Advances in PSMA PET-imaging for Detecting Prostate Cancer

If you are a male age 50 or older, then you probably undergo annual prostate specific antigen (PSA) screening for prostate cancer. The most commonly diagnosed type of cancer in the U.S. (excluding skin cancer), prostate cancer is the second leading cause of cancer death in American men, just behind lung cancer.

Fortunately, most men with prostate cancer do not die from it. A large majority of all prostate cancers are detected when confined to the prostate and can be treated more successfully than most other cancers.

Weill Cornell Medicine (WCM) is a frontrunner in the early detection and treatment of prostate cancer.

We are among a handful of medical centers in the nation also offering a pioneering imaging technology called prostate-specific membrane antigen positron emission tomography (PSMA PET). This imaging helps determine whether cancer has spread beyond the prostate gland and may guide future PSMA-based therapeutics to directly target cancer cells, thus improving outcomes, according to Joseph R. Osborne, M.D., Ph.D., Chief, Molecular Imaging and Therapeutics, Professor of Radiology and Director of the Radiology Health Equity laboratory. “PSMA PET imaging is very specific,” Dr. Osborne says. “It goes directly to the disease that we want to target.”

WCM’s pioneering technology

In most men with prostate cancer, the disease stays within the prostate gland. Men who have a high risk for metastatic disease typically undergo additional testing with a conventional CT or MRI scan, and a bone scan (since prostate cancer often spreads to the bones) to see if their cancer has spread. But neither imaging technology is as specific in localizing prostate cancer cells. Additionally, bone scans may detect non-cancerous bone damage (e.g., arthritis), leading to “false-positives” and unnecessary additional imaging.

PSMA PET is often more specific than CT or MRI scans in detecting small deposits of prostate cancer outside the gland, Dr. Osborne says. WCM’s Hematology & Oncology division offers this newly FDA-approved diagnostic tool, as well as clinical trials with PSMA-based therapeutics. This combination of diagnostics and therapeutics using the same platform defines our theranostics program. The PET scan involves the intravenous injection of a radioactive “tracer” that binds to the PSMA protein, which is often found in large amounts on prostate cancer cells, and makes an ideal target for PSMA PET imaging.

“The more specifically you can image the prostate cancer, the more specific treatment you can design to target it with more damaging radioactivity,” Dr. Osborne says. “We give people a minimal amount of a radioactive element to see if they have prostate cancer, and if they do, then we can offer them a clinical trial with a targeted, damaging amount of the radioactive element to wipe it out, while sparing normal tissues,” he explains.

Recently published PSMA PET therapeutic trials have also shown increased overall survival. In one study, prostate cancer patients receiving standard treatment lived for a median of 11.3 months, compared with 15.3 months with Lutetium-based PSMA therapy, Dr. Osborne says.

What is prostate cancer?

The prostate is a small gland just below the bladder. Part of the male reproductive system, it produces fluid that mixes with semen during ejaculation. Sometimes cells in the prostate become cancerous.

The disease occurs most commonly in African-American men. In addition to age and race, your risk may increase if your father or brother had the disease.

The incidence of prostate cancer increases with age: the older you are, the greater your chance of developing it. Rare in men younger than 40, the chance of having prostate cancer rises rapidly after age 50. About 6 in 10--or 60%--of cases of prostate cancer are found in men older than 65.

Symptoms and risks

Prostate cancer grows slowly and produces few, if any, noticeable symptoms. In fact, an infected or enlarged (noncancerous) prostate can mimic prostate cancer. Occasionally, though, these symptoms indicate prostate cancer:

• Slow or weak urine stream
• Frequent urination, especially at night
• Blood in urine or semen
• Loss of bladder or bowel control
• Erectile dysfunction
• Pain in the hips, back or chest
• Weakness or numbness in legs or feet

For this reason, it’s important to know your risk factors, which include:

• Age: Your chances of developing prostate cancer go up after you turn 50.
• Ethnicity:  African-American men are more likely to develop prostate cancer than Caucasians, Latinos and Asians.
• Family history:  Having a father or brother with prostate cancer doubles risk.
• Genetics:  Inherited gene mutations, including alterations to the BRCA genes often linked to breast cancer, may increase the odds of prostate cancer.
• Diet: Some studies suggest that men who eat a lot of  calcium, found in dairy products, may have a slightly higher chance of getting prostate cancer, although calcium has other important health benefits.

Early detection is key

When caught early and confined to the gland, prostate cancer is highly treatable. Yet, there are aggressive forms of the disease, which is why you and your doctor must carefully weigh the benefits of screening.

The Prostate Cancer Foundation urges men to begin annual screening for prostate cancer at age 50, providing they have no prostate-related symptoms or risk factors. If you are African American, then you should begin screening at age 45. If you have a family history of prostate cancer, then you should begin at age 40. If you are 55 to 69 but have no symptoms, then speak with your doctor.

Contact the Department of Molecular Imaging and Therapeutics to learn more about PSMA PET imaging. “Quality of life for prostate cancer patients has definitely improved,” Dr. Osborne says. “There’s no question they live longer and better with this technology.”