PubMed Health⌕ Search

Biomedical subjects

D M Brizel

Publications and source records attributed to D M Brizel.

At least 37 records · Page 2Linked to original sources

Tumor hypoxia adversely affects the prognosis of carcinoma of the head and neck.

PURPOSE: Tumor hypoxia adversely affects short term clinical radiation response of head and neck cancer lymph node metastases and long term disease-free survival (DFS) in cervix carcinoma. This study was performed to evaluate the relationship between tumor hypoxia and DFS in patients with squamous carcinoma of the head and neck (SCCHN). METHODS AND MATERIALS: Pretreatment tumor pO2 was assessed polarographically in SCCHN patients. All patients were AJCC Stage IV and had pretreatment oxygen measurements taken from locally advanced primaries (T3 or T4) or neck nodes > or = 1.5 cm diameter. Treatment consisted of once daily (2 Gy/day to 66-70 Gy) or twice daily irradiation (1.25 Gy B.I.D. to 70-75 Gy) +/- planned neck dissection (for > or = N2A disease) according to institutional treatment protocols. RESULTS: Twenty-eight patients underwent tumor pO2 measurement. The average pre-treatment median pO2 was 11.2 mm Hg (range 0.4-60 mm Hg). The DFS at 12 months was 42%. The DFS was 78% for patients with median tumor pO2 > 10 mm Hg but only 22% for median pO2 < 10 mm Hg (p = 0.009). The average tumor median pO2 for relapsing patients was 4.1 mm Hg and 17.1 mm Hg in non-relapsing (NED) patients (p = 0.007). CONCLUSION: Tumor hypoxia adversely affected the prognosis of patients in this study. Understanding of the mechanistic relationship between hypoxia and treatment outcome will allow for the development of new and rational treatment programs in the future.

Carcinoma, Squamous Cell↗

Interlaboratory variation in oxygen tension measurement by Eppendorf "Histograph" and comparison with hypoxic marker.

BACKGROUND AND OBJECTIVES: The median of pO2 values in tumor measured by Eppendorf "Histograph" with a needle-type electrode has been used as a prognostic indicator in cancer patients. However, it is not established that a pretreatment measured pO2 value can be used as a universal predictor of local control probability, because the variation in pO2 values, especially in hypoxic tissue, among institutes may not allow comparison of measured "absolute pO2 values." The purpose of this study was to examine the variation in oxygen tension measurement by Eppendorf "Histograph" among six laboratories using a single batch of mice and tumors and the same detailed protocol. These results were also compared to the immunohistochemical staining of 2-nitromidazole adducts. METHODS: C3H mice bearing FSaII murine fibrosarcoma subcutaneously were shipped to all laboratories, and the oxygen status in tumors and in normal subcutis was examined using Eppendorf "Histograph" and immunohistochemical hypoxic marker. RESULTS: All laboratories showed that the FSaII tumor was hypoxic with at least 77% of measured points under 10 mmHg in pO2 and with a median pO2 value less than that of normal subcutis. These results were further confirmed immunohistochemically. These findings are interpreted as evidence that the pO2 values measured by Eppendorf "Histograph" can be useful. However, the median values of tumor pO2 varied from 1.5 mmHg to 5.6 mmHg among the laboratories, and pO2 of normal subcutis also varied from 28 mmHg to 38 mmHg. There were also significant differences in hypoxic fraction, defined as the fraction under a given oxygen partial pressure (i.e., under 2.5, 5, or 10 mmHg), among institutes. CONCLUSIONS: Caution needs to be exercised in using the absolute, median, or distribution of pO2 values measured by the Eppendorf "Histograph" to compare the data between laboratories or to predict the radiation response in an individual subject.

Animals↗

Hyperbaric oxygen improves tumor radiation response significantly more than carbogen/nicotinamide.

