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.