Men with intermediate-risk prostate cancer (PCa) who have low oxygen levels in their prostate tumors prior to radiation treatment are at increased risk of PCa recurrence, according to researchers.
Michael Milosevic, MD, of Princess Margaret Hospital in Toronto, and his colleagues measured tumor oxygen levels in 247 men with localized intermediate-risk PCa prior to radiation therapy. After a median follow-up of 6.6 years, the five-year biochemical relapse-free rate was 78%. Tumor hypoxia, defined as an oxygen percentage less than 10 mm Hg, predicted early biochemical failure after treatment. The investigators defined biochemical failure as a PSA increase of 2 ng/mL or more above nadir.
“This is the first study to identify a relationship between pretreatment prostate hypoxia and local recurrence after radiotherapy,” the researchers noted in Clinical Cancer Research (2012;18:2108-2114).
The findings “provide a strong rationale for integrating radiotherapy with new hypoxia-targeted treatment approaches in future clinical trials,” the authors observed.