This laboratory previously demonstrated that hyperbaric oxygen and hyperbaric carbogen improved oxygenation in the R3230Ac tumor, but normobaric 100% O2 and carbogen did not. The current study assessed tumor growth after exposure to radiation plus either hyperbaric oxygen, carbogen or carbogen/nicotinamide and the relationship between pretreatment tumor oxygenation and growth time. R3230Ac carcinomas were grown in the flanks of F344 rats. Animals were randomized to one of seven radiation treatment groups: sham irradiation or irradiation plus room air, hyperbaric oxygen (100% O2/3 atmospheres), nicotinamide (0.3 mg/g intraperitoneally 20 min before irradiation), carbogen, carbogen/nicotinamide or hyperbaric oxygen/nicotinamide. Tumors received 20 Gy in a single dose. Median growth times were 6, 18, 18, 20, 22, 28 and 27 days for controls and irradiation plus room air, carbogen, nicotinamide, carbogen/nicotinamide, hyperbaric oxygen and hyperbaric oxygen/nicotinamide, respectively. Irradiation with hyperbaric oxygen, hyperbaric oxygen/ nicotinamide and carbogen/nicotinamide increased growth time (P < 0.001, P < 0.001 and P = 0.003, respectively) relative to room air. Hyperbaric oxygen was significantly more effective than carbogen/nicotinamide (P = 0.001). Growth times for all tumors exposed to hyperbaric oxygen were longer than those of the most fully oxygenated tumors (no baseline pO2 values < 10 mm Hg) not exposed to hyperbaric oxygen (P < 0.001). These results suggest that hyperbaric oxygen may improve radiation response by additional mechanisms separate from overcoming the oxygen effect.

Animals↗

Radiation therapy and hyperthermia improve the oxygenation of human soft tissue sarcomas.

The adverse prognostic impact of tumor hypoxia has been demonstrated in human malignancy. We report the effects of radiotherapy and hyperthermia (HT) on soft tissue sarcoma oxygenation and the relationship between treatment-induced changes in oxygenation and clinical treatment outcome. Patients receiving preoperative radiotherapy and HT underwent tumor oxygenation measurement pretreatment after the start of radiation/pre-HT and one day after the first HT treatment. The magnitude of improvement in tumor oxygenation after the first HT fraction relative to pretreatment baseline was positively correlated with the amount of necrosis seen in the resection specimen. Patients with <90% resection specimen necrosis experienced longer disease-free survival than those with > or = 90% necrosis. Increasing levels of tumor hypoxia were also correlated with diminished metabolic status as measured by P-31 magnetic resonance spectroscopy.

Cell Hypoxia↗

Tumor oxygenation predicts for the likelihood of distant metastases in human soft tissue sarcoma.

This study was performed to explore the relationship between tumor oxygenation and treatment outcome in human soft tissue sarcoma. Twenty-two patients with nonmestastatic, high-grade, soft tissue sarcomas underwent preoperative irradiation and hyperthermia and pretreatment measurement of tumor oxygenation. The 18-month actuarial disease-free survival was 70% for patients with tumor median oxygen pressure (pO2) values of >10 mm Hg but only 35% for those with median pO2 values of <10 mm Hg (P=0.01). There were eight treatment failures; the first site of recurrence was lung in all patients. Median pO2 was 7.5 mm Hg for metastasizing tumors versus 20 mm Hg for nonmetastasizing tumors (P=0.03). Potential mechanisms and implications for clinical trial design are discussed.

Cell Hypoxia↗

Arteriolar oxygenation in tumour and subcutaneous arterioles: effects of inspired air oxygen content.

Carbogen is thought to be more effective than normobaric oxygen in reducing tumour hypoxia because it may reduce hyperoxic vasoconstriction. In this study, tumour and normal arteriolar diameters were measured simultaneously with perivascular pO2 during air breathing followed by either carbogen or 100% oxygen to determine whether the action of carbogen is the result of alterations in feeding vessel diameter. Fischer-344 rats bearing dorsal flap window chambers, with or without implanted R3230AC tumours, were the experimental subjects. Arteriolar diameters were measured using optical techniques and perivascular pO2 was measured using recessed-tip electrodes (3-6 microns tip diameter). Baseline arteriolar pO2 averaged 30-50% of blood gas pO2 (mean = 97 mmHg). Both hyperoxic gases increased blood gas pO2 by 4-to 5-fold, but relative improvements in arteriolar pO2 were < or = 2.5 for all arterioles studied. This means that these normobaric high O2 gases are not very efficient in increasing O2 delivery to tumours. In addition, improvements in tumour arteriolar pO2 were transient for both hyperoxic gases. Oxygen and carbogen caused no change and mild vasodilatory responses in tumour arterioles, respectively. Normal arterioles on the other hand, tended toward vasoconstriction by carbogen breathing. Peri-arteriolar pO2 in tumours increased within the first 5 min of breathing either hyperoxic gas, followed by a decline back toward values seen with air-breathing. These results suggest that temporal changes in tumour oxygenation after exposure to carbogen or O2 may not be due to changes in perfusion. Other factors, such as changes in O2 consumption rate may be involved.

