prognosis HPV-negative patients. Further investigation of cetuximab may be warranted in the neoadjuvant setting and with non-platinum-based chemoradiation.

Phase II study of erlotinib and docetaxel with concurrent intensity-modulated radiotherapy in locally advanced head and neck squamous cell carcinoma

BACKGROUND

The purpose of this study was to establish the efficacy and toxicities of concurrent erlotinib and docetaxel with intensity-modulated radiotherapy (IMRT) for locally advanced head and neck squamous cell carcinoma (HNSCC).

METHODS

Patients received daily erlotinib for 2 weeks, followed by daily IMRT with concurrent weekly docetaxel and daily erlotinib, followed by daily erlotinib for up to 2 years. The primary objective was disease-free survival (DFS). Secondary objectives included overall survival (OS), patterns of failure, and toxicities. Forty-three patients were recruited for this study.

RESULTS

With a median follow-up of 48.7 months, the 3-year DFS, OS, locoregional failure-free survival, and distant metastasis-free survival was 69.5%, 81%, 82.4%, and 83.7%, respectively. The most common grade III/IV local toxicities were dysphagia, dermatitis, and mucositis. Patients with p16-positive tumors had significantly better outcomes.

CONCLUSION

The regimen is tolerable and effective. It is worthy of further investigation in selected patients and may be useful in patients who cannot tolerate cisplatin. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1770-E1776, 2016.

Targeting epidermal growth factor receptor for head and neck squamous cell carcinoma: still lost in translation?

The epidermal growth factor receptor (EGFR) is preferentially expressed in head and neck squamous cell carcinoma (HNSCC), and is a promising therapeutic target. Yet other than cetuximab, no agent targeting EGFR has been approved for this disease, and none has shown benefit over the standard of care. Several randomized trials of antibody and small molecule agents have found no new indication for these agents, despite their initial promise. In this review, we examine the major clinical evidence and discuss potential future developments of translational science in this area, including use of these agents in risk-stratified subgroups, inhibition of downstream/parallel targets, and combination with immunotherapy.

Interventions for the treatment of oral and oropharyngeal cancers: targeted therapy and immunotherapy

BACKGROUND

Oral cancers are the sixth most common cancer worldwide, yet the prognosis following a diagnosis of oral cavity or oropharyngeal cancers remains poor, with approximately 50% survival at five years. Despite a sharp increase in research into molecularly targeted therapies and a rapid expansion in the number of clinical trials assessing new targeted therapies, their value for treating oral cancers is unclear. Therefore, it is important to summarise the evidence to determine the efficacy and toxicity of targeted therapies and immunotherapies for the treatment of these cancers.

OBJECTIVES

To assess the effects of molecularly targeted therapies and immunotherapies, in addition to standard therapies, for the treatment of oral cavity or oropharyngeal cancers.

SEARCH METHODS

We searched the following electronic databases: Cochrane Oral Health Group Trials Register (to 3 February 2015), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2015, Issue 1), MEDLINE via Ovid (1946 to 3 February 2015) and EMBASE via Ovid (1980 to 3 February 2015). We searched the US National Institutes of Health Trials Register (clinicaltrials.gov), the World Health Organization Clinical Trials Registry Platform, the American Society of Clinical Oncology conference abstracts and the Radiation Therapy Oncology Group clinical trials protocols for ongoing trials. We placed no restrictions on the language or date of publication.

SELECTION CRITERIA

We included randomised controlled trials where more than 50% of participants had primary tumours of the oral cavity or oropharynx, and which compared targeted therapy or immunotherapy, plus standard therapy, with standard therapy alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies. We attempted to contact study authors for missing data or clarification where necessary. We combined sufficiently similar studies in meta-analyses using random-effects models when there were at least four studies and fixed-effect models when fewer than four studies. We obtained or calculated a hazard ratio (HR) and 95% confidence interval (CI) for the primary outcomes where possible. For dichotomous outcomes, we reported risk ratios (RR) and 95% CIs.

