Phase II study of the antiangiogenesis agent thalidomide in recurrent or metastatic squamous cell carcinoma of the head and neck

BACKGROUND

Thalidomide has been shown to have antiangiogenic effects in preclinical models as well as a significant antitumor effect in hematologic tumors such as multiple myeloma. The authors performed this Phase II study to determine the activity, toxicity profile, and antiangiogenic effect of thalidomide in patients with locoregionally recurrent or metastatic squamous cell carcinoma of the head and neck.

METHODS

Twenty-one patients with recurrent or metastatic squamous cell carcinoma of the head and neck were treated with single-agent thalidomide. All patients had received radiation therapy, and most had undergone surgery (95%) and/or chemotherapy (90%). Thalidomide was initiated at 200 mg;3>daily and increased to a target dose of 1000 mg daily. Patients continued treatment until disease progression, unacceptable toxicity, or death occurred.

RESULTS

All 21 patients eventually developed progressive disease. Median time to progression was 50 days (95% confidence interval, 28-70), with median overall survival time of 194 days (95% lower confidence boundary, 151), similar to the progression and survival times reported for this patient group with other agents. Thalidomide was generally well tolerated, with few patients experiencing Grades 3 to 4 toxicities. Serum vascular endothelial growth factor and basic fibroblast growth factor levels increased in six of seven patients, for whom paired serum samples were available and all of whom had progressive disease.

CONCLUSIONS

In this heavily pretreated population of patients with advanced squamous cell carcinoma of the head and neck, thalidomide does not appear to have single-agent antitumor activity. Further evaluation of the mechanism of action of thalidomide is indicated. Potentially, future evaluations of thalidomide may be performed in combination with other antiangiogenic or cytotoxic agents in patients with earlier stage disease or in patients with minimal residual disease.

Cyclin D1 and p16 alterations in advanced premalignant lesions of the upper aerodigestive tract: role in response to chemoprevention and cancer development

PURPOSE

To better understand the role of G(1)-S transition regulator abnormalities in the pathogenesis of advanced premalignant lesions of the upper aerodigestive tract and the biological effects of chemoprevention, we studied biopsies obtained sequentially from participants in a prospective trial using 13-cis retinoic acid, IFN-alpha, and alpha-tocopherol for 12 months.

EXPERIMENTAL DESIGN

Cyclin D1 and p16 expression were analyzed by immunohistochemistry, loss of heterozygosity by polymerase chain reacting amplification, and then electrophoretic separation of the products, methylation of the p16 promoter by methylation-specific polymerase chain reacting, and cyclin D1 gene amplification by fluorescence in situ hybridization.

RESULTS

Baseline dysregulation of cyclin D1 expression was found in 50% (14 of 28) and was reversed in 6 of 14 cases, whereas p16 expression was lost in 46% (13 of 28) and regained in 2 of 13 cases. Loss of heterozygosity at 9p21 occurred in 68% and p16(INK4a) promoter methylation occurred in 75% of cases, with increasing frequency from mild to severe dysplasia. Cyclin D1 gene amplification was identified in two cases. Cyclin D1 protein dysregulation at last follow-up alone and in combination with p16 loss was associated with histological progression and cancer development (P < 0.01).

CONCLUSIONS

Additional study of these alterations in a larger sample and exploration of the upstream signaling partners of these cell cycle regulators in vivo is warranted to identify cancer risk profiles that would be meaningful targets for chemopreventive intervention.

Combined interferon-alfa, 13-cis-retinoic acid, and alpha-tocopherol in locally advanced head and neck squamous cell carcinoma: novel bioadjuvant phase II trial

PURPOSE

Retinoids and interferons (IFNs) have single-agent and synergistic combined effects in modulating cell proliferation, differentiation, and apoptosis in vitro and clinical activity in vivo in the head and neck and other sites. Alpha-tocopherol has chemopreventive activity in the head and neck and may decrease 13-cis-retinoic acid (13-cRA) toxicity. We designed the present phase II adjuvant trial to prevent recurrence or second primary tumors (SPTs) using 13-cRA, IFN-alpha, and alpha-tocopherol in locally advanced-stage head and neck cancer.

PATIENTS AND METHODS

After definitive local treatment with surgery, radiotherapy, or both, patients with locally advanced SCCHN were treated with 13-cRA (50 mg/m(2)/d, orally, daily), IFN-alpha (3 x 10(6) IU/m(2), subcutaneous injection, three times a week), and alpha-tocopherol (1,200 IU/d, orally, daily) for 12 months, with a dose modification. Screening for recurrence or SPTs was performed every 3 months.

