Gene markers were found to improve the accuracy of the prostate cancer test that measures prostate-specific antigen (PSA) in the blood, a recent study has found.
Currently, the merits of PSA blood tests are divisive among scientists and doctors due the lack of a baseline for normal PSA levels, which means results could come back as false positives for some, or lead doctors to miss the cancer outright for others.
In a new study published online on Wednesday in Science Translational Medicine, researchers found that variations in the human genome sequence affected individual baseline PSA levels, which could make it easier to tailor PSA tests to each patient.
“Like virtually every protein in the body, PSA levels vary between individuals according to [single nucleotide sequences in the human genome, or SNPs] that regulate gene expression. The SNPs reported today enable us to personalize PSA thresholds, thereby changing the recommendation on whether to biopsy for a substantial proportion of men,” Kari Stefansson, senior author of the study and CEO of biopharmaceutical company deCODE, said in a statement.
The study, titled "Genetic correction of PSA values using sequence variants associated with PSA levels," examined the genes of 16,000 Icelandic men, who had never been diagnosed with prostate cancer, and found that four specific genetic snippets were correlated with individualized PSA levels, meaning that testing for the SNPs first could improve PSA test accuracy.
“The paper published today demonstrates that analysis of four SNPs can be used to derive a personalized PSA threshold that more accurately identifies those men who are more likely to have a positive biopsy and for whom one should therefore be recommended,” a press statement for the study read.
In 2007, based on the latest data available from the U.S. Centers for Disease Control and Prevention (CDC), more than 223,000 American men were diagnosed with prostate cancer and more than 29,000 men died of the disease.
