The Game Changer: New Test Helps Doctors Find Hidden Prostate Cancer

SAN FRANCISCO (KPIX) -- Dennis Brod is a husband, father and grandfather. He is also the living definition of a Renaissance man: a retired attorney, former public elected official, author, and self-described philosopher.

But his full life took a pause in 2014, when the North Bay resident got some bad news.

"I was diagnosed with a very severe case of prostate cancer," explained Brod.

At that time, there was no indication that the cancer had spread. But, in Brod's case, there was a high volume of cancer and experts deemed the cancer was aggressive.

Brod decided to have surgery. His surgeon was Dr. Peter Carroll at UCSF. After surgery, his treatment team told the retired attorney that they anticipated a cure. His blood tests 90 days later were causes for cautious celebration: still no detectable cancer cells.

However, one year later, another blood test told a different story: his PSA levels were rising again. It was a suspicious sign that prostate cancer cells were indeed hiding somewhere in his body.

"Something else had to be done, and my question was 'Where are the tumors?'" recounted Brod.

In cases like these, doctors don't really know.

Prostate cancer is one of the most common causes of cancer in men in the United States. More than 190,000 new cases are diagnosed every year

Most cancers are confined to the prostate gland and remain localized. Many men can safely surveil their cancers and in fact, the majority of men diagnosed with the disease are unlikely to die from it. However, in cases like Brod's where certain factors are linked to a higher risk of cancer eventually spreading or having already spread, there is a dilemma. The National Cancer Institute estimates 33,000 men will die from prostate cancer every year.

"The problem really is because we don't know where the disease is, it's very hard to treat," explained UCSF's Dr. Thomas Hope.

Dr. Hope is a nuclear medicine physician. Along with researchers at UCLA, including Dr. Jeremie Calais at the David Geffen School of Medicine, Dr. Hope and a virtual army of specialists collaborated on clinical trials designed to validate a new way to find these hidden prostate cancer cells. The technique is called a PSMA PET scan.

These specialists came from all walks of life in the medical community. It took a virtual village of experts from nuclear medicine technologists, as well as those with expertise in chemistry, and regulatory advice.

A PSMA Pet Scan involves special small molecules, a radioactive tag, and PET imaging.

"In my opinion, I would describe it as a game changer," remarked Dr. Carroll.

PSMA stands for Prostate Specific Membrane Antigen. It is a unique protein that's made excessively by prostate cancer cells and is detected in abundance on the surface of the tumors. It turns out that these special small molecules, like heat-seeking missiles, will seek out this PSMA protein and attach to them. What's key in this test is that on these molecules, a small radioactive tag or tracer has been added.

By infusion, doctors inject patients with a drug containing the molecules and radioactive tags. As expected, the molecules seek out the protein. When the molecule finds and binds to the protein on the prostate cancer cell, it releases the radiation – lighting up the location of the hidden cancer. It's then seen on the PET scan. The radioisotope used here is called Gallium-68 or Ga-68.

"The contrast of the brightness to the dark allows us to see it," explained Dr. Hope.

The clinical trials found the results of the test is so accurate, it can detect prostate cancer cells anywhere in the body.

"It's allowing us to localize the disease much more accurately and easily," noted Dr. Hope.

Prostate cancer specialists say that accuracy carries a huge benefit. It will allow doctors to more precisely determine where the disease is coming from in a substantial number of patients.

"It gives us an idea of how extensive the disease is and allows us to develop a treatment plan which is more precise in men," noted Dr. Carroll.

Dr. Carroll told KPIX 5 that the test allows doctors to develop treatment plans in certain newly diagnosed patients who are at high risk, or to shift gears in patients who have had a recurrence.

"And we'll change the treatment plan. It turns out there are many men who recur in sites we didn't think were sites they were most at risk for," explained Dr. Carroll.

Since his diagnosis, Brod has undergone five scans. He was part of the clinical trials at UCSF. He told KPIX 5 that the scans help him make choices regarding several different treatments.

"It's part of the whole package that my treatment team has delivered to me to keep me alive," said Brod.

Researchers are now studying if the technique can not only detect the cancer, but also perhaps serve as a treatment.

They are testing if these small molecules can carry a more-potent payload of radiation. The idea: first find the hidden tumors, then deliver the molecule carrying a stronger radioactive payload in order to kill the cancer itself.

PSMA PET has been used for several years in Australia and Europe. The USFDA has approved its use at UCSF and UCLA. Several other U.S. Medical Centers are currently using it as an "investigational technique".

But experts tell KPIX 5 that thanks to the work done at UCSF, and UCLA, that more medical centers can now apply to use the technology under expedited FDA approval.