Imaging Advance Tracks Prostate Cancer in Lymph Nodes

Engineered 'payload' based on common cold virus could aid doctors in treatment decisions

TUESDAY, July 15, 2008 (HealthDay News) -- A new imaging technique, based on an engineered version of the common cold virus, may help doctors detect the spread of prostate cancer to the lymph nodes earlier.

This, in turn, could help guide more effective treatment decisions, said the authors of a study published in the July 11 edition of Nature Medicine.

"It would represent a treatment advance in patients for whom outcome is not good," study senior author Dr. Lily Wu, a researcher at UCLA's Jonsson Cancer Center, said in a university news release. "This would help improve the prognosis for these patients by letting us find and treat these metastases early. If we can catch the cancer before it invades other organs, we have a better chance to change the outcomes for these patients."

Patients whose prostate cancer has traveled to their lymph nodes are more likely to have a recurrence. Finding these tiny metastases in the pelvic lymph nodes is key to making future treatment decisions, yet it is also supremely difficult to do with conventional imaging techniques.

Wu and her colleagues engineered a common cold virus armed with a specific "genetic payload" to travel directly to lymph nodes in mice and to express its payload only in prostate cells.

The payload consists of a protein that can be picked up on PET scans.

Wu and her colleagues next want to combine the imaging technique with treatment, so that a drug contained in the genetic payload could kill the traveling tumor cells.

"I think this is very exciting for many reasons," said Wu. "We now know we can reach these prostate cancer metastases at an earlier stage than before, and we know we can deliver genes to those cancer cells that produce proteins that can be imaged by PET. Now we will find out how effective this genetic toxic payload is in preventing further spread of the cancer to other vital organs."

More information

Visit the National Cancer Institute for more on prostate cancer.

SOURCE: University of California, Los Angeles, news release, July 11, 2008
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