Surgery for prostate cancer can have varying results: in some men, the disease never returns, while in others, it does. Doctors estimate the likelihood of recurrence by analyzing specific types of clinical data. For example, recurrence is more likely if a man's biopsy reveals an aggressive form of cancer. Extremely high or fast-rising levels of prostate-specific antigen (PSA) before surgery are also related to poorer results.
Researchers are working diligently to improve the techniques used to identify men who could benefit from additional treatment or monitoring. These risk-based classifications are aided by genetic tests and new types of medical imaging.
In December, researchers at Stanford University revealed promising results with a new imaging technique that highlights prostate cancers. The strategy employs a mildly radioactive tracer that searches the body for cancer cells. The intravenously administered tracer 68Ga-PSMA-11 binds specifically to a protein termed prostate-specific membrane antigen (PSMA). This protein is significantly more prevalent on the surface of prostate cancer cells than on normal prostate cells. On an imaging scan, tumors highlighted by 68Ga-PSMA-11 stand out like lit matches in a dark environment. PSMA scans are being utilized to diagnose early metastatic cancer, and the tracer can also be employed to transport chemotherapy medications directly into malignant tumors.
Methodology and results of research
The goal of this study was to see whether the scanning technique could predict prostate cancer recurrence following initial treatment. The researchers enrolled 73 men with intermediate- or high-risk tumor samples and administered 68Ga-PSMA-11 to each of them. The researchers next evaluated how much of the tracer was absorbed by the prostate as well as any potential cancer cells that were spreading throughout the body. After that, the males had their prostates removed.
The recurrence of cancer was determined by analyzing variations in PSA levels. The levels should drop to zero if a man's prostate has been eliminated; therefore, sustained rises or a rapid increase in PSA levels following surgery suggest that cancer is still present in the body. The term for this type of recurrence is "biochemical failure."
Three years were spent following the men. Men who had lower tracer uptake values prior to surgery fared better over time, according to the final findings. After their procedures, the males with lower tracer uptake values avoided biochemical failure for at least two years. In contrast, men with the greatest tracer uptake values and/or PSMA-detected metastases prior to surgery were more susceptible to biochemical failure during the research period.
Dr. Marc B. Garnick, Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, adds, "This study adds to the enthusiasm surrounding PSMA scans and how they can be used to predict prostate cancer outcomes." "Many improvements made possible by PSMA are improving the way prostate cancer is treated and how patients are followed up after they have been diagnosed and treated. Our study shows how important this important technology is."