Phase II neoadjuvant trial of paclitaxel by 96-hour continuous infusion (CIVI) in combination with cisplatin followed by chest radiotherapy for patients with stage III non-small-cell lung cancer.

Sixteen patients with untreated locally advanced (n = 15) or recurrent (n = 1) non-small-cell lung cancer (NSCLC) were enrolled in this study between July 1996 and March 1999. Eight patients had stage IIIA NSCLC, seven had stage IIIB disease, and one had recurrent disease after prior resection of stage I disease. Patients were treated with paclitaxel 30 mg/m2/d for 4 days by continuous intravenous infusion followed by cisplatin 80 mg/m2 on day 5. Therapy was administered every 3 weeks until disease progression or a maximum of four cycles. Thoracic radiation was started within 3 to 4 weeks of day 1 of the last cycle of paclitaxel and cisplatin. Fourteen patients (87.5%) received all four cycles of chemotherapy and subsequent radiation therapy. Forty-four percent of patients achieved a partial response, and 1 patient complete response (overall response rate, 50%). The median progression-free survival was 8.8 months. At a median potential follow-up of 3.7 years, the median survival for all 16 enrolled patients was 13.2 months, and the actuarial 1-, 2-, and 3-year survivals were 62.5%, 43.8%, and 21.9%. In contrast to predictions from in vitro cytotoxicity models, the sequential use of prolonged infusional paclitaxel and bolus cisplatin followed by thoracic radiation does not appear to have a greater impact over shorter chemotherapy

Cellular and biophysical evidence for interactions between adenosine triphosphate and P-glycoprotein substrates: functional implications for adenosine triphosphate/drug cotransport in P-glycoprotein overexpressing tumor cells and in P-glycoprotein low-level expressing erythrocytes.

P-glycoprotein is involved with the removal of drugs, most of them cations, from the plasma membrane and cytoplasm. Pgp is also associated with movement of ATP, an anion, from the cytoplasm to the extracellular space. The central question of this study is whether drug and ATP transport associated with the expression of Pgp are in any way coupled. We have measured the stoichiometry of transport coupling between drug and ATP release. The drug and ATP transport that is inhibitable by the sulfonylurea compound, glyburide (P. E. Golstein, A. Boom, J. van Geffel, P. Jacobs, B. Masereel, and R. Beauwens, Pfluger's Arch. 437, 652, 1999), permits determination of the transport coupling ratio, which is close to 1:1. In view of this result, we asked whether ATP interacts directly with Pgp substrates. We show by measuring the movement of Pgp substrates in electric fields that ATP and drug movement are coupled. The results are compatible with the view that substrates for Pgp efflux are driven by the movement of ATP through electrostatic interaction and effective ATP-drug complex formation with net anionic character. This mechanism not only pertains to drug efflux from tumor cells overexpressing Pgp, but also provides a framework for understanding the role of erythrocytes in drug resistance. The erythrocyte consists of a membrane surrounding a millimolar pool of ATP. Mammalian RBCs have no nucleus or DNA drug/toxin targets. From the perspective of drug/ATP complex formation, the RBC serves as an important electrochemical sink for toxins. The presence in the erythrocyte membrane of approximately 100 Pgp copies per RBC provides a mechanism for eventual toxin clearance. The RBC transport of toxins permits their removal from sensitive structures and ultimate clearance from the organism via the liver and/or kidneys.

Concurrent paclitaxel and radiation in the treatment of locally advanced head and neck cancer.

PURPOSE: To determine the feasibility of an organ preservation regimen consisting of infusional paclitaxel administered concurrently with radiotherapy to patients with locally advanced head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: Thirty-three previously untreated patients with stage III or IV tumors were enrolled onto the study. Paclitaxel was administered as a 120-hour continuous infusion every 3 weeks during the course of radiation therapy. Sixteen patients received a paclitaxel dose of 105 mg/m(2), and 17 patients received 120 mg/m(2). Radiation was delivered in a standard format at 1.8 Gy/d to a total dose of 70.2 to 72 Gy. RESULTS: Three months after therapy, a 76% complete response (CR) at the primary site and a 70% overall CR was achieved. At 36 months, locoregional control was 55.7%, overall survival was 57.8%, and disease-free survival was 51.1%. The median survival duration for all 33 patients was greater than 50 months at the time of this report. Local toxicities including mucositis, dysphagia, and skin reactions were severe but tolerable. All patients retained functional speech, and all but four patients were swallowing food 3 months after treatment. Steady-state plasma concentrations for paclitaxel were not achieved during a 120-hour infusion, suggesting a nonlinear process. Tumor volume quantified by pretreatment computerized tomography imaging was associated with likelihood of response and survival. CONCLUSION: Paclitaxel administered as a 120-hour continuous infusion in combination with radiotherapy is a feasible and promising treatment for patients with advanced HNSCC.