MAIN RESULTS

Twelve trials (2488 participants) satisfied the inclusion criteria. In the included trials, 12% of participants (298 participants) had tumours of the oral cavity and 59% (1468 participants) had oropharyngeal tumours. The remaining 29% had tumours of the larynx or hypopharynx and less than 1% had tumours at other sites.No included trial was at low risk of bias; seven had an unclear risk of bias, and five had a high risk of bias. We grouped trials by intervention type into three main comparisons: standard therapy plus epidermal growth factor receptor monoclonal antibody (EGFR mAb) therapy (follow-up period 24 to 70 months); standard therapy plus tyrosine kinase inhibitors (TKIs) (follow-up period 40 to 60 months) and standard therapy plus immunotherapy (follow-up period 24 to 70 months), all versus standard therapy alone.Moderate quality evidence showed that EGFR mAb therapy may result in 18% fewer deaths when added to standard therapy (HR of mortality 0.82; 95% CI 0.69 to 0.97; 1421 participants, three studies, 67% oropharyngeal tumours, 2% oral cavity tumours).There was also moderate quality evidence that EGFR mAb may result in 32% fewer locoregional failures when added to radiotherapy (RT) (HR 0.68; 95% CI 0.52 to 0.89; 424 participants, one study, 60% oropharyngeal tumours).A subgroup analysis separating studies by type of standard therapy (radiotherapy (RT) or chemoradiotherapy (CRT)) showed some evidence that adding EGFR mAb therapy to RT may result in a 30% reduction in the number of people whose disease progresses (HR 0.70; 95% CI 0.54 to 0.91; 424 participants, one study, 60% oropharyngeal tumours, unclear risk of bias). For the subgroup comparing EGFR mAb plus CRT with CRT alone there was insufficient evidence to determine whether adding EGFR mAb therapy to CRT impacts on progression-free survival (HR 1.08; 95% CI 0.89 to 1.32; 891 participants, one study, 70% oropharyngeal tumours, high risk of bias). The high subgroup heterogeneity meant that we were unable to pool these subgroups.There was evidence that adding cetuximab to standard therapy may result in increased skin toxicity and rash (RR 6.56; 95% CI 5.35 to 8.03; 1311 participants, two studies), but insufficient evidence to determine any difference in skin toxicity and rash in the case of nimotuzumab (RR 1.06; 95% CI 0.85 to 1.31; 92 participants, one study).There was insufficient evidence to determine whether TKIs added to standard therapy impacts on overall survival (HR 0.99; 95% CI 0.62 to 1.57; 271 participants, two studies; very low quality evidence), locoregional control (HR 0.89; 95% CI 0.53 to 1.49; 271 participants, two studies; very low quality evidence), disease-free survival (HR 1.51; 95% CI 0.61 to 3.71; 60 participants, one study; very low quality evidence) or progression-free survival (HR 0.80; 95% CI 0.51 to 1.28; 271 participants, two studies; very low quality evidence). We did find evidence of an increase in skin rash (erlotinib: RR 6.57; 95% CI 3.60 to 12.00; 191 participants, one study; lapatinib: RR 2.02; 95% CI 1.23 to 3.32; 67 participants, one study) and gastrointestinal complaints (lapatinib: RR 15.53; 95% CI 2.18 to 110.55; 67 participants, one study).We found very low quality evidence from one small trial that adding recombinant interleukin (rIL-2) to surgery may increase overall survival (HR 0.52; 95% CI 0.31 to 0.87; 201 participants, 62% oral cavity tumours, 38% oropharyngeal tumours) and there was insufficient evidence to determine whether rIL-2 impacts on adverse effects.

AUTHORS' CONCLUSIONS

We found some evidence that adding EGFR mAb to standard therapy may increase overall survival, progression-free survival and locoregional control, while resulting in an increase in skin toxicity for some mAb (cetuximab).There is insufficient evidence to determine whether adding TKIs to standard therapies changes any of our primary outcomes.Very low quality evidence from a single study suggests that rIL-2 combined with surgery may increase overall survival compared with surgery alone.

Sensitization of Radiation or Gemcitabine-Based Chemoradiation Therapeutic Effect by Nimotuzumab in Pancreatic Cancer Cells

This study was performed to observe the effect of the combination of nimotuzumab with radiation or gemcitabine-based chemoradiation on antipancreatic cancer cell therapy. Pancreatic cancer cells (PANC-1) were treated with nimotuzumab alone or combined with radiation (2, 4, or 8 Gy), which was either with or without gemcitabine chemotherapy. Cell proliferation, cell cycle distribution, and apoptosis were observed. The inhibition rate, the percentage of G2/M phase arrest, and the apoptosis rate of the combined nimotuzumab with radiation group was significantly higher than the group without nimotuzumab (P < .001). The inhibition rate, the percentage of G2/M phase, and the apoptosis rate of the nimotuzumab therapy combined with gemcitabine-based chemoradiation group were obviously higher than that in gemcitabine-based chemoradiation group (P < .001). In conclusion, nimotuzumab could enhance the anticancer effect of radiation and gemcitabine-based chemoradiation in PANC-1 cancer cells because of the enhancement of cell cycle arrest and apoptosis.

Randomized phase III trial of concurrent accelerated radiation plus cisplatin with or without cetuximab for stage III to IV head and neck carcinoma: RTOG 0522

PURPOSE

Combining cisplatin or cetuximab with radiation improves overall survival (OS) of patients with stage III or IV head and neck carcinoma (HNC). Cetuximab plus platinum regimens also increase OS in metastatic HNC. The Radiation Therapy Oncology Group launched a phase III trial to test the hypothesis that adding cetuximab to the radiation-cisplatin platform improves progression-free survival (PFS).

