Prostate Cancer Recurrence

Despite the best of treatments, prostate cancer can still return even years or decades later. It’s able to lie dormant and undetectable for many years and come back long after a “successful” treatment — an ability somewhat unique to prostate cancer. Most frequently, these dormant cancer cells quietly spread, moving to hide in the bone marrow. Here, as long as they lay low, they’re usually never found at first.

Unfortunately, for almost one-third of prostate cancer patients, the disease may return even after successfully completing treatment. Luckily, it’s easily caught as long as your prostate-specific antigen (PSA) levels remain regularly monitored after treatment completion. A spike in PSA levels would raise alarms of a possible recurrence, carrying a higher risk of cancer spreading beyond the prostate, and death.

However, there still remain limitations in relying on PSA as a gauge. Even benign growth of the prostate may raise false alarms. As such, it’s critical that your doctor continues to balance between the risks of restarting new treatments and the chances of your cancer making an aggressive return.

When it comes to checking your PSA levels after successfully treating prostate cancer, it can depend on your risk of recurrence and personal preferences. The National Comprehensive Cancer Network recommends monitoring every 6 to 12 months for the first five years, followed by annual screening after that. However, if you were previously at high risk (e.g. clinical stage T3, PSA level above 20 ng/mL or Gleason score of 8 and above), undergoing post-treatment screening every three months would be recommended.

If there is no evidence yet of metastasis beyond the prostate, your doctor may recommend active surveillance before considering further treatment. Identifying your risk of aggressive disease and severe spread is important at this point. A good predictor of this is PSA doubling time, a measure of how long it takes for your PSA level to increase to twice the level of your last test. The longer it takes, the better. In particular, it helps your doctor to estimate how fast your cancer is spreading. This is important as the risk of death and spread beyond the prostate increases significantly for those with short PSA doubling times below 9 months.

Depending on your situation, treatments for recurrent prostate cancer available include:

• Externally-delivered radiation therapy

If you have already undergone prostatectomy, you can consider externally-delivered radiation therapy. Following up your treatment with radiation therapy has a chance to eliminate the recurrence, and will help delay the need for stronger treatments in the long term (e.g. androgen deprivation therapy). It should be noted that this is most effective only if your PSA levels are below 1 ng/mL. This treatment can also be combined with androgen deprivation therapy to reduce the amount of radiation required.

• Prostatectomy

If you underwent externally-delivered radiation therapy as your first round of treatment, you can consider surgical removal of the prostate as a potential follow-up treatment. This will work best if your cancer has not yet spread.

If you do not wish to proceed with surgery, and your original treatment was externally-delivered radiation therapy, other options include:

• Cryotherapy

Cryotherapy for prostate cancer subjects cancer cells to extreme cold in order to destroy them.

• High-intensity focused ultrasound (HIFU)

HIFU treatment for prostate cancer utilizes high levels of ultrasound to target and kill prostate cancer cells.

• Brachytherapy

Brachytherapy delivers radiation directly into your tumor, while avoiding the healthy tissues surrounding it. There are two types, known as low-dose rate brachytherapy and high-dose brachytherapy.

• Androgen deprivation therapy

While this option can be considered, there are conflicting options on whether it is worth it to continue androgen deprivation therapy after prostate cancer recurrence. Despite it being the first option for treating advanced prostate cancer, it is associated with many detrimental side effects that may worsen your quality of life. These can include depression, fatigue and difficulties with sexual function.

Your doctor will therefore need to assess whether this treatment is right for you, according to your risk for advanced prostate cancer. Alternatively, intermittently delivered androgen deprivation therapy may be considered to delay your cancer’s progression while avoiding the negative side effects associated with the full treatment.