Radiation dose to otologic structures during head and neck cancer radiation therapy.

BACKGROUND: Otologic structures are often contained within head and neck cancer radiation treatment ports. The dosimetry to otologic structures has not been routinely analyzed and radiation treatment planning does not currently attempt to specifically avoid the inner ear structures when dosimetry is calculated. Recent studies demonstrate that up to 30% of patients experience sensorineural hearing loss on multimodality therapy with cisplatin and radiation. METHODS: In the current case series, radiation dosimetry to otologic structures was calculated from computed tomogram treatment plans on patients. Fifteen nasopharyngeal, oral cavity, oropharyngeal, and hypopharyngeal cancer patients were analyzed. RESULTS: Between 8% and 102% of the total dose is delivered to the petrous bone/cochlea, with 4 of 15 patients getting more than 50% of the dose to at least one cochlea The mastoid air cells received between 3% and 75% of the total dose, with higher doses being delivered to patients with bulky high neck metastases or nasopharyngeal tumors. The eustachian tubes received between 20% and 102% of the total dose, with 10 of 15 patients receiving more than 50% of the dose to this anatomic site. CONCLUSION: We conclude that the cochlea and eustachian tubes receive significant radiation during treatment, particularly in nasopharyngeal cancer patients. Careful design of radiation treatment ports may allow for the reduction of radiation to hearing structures.

Safety and efficacy of adenovirus-mediated transfer of the human aquaporin-1 cDNA to irradiated parotid glands of non-human primates.

This study evaluated the safety and efficacy of a single administration of a recombinant adenovirus encoding human aquaporin-1 (AdhAQP1) to the parotid glands of adult rhesus monkeys. In anticipation of possible clinical use of this virus to correct irradiation damage to salivary glands, AdhAQP1 was administered (at either 2 x 10(9) or 1 x 10(8) plaque-forming units/gland) intraductally to irradiated glands and to their contralateral nonirradiated glands. Radiation (single dose, 10 Gy) significantly reduced salivary flow in exposed glands. Virus administration resulted in gene transfer to irradiated and nonirradiated glands and was without untoward local (salivary) or systemic (sera chemistry, complete blood count) effects in all animals. However, the effect of AdhAQP1 administration varied and did not result in a consistent positive effect on salivary flow rates for all animals under these experimental conditions. We conclude that a single adenoviral-mediated gene transfer to primate salivary glands is well-tolerated, although its functional utility in enhancing fluid secretion from irradiated parotid glands is inconsistent.

Principles of chemoradiation: theoretical and practical considerations.

Chemotherapy agents known to enhance the effects of radiation in preclinical studies have been used concurrently with radiotherapy in numerous clinical trials with the prospect of further enhancing radiation-induced local tumor control. While some success in several tumor histologies has been achieved using this approach, a major concern has been enhancement in normal tissue toxicity. This brief review addresses both theoretical and practical issues with respect to chemoradiation clinical trials. Recommendations for clinical trials are provided that, if implemented, can increase our understanding of basic mechanisms (in patients) and provide a more rational approach for future trials.

Expression of proinflammatory and proangiogenic cytokines in patients with head and neck cancer.