PATIENTS AND METHODS

Eligible patients with stage III or IV HNC were randomly assigned to receive radiation and cisplatin without (arm A) or with (arm B) cetuximab. Acute and late reactions were scored using Common Terminology Criteria for Adverse Events (version 3). Outcomes were correlated with patient and tumor features and markers.

RESULTS

Of 891 analyzed patients, 630 were alive at analysis (median follow-up, 3.8 years). Cetuximab plus cisplatin-radiation, versus cisplatin-radiation alone, resulted in more frequent interruptions in radiation therapy (26.9% v. 15.1%, respectively); similar cisplatin delivery (mean, 185.7 mg/m2 v. 191.1 mg/m2, respectively); and more grade 3 to 4 radiation mucositis (43.2% v. 33.3%, respectively), rash, fatigue, anorexia, and hypokalemia, but not more late toxicity. No differences were found between arms A and B in 30-day mortality (1.8% v. 2.0%, respectively; P = .81), 3-year PFS (61.2% v. 58.9%, respectively; P = .76), 3-year OS (72.9% v. 75.8%, respectively; P = .32), locoregional failure (19.9% v. 25.9%, respectively; P = .97), or distant metastasis (13.0% v. 9.7%, respectively; P = .08). Patients with p16-positive oropharyngeal carcinoma (OPC), compared with patients with p16-negative OPC, had better 3-year probability of PFS (72.8% v. 49.2%, respectively; P < .001) and OS (85.6% v. 60.1%, respectively; P < .001), but tumor epidermal growth factor receptor (EGFR) expression did not distinguish outcome.

CONCLUSION

Adding cetuximab to radiation-cisplatin did not improve outcome and hence should not be prescribed routinely. PFS and OS were higher in patients with p16-positive OPC, but outcomes did not differ by EGFR expression.

Postoperative chemoradiotherapy and cetuximab for high-risk squamous cell carcinoma of the head and neck: Radiation Therapy Oncology Group RTOG-0234

PURPOSE

To report results of a randomized phase II trial (Radiation Therapy Oncology Group RTOG-0234) examining concurrent chemoradiotherapy and cetuximab in the postoperative treatment of patients with squamous cell carcinoma of the head and neck (SCCHN) with high-risk pathologic features.

PATIENTS AND METHODS

Eligibility required pathologic stage III to IV SCCHN with gross total resection showing positive margins and/or extracapsular nodal extension and/or two or more nodal metastases. Patients were randomly assigned to 60 Gy radiation with cetuximab once per week plus either cisplatin 30 mg/m(2) or docetaxel 15 mg/m(2) once per week.

RESULTS

Between April 2004 and December 2006, 238 patients were enrolled. With a median follow-up of 4.4 years, 2-year overall survival (OS) was 69% for the cisplatin arm and 79% for the docetaxel arm; 2-year disease-free survival (DFS) was 57% and 66%, respectively. Patients with p16-positive oropharynx tumors showed markedly improved survival outcome relative to patients with p16-negative oropharynx tumors. Grade 3 to 4 myelosuppression was observed in 28% of patients in the cisplatin arm and 14% in the docetaxel arm; mucositis was observed in 56% and 54%, respectively. DFS in this study was compared with that in the chemoradiotherapy arm of the RTOG-9501 trial (Phase III Intergroup Trial of Surgery Followed by Radiotherapy Versus Radiochemotherapy for Resectable High Risk Squamous Cell Carcinoma of the Head and Neck), which had a hazard ratio of 0.76 for the cisplatin arm versus control (P = .05) and 0.69 for the docetaxel arm versus control (P = .01), reflecting absolute improvement in 2-year DFS of 2.5% and 11.1%, respectively.

CONCLUSION

The delivery of postoperative chemoradiotherapy and cetuximab to patients with SCCHN is feasible and tolerated with predictable toxicity. The docetaxel regimen shows favorable outcome with improved DFS and OS relative to historical controls and has commenced formal testing in a phase II/III trial.

