Groundbreaking blood test can detect prostate cancer, study finds
[Feb. 3, 2023: Christina Elston, Cedars-Sinai]
A new blood test developed by Cedars-Sinai investigators opens up new tools that will help optimize treatment and quality of life for prostate cancer patients. (CREDIT: Creative Commons)
Cedars-Sinai Cancer investigators have developed a new nanotechnology-based test that can detect and profile prostate cancers—even in microscopic amounts. Their work, published in the peer-reviewed journal nanotoday, suggests that this “liquid biopsy” test could spare many patients unnecessary treatment-related side effects, directing them instead to effective therapies that could prolong their lives.
“This research will revolutionize the liquid biopsy in prostate cancer,” said Edwin Posadas, MD, medical director of the Urologic Oncology Program and co-director of the Experimental Therapeutics Program in Cedars-Sinai Cancer. “The test is fast, minimally invasive and cost-effective, and opens up a new suite of tools that will help us optimize treatment and quality of life for prostate cancer patients.”
Cancer of the prostate, a walnut-sized gland just below the bladder, is the most common cancer and second-leading cause of cancer death among U.S. men.
The test developed by Posadas and co-investigators isolates and characterizes extracellular vesicles, also called EVs, from blood samples. EVs are microscopic packets of protein and genetic material that are shed by cells. The EV Digital Scoring Assay can pull these EV packets from the blood with unprecedented efficiency and analyze them in a manner that is faster than any currently available test.
The investigators tested blood samples from 40 patients with prostate cancer and found that the test was able to distinguish cancer localized to the prostate from cancer that had spread to other parts of the body.
Posadas envisions this test being used to help patients who have their prostate gland removed and later experience a rise in levels of prostate-specific antigen (PSA) in their blood. This happens in about 30% of post-surgical patients, and elevated PSA levels can indicate cancer recurrence.
If a remnant of the cancer has been left behind in the prostate bed, where the prostate gland once was, Posadas said focused radiation therapy can cure the disease or delay progression. But that treatment is not without risks.
Dan Theodorescu, MD, PhD (CREDIT: Cedars-Sinai)
“The bladder and rectum are near the prostate bed and can be damaged during the course of radiation therapy,” Posadas said. “The risk is only worth it if a man is going to benefit.”
If microscopic cancer deposits have spread outside the prostate area, focused radiation treatment will not prevent disease progression. These deposits, called micro-metastases, are not always detectable, even via the most advanced imaging, but investigators were able to detect them using the EV test.
“This would allow many patients to avoid the potential harms of radiation that isn’t targeting their disease, and instead receive systemic therapy that could slow disease progression,” Posadas said.
In retrospective case studies, investigators tested blood samples taken over time from three prostate cancer patients, including one patient who had undergone focused radiation treatments.
“At the time he was being treated, I was concerned that he was not benefiting,” Posadas said. “And the test results mirrored his clinical behavior and showed that, indeed, the treatments were not effective because he had micro-metastatic disease.”
The test is the latest in a yearslong series of Cedars-Sinai Cancer breakthroughs involving EVs. Posadas said that it could also be adapted to guide treatment as prostate cancer therapies become more targeted at the molecular level, ultimately extending patients’ lives. Posadas and his team of investigators are now working to further refine the test so that it can be studied in greater detail.
“This type of liquid biopsy, coupled with innovations such as our Molecular Twin initiative, is key to next-generation precision medicine that represents the newest frontier in cancer treatment,” said Dan Theodorescu, MD, PhD, director of Cedars-Sinai Cancer and the PHASE ONE Distinguished Chair.
“And the type of progress we are making is only possible at an institution such as Cedars-Sinai Cancer, where we have patients, clinicians, scientists and creative engineering minds converging as one unit to address the most challenging problems in cancer”, Theodorescu continued.
Posadas and the team aim to work with local and national partners and hope to see the test come into wide clinical practice in the near future.
Symptoms of prostate cancer:
Prostate cancer may cause no signs or symptoms in its early stages.
Prostate cancer that's more advanced may cause signs and symptoms such as:
Decreased force in the stream of urine
Blood in the urine
Blood in the semen
Losing weight without trying
Causes of prostate cancer:
It's not clear what causes prostate cancer.
The prostate gland is located just below the bladder in men and surrounds the top portion of the tube that drains urine from the bladder (urethra). (CREDIT: Getty Images)
Doctors know that prostate cancer begins when cells in the prostate develop changes in their DNA. A cell's DNA contains the instructions that tell a cell what to do. The changes tell the cells to grow and divide more rapidly than normal cells do. The abnormal cells continue living, when other cells would die.
Prostate gland: The prostate gland is located just below the bladder in men and surrounds the top portion of the tube that drains urine from the bladder (urethra). The prostate's primary function is to produce the fluid that nourishes and transports sperm (seminal fluid).
The accumulating abnormal cells form a tumor that can grow to invade nearby tissue. In time, some abnormal cells can break away and spread (metastasize) to other parts of the body.
Risk factors for prostate cancer:
Factors that can increase your risk of prostate cancer include:
Older age. Your risk of prostate cancer increases as you age. It's most common after age 50.
Race. For reasons not yet determined, Black people have a greater risk of prostate cancer than do people of other races. In Black people, prostate cancer is also more likely to be aggressive or advanced.
Family history. If a blood relative, such as a parent, sibling or child, has been diagnosed with prostate cancer, your risk may be increased. Also, if you have a family history of genes that increase the risk of breast cancer (BRCA1 or BRCA2) or a very strong family history of breast cancer, your risk of prostate cancer may be higher.
Obesity. People who are obese may have a higher risk of prostate cancer compared with people considered to have a healthy weight, though studies have had mixed results. In obese people, the cancer is more likely to be more aggressive and more likely to return after initial treatment.
Prevention of prostate cancer:
The Mayo Clinic believes that people can reduce their risk of prostate cancer if they:
Choose a healthy diet full of fruits and vegetables. Eat a variety of fruits, vegetables and whole grains. Fruits and vegetables contain many vitamins and nutrients that can contribute to your health.
Whether you can prevent prostate cancer through diet has yet to be conclusively proved. But eating a healthy diet with a variety of fruits and vegetables can improve your overall health.
Choose healthy foods over supplements. No studies have shown that supplements play a role in reducing your risk of prostate cancer. Instead, choose foods that are rich in vitamins and minerals so that you can maintain healthy levels of vitamins in your body.
Exercise most days of the week. Exercise improves your overall health, helps you maintain your weight and improves your mood. Try to exercise most days of the week. If you're new to exercise, start slow and work your way up to more exercise time each day.
Maintain a healthy weight. If your current weight is healthy, work to maintain it by choosing a healthy diet and exercising most days of the week. If you need to lose weight, add more exercise and reduce the number of calories you eat each day. Ask your doctor for help creating a plan for healthy weight loss.
Talk to your doctor about increased risk of prostate cancer. If you have a very high risk of prostate cancer, you and your doctor may consider medications or other treatments to reduce the risk. Some studies suggest that taking 5-alpha reductase inhibitors, including finasteride (Propecia, Proscar) and dutasteride (Avodart), may reduce the overall risk of developing prostate cancer. These drugs are used to control prostate gland enlargement and hair loss.
However, some evidence indicates that people taking these medications may have an increased risk of getting a more serious form of prostate cancer (high-grade prostate cancer). If you're concerned about your risk of developing prostate cancer, talk with your doctor.
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Note: Materials provided above by Cedars-Sinai. Content may be edited for style and length.
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