NEW YORK (GenomeWeb) – Researchers from Johns Hopkins University have published data from an independent validation study in The Journal of Urology reporting that increased methylation of GSTP1 could be associated with a risk of prostate cancer recurrence in men with early-stage disease.
GSTP1 is one of the three genes assessed by MDxHealth's ConfirmMDx test. Past studies have also indicated that this gene is associated with different stages of prostate cancer. The published data suggest, MDxHealth said in a statement, that "epigenetic analysis could play a clinical role in identifying patients who have a slow growing cancer eligible for active surveillance from those with a higher risk of recurrence who may benefit from a more aggressive therapeutic approach."
In the study, researchers led by JHU's Leonel Maldonado evaluated the prognostic value of nine epigenetic genes -- AIM1, APC, CCND2, GPX3, GSTP1, MCAM, RARβ2, SSBP2 and TIMP3 – in tissue samples from approximately 450 patients, using by quantitative fluorogenic methylation-specific PCR. These patients with localized disease were enrolled in a nested case-control, had received surgery, and had experienced biochemical recurrence, clinical recurrence, systematic metastasis, or had died from the disease. Among the nine genes, only higher GSTP1 methylation status was significantly associated with an increased risk of disease recurrence for early stage prostate cancer patients.
"This suggests that GSTP1 promoter methylation may be a potential tissue based recurrence marker," the researchers concluded.
Current methods of gauging the risk of recurrence in prostate cancer patients with early-stage disease, including the use of clinical factors, PSA serum levels, and Gleason score, are imprecise from a prognostic standpoint. Close to 1 million men in the US receive a negative prostate biopsy result annually, even though 25 percent of them have occult prostate cancer. This imprecision in detecting cancer results in a high rate of repeat biopsies for men, with more than 40 percent receiving at least one repeat biopsy.
The latest published findings "illustrate the clinical importance of using epigenetic biomarkers, like GSTP1, to not only identify patients with prostate cancer but also inform the treating urologist about the aggressiveness of the disease for treatment decision making," Wim van Criekinge, MDxHealth's chief scientific officer, said in a statement.