Head and neck squamous cell carcinoma: optimizing the therapeutic index

The four recent noteworthy strategies aimed at improving therapeutic outcomes for the curative treatment of head and neck squamous cancers include the development of altered fractionation regimens, integration of chemotherapy, incorporation of intensity-modulated radiation therapy and introduction of targeted biologic therapy. Clinical investigations during the last 30 years have demonstrated the benefits of biologically sound altered fractionation and concurrent chemoradiation regimens in improving locoregional control and overall survival. These results have contributed to redefining the standard of care, with the caveat that proper patient selection for those who will benefit from potentially toxic combined modality treatment regimens remains controversial. These benefits have come at the expense of increased acute toxicity (i.e., mucositis) and sometimes at the expense of late toxicity (i.e., fibrosis and dysphagia). There are two additional developments that may help to further widen the therapeutic ratio. Intensity-modulated radiation therapy allows for the delivery of a highly conformal 3D radiation dose distribution around intended targets, thereby limiting the volumes of mucosa receiving a high dose per fraction and high total doses. The technical basis for intensity-modulated radiation therapy delivery reopens many fractionation questions that are still being addressed and challenges us to determine which of these is optimal for use with intensity-modulated radiation therapy alone or in combination with concurrent sensitizers. Finally, combined radiation therapy and biologic therapies directed at targets expressed predominately or exclusively by tumor cells have the promise to help increase tumor cell kill, while at least not substantially increasing normal tissue toxicity. These strategies are reviewed in a clinical context.

The anti-EGFR antibody cetuximab sensitizes human head and neck squamous cell carcinoma cells to radiation in part through inhibiting radiation-induced upregulation of HIF-1α

In this study, we investigated the mechanisms underlying cetuximab-mediated radiosensitization of HNSCC. Irradiation of HNSCC cells upregulated hypoxia-inducible factor-1 alpha (HIF-1α) via a mechanism involving de novo synthesis of HIF-1α protein. Radiation-induced upregulation of HIF-1α was completely abolished by concurrent treatment of HNSCC cells with cetuximab. Experimental elevation of constitutively expressed HIF-1α abolished cetuximab-mediated radiosensitization in HNSCC cells, whereas downregulation of HIF-1α by siRNA or a small molecule inhibitor enhanced responses of cetuximab-resistant HNSCC cells to cetuximab plus radiation. Our data suggest that cetuximab sensitizes cancer cells to ionizing radiation in part through inhibition of radiation-induced upregulation of HIF-1α.

Lapatinib in combination with radiation diminishes tumor regrowth in HER2+ and basal-like/EGFR+ breast tumor xenografts

PURPOSE

To determine whether lapatinib, a dual epidermal growth factor receptor (EGFR)/HER2 kinase inhibitor, can radiosensitize EGFR+ or HER2+ breast cancer xenografts.

METHODS AND MATERIALS

Mice bearing xenografts of basal-like/EGFR+ SUM149 and HER2+ SUM225 breast cancer cells were treated with lapatinib and fractionated radiotherapy and tumor growth inhibition correlated with alterations in ERK1 and AKT activation by immunohistochemistry.

RESULTS

Basal-like/EGFR+ SUM149 breast cancer tumors were completely resistant to treatment with lapatinib alone but highly growth impaired with lapatinib plus radiotherapy, exhibiting an enhancement ratio average of 2.75 and a fractional tumor product ratio average of 2.20 during the study period. In contrast, HER2+ SUM225 breast cancer tumors were highly responsive to treatment with lapatinib alone and yielded a relatively lower enhancement ratio average of 1.25 during the study period with lapatinib plus radiotherapy. Durable tumor control in the HER2+ SUM225 model was more effective with the combination treatment than either lapatinib or radiotherapy alone. Immunohistochemical analyses demonstrated that radiosensitization by lapatinib correlated with ERK1/2 inhibition in the EGFR+ SUM149 model and with AKT inhibition in the HER2+ SUM225 model.

CONCLUSION

Our data suggest that lapatinib combined with fractionated radiotherapy may be useful against EGFR+ and HER2+ breast cancers and that inhibition of downstream signaling to ERK1/2 and AKT correlates with sensitization in EGFR+ and HER2+ cells, respectively.

Phase II study of cetuximab in combination with cisplatin and docetaxel in patients with untreated advanced gastric or gastro-oesophageal junction adenocarcinoma (DOCETUX study)

BACKGROUND

The conventional treatment options for advanced gastric patients remain unsatisfactory in terms of response rate, response duration, toxicity, and overall survival benefit. The purpose of this phase II study was to evaluate the activity and safety of cetuximab combined with cisplatin and docetaxel as a first-line treatment for advanced gastric or gastro-oesophageal junction adenocarcinoma.

METHODS

Untreated patients with histologically confirmed advanced gastric or gastro-oesophageal adenocarcinoma received cetuximab at an initial dose of 400 mg m(-2) i.v. followed by weekly doses of 250 mg m(-2), cisplatin 75 mg m(-2) i.v. on day 1, docetaxel 75 mg m(-2) i.v. on day 1, every 3 weeks, for a maximum of 6 cycles, and then cetuximab maintenance treatment was allowed in patients with a complete response, partial response, or stable disease.

RESULTS

Seventy-two patients (stomach 81.9% and gastro-oesophageal junction 18.1%; locally advanced disease 4.2%; and metastatic disease 95.8%) were enrolled. The ORR was 41.2% (95% CI, 29.5-52.9). Median time to progression was 5 months (95% CI, 3.7-5.4). Median survival time was 9 months (95% CI, 7-11). The most frequent grades 3-4 toxicity was neutropenia (44.4%). No toxic death was observed.