RESULTS

Tumors of 11 (24%) of the 45 treated patients were stage III, and 34 (76%) were stage IV. Thirty-eight (86%) of 44 patients completed the full 12-month treatment (doses modified as needed). Toxicity generally was consistent with previous IFN and 13-cRA reports and included mild to moderate mucocutaneous and flu-like symptoms; occasional significant fatigue (grade 3 in 7% of patients), mild to moderate hypertriglyceridemia in 30% of patients who continued treatment along with antilipid therapy, and mild hematologic side effects. Six patients did not complete the planned treatment because of intolerable toxicity or social problems. At a median 24-months of follow-up, our clinical end point rates were 9% for local/regional recurrence (four patients), 5% for local/regional recurrence and distant metastases (two patients), and 2% for SPT (one patient), which was acute promyelocytic leukemia (ie, not of the upper aerodigestive tract). Median 1- and 2-year rates of overall survival were 98% and 91%, respectively, and of disease-free survival were 91% and 84%, respectively.

CONCLUSION

The novel biologic agent combination of IFN-alpha, 13-cRA, and alpha-tocopherol was generally well tolerated and promising as adjuvant therapy for locally advanced squamous cell carcinoma of the head and neck. We are currently conducting a phase III randomized study of this combination (v no treatment) to confirm these phase II study results.

Plasticity and adaptation of Ca2+ signaling and Ca2+-dependent exocytosis in SERCA2(+/-) mice

Darier's disease (DD) is a high penetrance, autosomal dominant mutation in the ATP2A2 gene, which encodes the SERCA2 Ca2+ pump. Here we have used a mouse model of DD, a SERCA2(+/-) mouse, to define the adaptation of Ca2+ signaling and Ca2+-dependent exocytosis to a deletion of one copy of the SERCA2 gene. The [Ca2+]i transient evoked by maximal agonist stimulation was shorter in cells from SERCA2(+/-) mice, due to an up-regulation of specific plasma membrane Ca2+ pump isoforms. The change in cellular Ca2+ handling caused approximately 50% reduction in [Ca2+]i oscillation frequency. Nonetheless, agonist-stimulated exocytosis was identical in cells from wild-type and SERCA2(+/-) mice. This was due to adaptation in the levels of the Ca2+ sensors for exocytosis synaptotagmins I and III in cells from SERCA2(+/-) mice. Accordingly, exocytosis was approximately 10-fold more sensitive to Ca2+ in cells from SERCA2(+/-) mice. These findings reveal a remarkable plasticity and adaptability of Ca2+ signaling and Ca2+-dependent cellular functions in vivo, and can explain the normal function of most physiological systems in DD patients.

p53 protein accumulation and genomic instability in head and neck multistep tumorigenesis

Head and neck cancer develops in a multistep process and is associated with increasing frequencies of p53 alterations and with increasing genomic instability. To study the relationship of p53 alterations and genomic instability during head and neck tumorigenesis, we analyzed p53 protein expression and chromosome 9 and 17 polysomy in 48 squamous cell carcinomas of the head and neck and their adjacent normal epithelium (31 sites), hyperplastic (24 sites), and dysplastic lesions (26 sites). Normal oral epithelium obtained from seven nonsmoking, cancer-free individuals served as negative controls. Six (19%) of 31 lesions in adjacent normal epithelium, 7 (29%) of 24 hyperplastic lesions, 12 (46%) of 26 dysplastic lesions, and 28 (58%) of 48 squamous cell carcinomas expressed p53. In contrast, no normal control epithelium had detectable p53 expression. To determine the relationship between dysregulated p53 expression and genomic instability during tumorigenesis, we compared p53 immunohistochemistry distributions and chromosome polysomy levels (by chromosome in situ hybridization) in different histological groups associated with tissue progression. Although the degree of chromosome polysomy increased for all of the groups during histological progression, lesions with dysregulated p53 expression showed nearly 2-4-fold increased levels of chromosome polysomy. This trend was significant for dysplastic lesions (P = 0.005 and P = 0.002 for chromosomes 9 and 17, respectively) and for squamous cell carcinoma (P = 0.005 and P = 0.002 for chromosomes 9 and 17, respectively). Image analysis studies for 28 p53-expressing tumors and their adjacent premalignant lesions demonstrated a strong spatial correlation between stepwise transitions from low to high p53 expression and increased chromosome polysomy frequencies in 13 (46%) of 28 cases. These findings suggest that altered p53 expression is associated with increased genetic instability in preneoplastic epithelium and may play a driving force for increasing the rate of accumulation of genetic events during head and neck tumorigenesis.

Recent advances in the management of squamous cell carcinoma of the head and neck

Therapeutic outcomes of the currently used chemotherapeutic agents for recurrent or advanced head and neck squamous cell carcinoma, such as methotrexate or a combination of 5-fluorouracil and cisplatin, are far beyond satisfaction. New chemotherapeutic agents, such as taxanes, paclitaxel and docetaxel, are among the most active drugs for head and neck cancer and a number of multidrug regimens containing a taxane and cisplatin have produced equivalent or higher response rates than conventional regimens. In addition, early clinical trials of novel molecular-targeted agents, such as epidermal growth factor receptors, tyrosine kinase inhibitors and gene targeted therapy, have shown encouraging results. Further clinical trials will be needed to optimally combine the biologic agents with chemotherapy and assess their effects on long-term control of cancer.

