significance and draw backs of PSA test in detection of benign and malignant lesions of prostate

1. ROLE OF PSA LEVEL IN
BENIGN AND MALIGNANT
PROSTATIC LESIONS
Saba Sahar
Roll no. 171

2. • The prostate is a compound tubuloalveolar exocrine gland of the male
reproductive system
• Prostate can be divided into several biologically distinct regions
:Peripheral zone , Central zone , Transition zone , Anterior fibromuscular
zone (or stroma)
• Histology : Glands with Two cell layers ; flat basal layer, overlying
columnar secretory cell layer with surrounding fibromuscular stroma
• Most hyperplastic lesions – Inner transition zone
• Most carcinomas – Peripheral zone
Anatomy & histology

6. What is PSA ?
• Prostate-specific antigen, or PSA, is a serine protease
produced by normal, as well as malignant cells of the
prostate gland and is normally secreted in the semen .
• Liquefies the seminal coagulum formed after ejaculation .
• It is increased in prostitis , hyperplasia and malignancy .
• The PSA test measures the level of PSA in serum.
• A serum PSA level of 4ng/ml is cut off between normal and
abnormal ; however some guidelines designate values
above 2.5 ng/ml as abnormal.

7. Significance of
PSA• Most localized cancers are clinically silent and are detected by
routine monitoring of PSA concentrations in older men
• Prostate cancer mortality has decreased significantly over the past
several decades, in part due to increased detection of diseases
through screening i.e serum PSA measurement
• In Men Over 50 : BPH May Be the Cause of High PSA
• The PSA test was originally approved by the FDA in 1986 to
monitor the progression of prostate cancer in men who had
already been diagnosed with the disease.
• In 1994, the FDA approved the use of the PSA test in conjunction
with a digital rectal exam (DRE) to test asymptomatic men for
prostate cancer

8. • Once cancer is diagnosed , serial measurements of PSA are
of great value in assessing response to therapy .
• Increasing PSA levels after radical prostectomy or
radiotherapy for localized disease – Indictive of recurrent or
disseminated disease.
• A significant rise in serum PSA levels , even if PSA is within
the normal range should prompt a workup .
• Monitors progressive or recurrent disease

9. PSA IN BENIGN VS. MALIGNANT
CONDITIONS
• PSA present in serum – mostly bound to plasma proteins
• Serum PSA also includes a minor free fraction
Percentage of free PSA (ratio of free PSA to total PSA)
is LOWER in men with PROSTATE CANCER , than in
men with benign prostatic diseases .

10. LIMITATIONS OF PSA
TEST
• Imperfect cancer screening test
• Not CANCER SPECIFIC
• Significant number of false negative and false positive results
• Also raised in BPH , Prostitis , Prostatic infarcts, instrumentation
of prostate and ejaculation .
• Conversely , 20% to 40% of patients with organ confined
prostate cancer have a PSA value of 4ng/ml or less.
• Less specificity and sensitivity

11. To enhance specificity and
sensitivity of PSA test
• Correct PSA for estimated prostate size to account for
elevations in PSA that are associated with enlarged
prostates (BPH)
• Use a sliding scale that takes the rise in PSA that occurs
with AGE into account
• Focus on changes in PSA measurements in serial over time