CONCLUSIONS

The addition of cetuximab to the cisplatin/docetaxel regimen improved the ORR of the cisplatin/docetaxel doublet in the first-line treatment of advanced gastric and gastro-oesophageal junction adenocarcinoma, but this combination did not improve the TTP and OS. The toxicity of cisplatin/docetaxel chemotherapy was not affected by the addition of cetuximab.

Phase I Study of C-TPF in Patients With Locally Advanced Squamous Cell Carcinoma of the Head and Neck

Purpose

Phase I study to determine the maximum tolerated dose (MTD) of fluorouracil (FU) in the docetaxel/cisplatin/FU (TPF) regimen when combined with cetuximab (C) for induction treatment of locally advanced squamous cell carcinoma of the head and neck (SCCHN).

Patients and Methods

Patients with previously untreated SCCHN were enrolled. FU cohorts were 700, 850, and 1,000 mg/m2/d for 4 days via continuous infusion. TPF given every 3 weeks for three cycles and C was given weekly for a total of 9 weeks, starting on day 1 of TPF. All patients received chemoradiotherapy after C-TPF.

Results

A total of 30 patients were enrolled and 28 were assessable. The median age was 57 years, 92% had stage 4 disease, 71% were oropharynx, and 100% had a performance status of 0. No dose-limiting toxicity (DLT) was encountered on dose levels 1 and 2. At dose level 3 of 1000 mg/m2, one DLT was encountered and three more patients were enrolled with no DLTs. In the expansion cohort at the MTD, three DLT's were encountered. The decision was made to decrease the FU from 1,000 mg/m2to dose level 2 of 850 mg/m2. A total of 13 patients were enrolled at the MTD of 850 mg/m2. The number of average weeks that C was delivered was seven of nine planned.

Conclusion

C-TPF appears to be safe and feasible as given in this study. GI toxicity (mucositis, enteritis, and diarrhea) appears to be the major combined DLT. Reducing the FU in TPF to 850 mg/m2reduces GI toxicity and is the recommended phase II dose.

Cetuximab in combination with carboplatin and docetaxel for patients with metastatic or advanced-stage nonsmall cell lung cancer: a multicenter phase 2 study

BACKGROUND

Cetuximab, an immunoglobulin (Ig) G1 chimeric monoclonal antibody against the epidermal growth factor receptor, has demonstrated evidence of activity in nonsmall cell lung cancer (NSCLC). When administered in combination with carboplatin and docetaxel, a commonly used regimen for advanced NSCLC, cetuximab has exhibited synergistic interaction in preclinical studies. Therefore, a phase 2 study was conducted to evaluate the efficacy of the combination of cetuximab, carboplatin, and docetaxel for the treatment of advanced NSCLC.

METHODS

Chemotherapy-naïve patients aged >or=18 years with stage IIIB (with effusion) or stage IV NSCLC received cetuximab (at a dose of 400 mg/m(2) on Day 1 and 250 mg/m(2) on Days 8 and 15) plus docetaxel (at a dose of 75 mg/m(2) on Day 1) and carboplatin (area under the concentration vs time curve [AUC]=6 on Day 1) every 21 days for up to 6 cycles (graded according to the American Joint Committee on Cancer Staging System). Thereafter, patients without evidence of disease progression were continued on single-agent cetuximab for a maximum of 1 year or until disease progression. The primary endpoint was response rate.

RESULTS

Eighty patients were enrolled. The median number of cycles administered was 4 (range, 1-6 cycles). The objective response rate was 15.2%, with a median progression-free survival of 4.6 months and a median overall survival of 10.3 months. The salient grades 3 of 4 adverse events were neutropenia (30%), hypotension (3%), hypokalemia (4%), and hypomagnesemia (3%). Twenty-five patients received single-agent cetuximab (median duration, 12 weeks) and this was well tolerated.

CONCLUSIONS

The results of this large, multicenter, phase 3 study indicate that the novel combination of cetuximab with docetaxel and carboplatin demonstrate modest anticancer activity for patients with advanced and metastatic NSCLC and has an acceptable toxicity profile.

The use of xenograft models for the selection of cancer treatments with the EGFR as an example

Mouse models of cancer have consistently been used to qualify new anti-cancer drugs for development of human clinical trials. The most used models are xenografts of human tumors grown subcutaneously in immunodeficient mice such as athymic (nude) or severe combined immune deficient (SCID) mice. However, the number of anti-cancer agents that fail in the clinic far outweighs those considered effective, suggesting that the selection procedure for progression of molecules into the clinic requires improvement. This has provoked considerable skepticism about the value of using such preclinical models. As a result, a shift has occurred towards developing and using spontaneous mouse tumor arising in transgenic and/or knockout mice engineered to recapitulate various genetic alterations thought to be causative of specific types of human cancers. Alternatively, the option has been to improve human tumor xenograft models by using orthotopic transplantation and, therefore, promotion of metastatic spread of the resultant 'primary' tumors. Here we review the value and the limitations of xenograft models and their role in developing new anti-cancer treatments.

