PSA-Based Diagnoses Are Leading to Improved Prostate Cancer Outcomes

Prostate-specific antigen (PSA) testing has changed the face ofprostate cancer, leading to earlier diagnosis and improved outcome,says David F. Paulson, md, professor and chairman, Division ofUrology, Duke University Medical School.

Citing statistics from North Carolina, he said that before 1990,90% of all prostate cancers were detected by digital rectal examination(DRE). In 1991, an increase in PSA-prompted biopsy began to beobserved. By 1992, 65% of all new cases of prostate cancer werediagnosed as a result of PSA testing, and by 1993, that figurehad risen to 90%.

In his presentation at a Lenox Hill Hospital program on prostatecancer, Dr. Paulson said that PSA-prompted diagnosis has resultedin a dramatic change in the presentation and outcome of the disease."We are seeing more organ-confined and specimen-confineddisease. PSA-driven diagnosis tends to shift patients into thesetwo most favorable categories," resulting in earlier andmore effective treatment.

Dr. Paulson favors using low PSA cut-offs to prompt biopsy, assertingthat it will increase the population that is potentially curable.He suggests an abnormal DRE and a crude cut-off level of 4 ng/mL,rather than PSA density, as the indication for biopsy.

He cautions that high Gleason score disease will yield low PSAlevels, since it decreases the ability of the gland to producePSA. And he regards transurethral ultrasound as useful only tolocate the prostate to obtain an adequate sampling for biopsy.

Dr. Paulson recommends prostate cancer screening for all men over50, all black men over 40, and any man over 40 with a family historyof the disease.

Residual Disease Dilemma

Although early detection improves the outcome of radical surgery,patients with residual disease still present a treatment dilemma.Dr. Paulson is unenthusiastic about postoperative androgen deprivationand adjunctive radiotherapy.

He explained that radiation drives PSA down, giving a 6-monthto 2- or 3-year interval of apparent disease control, but in termsof long-term survival, radiation does not make a difference, hesaid. After PSA levels rise, it may be necessary to fall backon androgen deprivation therapy, if only to please the patient,he noted.

In Dr. Paulson's view, if it cannot be established that the patientis margin-positive and if PSA is undetectable postoperatively,there is no loss of survival advantage in delaying radiation untilthe PSA level becomes elevated. Even then, it should be undertakenonly if the patient wants it.

He regards both small volume node-positive and margin-positivepatients as destined eventually to do poorly. Even though thereis little that can be done to improve survival in these cases,he recommends node dissection with radical prostatectomy,ratherthan node dissection alone.