Multi-Institutional Phase I/II Trial of Oral Bexarotene in Combination With Cisplatin and Vinorelbine in Previously Untreated Patients With Advanced Non–Small-Cell Lung Cancer

PURPOSE: Bexarotene (Targretin; Ligand Pharmaceuticals, Inc, San Diego, CA) is a retinoid-X-receptor (RXR)-selective retinoid with preclinical antitumor activity in squamous cell cancers. In this phase I/II trial, we combined bexarotene with cisplatin and vinorelbine in the treatment of patients with non–small-cell lung cancer (NSCLC).

PATIENTS AND METHODS: Forty-three patients who had stage IIIB NSCLC with pleural effusion or stage IV NSCLC and had received no prior therapy received bexarotene in combination with cisplatin (100 mg/m2) and vinorelbine (alternating doses of 30 mg/m2 and 15 mg/m2). In the phase I portion, the daily dose of bexarotene was escalated in cohorts of three patients from 150 mg/m2 to 600 mg/m2, beginning 1 week before the start of the cisplatin-vinorelbine regimen. Once the maximum-tolerated dose (MTD) of bexarotene was determined, the study entered the phase II portion. Response rate was the primary end point; median survival time and 1-year survival rate were secondary end points.

RESULTS: In the phase I portion, the daily MTD of bexarotene was determined to be 400 mg/m2. Eight of 43 patients exhibited major responses. Seven (25%) of the 28 patients in the phase II portion responded to treatment. The median survival time in the phase II portion was 14 months; nine (32%) of the 28 patients were still alive at a minimum follow-up of 2 years. One-year and projected 3-year survival rates were 61% and 30%, respectively. The most common grade 3 and 4 adverse events were hyperlipemia, leukopenia, nausea, vomiting, pneumonia, dyspnea, anemia, and asthenia. Grade 3 and 4 laboratory abnormalities with incidences greater than 5% were decreased hemoglobin levels and WBC, absolute neutrophil, and absolute lymphocyte counts and increased prothrombin time and creatinine and amylase levels. Of the two cases of pancreatitis, one required hospitalization and both were associated with increased triglyceride levels. There was one death secondary to renal insufficiency unrelated to bexarotene treatment.

CONCLUSION: In patients with advanced NSCLC, bexarotene with cisplatin and vinorelbine yielded acceptable phase II response rates (25%) and was associated with better-than-expected survival (14-month median survival time; 61% 1-year, 32% 2-year, and 30% projected 3-year survival rates). The regimen should be studied in larger clinical trials.

Targeting growth factor receptors: integration of novel therapeutics in the management of head and neck cancer

Tyrosine kinase (type 1) growth factor receptors include the erbB family. These cell surface receptors were discovered in the context of cellular transformation and have subsequently been found to be overexpressed in many types of human cancer. Cumulative evidence suggests that upregulation of the most well-characterized receptor, erbB1, also known as the epidermal growth factor receptor, plays a significant role in the development and progression of head and neck squamous cell carcinoma. A variety of strategies have been developed that specifically target epidermal growth factor receptor, including monoclonal antibodies, ligand-linked immunotoxins, tyrosine kinase inhibitors, and antisense approaches. Epidermal growth factor receptor blockade in head and neck squamous cell carcinoma cell lines and preclinical animal models inhibits cell proliferation and tumor growth. Clinical trials are under way to test the safety and efficacy of many of these targeting strategies in head and neck squamous cell carcinoma patients. Encouraging preliminary results combining an epidermal growth factor receptor targeting approaches with chemotherapy or radiotherapy suggest that interference with this growth factor receptor may enhance antitumor efficacy of standard therapies. As erbB family member interactions and downstream signaling pathways are elucidated in head and neck squamous cell carcinoma, specific targeting strategies may become incorporated into standard treatment approaches.

Epidermal growth factor receptor-targeted therapy with C225 and cisplatin in patients with head and neck cancer