Altered immune, inflammatory, and angiogenesis responses are observed in patients with head and neck squamous cell carcinoma (HNSCC), and many of these responses have been linked with aggressive malignant behavior and a decrease in prognosis. In this study, we examined the hypothesis that HNSCC cells produce cytokines that regulate immune, inflammatory, and angiogenesis responses. We identified important regulatory cytokines in supernatants of well-defined and freshly cultured HNSCC cell lines by ELISA and determined whether these cytokines are detected in tumor cell lines and tissue specimens by immunohistochemistry. The serum concentration of the cytokines and cytokine-dependent acute phase inflammatory responses (i.e., fibrinogen, C-reactive protein, and erythrocyte sedimentation rate) from patients with HNSCC was determined, and the potential relationship of serum cytokine levels to tumor volume was analyzed. Cytokines interleukin (IL)-1alpha, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor were detected in similar concentration ranges in the supernatants of a panel of established University of Michigan squamous cell carcinoma (UM-SCC) cell lines and supernatants of freshly isolated primary HNSCC cultures. Evidence for the expression of IL-1alpha, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor, and VEGF in HNSCC cells within tumor specimens in situ was obtained by immunohistochemistry. In a prospective comparison of the cytokine level and cytokine-inducible acute-phase proteins in serum, we report that cytokines IL-6, IL-8, and VEGF were detected at higher concentrations in the serum of patients with HNSCC compared with patients with laryngeal papilloma or age-matched control subjects (at P < 0.05). The serum concentrations of IL-8 and VEGF were found to be weakly correlated with large primary tumor volume (R2 = 0.2 and 0.4, respectively). Elevated IL-1- and IL-6-inducible acute-phase responses were also detected in cancer patients but not in patients with papilloma or control subjects (at P < 0.05). We therefore conclude that cytokines important in proinflammatory and proangiogenic responses are detectable in cell lines, tissue specimens, and serum from patients with HNSCC. These cytokines may increase the pathogenicity of HNSCC and prove useful as biomarkers or targets for therapy.

Taxanes as radiosensitizers for head and neck cancer.

Combinations of paclitaxel and radiation therapy or paclitaxel with other chemotherapy agents and radiation have been tested with variable results in patient populations. To date, three phase I trials have been conducted using paclitaxel alone in combination with radiotherapy for the treatment of patients with head and neck cancer. Dose-limiting toxicity in the 1-hour infusion was mucositis, whereas in the 24-h/wk infusion, fever was the dose-limiting toxicity. In the long-term infusion (24 h/d, 7 d/wk), no dose-limiting toxicity was seen at the doses of paclitaxel given. In two of the protocols in which biopsies were obtained, a G2/M block was observed. A phase I protocol using paclitaxel in combination with fluorouracil and hydroxyurea with radiation and a phase II protocol using paclitaxel with cisplatin in operable head and neck cancers have been reported. Preliminary results suggest that paclitaxel in combination with radiotherapy is a reasonable experimental treatment that deserves further study in patients with stage III and IV squamous cell carcinomas of the head and neck.

Phase I study of paclitaxel as a radiation sensitizer in the treatment of mesothelioma and non-small-cell lung cancer.

PURPOSE: To determine the maximum-tolerated dose (MTD) and dose-limiting toxicities of paclitaxel with concurrent thoracic irradiation in patients with malignant pleural mesothelioma and locally advanced non-small-cell lung cancer (NSCLC) using a 120-hour continuous infusion regimen. A secondary objective was to assess the effect of paclitaxel on the cell cycle through serial tumor biopsies. PATIENTS AND METHODS: Paclitaxel was administered as a 120-hour (5-day) continuous infusion repeated every 3 weeks during the course of radiation therapy. The starting dose of paclitaxel was 90 mg/m2. Doses were escalated at 15-mg/m2 increments in successive cohorts of three patients. In NSCLC patients, radiation was delivered to the primary tumor and regional lymph nodes for a total tumor dose of 6,120 cGy. In mesothelioma patients, hemithoracic irradiation was delivered as the initial treatment field with a conedown to the tumor volume for a total dose of 5,760 to 6,300 cGy. Tumor biopsies were obtained, if possible, before and during paclitaxel treatment. RESULTS: Thirty patients were entered onto this study through three dose levels (from 90 mg/m2 to 120 mg/m2). The MTD was determined to be 105 mg/m2. The dose-limiting toxicity was grade 4 neutropenia (two patients). Grade 2 gastrointestinal (GI) toxicity (nausea and vomiting) was also observed at 120 mg/m2. Three of 30 patients developed a hypersensitivity reaction. Six patients had grade 2 lung injury manifested by a persistent cough that required antitussives. Five patients underwent tumor biopsies. None of the patients showed a significant block of cells in mitosis (G2/M) after paclitaxel infusion. CONCLUSION: The MTD of paclitaxel, when administered as a 120-hour continuous infusion with concurrent radiotherapy, was determined to be 105 mg/m2. The dose-limiting toxicity was neutropenia. Continuous infusion paclitaxel administered with large field irradiation of the lung is well tolerated and deserves continued evaluation.

