[Influence of hemoglobin value on hematogenous tumor cell dissemination at the time of primary breast carcinoma diagnosis].
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Breast Neoplasms↗
Biomedical subjects
Peter Vaupel
Publications and source records attributed to Peter Vaupel.
Oxygenation status of gynecologic tumors: what is the optimal hemoglobin level?
BACKGROUND: Tumor hypoxia has been linked to the development of treatment resistance, tumor progression, and poor prognosis. Since anemia is a major causative factor for the development of hypoxia, the association between blood hemoglobin concentration (cHb) and tumor oxygenation was examined in this study. PATIENTS AND METHODS: Pretreatment O(2) tension (pO(2)) measurements were performed in 59 primary carcinomas of the uterine cervix in which a stringent histopathologic examination of the electrode tracks was mandatory in order to exclude measurements in necrotic, stromal or normal cervical tissue. In addition, pO(2) readings in twelve primary cancers and 17 local recurrences of vulvar cancers were included in this study. cHb was determined at the time of pO(2) measurements. RESULTS: Data presented clearly show that an optimal Hb level with regard to the median pO(2) values of cervical and vulvar cancers should prevail at cHb values of between 12 and 14 g/dl (7.45-8.60 mmol/l). In anemic patients (cHb < 12 g/dl), the deterioration of the tumor oxygenation status can be explained by a reduced O(2) transport capacity. At cHb values > 14 g/dl, a worsening of the tumor oxygenation is apparent, most probably due to a drop in perfusion following a drastic increase in viscous resistance to flow. This pathogenetic mechanism is thought to counteract and finally to abrogate the high O(2) transport capacity in this cHb range. CONCLUSIONS: This study suggests that cHb values of between 12 and 14 g/dl are optimal with regard to the oxygenation status in the tumor entities investigated, a finding which may have far-reaching implications in the clinical setting.
Adult↗
Dynamics of tumor oxygenation and red blood cell flux in response to inspiratory hyperoxia combined with different levels of inspiratory hypercapnia.
BACKGROUND AND PURPOSE: Increasing arterial oxygen partial pressure (pO2) by breathing hyperoxic gases is an effective means of improving tumor oxygenation, although the efficacy of adding CO2 to the inspiratory gas has been discussed controversially. This study aimed at analyzing the impact of different inspiratory CO2 fractions on the time course of oxygenation and perfusion changes in experimental tumors during and after inspiratory hyperoxia. MATERIAL AND METHODS: Perfusion and oxygenation of rat DS-sarcomas were studied during spontaneous breathing of pure oxygen or hyperoxic gas mixtures containing different CO2 fractions (1, 2.5 or 5%). Red blood cell (RBC) flux was assessed as a measure of tumor perfusion using the laser Doppler technique and temporal changes in mean tumor pO2 were measured polarographically. RESULTS: Mean tumor pO2 increased 3.6-fold with pure oxygen, approx. 3.3-fold when 1 or 2.5% CO2 was added and 2.7-fold during carbogen breathing. RBC flux also increased by 25-30% with all gases. With pure oxygen and with 1% CO2 (+99% O2), perfusion changes paralleled those of the mean arterial blood pressure whereas with higher CO2 fractions, a decrease in resistance to flow was observed. The differences found with the various gas mixtures were more pronounced after the end of hyperoxia. With pure oxygen, perfusion immediately returned to pretreatment values whereas with higher CO2 fractions perfusion remained elevated for at least 30 min. CONCLUSIONS: Higher inspiratory CO2 fractions (2.5 or 5%) lead to a prolonged improvement of tumor perfusion after the end of inspiratory hyperoxia when compared with pure oxygen breathing. Since no principal differences in oxygenation and perfusion were seen between the gases containing 2.5 and 5% CO2, the former may be preferable for inspiratory hyperoxia.
Animals↗
Hyperoxia-induced improvement of the in vitro response to gemcitabine in transitional cell carcinoma.
BACKGROUND: Anemic tissue hypoxia can decrease the effects of chemotherapy in bladder cancer. Hypoxia leads to overexpression of hypoxia-inducible factor (HIF) and increased synthesis of epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF). Tumor cell survival, invasion and angiogenesis thereby compromise treatment. MATERIALS AND METHODS: Monolayer cultures of RT112, RT4, T24 and TCC SUP cells were incubated with or without gemcitabine and different gas mixtures (hypoxia, normoxia or hyperoxia). Cell proliferation (microculture tetrazolium assay), VEGF (enzyme-linked immunosorbent assay) and HIF-1alpha (Western blot analysis) were determined. RESULTS: Hypoxia led to increased proliferation of transitional cell carcinoma (TCC) cells and elevated levels of HIF-1alpha and VEGF. Hyperoxia inhibited cell growth and lowered the concentration of VEGF. Treatment with gemcitabine was less effective under hypoxia. CONCLUSION: Hypoxia enhances TCC growth and may intensify angiogenesis mediated by VEGF. Hypoxia compromises treatment with gemcitabine. Correction of anemia might provide advantages in chemotherapeutic strategies for TCC.
Antimetabolites, Antineoplastic↗