C225, a human-mouse chimerized monoclonal antibody directed against the epidermal growth factor receptor (EGFr), has a synergistic effect with cisplatin in xenograft models. To determine the tumor EGFr saturation dose with C225 and the fate of infused C225, we conducted a Phase Ib study with C225 in combination with cisplatin in patients with recurrent squamous cell carcinoma of the head and neck. Using tumor samples, we assessed tumor EGFr saturation by antibody using immunohistochemistry studies, the EGFr tyrosine kinase assay, and detection of the EGFr/C225 complex formation by immunoblot. Potential candidates were screened for EGFr expression in their tumors, and 12 patients who had high levels of EGFr expression and tumors easily accessible for repeated biopsies (pretherapy, 24 h after first C225 infusion, 24 h before third C225 infusion) were entered at three different dose levels of C225 with a fixed dose of cisplatin. The median value of tumor EGFr saturation increased to 95% at the higher dose levels. EGFr tyrosine kinase activity was significantly reduced after C225 infusion, and EGFr/C225 complexes were also detected at higher doses of C225. The loading dose of C225 at 400 mg/m(2) with a maintenance dose at 250 mg/m(2) achieved a high percentage of saturation of EGFr in tumor tissue, and these doses were recommended for Phases II or III clinical trials. Six (67%) of nine evaluable patients achieved major responses, including two (22%) complete responses. Mild to moderate degrees of allergic reaction and folliculitis-like skin reactions were demonstrated. We conclude that infused C225 binds and significantly saturates tumor EGFr, which may render a high degree of antitumor activity, and provides a novel mechanism for targeting cancer therapy for patients who have EGFr expression in their tumors.

Phase II study of paclitaxel, ifosfamide, and carboplatin in patients with recurrent or metastatic head and neck squamous cell carcinoma

BACKGROUND

In the current study the authors assessed the antitumor activity (including response rate, duration of response, and survival) and toxicity profile (including anorexia, fatigue, emesis, and peripheral neuropathy) of a combination of paclitaxel, ifosfamide, and carboplatin (TIC) in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). The trial hypothesis was that the TIC therapeutic index would be as high as that of paclitaxel, ifosfamide, and cisplatin (TIP) in this setting, but with less toxicity.

METHODS

Patients with recurrent or metastatic SCCHN were treated with 175 mg/m(2) of paclitaxel as a 3-hour infusion on Day 1, 1000 mg/m(2) of ifosfamide as a 2-hour infusion on Days 1-3, 600 mg/m(2) of mesna on Days 1-3, and carboplatin (area under the concentration-time curve of 6) as a 30-minute infusion on Day 1; the regimen was repeated every 3-4 weeks. All patients were premedicated with dexamethasone, diphenhydramine, and cimetidine before paclitaxel infusion. Prophylactic hematopoietic growth factors were not given.

RESULTS

Among 56 patients entered onto the study, 55 patients were analyzed for survival rates (locoregional recurrence alone in 56% of patients and distant metastasis with or without locoregional recurrence in 44% of patients). Fifty-four patients were evaluable for tumor response and toxicity. A total of 32 patients (59%) had disease that responded to treatment; the complete response rate was 17% (9 of 54 patients). The median duration of the responses was 3.7 months (95% confidence interval [95% CI], 3.4-7.8 months) and that of complete responses was 9.7 months (95% CI, 7.4 months to date of last follow-up). The median duration of follow-up care in all patients was 13.5 months. The median survival time for all patients was 9.1 months (95% CI, 7.9-12.2 months). The regimen was well tolerated. Neutropenic fever developed in 30% of the patients; 1 patient died of neutropenia and sepsis. Other toxic effects included Grade 2-3 anorexia in 13% of patients, Grade 2-3 weight loss in 11% of patients, Grade 2-3 fatigue in 27% of patients, Grade 2-3 nausea/emesis in 13% of patients, and Grade 2-3 peripheral neuropathy in 9% of patients (toxicity grading based on the National Cancer Institute's Common Toxicity Criteria). Red blood cell and platelet transfusions were required in 13% and 7% of patients, respectively.

CONCLUSIONS

The TIC regimen had high antitumor activity in patients with recurrent or metastatic SCCHN, with a 59% major response rate (17% complete response rate with relatively durable complete responses). Neutropenic fever developed in 30% of the patients, the incidence of which might have been decreased by prophylactic antibiotics or hematopoietic growth factor support. Other toxic effects included significantly lower rates and less severe instances of anorexia, emesis, fatigue, and peripheral neuropathy than those reported with the previously studied TIP regimen. The TIC regimen currently is being studied as an induction chemotherapy regimen in previously untreated patients with locally advanced SCCHN. The activity of TIC (a novel paclitaxel and ifosfamide-based regimen) in patients with recurrent or metastatic SCCHN should be confirmed in a Phase III randomized trial.