Antagonism of paclitaxel cytotoxicity by X-rays.

We have employed in vitro clonogenic assays and DNA flow cytometry to examine the effect of X-ray irradiation on the response of human tumor cells to paclitaxel. Irradiation caused the development of cell cycle delays in G1 and G2/M in the human breast MCF-7 and lung A549 adenocarcinoma cell lines. Irradiation given just prior to or concurrently with exposure to paclitaxel reduced cytotoxicity due to paclitaxel. For example, the surviving fraction of both MCF-7 and A549 cells was 0.03 after 24 h of exposure to 50 nM paclitaxel. However, if the cells were irradiated with 3 Gy just prior to the start of 24 h of paclitaxel exposure, the surviving fractions of MCF-7 and A549 cells were 0.08. Since 3 Gy alone reduced the survival of MCF-7 and A549 cells by 65% and 50%, respectively, the surviving fractions of MCF-7 and A549 cells were 7.6 and 5.3 fold higher after treatment with radiation and paclitaxel than would have been predicted if the cytotoxicities of the different treatments had been additive. Incubation of cells in 5 mM pentoxifylline after irradiation reduced the G2/M block induced by radiation and partially reversed the antagonism of paclitaxel cytotoxicity. These data show that radiation, by inducing cell cycle delays, can antagonize the cytotoxicity of paclitaxel. These results have implications for the development of clinical protocols which combine radiation and paclitaxel in treatment plans.

Protection against SR 4233 (Tirapazamine) aerobic cytotoxicity by the metal chelators desferrioxamine and tiron.

PURPOSE: Metal chelating agents and antioxidants were evaluated as potential protectors against aerobic SR 4233 cytotoxicity in Chinese hamster V79 cells. The differential protection of aerobic and hypoxic cells by two metal chelators, desferrioxamine and Tiron, is discussed in the context of their potential use in the on-going clinical trials with SR 4233. METHODS AND MATERIALS: Cytotoxicity was evaluated using clonogenic assay. SR 4233 exposure was done in glass flasks as a function of time either alone or in the presence of the following agents: superoxide dismutase, catalase, 5,5-dimethyl-1-pyrroline, Trolox, ICRF-187, desferrioxamine, Tiron (1,2-dihydroxybenzene-3,5-disulfonate), and ascorbic acid. Experiments done under hypoxic conditions were carried out in specially designed glass flasks that were gassed with humidified nitrogen/carbon dioxide mixture and with a side-arm reservoir from which SR 4233 was added to cell media after hypoxia was obtained. Electron paramagnetic resonance studies were also performed. RESULTS: Electron paramagnetic resonance and spectrophotometry experiments suggest that under aerobic conditions SR 4233 undergoes futile redox cycling to produce superoxide. Treatment of cells during aerobic exposure to SR 4233 with the enzymes superoxide dismutase and catalase, the spin trapping agent DMPO, the water-soluble vitamin E analog Trolox, and the metal chelator ICRF-187 provided little or no protection against aerobic SR 4233 cytotoxicity. However, two other metal chelators, desferrioxamine and Tiron, afforded significant protection against aerobic SR 4233 cytotoxicity (protection factors at 50% survival were 3.8 and 3.1, respectively), while exhibiting minimal protection to hypoxic cells treated with SR 4233. CONCLUSIONS: One potential mechanism of aerobic cytotoxicity is redox cycling of SR 4233 with molecular oxygen resulting in several potentially toxic oxidative species that overburden the intrinsic intracellular detoxification systems such as superoxide dismutase, catalase, and glutathione peroxidase. This study identifies two metal chelating agents, desferrioxamine and Tiron, that were able to protect against aerobic but not hypoxic SR 4233 cytotoxicity.

National Cancer Institute (phase II) study of high-grade glioma treated with accelerated hyperfractionated radiation and iododeoxyuridine: results in anaplastic astrocytoma.