Biology of Interactions: Antiepidermal Growth Factor Receptor Agents

Epidermal growth factor receptor (EGFR) signaling inhibition represents a highly promising arena for the application of molecularly targeted cancer therapies. Evolving from several decades of systematic research in cancer cell biology, a series of EGFR inhibitors from both the monoclonal antibody (mAb) and tyrosine kinase inhibitor (TKI) class have been developed and promoted into clinical application. Several EGFR inhibitors have recently gained US Food and Drug Administration approval for cancer therapy in the United States (and many other countries), including the mAbs cetuximab and panitumumab, and the small molecule TKIs gefitinib, erlotinib, and lapatinib. The rapidly expanding preclinical and clinical data contributing to these US Food and Drug Administration drug registrations validates a central role of the EGFR as an important molecular target in epithelial malignancies. In this review, we focus primarily on the biology of EGFR interactions. Through improved understanding of EGFR biology in human cancers, there is anticipation that more tumor-selective therapy approaches with diminished collateral normal tissue toxicity can be advanced. Many questions remain to be answered, particularly with regard to how best combine EGFR inhibitors with conventional cancer therapies, and how to select those patients (tumors) most likely to benefit from EGFR inhibition strategies.

Enhancement of tumor radioresponse by wortmannin in C3H/HeJ hepatocarcinoma

The objective of this study was to explore whether a specific inhibitor of PI3K, wortmannin, could potentiate the antitumor effect of radiation in vivo, particularly on radioresistant murine tumors. C3H/HeJ mice bearing syngeneic hepatocarcinoma (HCa-I) were treated with 25 Gy radiation, wortmannin, or both. Wortmannin was administered intraperitoneally (1 mg/kg) once daily for 14 days. Tumor response to treatment was determined by a tumor growth delay assay. Possible mechanisms of action were explored by examining the level of apoptosis and regulating molecules. The expression of regulating molecules was analyzed by Western blot for p53 and p21(WAF1/CIP1), and immunohistochemical staining for p21(WAF1/CIP1), CD31 and VEGF. In the tumor growth delay assay, wortmannin increased the effect of tumor radioresponse with an enhancement factor (EF) of 2.00. The level of apoptosis achieved by the combined treatments was shown to be no more than an additive effect; peak apoptotic index was 11% in radiation alone, 13% in wortmannin alone, and 19% in the combination group. Markedly increased areas of necrosis at 24 h in the combination group were noted. Western blotting showed upregulation of p21(WAF1/CIP1) in the combination treatment group, which correlated with low levels of VEGF. Microvascular density was evidently also reduced, based on low expression of CD31. In murine hepatocarcinoma, the antitumor effect of radiation was potentiated by wortmannin. The mechanism seems to involve not only the increase of induced apoptosis but also enhanced vascular injury. Wortmannin, in combination with radiation therapy, may have potential benefits in cancer treatment.

The epidermal growth factor receptor in malignant gliomas: pathogenesis and therapeutic implications

Activated epidermal growth factor receptor (EGFR) has emerged as an important therapeutic target for a variety of solid tumors, particularly malignant gliomas. Mutation or amplification of EGFR is commonly observed in malignant gliomas and these modifications are associated with increased cell proliferation and radiation resistance. Small-molecule kinase inhibitors targeting the intracellular kinase domain of the EGFR and monoclonal antibodies against the extracellular domain of the EGFR have demonstrated in vitro efficacy and have spawned clinical trials incorporating EGFR inhibition into the management of malignant gliomas, for example, combining EGFR inhibitors with radiation therapy. This early clinical experience indicates that EGFR inhibitors are well tolerated; however, it remains unclear how best to integrate EGFR inhibition into the management of malignant gliomas. As signaling pathways become better defined, patients may be treated with EGFR inhibitors based on the molecular features of their tumors and treatment efficacy may be improved by combining EGFR inhibition with other small kinase inhibitors and radiation therapy.

Importance of maintenance therapy in C225-induced enhancement of tumor control by fractionated radiation

PURPOSE

C225 strongly enhances tumor radioresponse when given concurrently with radiotherapy. We investigated whether additional therapeutic benefit could be achieved by continuing maintenance treatment with C225 after the completion of fractionated radiotherapy.