Chromosome polysomy and histological characteristics in oral premalignant lesions

Head and neck tumorigenesis has been postulated to represent a multistep process driven by the accumulation of carcinogen-induced genetic changes throughout the exposed tissue field. To better explore this genetic instability process at the tissue level, 59 regions within 26 biopsy tissue specimens from individuals with oral leukoplakia have been subjected to chromosome 9 in situ hybridization analysis, and the degree of chromosome instability was related to known clinical/pathological parameters associated with tumor risk. Whereas chromosome indices were similar between high-risk lesion sites and low-risk lesion sites, high-risk lesions showed higher levels of chromosome polysomy than did low-risk sites [median PIs (polysomy indices), 2.1 versus 1.4, respectively]. Similarly, dysplastic regions showed significantly higher chromosome polysomy levels than hyperplastic regions (median PIs, 2.4 versus 1.5, respectively). Interestingly, however, hyperplastic regions in the same biopsy as dysplastic regions showed two-times higher polysomy levels than those in biopsies without dysplasia (median PIs, 2.6 versus 1.3, respectively), suggesting that chromosome polysomy determinations provide a field measurement for the degree of ongoing genetic insult. Finally, chromosome polysomy tended to persist or increase in the superficial epithelial layers in regions showing koilocytosis, whereas their frequency decreased in nonkoilocytotic regions, suggesting that epigenetic factors may serve to perpetuate the levels of genetically unstable cells in the epithelium. These results provide direct support for the field cancerization process and suggest that measurements of genetic instability might provide additional biological information beyond histology and lesion site characteristics in the assessment of head and neck cancer risk.

Phase I trial of oral green tea extract in adult patients with solid tumors

PURPOSE

This trial was designed to determine the maximum-tolerated dose, toxicity, and pharmacology of oral green tea extract (GTE) once daily or three times daily.

PATIENTS AND METHODS

Cohorts of three or more adult cancer patients were administered oral GTE with water after meals one or three times daily for 4 weeks, to a maximum of 6 months, depending on disease response and patient tolerance. Pharmacokinetic analyses were encouraged but optional.

RESULTS

Dose levels of 0.5 to 5.05 g/m(2) qd and 1.0 to 2.2 g/m(2) tid were explored. A total of 49 patients were studied.

PATIENT CHARACTERISTICS

median age, 57 years (range, 27 to 77 years); 23 patients were women (47%); 98% had a Zubrod PS of 1%; 98% had PS of 1; and 21 had non-small-cell lung, 19 had head & neck cancer, three had mesothelioma, and six had other. Mild to moderate toxicities were seen at most dose levels and promptly reversed on discontinuation of GTE. Dose-limiting toxicities were caffeine related and included neurologic and gastrointestinal effects. The maximum-tolerated dose was 4.2 g/m(2) once daily or 1.0 g/m(2) three times daily. No major responses occurred; 10 patients with stable disease completed 6 months of GTE. Pharmacokinetic analyses found accumulation of caffeine levels that were dose dependent, whereas epigallocatechin gallate levels did not accumulate nor appear dose related.

CONCLUSION

A dose of 1.0 g/m(2) tid (equivalent to 7 to 8 Japanese cups [120 mL] of green tea three times daily) is recommended for future studies. The side effects of this preparation of GTE were caffeine related. Oral GTE at the doses studied can be taken safely for at least 6 months.

Multicenter phase I-II trial of docetaxel, cisplatin, and fluorouracil induction chemotherapy for patients with locally advanced squamous cell cancer of the head and neck

PURPOSE

We conducted a phase I-II, multi-institutional trial to determine the maximum-tolerated dose (MTD) of cisplatin in an induction chemotherapy regimen of docetaxel, cisplatin, and fluorouracil for squamous cell cancer of the head and neck (SCCHN) and to determine the safety, tolerability, and efficacy of the regimen at MTD.

PATIENTS AND METHODS

A total of 43 patients with previously untreated, locally advanced, curable SCCHN were entered. Overall, 29 patients (67%) had N2 or N3 nodal disease and nine (21%) had T4 primary tumors. All patients received docetaxel 75 mg/m(2) on day 1; cisplatin at 75 (level I) or 100 (level II) mg/m(2) on day 1; and a continuous fluorouracil infusion at 1,000 mg/m(2)/d on days 1 through 4. Patients were treated with prophylactic antibiotics on days 5 through 15. Cycles were repeated every 21 days for a total of three cycles. Patients then received definitive therapy based on institutional preferences.

RESULTS

Thirteen patients were treated at level I, and 30 patients were treated at level II. All 43 patients were assessable for toxicity. There were no major differences in toxicity between level I and level II. Cisplatin-associated grade 3 or 4 hypomagnesemia or hypocalcemia occurred in 13 (30%) and hearing loss in two patients (5%). Grade 3 or 4 neutropenia was observed in 41 patients (95%) and febrile neutropenia occurred in eight (19%). There was one serious infection (2%). There were 17 (40% [95% confidence interval [CI], 25% to 56%]) clinical complete responders (CR), 23 (54% [95% CI, 39% to 69%]) partial responders (PR), one (2%) with no change, and two (5%) unassessable patients. Major responses (CR, PR) were observed in 40 (93% [95% CI, 81% to 99%]) patients. Primary site CR was documented in 24 (54%) of patients. Postchemotherapy primary site biopsies were performed in 25 patients (58%) and pathologically negative biopsy was obtained in 11 (92%) of 12 primary site clinical CRs and seven (54%) of 13 with PR or no change. Overall, negative biopsies were obtained in 18 patients (72%).

