Prostate-Specific Antigen (PSA) is a protein produced by the prostate gland, a small organ in men involved in reproduction. Both healthy and cancerous prostate cells create PSA, which is detectable in the bloodstream. While often associated with prostate cancer, PSA serves as a general marker for prostate health and can be elevated by non-cancerous issues like inflammation or enlargement.
Understanding Hormone Therapy for Prostate Cancer
Hormone therapy for prostate cancer, also known as androgen deprivation therapy (ADT), reduces male hormones (androgens) in the body. Prostate cancer cells often rely on these hormones, primarily testosterone, to grow and spread. By decreasing androgen levels or blocking their action, hormone therapy can slow or stop cancer growth.
Luteinizing hormone-releasing hormone (LHRH) agonists and antagonists prevent testosterone production. Anti-androgens block cancer cells from using testosterone. These therapies are used for various stages of prostate cancer, sometimes alongside other treatments like radiation, to enhance effectiveness or manage advanced disease.
Expected PSA Levels After Hormone Therapy
Following hormone therapy, the goal is to achieve very low, often undetectable, PSA levels. A successful response to treatment is indicated by a significant drop in PSA. The lowest point PSA reaches after treatment is referred to as the PSA nadir.
For many, an optimal PSA nadir is below 0.1 ng/mL or 0.2 ng/mL, depending on clinical context and test sensitivity. Reaching such low levels correlates with better outcomes and reduced progression risk. Individual responses vary, and not all patients achieve the same nadir, but a substantial reduction is anticipated.
Interpreting PSA Fluctuations and Trends
When monitoring PSA levels after hormone therapy, a single reading is less informative than the trend over time. PSA levels can fluctuate, and a minor, temporary increase may not signify a problem. Healthcare providers look for persistent or consecutive rises in PSA to assess treatment effectiveness.
A consistent rise in PSA after an initial decline following hormone therapy indicates treatment resistance. This phenomenon, known as castration-resistant prostate cancer, means cancer cells are growing even with very low androgen levels. Such a rise may signal disease progression or recurrence.
The rate at which PSA levels rise, often expressed as PSA doubling time (PSADT), indicates cancer aggressiveness. A shorter PSA doubling time suggests a more rapidly progressing disease and a higher likelihood of distant spread. Conversely, a longer doubling time may indicate a slower-growing cancer.
The Role of Regular Monitoring and Follow-Up
Regular monitoring of PSA levels is important for ongoing care after hormone therapy for prostate cancer. These tests help track the cancer’s response to treatment and detect early recurrence. PSA tests are performed every three to six months.
PSA testing is part of a broader surveillance strategy including physical examinations and imaging studies to assess disease status. Consistent follow-up allows the healthcare team to identify trends in PSA levels and make informed decisions about potential treatment changes. Patients should discuss their PSA results and any concerns with their healthcare providers to understand their situation and plan for management.