METHODS AND MATERIALS

A431 xenografts were treated with local irradiation or combined with C225 by two different schedules: (1) 6 h before the first dose of irradiation and at 3-day intervals for a total of 3 doses during the 7-day fractionated radiotherapy, or (2) 6 doses of C225 given both during radiotherapy and continuing for 3 additional doses after radiotherapy. Tumor cure was assessed by the radiation dose yielding local tumor control in 50% of animals (TCD50), and time to recurrence was also determined.

RESULTS

Both treatment schedules increased radiocurability as evidenced by reductions in TCD50, but the effect was greater when C225 was given both during and after radiotherapy. C225 reduced the TCD50 of 83.1 (73.2-124.8) Gy by radiation only to 46.2 (39.1-57.5) Gy when given during radiotherapy and to 30.8 (22.2-38.0) Gy when given during and after radiotherapy. Dose modification factors were 1.8 when C225 was given during radiotherapy and 2.7 when given both during and after radiotherapy. C225 was also effective in delaying the onset of tumor recurrences, and was more effective when given as both concurrent and maintenance therapy.

CONCLUSIONS

Data showed that C225 strongly enhanced the curative effect of fractionated radiation, and its effect was greater if administration was extended beyond the end of radiotherapy. This important finding may influence future designs of clinical trials combining anti-EGFR (anti-epidermal growth factor receptor) agents with radiotherapy.

Amplification of the epidermal growth factor receptor in astrocytic tumours by chromogenic in situ hybridization: association with clinicopathological features and patient survival

Chromogenic in situ hybridization (CISH) was used to detect amplification of the epidermal growth factor receptor (EGFR) gene in tissue microarrays of tumours derived from 287 patients with grade II-IV diffuse astrocytomas. Amplification was found in 32% of the tumours with a highly significant association with histological grade (4% in grade II, 21% in grade III and 39% in grade IV; P < 0.001). Amplification of the EGFR gene was more common in primary than in secondary glioblastomas (41%vs. 16%, P = 0.033). Overexpression of EGFR mRNA and protein (wild-type and vIII variant) was found to correlate with EGFR gene amplification (P = 0.028, P = 0.035 and P = 0.014 respectively), but wild-type EGFR protein was also frequently overexpressed in tumours without EGFR gene amplification. Patients with older age (P < 0.001) and tumours with lack of p53 overexpression (P = 0.03) and higher apoptosis rate (P < 0.001) had significantly more EGFR gene amplifications than their counterparts. No such correlation with apoptosis was found in glioblastomas. The survival of patients with EGFR gene-amplified grade III tumours was significantly shorter than in those with grade III non-amplified tumours (P = 0.03). No such difference was noted in glioblastomas (grade IV tumours). Our data verify the central role of EGFR in the pathobiology of astrocytic tumours, and highlight the advantages of CISH as a simple and practical assay to screen for EGFR gene amplification in astrocytic tumours.

Cetuximab preclinical antitumor activity (monotherapy and combination based) is not predicted by relative total or activated epidermal growth factor receptor tumor expression levels

Although Erbitux (cetuximab) has proven therapeutic benefit in the clinical setting, the molecular determinants predicting responsiveness to this agent are still not very well understood. Here, we assessed the relationship between basal total and activated (pY1068) epidermal growth factor receptor (EGFR) levels in a tumor and the responsiveness to cetuximab monotherapy or combination-based treatment using human xenograft models. Cetuximab treatment alone (0.25-1 mg/mouse/injection, q3d, i.p.) effectively delayed the growth of GEO and L2987 tumors by a minimum of 10 days corresponding to log cell kill values of >or=1.0. Borderline activity was seen in the A549 and WiDr xenografts. However, cetuximab failed to show any significant antitumor activity in the HT29, HCT116, LOVO, Colo205, LX-1, HCC70, and N87 models. All of the studied tumors had detectable yet variable levels of EGFR. For combination regimens, cetuximab (1 mg/mouse/injection, q3dx5, i.p.) and cisplatin (4.5 mg/kg/injection, q3dx5, i.v.) proved to be significantly more efficacious than individual monotherapies in the cisplatin-refractory yet cetuximab-responsive GEO tumor model (P < 0.001). However, no therapeutic enhancement was observed in the cisplatin and cetuximab weakly responsive A549 xenograft. Similarly, combinations of CPT-11 (48 mg/kg/injection, q3dx5, i.v.) with cetuximab (1 mg/mouse/injection, q3dx5, i.p.) failed to show any improvements over individual monotherapies in the cetuximab resistant/weakly responsive HT29, A549, and WiDr models. We conclude that preclinical activity associated with cetuximab monotherapy does not correlate directly with relative basal levels of total or activated (pY1068) EGFR in a tumor. Moreover, robust single-agent activity by cetuximab may be the best predictor for this agent to potentiate chemotherapy-mediated antitumor activities.