CONCLUSION

TPF induction chemotherapy can be delivered safely with a cisplatin dose of 100 mg/m(2) in previously untreated patients with SCCHN. The regimen is associated with a high rate of primary site clinical and pathologic CRs. Phase III comparison with cisplatinum and fluorouracil chemotherapy is warranted.

Visualization of the timing of gene amplification during multistep head and neck tumorigenesis

Head and neck tumorigenesis is thought to represent a multistep process whereby carcinogen exposure leads to genetic instability in the tissue and the accumulation of specific genetic events, which result in dysregulation of proliferation, differentiation, and cell loss and the acquisition of invasive capacity. Chromosome 11q13 amplification is frequently observed in head and neck squamous cell carcinoma (HNSCC), and the amplified gene products are assumed to play important functional roles in the tumor phenotype. However, it is not well understood whether gene amplification precedes carcinoma development or results from the unstable nature of intact tumors. To determine the timing of gene amplification during tumorigenesis, tissue sections from amplified HNSCC specimens (containing a contiguous transition from normal epithelium to hyperplasia to dysplasia to carcinoma) were probed for INT2 gene copy number by chromosome in situ hybridization. In addition, representative epithelia were microdissected from the tissue sections, and the DNA was isolated and assessed for INT2 gene copy number by semiquantitative PCR. In those cases containing amplified INT2 in the carcinoma, gene amplification appeared to precede HNSCC development. In one case, INT2 gene amplification appeared in the hyperplasia to dysplasia transition, whereas in two other cases, gene amplification was apparent at dysplasia. These results suggest that gene amplification can occur early during head and neck tumorigenesis and that genetic instability is an important driving force in the tumorigenesis process.

The mammalian Sec6/8 complex interacts with Ca(2+) signaling complexes and regulates their activity

The localization of various Ca(2+) transport and signaling proteins in secretory cells is highly restricted, resulting in polarized agonist-stimulated Ca(2+) waves. In the present work, we examined the possible roles of the Sec6/8 complex or the exocyst in polarized Ca(2+) signaling in pancreatic acinar cells. Immunolocalization by confocal microscopy showed that the Sec6/8 complex is excluded from tight junctions and secretory granules in these cells. The Sec6/8 complex was found in at least two cellular compartments, part of the complex showed similar, but not identical, localization with the Golgi apparatus and part of the complex associated with Ca(2+) signaling proteins next to the plasma membrane at the apical pole. Accordingly, immunoprecipitation (IP) of Sec8 did not coimmunoprecipitate betaCOP, Golgi 58K protein, or mannosidase II, all Golgi-resident proteins. By contrast, IP of Sec8 coimmunoprecipitates Sec6, type 3 inositol 1,4,5-trisphosphate receptors (IP(3)R3), and the Gbetagamma subunit of G proteins from pancreatic acinar cell extracts. Furthermore, the anti-Sec8 antibodies coimmunoprecipitate actin, Sec6, the plasma membrane Ca(2+) pump, the G protein subunits Galphaq and Gbetagamma, the beta1 isoform of phospholipase C, and the ER resident IP(3)R1 from brain microsomal extracts. Antibodies against the various signaling and Ca(2+) transport proteins coimmunoprecipitate Sec8 and the other signaling proteins. Dissociation of actin filaments in the immunoprecipitate had no effect on the interaction between Sec6 and Sec8, but released the actin and dissociated the interaction between the Sec6/8 complex and Ca(2+) signaling proteins. Hence, the interaction between the Sec6/8 and Ca(2+) signaling complexes is likely mediated by the actin cytoskeleton. The anti-Sec6 and anti-Sec8 antibodies inhibited Ca(2+) signaling at a step upstream of Ca(2+) release by IP(3). Disruption of the actin cytoskeleton with latrunculin B in intact cells resulted in partial translocation of Sec6 and Sec8 from membranes to the cytosol and interfered with propagation of agonist-evoked Ca(2+) waves. Our results suggest that the Sec6/8 complex has multiple roles in secretory cells including governing the polarized expression of Ca(2+) signaling complexes and regulation of their activity.

Treatment of patients with recurrent or metastatic squamous cell carcinoma of the head and neck: current status and future directions

Patients with advanced squamous cell head and neck cancer have a dismal long-term survival rate not only because of metastatic disease, but also primarily because of failure in local disease control. The role of chemotherapy in recurrent or metastatic head and neck cancer has largely been palliative. Several chemotherapy agents, including docetaxel, paclitaxel, and ifosfamide, have been extensively studied, either alone or in combination regimens, for the treatment of recurrent or metastatic disease. These have resulted in response rates that are similar or higher than those obtained with the gold standard combination, cisplatin/ fluorouracil. Single-agent and combination studies of vinorelbine and gemcitabine have demonstrated modest activity in recurrent or metastatic disease. Phase III trials are planned that will compare taxane-based regimens with cisplatin and 5-fluorouracil in recurrent or metastatic head and neck cancer. Meanwhile, new drug and compound development, including monoclonal antagonists to the epidermal growth factor receptor, farnesyl transferase inhibitors, and oncolytic viruses are being tested in this setting.