Animals↗

Monitoring of neoadjuvant therapy response of soft-tissue and musculoskeletal sarcoma using fluorine-18-FDG PET.

UNLABELLED: The purpose of this study was to investigate the potential role of FDG-PET in the monitoring of neoadjuvant therapy of soft-tissue and musculoskeletal sarcomas. METHODS: Nine patients were studied. Neoadjuvant therapy consisted of either chemotherapy or combined radiotherapy and hyperthermia. The FDG-PET studies were obtained, when possible, prior to therapy, 1-3 wk after commencement of therapy, and prior to surgery after completion of neoadjuvant therapy. In two patients, all three studies were completed. The remainder of patients underwent one or two studies at varying timepoints. RESULTS: In tumors treated with combined radiotherapy and hyperthermia, well-defined regions of absent uptake developed within responsive tumors, correlating pathologically with necrosis. Following treatment, a peripheral rim of FDG accumulation was found to correlate pathologically with the formation of a fibrous pseudocapsule. In tumors treated with chemotherapy, FDG accumulation decreased more homogeneously throughout the tumor, in responsive cases. Despite 100% tumor cell kill in some patients, persistent tumor FDG uptake was observed which correlated pathologically with uptake within benign therapy-related fibrous tissue. Significant FDG accumulation was also observed at the site of an uncontaminated incisional biopsy. CONCLUSION: These initial results demonstrate changes in tumor accumulation of FDG during and after neoadjuvant therapy; these changes are dependent on the type of neoadjuvant therapy administered. Prominent FDG accumulation was observed in benign tissues both within and adjacent to the treated tumor.

Adolescent↗

Patterns and variability of tumor oxygenation in human soft tissue sarcomas, cervical carcinomas, and lymph node metastases.

PURPOSE: The validity of tumor pO2 measurement as a predictive outcome assay depends upon demonstrating that intrapatient pO2 variation is less than interpatient variation. No consensus exists regarding the appropriate distance between individual measurements. This distance could affect the calculation of the hypoxic fraction (% pO2s < 5 mm Hg) and the assessment of intra/interpatient heterogeneity. This study was performed to evaluate tumor oxygenation and to assess the effects of two different measurement intervals on pO2 heterogeneity in three different sets of patients. MATERIALS AND METHODS: Fifteen patients with soft tissue sarcoma, nine patients with cervical carcinoma, and eight patients with squamous carcinoma metastatic to lymph nodes underwent pretreatment polarographic pO2 measurements. Two grossly distinct sites were studied in each tumor, and 2-3 linear tracks were measured at each site. Track lengths varied from 20-36 mm. Distance between measured points was either 0.7-0.8 mm or 0.4 mm. Mean pO2, median pO2, and hypoxic fraction were calculated for each track. Data for each patient were also averaged across all tracks obtained for that patient. Track-specific data were used to evaluate intrapatient variation. The range of average values for each patient was used to assess interpatient heterogeneity. The ratio of these measures provided an assessment of within- vs. between-patient heterogeneity. RESULTS: The median number of pO2 measurements/patient was 200 (range: 88-356). The average length of hypoxic regions varied from 4.5-5.6 mm. Median tumor pO2s for the cervix, lymph node, and sarcoma patients were 4.5 mm Hg, 12.6 mm Hg, and 18.0 mm Hg, respectively (p = 0.07). Median hypoxic fractions were 0.61, 0.36, and 0.31, respectively (p = 0.07). Intrapatient heterogeneity was less than interpatient heterogeneity for all parameters in all patients, except for mean pO2 for the cervix patients measured at 0.7-mm increments (1.51). Assessment of oxygenation was not affected by the distance between samples. CONCLUSIONS: Heterogeneity of tumor oxygenation within tumors is less than that between tumors. Both 0.4 mm and 0.7-0.8 mm sampling increments provide similar data. Longer term follow-up of large numbers of uniformly treated patients is required to define the value of tumor oxygen measurement as a predictor of treatment outcome.

