Tumor hypoxia independently predicted biochemical recurrence in men with clinically localized prostate cancer following radiotherapy, radiation oncologists from Princess Margaret Hospital reported at the AACR Annual Meeting and simultaneously in the AACR journal Clinical Cancer Research (2012;18:2108-2114).
The team measured oxygen levels in 247 men with localized prostate cancer prior to radiation therapy and followed them for a median of 6.6 years. The five-year biochemical relapse-free rate was 78%. Biochemical failure was defined as a PSA increase of 2 ng/mL or more above nadir.
Hypoxia, defined for the study as an oxygen percentage less than 10 mm Hg in tumors, independently predicted early biochemical failure after treatment, the study showed.
"This is the first study to identify a relationship between pretreatment prostate hypoxia and local recurrence after radiotherapy," said lead author Michael F. Milosevic, MD, Professor of Radiation Oncology.
"We've not only shown that men do worse if they have low oxygen levels in their prostate cancer, but that they also do worse over a shorter period of time. These patients seem to develop cancer recurrence within only a few years of completing treatment."