Phase II study of intravenous Doxil in malignant pleural mesothelioma

Twenty-four patients with pleural mesothelioma received 50 mg/m2 of Doxil every four weeks. At follow-up, the disease had stabilized in 43% percent of patients and had progressed in 57%. No objective responses were observed. Estimated median survival of all patients was 37 weeks. Major toxicities were erythrodysesthesia of hands and feet and myelosuppression. No cardiac toxicity was observed. We concluded that Doxil at this dosage and schedule is inactive against pleural mesothelioma.

Gating of store-operated channels by conformational coupling to ryanodine receptors

We report here that RyRs interact with and gate the store-operated hTrp3 and Icrac channels. This gating contributes to activation of hTrp3 and Icrac by agonists. Coupling of hTrp3 to IP3Rs or RyRs in the same cells was found to be mutually exclusive. Biochemical and functional evidence suggest that mutually exclusive coupling reflects clustering and segregation of hTrp3-IP3R and hTrp3-RyR complexes in plasma membrane microdomains. Gating of CCE by RyRs indicates that gating by conformational coupling is not unique to skeletal muscle but is a general mechanism for communication between events in the plasma and endoplasmic reticulum membranes.

Expression of vascular endothelial growth factor and microvessel density in head and neck tumorigenesis

Angiogenesis is a fundamental process in tumor growth and metastasis, and its significance and that of vascular endothelial growth factor (VEGF) expression as prognostic indicators have been documented for various types of human tumors. However, the mechanisms responsible for angiogenesis in head and neck squamous cell carcinoma are not well defined. To examine the relationship between angiogenesis and the phenotypic progressions of head and neck tumorigenesis, we used immunohistochemistry to analyze VEGF expression and microvessel density in 70 paraffin-embedded specimens that contained adjacent normal epithelium, premalignant lesions, or both from 57 patients with head and neck squamous cell carcinoma. Ten samples of normal oral mucosa were obtained from people who did not smoke or drink alcohol and included in the analysis as normal controls. Microvessel density was evaluated by averaging 10 microscopic fields (x400) in a defined area of each specimen. The degree of VEGF expression was assessed on a cell-by-cell basis in 10 microscopic fields (x200) in a defined area on a scale ranging from 0 (no expression) to 3+ (highest level of expression). In addition, the weighted mean index of VEGF expression was calculated. The mean +/- SD weighted mean index of VEGF expression in normal control epithelium (1.10 +/- 0.38, n = 10) was higher than it was in adjacent normal epithelium (0.82 +/- 0.27, n = 13; P = 0.04). VEGF expression decreased as samples ranged from normal adjacent epithelium to hyperplasia (0.78 +/- 0.28, n = 21), mild dysplasia (0.70 +/- 0.29, n = 28), moderate dysplasia (0.67 +/- 0.29, n = 11), severe dysplasia (0.51 +/- 0.39, n = 6), and squamous cell carcinoma (0.20 +/- 0.27, n = 70; overall P = 0.0001). VEGF expression was two times lower in cases with nodal disease (0.17 +/- 0.26, n = 29) than it was in nonnodal disease (0.32 +/- 0.29, n = 16; P = 0.02). Microvessel density showed no significant difference from adjacent normal epithelium premalignant lesions to cancer. In tumor, no correlation was seen between VEGF expression or microvessel density and differentiation, primary tumor site, T stage, or smoking status. These findings indicate that VEGF expression is down-regulated during head and neck tumorigenesis. However, further studies are required to better understand the mechanism of VEGF down-regulation in head and neck tumorigenesis.

Predicting cancer development in oral leukoplakia: ten years of translational research