Carcinoma, Squamous Cell↗

The mechanisms by which hyperbaric oxygen and carbogen improve tumour oxygenation.

Hyperbaric oxygen (HBO) has been proposed to reduce tumour hypoxia by increasing the amount of dissolved oxygen in the plasma. That this actually occurs has not been verified experimentally. This study was performed to explore changes in tumour oxygenation induced by treatment with normobaric and hyperbaric oxygen and carbogen. R3230Ac mammary adenocarcinomas were implanted into Fisher 344 rats. Arterial blood gases, blood pressure and heart rate were monitored. Tumour oxygenation was measured polarographically in five sets of animals. They received either normobaric 100% oxygen, hyperbaric (3 atmospheres; atm) 100% oxygen, normobaric carbogen or hyperbaric (3 atm) carbogen (HBC) +/- bretylium. HBO reduced the mean level of low pO2 values (< 5 mmHg) from 0.49 to 0.07 (P = 0.0003) and increased the average median pO2 from 8 mmHg to 55 mmHg (P = 0.001). HBC reduced the level of low pO2 values from 0.82 to 0.51 (P = 0.002) an increased median pO2 from 2 mmHg to 6 mmHg (P = 0.05). Normobaric oxygen and carbogen did not change tumour oxygenation significantly. Sympathetic blockade with bretylium before HBC exposure improved oxygenation significantly more than HBC alone (low pO2 0.55-0.17, median pO2 4-17 mmHg). HBO and hyperbaric carbogen improved tumour oxygenation in this model, while normobaric oxygen or carbogen had no effect. Sympathetic-mediated vasoconstriction during hyperbaric carbogen caused it to be less effective than HBO. This mechanism also appeared to operate during normobaric carbogen breathing.

Adenocarcinoma↗

Pretreatment oxygenation profiles of human soft tissue sarcomas.

PURPOSE: Tumor oxygenation is thought to influence the radiocurability of many malignancies. Advances in polarographic electrode technology have facilitated the in situ measurement of human tumor pO2. The optimal method of defining a "hypoxic" tumor is not known. Characterization of intra-tumor and intertumor pO2 heterogeneity could help with this process. This study was performed to evaluate pretreatment tumor oxygenation status and pO2 heterogeneity in patients with soft tissue sarcoma. METHODS AND MATERIALS: Nine patients with soft tissue sarcomas underwent pretreatment pO2 measurements with the Eppendorf pO2 histograph. Two grossly distinct anatomic sites within each tumor were measured in all but one patient; these were localized under computerized tomography guidance to ensure that all measurements were obtained from tumor tissue. Multiple probe tracks were studied at each site. Measurements were performed in resting, awake patients. RESULTS: A total of 1588 pO2 readings was obtained (mean = 176/patient). Measurement path lengths ranged from 22-36 mm. The average hypoxic fraction (pO2 < 5 mm Hg) was 29% (range 0-76%). Arterial pO2 was positively correlated with mean and median tumor pO2. Tumor hypoxic fraction increased with increasing tumor volume. Linear pO2 profiles and frequency histograms provided similar estimates of the extent of hypoxia in individual tumors. Marked variation in oxygenation existed both within and between individual tumors. The intertumor variation was greater than the intratumor variation. CONCLUSION: Radiobiologic hypoxia exists in human soft tissue sarcomas. The pO2 variation within individual tumors is less than the variation between tumors. Further study is necessary to identify the best parameter for defining tumor hypoxia and to discern the relationship between tumor pO2 and treatment outcome.

Cell Hypoxia↗

A pilot study of etoposide, vinblastine, and doxorubicin plus involved field irradiation in advanced, previously untreated Hodgkin's disease.

