A novel imaging technique is being studied as a tool to specifically detect prostate cancer cells located within the prostate gland, along with prostate cancer cells that have metastasized to other sites of the body. The technique uses a radiolabeled amino acid compound called Tc-99m MIP-1404, which is injected into the blood stream and then attaches to the PSMA enzyme located on prostate cancer cells. The radiolabeled prostate cancer cells are then detected with a computed tomography (CT) scan. In phase I patient trials, Tc-99m MIP-1404 was ready to be imaged by CT scan within 1 hour after injection into the body and pointed out more tumors than standard bone scans. Phase II clinical trials are ongoing.
Peter Ubel, author of the book Critical Decisions, discusses the potential impact of Oncotype DX, a new prostate cancer test, on treatment decisions. The test, which has not yet gone through a rigorous peer review process, may help identify low-risk tumors that do not need aggressive treatment. Ubel analyzes the role of human psychology on cancer treatment decisions and feels that such a test may not be accepted by patients as a reason to forego curative treatment.
Scientist at the University of California Irvine developed new technology that can detect a prostate cancer marker called prostate-specific membrane antigen (PSMA) in urine. The technology combines protein receptors with pencil-like viruses, creating a sensor that is inexpensive, resilient, and easy to mass produce. Human clinical trials have not started yet, but the scientists hope to market the test as an at-home prostate cancer test, similar to over-the-counter pregnancy tests.
About 20% of men have multiple medical problems that make it unnecessary for them to have a prostate biopsy. A study published online in the medical journal Cancer involved 104 patients and used written assessments of medical problems to identify men who would not benefit from biopsy to diagnose prostate cancer. The authors feel physicians should assess the number and severity of medical conditions a patient has before deciding to proceed with a prostate biopsy.
A new genetic test for prostate cancer was presented at the American Urological Association (AUA) annual meeting. The test analyzes prostate tissue biopsy samples as small as 1mm, looking for activity of 17 different genes and assigns a score called the genomic prostate score (GPS). When used in combination with current diagnostic tests, the GPS helps differentiate high-risk from low-risk prostate cancer more accurately. In a clinical trial involving 395 patients, using GPS increased the proportion of men who could be considered for active surveillance by 15-20%.
Two recent surveys of pulmonologists (lung physicians) and pathologists (physicians specializing in medical diagnosis) revealed their increased involvement in lung cancer biomarker testing, but challenges remain. Testing for biomarkers (certain genetic abnormalities in cancer) is crucial for choosing appropriate treatments, including targeted therapies. According to the surveys, almost half of pulmonologists and one-third of pathologists now test tissues for biomarkers immediately after a non-small cell lung cancer (NSCLC) diagnosis. A majority of both groups also said they do not always acquire tissue samples of sufficient size or quality for biomarker testing and many feel they do not have enough information about the size of tissue needed. The physicians also disagree about the best tissue collection method.
In the last decade, the number of blood infections after prostate biopsy has increased drastically, often involving difficult-to-treat bacteria that are resistant to multiple antibiotics. To decrease risk of infection, doctors are being more careful about whom they select to biopsy, leading to a lower number of biopsies being performed across the country. One cancer center has started testing patients’ rectal bacteria for resistance to antibiotics prior to performing a prostate biopsy in order to make better treatment decisions in the event of infection.
Multispectral photoacoustic imaging may offer a superior alternative to transrectal ultrasound, the current standard in prostate cancer diagnosis. The technology combines laser optics with ultrasound imaging; in a clinical trial it correctly predicted 25 out of 26 noncancerous prostate biopsy samples and 13 out of 16 cancerous samples. The imaging technique is expected to be available in about 5 years.
In an attempt to develop an evidence-based recommendation for prostate cancer screening, researchers from the U.S. and Sweden reviewed data from a large clinical trial involving over 21,000 men. They found that men who have a prostate-specific antigen (PSA) blood level higher than 1.5 ng/mL when they are ages 45 to 49 years of age have a 44% risk of death from prostate cancer within 25 to 30 years. In contrast, men with low PSA values are at a much lower risk of death from prostate cancer and do not need yearly prostate cancer screening. The findings suggest men should be screened for prostate cancer with a PSA blood test at least once before age 50 years.