by Jennifer Bond

Positron Emission Tomography, or PET, imaging, a nuclear medicine procedure in which a tiny amount of a radioactive substance is used to examine tissue, has fast gained popularity in the staging, restaging and response to therapy for lung and gynecological cancers.

But a 2018 study indicates it may also play an important role in the early detection of prostate cancer.

The study, published in The Journal of Nuclear Medicine (JNM), has revealed that a new nuclear imaging agent targeting the presence of copper in cancerous growths, can detect prostate cancer recurrence early in patients with rising PSA readings. PSA (protein-specific antigen levels) which are higher than 4.0 ng/mL are generally used to justify a biopsy of the prostate to determine whether cancer is present or not.

What makes copper a good image biomarker?

Previous studies have shown that cancerous prostate tumors tend to have a higher level of copper, since the latter plays a role in cell proliferation. The novel PET/CT agent, copper-64 chloride, has been tested both on human beings and laboratory animals, with findings showing that tumorous tissue does have an increased copper uptake when compared to healthy tissue. In the above-mentioned JNM study, researchers worked with 50 patients, conducting PET/CT scans with the copper-64 and with F-choline, comparing the results of both. They found that copper-64 had a higher detection rate than F-choline for searching for cancer in patients with biochemical relapse.

Why is early detection key for prostate cancer?

Since early detection tests for prostate cancer have become the norm on the United States, prostate cancer death rates have dropped considerably. However, scientists are still at odds as to whether or not the lower death rates can be attributed to screening. Because most prostate cancers are slow growing, doctors often do not know if treatment with surgery or radiation is ideal. These treatments can have side-effects, potentially affecting their urinary and bowel health or their sexual function.

Two large-scale studies conflict in their findings regarding the usefulness of testing. However, the American Cancer Society notes that young men should perhaps consider testing, since early detection could significantly lengthen their lives. They should also aim to increase their awareness of causes of prostate cancer, in order to be aware of common myths. Although testosterone blockers are often used to treat prostate cancer, for instance, long-term testosterone therapy does not per se increase the risk of prostate cancer. These and other prostate-related issues should be discussed by men with their doctors.

Keeping prostate cancer at bay

Increased awareness and early detection of prostate cancer can aid with prostate cancer prevention strategies. The latter include adopting a Mediterranean style (and low-fat) diet, staying at a healthy weight (since men with a BMI of 30 or may have an increased prostate cancer rate), and staying active. Men should also discuss family history and other risk factors with their doctor.

Early detection of prostate cancer relapse is now possible thanks to a novel PET/CT agent called copper-64 chloride. Laboratory and human studies reveal that this agent can be used with men whose PSA readings are high. Although studies are still at odds as to the utility of prostate cancer screening, in men who have already had prostate cancer, early detection is clearly of utmost importance.