BACKGROUND: Advanced stage Hodgkin's disease (HD) usually is treated with combination chemotherapy with or without supplemental irradiation. The risk of significant acute and long term toxicity when the chemotherapy regimen contains alkylating agents has provided the impetus for the development of systemic combinations that do not include alkylating agents. This trial was designed to assess the toxicity and efficacy of a regimen of etoposide, vinblastine, and doxorubicin (EVA) as part of a combined modality approach in patients with moderate to high risk HD. METHODS: This was a prospective pilot study that included 26 previously untreated patients. They received 6 cycles of EVA, and complete responders received low dose (1500-2500 cGy) involved field radiation. RESULTS: Four patients were hospitalized for sepsis during chemotherapy. Complete response was achieved in 54% of patients, and 46% patients experienced induction failures. Two year failure-free survival is 44%, while 2 year overall survival is 86%. Median follow-up is 27 months. CONCLUSIONS: The EVA regimen is no more efficacious than other programs already in use and may be less so. It also is potentially leukemogenic because of the presence of etoposide. New combinations that do not contain etoposide should be explored in therapy programs for advanced HD in the hopes of discovering an efficacious treatment program that has minimal long term side effects.

Adolescent↗

A phase I/II trial of twice daily irradiation and concurrent chemotherapy for locally advanced squamous cell carcinoma of the head and neck.

PURPOSE: This study was designed to test the toxicity and efficacy of a regimen of twice daily irradiation and concurrent multiagent chemotherapy for patients with locally advanced squamous cell carcinoma of the head and neck. METHODS AND MATERIALS: This was a prospective Phase I/II trial. Patients received 125 cGy b.i.d. to 7000 cGy with a 6 hr interfraction interval. Chemotherapy was given during weeks 1 and 6 of irradiation and consisted of a 5 day infusion of 5-fluorouracil at 600 mg/M2/day and 5 daily injections of cisplatin at 12 mg/M2/day. Two additional cycles of chemotherapy were given after the completion of radiotherapy. RESULTS: Forty-six patients were evaluable: 28 had technically unresectable disease and 18 had resectable tumors. All had Stage III or IV disease: 84% had T3 or T4 primaries while 53% had > or = N2 neck disease. The primary acute toxicity, confluent mucositis, was seen in 74% of patients. Late side effects occurred in four patients. Median follow-up is 36 months (range 25-44 months). Kaplan-Meier estimates of 2-year disease-free survival and overall survival are 65% and 73%, respectively, while 2-year local regional control and distant disease-free survival are 72% and 88%, respectively. Multivariate analysis revealed that resectability and receiving > 2 cycles of chemotherapy significantly influenced local regional control while age < 60 significantly influenced disease-free survival. CONCLUSION: This form of treatment can be delivered safely. The encouraging results have led to the initiation of a Phase III trial comparing this regimen with b.i.d. radiation alone.

Animals↗

The effect of the perflubron emulsion Oxygent on the calibration characteristics of polarographic oxygen electrodes.

The perfluorocarbon emulsion Oxygent improves normal tissue oxygenation. A clinical trial is planned to evaluate this effect in tumors. Polarographic oxygen electrodes were calibrated in solutions of saline +/- perflubron to assess whether Oxygent influenced probe behavior. Calibrations were linear under both conditions. There were no major differences in estimated oxygen tensions.

Calibration↗

Cyclophosphamide, doxorubicin, vincristine, and prednisone for primary central nervous system lymphoma: short-duration response and multifocal intracerebral recurrence preceding radiotherapy.

The activity of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in the treatment of primary central nervous system lymphoma (PCNSL) prior to radiotherapy was studied in six patients. Primary lesions were reduced by 80% or more on contrast-enhancing cross-sectional area in four patients and to a lesser extent in two others after two cycles of chemotherapy. The primary lesion sites demonstrated no contrast enhancement in the three patients who completed four cycles of therapy. However, concurrent with response at the primary disease sites, multiple lesions occurred at distant, noncontiguous CNS parenchymal sites in five patients after two to four cycles of chemotherapy. Median survival was 8.5 months for the six enrolled patients and 16.5 months for the four patients completing craniospinal radiotherapy. PCNSL is highly responsive to standard systemic non-Hodgkin's lymphoma chemotherapy regimens, but the pattern and rapidity of relapse suggest mechanisms of failure including inherent or rapidly evolving antineoplastic drug resistance and perhaps limited drug delivery to occult sites of disease in the brain.

Aged↗

A comparison of tumor and normal tissue microvascular hematocrits and red cell fluxes in a rat window chamber model.