Inhibition of the epidermal growth factor receptor in combined modality treatment for locally advanced non-small cell lung cancer

Epidermal growth factor receptor 1 (EGFR 1 ) is a 170-kd glycoprotein that plays many roles in the growth of non-small cell lung cancer (NSCLC). There are four known receptors in the EGFR family. Binding of a ligand such as epidermal growth factor (EGF) or transforming growth factor-alpha (TGF-alpha) causes EGFR to undergo a conformational change leading to autophosphorylation of EGFR and activation of the EGFR growth factor pathway. The protein products of the genes that are then expressed increase cell proliferation and angiogenesis and inhibit programmed cell death. EGFR is expressed in 40% to 80% of NSCLC. EGFR tyrosine kinase activity can be inhibited by antibody therapy, such as cetuximab, against the extracellular domain of EGFR or small-molecule therapy, such as gefitinib or erlotinib that blocks the adenosine triphosphate (ATP) binding site of the cytoplasmic domain. Both forms of EGFR inhibition have single-agent antitumor activity against previously treated NSCLC. Interestingly, EGFR expression does not correlate with response to EGFR inhibition therapy. Increased likelihood of responding to small-molecule therapy is associated with female gender, never smoking, adenocarcinoma, and acquired mutations of the EGFR ATP binding site in tumor cells. In previously treated NSCLC, the small-molecule erlotinib improved both quality of life and median survival as a single agent compared with best supportive care. Southwest Oncology Group 0023 is a large, phase III, randomized trial comparing concurrent chemoradiotherapy and consolidation docetaxel with or without maintenance small-molecule therapy with gefitinib. There is also strong preclinical evidence that EGFR inhibition is additive or synergistic with radiotherapy in NSCLC. In locally advanced head and neck cancer, the addition of cetuximab antibody therapy to radiation increased median survival from 28 to 54 months. Cancer and Leukemia Group B 30106 and a multi-institutional Australian phase I trial have shown that gefitinib can be added to concurrent chemoradiotherapy for stage III NSCLC without excessive toxicity. A phase I trial at the University of Chicago (Chicago, IL) has evaluated erlotinib with concurrent chemoradiotherapy in stage III NSCLC. Radiation Therapy Oncology Group 0324 is an on-going phase II trial studying cetuximab and concurrent chemoradiotherapy in stage III NSCLC.

Preclinical experience with docetaxel in gastrointestinal cancers

Docetaxel is a semisynthetic taxane that acts primarily by promoting microtubule assembly and preventing the depolymerization of assembled microtubules, thereby inducing mitotic block and inhibition of cell proliferation. This agent also induces apoptosis and appears to prevent angiogenesis. Although docetaxel has shown efficacy in a wide variety of tumors, it has only recently been evaluated in the treatment of gastrointestinal cancers. Data from preclinical studies have shown that docetaxel has substantial in vitro and in vivo activity against gastric, esophageal, and pancreatic tumors. The cytotoxic activity of docetaxel is generally time- and dose-dependent, and greater than that produced by other chemotherapeutic agents, including paclitaxel and anthracyclines. Studies evaluating combination regimens suggest that docetaxel has additive-to-synergistic antitumor activity against gastrointestinal cancers over that produced by the individual agents, and the increased antitumor activity appears to be schedule-dependent. These data suggest that docetaxel has promising therapeutic activity in the treatment of gastrointestinal cancers and provides a rationale for its inclusion in therapeutic protocols either as a single agent or in combination regimens. In addition to combination regimens with conventional chemotherapeutic agents, early studies with a number of novel molecularly targeted therapies in combination with docetaxel have shown encouraging results. These studies provide a basis for pursuing future clinical trials with docetaxel-based combinations of novel therapies for improving response rates in the treatment of gastrointestinal cancers.

Current treatments and promising investigations in a multidisciplinary setting

The care of the patient with squamous cell carcinoma of the head and neck (SCCHN) requires a multidisciplinary approach. For many years, radiotherapy following surgery was considered the standard approach to the treatment of locally advanced resectable disease. Data from randomized trials have confirmed the benefits of concurrent chemotherapy and radiotherapy (chemoradiotherapy) in this setting and this is now the gold standard for treatment. Chemoradiotherapy is also the recommended approach for unresectable disease. Neoadjuvant chemotherapy has been useful in resectable disease where organ preservation is desirable, but a concomitant approach is superior. Although survival benefits have not been consistently demonstrated, the theoretical potential of this approach has lead to continued investigations using newer agents, such as the taxanes. Novel targeted agents, such as antagonists of the epidermal growth factor receptor (EGFR), are showing promise in the treatment of patients with both locally advanced and recurrent/metastatic SCCHN. Treatment issues that require immediate attention include identifying optimal chemoradiotherapy regimens, clarifying the role of neoadjuvant chemotherapy, defining the optimal integration of targeted therapies into combined modality approaches and identifying useful prognostic and predictive factors.