Prostate cancer is the most common solid-organ cancer and the second-leading cause of cancer death in Western men. In India, as per GLOBOCAN 2020 data, Prostate cancer is the 12th most common cancer.
Prostate is a small gland, about the size and shape of a walnut, and is part of the male reproductive system. It lies below the bladder and just in front of the rectum. The prostate gland helps make semen.
Prostate-specific antigen (PSA) is a protein produced by normal prostate cells and plays an important role in fertility. PSA can be elevated in infection, age related benign prostatic hyperplasia (BPH) and cancer. Rising PSA levels are usually associated with Prostate Cancer.
PSA testing not only helps identify men in whom a prostate biopsy would be appropriate but also assists in assessing the response to therapy and also determining tumour / cancer progression.
The serum biomarker PSA has been widely used over the last 40 years. It is considered an imperfect marker as it is prostate specific and NOT cancer specific. The normal range of PSA is 0-4ng/mL.
Prostate-specific antigen (PSA) testing with a cut off of 4.0 ng/mL has a sensitivity of 67.5-80%, which implies that 20-30% of cancers are missed when only the PSA level is obtained.
Sensitivity can be improved by lowering the cut off or by monitoring PSA values so that a rise in PSA level of more than 20-25% per year or an increase of 0.75 ng/mL in 1 year would trigger performance of a biopsy regardless of the PSA value.
PSA Testing to Monitor Therapy
Serial PSA measurements provide the most effective means of detecting early recurrence after radical surgery. Postoperatively, most men have a rapid decline in their PSA levels, which are expected to become undetectable within 1 month.
A PSA level that is elevated after a period during which it was undetectable, connotes the presence of prostate cells somewhere in the body generally, a detectable and rising PSA level indicates the presence of residual cancer cells.
TAKE AWAY POINTS
Prostate cancer is a significant killer of men (more so in the Western World but number are increasing in India)
Prostate cancer is asymptomatic during its curable stages.
PSA screening can save lives.
Patients with low-risk prostate cancer do not generally need treatment, whereas those with intermediate- and high-risk cancers usually benefit from curative therapy.
Not all men with a raised PSA need a prostate biopsy, thanks to MRI scanning.