This laboratory has previously used a window chamber model to measure red blood cell velocity in mammary tumors and normal granulation tissues of the F-344 rat. Because red cell flux and hematocrit more accurately reflect the oxygen carrying potential of blood, we used this model to measure these parameters. Red blood cells were labelled with fluorescein isothiocyanate, and 0.2 ml. packed cells were injected intravenously into rats bearing an 8 to 10 day old R-3230 mammary carcinoma. beta-phycoerythrin (0.15 mg.) was also injected and served as a plasma dye to outline the blood vessels. A sample of peripheral blood was then taken and analyzed by flow cytometry to determine the labeled fraction of red blood cells. Flowing tumor and normal tissue vessels were recorded onto a VCR, and these video images were used to determine vascular length and diameter, RBC flux and velocity, and hematocrit. Median vessel diameter and loge (red blood cell flux) were significantly greater in tumors than in normal tissues (p = 0.007 and p < 0.025, respectively). After controlling for these variables, the median tumor hematocrit of 19% was not significantly greater than the median normal tissue hematocrit of 15%. This technique provides a nontoxic and reproducible method that is now being used to assist in the in vivo definition of tumor oxygenation.

Animals↗

The radiation dose-response relationship in a human glioma xenograft and an evaluation of the influence of glutathione depletion by buthionine sulfoximine.

We have used an extensively characterized human glioma cell line in an athymic mouse model to evaluate new therapeutic approaches for human supratentorial high grade gliomas. The tumor, D-54MG, is a subline of a human anaplastic glioma. Eight days after homozygous nu/nu BALB/c athymic mice received intracranial (IC) injections of a tumor homogenate, the whole brain was irradiated with either single fractions of 4, 8, 9, and 12 Gy or twice daily fractions, separated by least 6 hr, of 2.28 Gy x 2 or 7.53 Gy x 2. To evaluate whether or not glutathione depletion influenced animal survival, animals at each dose level received either intraperitoneal (IP) buthionine sulfoximine (BSO) alone or I.P. BSO plus BSO in the drinking water. There was a stepwise prolongation of animal survival with increasing doses of external beam radiation. Mean survival in 9 of the 10 control groups (8-12 animals per group) ranged from 14.1 to 18.8 days. Mean survival ranged from 15.3 to 22.5 days at 4 Gy, 25 to 30 days at 8 Gy, 22.3 to 29.7 days at 9 Gy, and 32.9 to 33.6 days at 12 Gy single dose irradiation. At 2.28 Gy x 2 split dose irradiation mean survival was 29.3 days, for 7.53 Gy x 2 mean survival was over 47 days. The data for single fraction irradiation fit a linear regression line (r = 0.908) of mean animal survival = (1.22 [dose in Gy] + 16.7) days. Tumor GSH levels were decreased with all BSO dosing regimens tested. The most aggressive regimen (I.P. BSO+oral BSO for 5 days), reduced tumor GSH to 6.2% of control. Increased survival in irradiated glutathione depleted mice versus mice receiving radiation alone was not seen.

Animals↗

Improved survival in advanced Hodgkin's disease with the use of combined modality therapy.

To compare the effectiveness of combined modality therapy and chemotherapy alone for the treatment of advanced Hodgkin's disease (Stages IIB-IV), records of 154 patients who achieved a complete or partial response to induction combination chemotherapy were analyzed. Sixty-seven patients received consolidation radiotherapy and 87 patients received no further treatment. Thirty of 154 patients participated in a prospective randomized trial of the Southeastern Cancer Study Group (SEG). Ten-year actuarial survival (Hodgkin's disease deaths only) was 93% for the combined modality therapy patients compared with 59% for the chemotherapy alone patients (p less than 0.0005). Combined modality therapy patients had an 87% 10-year actuarial freedom from relapse as opposed to 56% for the chemotherapy alone patients (p less than 0.0005). Relapse occurred in 33 of the chemotherapy alone patients, 28 (85%) being in sites involved at initial diagnosis. Seven combined modality therapy patients recurred with only two true in-field failures. Multi-variate analysis demonstrated treatment (combined modality) as the only variable affecting outcome. Patients prospectively treated with combined modality therapy in the Southeastern Cancer Study Group trial also showed a statistically significant improvement in both survival and freedom from relapse compared with patients receiving chemotherapy only. There was no apparent increase in toxicity from using combined modality therapy compared with chemotherapy. Three chemotherapy patients and one combined modality therapy patients developed acute leukemia.

Antineoplastic Combined Chemotherapy Protocols↗