Predicting Prostate Cancer Relapse

Prostate cancer recurrence predicted tumor hypoxemia

(RxWiki News) More and more studies are showing that the best treatment for a given type of cancer may not be the same for everybody. A new study looking at prostate cancer adds to the growing amount of evidence supporting individualized treatment.

"We've not only shown that men do worse if they have low oxygen levels (hypoxia) in their prostate cancer, but that they also do worse over a shorter period of time," says Michael Milosevic, MD, radiation oncologist working from Toronto's public Princess Margaret Hospital.

"These patients seem to develop cancer recurrence within only a few years of completing treatment."

One study examined the average level of oxygen over time in a prostate tumor and followed the patients for several years to obtain data on correlation with prostate cancer relapse, finding that low levels of oxygen in the prostate tumors were associated with an increased risk of relapse.

"Ask your oncologist about tumor oxygen monitoring."

Although low levels of oxygen in a tumor could indicate that the cancer is dying, the reverse turned out to be the case. The research data published by the Ontario Cancer Institute demonstrated that low levels of oxygen in prostate cancer tumors were a significant factor in predicting prostate cancer recurrence.

Tumors are hungry groups of cells, using higher levels of oxygen and nutrients to fuel their accelerated growth. Some cancers can be detected by looking for increased levels of oxygen consumption on a cellular level.

The study measured oxygen levels in the tumors of 247 men before their treatment with radiation therapy, and followed their progress for an average of 6.6 years. Researchers stated that out of all other factors identified so far, this is the only one that has successfully predicted local recurrence.

"This information could change the way prostate cancer is treated and goes a long way to ensuring that all patients receive the right treatment from the outset – based on their individual tumor," said Dr. Milosevic. "At the heart of it, this is what personalized medicine is all about."

Identifying prostate cancers at high risk for recurrence with this technique could allow more aggressive treatment and monitoring to catch the cancer earlier, establishing better patient outcomes in the 25 percent of prostate cancer patients in which the cancer comes back.

The study was published on April 1, 2012 in Clinical Cancer Research, a journal of the American Association of Cancer Research.

The research was funded by United States Army Prostate Cancer Research Program, together with grants from the National Cancer Institute of Canada, the Canadian Cancer Society Research Institute, and the Princess Margaret Hospital Foundation.

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Review Date: 
April 17, 2012