Low, But Rising, PSA Can Predict Poor Prognosis and High-Grade CaP

Among prostate cancer patients, higher pre-operation PSA levels and higher Gleason scores are often associated with a poorer prognosis after radical prostatectomy.

However, some prostate cancer tumors actually secrete less PSA than other tumors and in these patients, PSA levels are relatively low.

Against expectations, a lower PSA with a diagnosis of prostate cancer could prove to be a Gleason 8-10, more aggressive cancer.

230 radical prostatectomy patients, who had a Gleason score of 8-10 in their post prostatectomy biopsies and a preoperation PSA of 2.5 or less, were followed for 77 months after surgery. They were compared to 3,248 patients with higher diagnostic PSA scores.

The findings revealed that patients with PSA levels lower than 2.5 ng/mL had a proportionately higher recurrence rate than those with PSA 2.6 to 4.0 as well as those from 4.1 to 10. Only patients with a PSA over 10 had a slightly higher recurrence rate than those with PSA less than 2.5.

Also, the 7-year metastasis free survival was lower in patients with PSA 2.5 or less. Cancer specific survival was also lowest in these patients.

Patients with Gleason score 8-10 and a pre-operation PSA of 2.5 or less generally have proportionately worse outcomes after radical prostatectomy than those with intermediate PSA values.

“This data should provide a wake-up call to physicians who might think there is no need to perform a biopsy in men whose PSA remains low or who might be less concerned about disease aggressiveness in patients found to have high-grade tumors but who have low PSA levels,” Dr. Barry McGuire said.

Dr. Catalona, the senior author of the research, said: “The message from this study is that PSA does not correlate with prognosis across the board. I would caution against those who argue for no routine PSA screening — where PSA Velocity can be followed – and who believe there is no need to worry about men with a low PSA level. They are sticking their heads in the sand.

“PSA screening should start at age 40 and biopsies recommended for men who have persistently rising PSA in follow-up, no matter the PSA level.”