Hypoxia in human prostate carcinoma - An Eppendorf Po-2 study

The purpose of this study was to characterize the extent of hypoxia in huma n prostate carcinoma using the Eppendorf Po-2 microelectrode. Custom-made E ppendorf Po2 microelectrodes were used to obtain Po-2 measurements from the pathologically involved region of the prostate (as determined by the pretr eatment sextant biopsies), as well as from a region of normal muscle for co mparison. Fifty-nine patients with localized prostate cancer were studied, all of whom received brachytherapy implants under spinal anesthesia. A mult ivariate mixed effects analysis for prediction of tumor oxygenation was per formed including the following covariates: type of tissue (prostate versus muscle), prostatic-specific antigen, disease stage, patient age and race, t umor grade, volume, perineural invasion, and hormonal therapy. Because of d ifferences in patient characteristics, control measurements were obtained f rom normal muscle in all patients. This internal comparison showed that the oxygen measurements from the pathologically involved portion of the prosta te were significantly lower (average median Po-2 = 2.4 mm Hg) compared with the measurements from normal muscle (average median Po-2 = 30.0 mm. Hg), p < 0.0001. A multivariate, linear, mixed analysis demonstrated that the onl y significant predictor of oxygenation was the type of tissue (prostate ver sus muscle). This study, using in vivo electrode oxygen measurements, sugge sts that hypoxia exists in human prostate carcinoma. More patients will be accrued to this study to ultimately correlate the oxygenation status in pro state carcinoma tunors with treatment outcome.