Our 10-year translational study of the oral premalignant lesion (OPL) model has advanced the basic understanding of carcinogenesis. Although retinoids have established activity in this model, a substantial percentage of our OPL patients progress to cancer, especially after treatment is stopped. On the basis of our 10-year OPL study, we have developed the first comprehensive tool for assessing cancer risk of OPL patients. This cancer risk assessment tool incorporates medical/demographic variables, epidemiological factors, and cellular and molecular biomarkers. Between 1988 and 1991, 70 advanced OPL patients were enrolled in a chemoprevention trial of induction with high dose isotretinoin (1.5 mg/kg/day for 3 months) followed by 9 months of maintenance treatment with either low dose isotretinoin (0.5 mg/kg/day) or beta-carotene (30 mg/d; total treatment duration, 1 year). We assessed the relationship between cancer risk factors and time to cancer development by means of exploratory data analysis, logrank test, Cox proportional hazard model, and recursive partitioning. With a median follow-up of 7 years, 22 of our 70 patients (31.4%) developed cancers in the upper aerodigestive tract following treatment. The overall cancer incidence was 5.7% per year. The most predictive factors of cancer risk are OPL histology, cancer history, and three of the five biomarkers we assessed (chromosomal polysomy, p53 protein expression, and loss of heterozygosity at chromosome 3p or 9p). In the multivariable Cox model, histology (P = 0.0003) and the combined biomarker score of chromosomal polysomy, p53, and loss of heterozygosity (P = 0.0008) are the strongest predictors for cancer development. Retinoic acid receptor beta and micronuclei were not associated with increased cancer risk. We have demonstrated a successful strategy of comprehensive cancer risk assessment in OPL patients. Combining conventional medical/demographic variables and a panel of three biomarkers can identify high risk patients in our sample. This result will need to be validated by future studies. With the identification of high risk individuals, more efficient chemoprevention trials and molecular targeting studies can be designed.

Cellular and humoral immune responses to adenovirus and p53 protein antigens in patients following intratumoral injection of an adenovirus vector expressing wild-type. P53 (Ad-p53)

The immune responses of 10 patients with advanced non-small cell lung cancer receiving monthly intratumoral injections of a recombinant adenovirus containing human wild-type p53 (Ad-p53) to adenovirus and transgene antigens were studied. The predominate cellular and humoral immune responses as measured by lymphocyte proliferation and neutralizing antibody (Ab) formation were to adenovirus serotype 5 vector antigens, with increased responses in posttreatment samples. Consistent alterations in posttreatment cellular and humoral immune responses to p53 epitopes were not observed, and cytotoxic Abs to human lung cancer cells were not generated. Patients in this study had evidence of an antitumoral effect of this treatment with prolonged tumor stability or regression; however, neither Abs to p53 protein nor increased lymphocyte proliferative responses to wild-type or mutant p53 peptides have been consistently detected.

Adenovirus-mediated p53 gene transfer in sequence with cisplatin to tumors of patients with non-small-cell lung cancer

PURPOSE

To determine the safety and tolerability of adenovirus-mediated p53 (Adp53) gene transfer in sequence with cisplatin when given by intratumor injection in patients with non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with advanced NSCLC and abnormal p53 function were enrolled onto cohorts receiving escalating dose levels of Adp53 (1 x 10(6) to 1 x 10(11) plaque-forming units [PFU]). Patients were administered intravenous cisplatin 80 mg/m(2) on day 1 and study vector on day 4 for a total of up to six courses (28 days per course). Apoptosis was determined by the terminal deoxynucleotidyl- transferase-dUTP nick-end labeling assay. Evidence of vector-specific sequences were determined using reverse-transcriptase polymerase chain reaction. Vector dissemination and biodistribution was monitored using a series of assays (cytopathic effects assay, Ad5 hexon enzyme-linked immunosorbent assay, vector-specific polymerase chain reaction assay, and antibody response assay).

RESULTS

Twenty-four patients (median age, 64 years) received a total of 83 intratumor injections with Adp53. The maximum dose administered was 1 x 10(11) PFU per dose. Transient fever related to Adp53 injection developed in eight of 24 patients. Seventeen patients achieved a best clinical response of stable disease, two patients achieved a partial response, four patients had progressive disease, and one patient was not assessable. A mean apoptotic index between baseline and follow-up measurements increased from 0.010 to 0.044 (P =.011). Intratumor transgene mRNA was identified in 43% of assessable patients.

CONCLUSION

Intratumoral injection with Adp53 in combination with cisplatin is well tolerated, and there is evidence of clinical activity.

Paclitaxel (Taxol)/ifosfamide-based chemotherapy in patients with recurrent or metastatic squamous cell carcinoma of the head and neck

Squamous cell carcinoma of the head and neck (SCCHN) is a functionally and cosmetically devastating tumor, and its treatment and the economic costs associated with aggressive treatment are substantial. Even with aggressive standard local surgery, radiotherapy, or both, locally advanced tumors recur in approximately two thirds of patients and the prognosis for those whose disease recurs or metastasizes is dismal. Newer chemotherapeutic agents such as ifosfamide and taxanes (paclitaxel [Taxol; Bristol-Myers Squibb Company, Princeton, NJ] and docetaxel) have shown higher response rates than those seen with conventional agents and renew hope of prolonged survival, improved quality of life, and greater convenience. We recently conducted two consecutive phase II studies using paclitaxel/ifosfamide/cisplatin and paclitaxel/ifosfamide/carboplatin for patients with recurrent or metastatic SCCHN. These two regimens yielded high response rates (including complete responses) and appear to be promising therapies for SCCHN. This report describes our experience with these two regimens, including a comparison of their toxic effects.