Radical prostatectomy is the surgical removal of the prostate gland, typically performed as a definitive treatment for localized prostate cancer. This surgery aims to cure the patient by excising the tumor-bearing organ. While successful in cancer control, the procedure or subsequent treatments can disrupt the body’s hormonal balance. Testosterone, the primary male sex hormone, plays a broad role in maintaining bone density, muscle mass, energy, and sexual function. A significant challenge for survivors is managing the potential decline in this hormone, known as hypogonadism, and determining whether testosterone replacement therapy (TRT) is a safe option.
Immediate Impact of Prostatectomy on Testosterone Levels
The removal of the prostate gland itself does not eliminate the source of testosterone, which is produced predominantly by the testicles. For men who undergo radical prostatectomy alone, total testosterone levels may experience a temporary dip in the immediate post-operative period, often recovering to pre-surgical baseline levels within three months. This transient reduction is usually a response to the surgical stress on the body.
The more common and significant cause of low testosterone in this patient population is the use of Androgen Deprivation Therapy (ADT). ADT is a medical treatment that actively suppresses testosterone production, often administered before, during, or after surgery to shrink the tumor or treat high-risk disease. This therapy causes a rapid and profound drop in circulating testosterone to castration levels, generally defined as below 50 ng/dL. While ADT is a temporary treatment, a substantial percentage of men may not see their natural testosterone levels fully recover even months or years after the treatment is stopped.
Recognizing Symptoms of Low Testosterone (Hypogonadism)
Low testosterone, or hypogonadism, is defined by having a low circulating level of the hormone, typically below 300 ng/dL, alongside attributable symptoms. A pervasive symptom is profound fatigue, which significantly impacts daily energy levels and physical performance. Patients often report a noticeable decrease in lean muscle mass over time, accompanied by an increase in body fat.
The hormonal shift frequently affects psychological well-being, manifesting as mood changes, including increased irritability or symptoms of depression. Sexual complaints are also prominent, such as a distinct reduction in libido. Low testosterone can worsen post-surgical erectile dysfunction, which is often a result of nerve damage caused by the prostatectomy. Some men may also experience physical discomforts like hot flashes, commonly associated with the rapid hormonal changes induced by ADT. Recognition of these specific symptoms is the first step toward seeking blood work to confirm a diagnosis.
Safety Considerations for Testosterone Replacement Therapy
The use of testosterone replacement therapy (TRT) in prostate cancer survivors was historically avoided based on early work that showed testosterone could stimulate prostate cancer growth. This created a long-standing medical fear of cancer recurrence. Modern oncology, however, has largely challenged this dogma for men who have been successfully treated and show no evidence of residual disease.
The current understanding is explained by the “Saturation Hypothesis.” This posits that prostate cells’ androgen receptors become fully stimulated, or saturated, at relatively low testosterone concentrations, typically between 200 and 250 ng/dL. Raising the circulating testosterone level above this saturation point does not cause further cell proliferation or cancer growth. This theory suggests that restoring a hypogonadal man’s testosterone up to a normal level is unlikely to stimulate cancer recurrence, provided the cancer was completely removed.
TRT is reserved only for highly selected patients who meet strict oncological and hormonal criteria. Eligibility requires a documented, persistent low testosterone level (below 300 ng/dL) and corresponding symptoms of hypogonadism. Most critically, the patient must have an undetectable Prostate-Specific Antigen (PSA) level for a defined period, often six months to two years, confirming the absence of biochemical recurrence (BCR). TRT is contraindicated for men with active prostate cancer or untreated disease. Initial PSA and baseline testosterone levels are mandatory pre-treatment steps.
Methods of Testosterone Replacement and Ongoing Monitoring
Once a patient is determined to be an appropriate candidate, there are several methods available for testosterone administration, each with its own schedule and delivery mechanism.
Methods of Administration
- Transdermal options include gels and patches applied daily to the skin, offering a stable daily release of the hormone.
- Injectable testosterone is typically given intramuscularly every one to three weeks, providing a potent dose but potentially leading to noticeable peaks and troughs in hormone levels.
- Subcutaneous pellets are implanted under the skin, offering the longest duration of therapy by releasing testosterone consistently for three to six months.
Regardless of the chosen method, rigorous, long-term surveillance is mandatory to ensure safety and therapeutic effectiveness. The primary safety measure is the frequent monitoring of the PSA level, the most sensitive indicator of potential prostate cancer recurrence. After starting TRT, a physician will typically check the PSA at short intervals, such as six weeks, three months, and six months, before moving to a schedule of every six months thereafter.
In addition to PSA, regular blood tests monitor the total testosterone level to confirm it is within the desired therapeutic range (often targeted toward 450–700 ng/dL). Another critical lab test is the hematocrit, which measures the proportion of red blood cells. Testosterone can stimulate red blood cell production, leading to polycythemia, which increases the risk of blood clots. Hematocrit is typically checked six to eight weeks after starting TRT, then quarterly for the first year, and twice yearly afterward.