PURPOSE: We report the outcome of a Phase II study of a cohort of patients with high-grade glioma treated with accelerated hyperfractionated radiation and the radiation sensitizer, iododeoxyuridine (IdUrd). METHODS AND MATERIALS: Between January 1988 and December 1990, 39 consecutive patients with high-grade glioma were enrolled and treated on a Phase II protocol including hyperfractionated radiation and IdUrd. Thirty-two patients were male and seven were female. Age range was 19 to 71 years with a median age of 38 years. IdUrd (1000 mg/m2 per day) was administered in two separate 14-day courses, the first during the initial radiation field and the second during the final cone-down field. All patients were treated consistently with partial brain technique and received 1.5 Gy/fraction twice daily to a mean total dose of 71.25 Gy (range 66-72 Gy excluding one patient who did not complete treatment). The initial field was treated to 45 Gy followed by a cone-down field covering the tumor volume plus a 1-cm margin to the final dose. Patients were assessed for acute and long-term morbidity and followed for outcome. Two patients had biopsies during the course of treatment. Flow cytometry and high performance liquid chromatography was used to evaluate the labeling index and the percent replacement of IdUrd in the biopsy specimen. RESULTS: Thirty-eight of 39 patients completed therapy. One patient died on treatment at 48 Gy and is included in the survival analysis. No patient was lost to follow-up. Twenty-one patients had Grade 3 (anaplastic astrocytoma) tumors and 18 patients had Grade 4 (glioblastoma multiforme). Median survival for the entire cohort was 23 months. For the glioblastoma multiforme patients, median survival was 15 months. The median survival of the anaplastic astrocytoma patients has not yet been reached. In the patients assessed, the range of IdUrd tumor cell incorporation was only 0-2.4%. CONCLUSION: Accelerated hyperfractionated radiation therapy with IdUrd was administered with acceptable acute toxicity. The major acute side effects of mucositis and thrombocytopenia were related to IdUrd infusion and were dose-dependent. There were no unacceptable acute toxicities referable to the radiation as delivered. With a median potential follow-up of 51 months, the actuarial median survival of the glioblastoma multiforme patients is comparable with the best previously published reports. The outcome of patients with anaplastic astrocytoma compares very favorably with even the most aggressive multi-modality approaches in the recent literature with a minimum of acute morbidity.

Myocytolysis (vacuolar degeneration) of myocardium: immunohistochemical evidence of viability.

Human myocardium with focal myocytolysis (vacuolar degeneration, colliquative myocytolysis) was examined by routine light microscopy and by immunoperoxidase staining techniques for creatine kinase (CK) M and B, myoglobin, lactate dehydrogenase (H4)(LDH-1), and aspartate aminotransferase (AST, GOT). Sections of myocardium were selected from autopsy and surgical specimens from patients with and without clinical morphologic evidence of ischemic heart disease. Areas of coagulation necrosis showed loss of enzyme staining, while both normal and myocytolytic cells stained darkly. These results indicate that fibers with myocytolysis retain enzymes and other proteins, indicating sarcolemmal integrity, which is not present in fibers with coagulation necrosis. The implication of these findings is that fibers with myocytolysis are viable; thus, myocytolysis may be a reversible form of myocardial alteration that does not necessarily lead to cell death and eventual myocardial fibrosis.

Distribution of LDH-1 in normal, ischemic, and necrotic myocardium. An immunoperoxidase study.

To study the distribution of lactate dehydrogenase (LDH-1) (H4) in normal, ischemic, and necrotic myocardium using the peroxidase-antiperoxidase technic, the authors studied formalin-fixed paraffin-embedded sections of human (n = 11) and canine (n = 28) myocardium. All normal control myocardium showed positive immunostaining for LDH-1 (H4). In infarcts 10 hours or more old, the histologically necrotic myocardium (by triphenyl tetrazolium chloride staining) (TTC) showed markedly diminished immunostaining. In 24-dogs ischemia was induced in a closed-chest model using a balloon-tipped catheter inflated in the left anterior descending coronary artery. In dogs with 3 hours or more of occlusion, myocardium that was necrotic by TTC staining, light and/or electron microscopy, showed diminished staining for LDH-1, while normal, control myocardium stained intensely. In four dogs, ischemia was induced by a controlled perfusion apparatus by which left main coronary flow was reduced by 50%. Ischemia without necrosis was documented by demonstration of glycogen loss with no light or electron microscopic evidence of necrosis. These ischemic fibers stained intensely for LDH-1, as did controls. Thus, by immunoperoxidase staining, LDH-1 can be demonstrated in normal human and canine myocardium. In experimental models of ischemia in dogs, tissue that was ischemic but not necrotic showed no diminished staining. LDH-1 loss can be detected in necrotic myocardium as early as 3 hours after coronary artery occlusion.