Embolization (the blocking of blood flow) has been applied to cancer therapies for decades. This has been particularly successful for patients with tumors of the liver and kidney. Prostate cancer has well-established, effective treatment strategies that run the gamut from watchful waiting to radiation therapy and surgery but there are specific instances where patients may benefit from the application of PAE (Prostate Artery Embolization).
Treatment strategies for prostate cancer depend on the stage of the cancer T2 vs T4 and PAE can be considered in every treatment stage in some form:
First line or salvage therapy after curative treatments
Single treatment or in combination with other modalities
Neoadjuvant (before primary cancer therapies) or adjuvant (auxillary treatment)
Palliation (bleeding, LUTS, etc. )
Let's fist discuss the application of PAE in the setting of palliation. Embolization for bleeding has been around for ages. In fact, the first successful therapeutic embolization performed for bleeding from prostate cancer was reported by a German group in 1979. This procedure, performed in a 79-year-old after multiple trans-urethral operations failed, was successful in stopping the bleeding and was not associated with any complications (1). Over time, this technique was perfected and reported numerous times (2,3). Recently, in 2017, PAE was shown to be an effective treatment alternative for patients with bleeding from prostate cancer (4). In fact, there are some who feel this therapy should be considered as first-line to control bleeding from prostate cancer over other forms of treatment such as radiation therapy.
To summarize, embolization is an effective and safe method to control bleeding from prostate cancer with a very few side-effects and should be considered first-line therapy.
Furthermore, up to 50% of men with prostate cancer will develop lower urinary tract symptoms (LUTS) secondary to an enlarged prostate. TURP carries a higher risk of complications in this patient population, above and beyond the side-effects experienced in patients without cancer. Prostate artery embolization has been demonstrated to be both safe and effective in this patient population (5). Click here to learn more about PAE for LUTS from BPH.
Now let's switch gears and discuss the role of PAE in the neoadjuvant setting. Neoadjuvant therapies are often performed prior to the primary cancer treatment to either augment primary treatment or decrease the potential risks and side-effects of that therapy. For patients with prostate cancer, primary treatment usually involves radiation therapy or SBRT. It is well-known that the risk of complications associated with prostate cancer radiation increase with increasing size of the prostate (6). Hormonal therapy or what is known as androgen deprivation therapy (ADT) is a fairly standard treatment used to shrink the prostate prior to radiation therapy. However, the treatment is associated with substantial side-effects including loss of libido, erectile dysfunction, osteoporosis (weakening of the bones), dementia, among others. Studies have demonstrated that PAE can significantly reduce the volume of the prostate (average 50% reduction in one study) without sexual side-effects, obviating the need for ADT and reducing the risk of subsequent SBRT (6).
PAE can significantly shrink the prostate without sexual side-effects, obviating the need for androgen therapy prior to SBRT for prostate cancer
Finally, what about patients who have progressed beyond first line therapy or those who did not respond as expected? This is the so-called salvage therapy application. There have been a couple of small studies looking at this application of PAE for patients with prostate cancer. These found that embolization does not kill all of the tumor and thus may not be an adequate treatment in and of itself. But then you have to ask yourself what is the goal of therapy and specifically, what is the goal of embolization? If you are a patient who has local progression despite first line therapy, and you know you can't get ride of the cancer entirely but you want to control it as best you can with minimal side-effects, then, perhaps, embolization is the way to go. Of course, more study needs to be done in this area. Similar to embolization is a therapy called chemoembolization. What is chemoembolization? It is the same type of embolization we perform for BPH, however, the beads are saturated with a chemotherapeutic drug that slowly leaks into the surrounding tumor tissue. This has been performed for decades for tumors in the liver with great success. Two years ago researchers looked at 20 patients with prostate cancer who refused either prostatectomy or hormonal therapy. These patients underwent prostate chemoembolization for their stage T2 (early) prostate cancer. They found an 80% technical success rate and an 82% biochemical success rate. A biochemical success means that the PSA dropped to below 2.0ng/ml. This biochemical response was sustained at 12-18 months in 63% of patients (8). This is an astounding success for an early study. Of course, more studies need to be performed but chemoembolization is a promising therapy for patients requiring salvage therapy or for patients with early cancer who are either unable or unwilling to undergo standard treatment regimens.
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To learn more about prostate artery embolization, visit www.utahprostatesolutions.com and to learn more about Comprehensive Integrated Care visit www.utahcic.com
References:
Intra-arterial Embolizatin of Bleeding Prostate Cancer; Urologe A. 1979
Embolization to Control Hemorrhage from Pelvic Neoplasms; Radiology 1989
Prostate Artery Embolization for Control of Hematuria in Patients with Advanced Cancer; JVIR 2017
Palliative Prostate Artery Embolization for Prostate Cancer; CVIR 2019
SBRT for Prostate Cancer in Men with Large Prostates; Radiation Onc 2014
Prostate Artery Embolization Obviates the Need for Androgen Deprivation Therapy Prior to SBRT in Prostate Cancer; JVIR 2019.
Prostate Artery Embolization in the Treatment of Localized Prostate Cancer; JVIR 2018
Safety and Efficacy of Prostate Artery Chemoembolization for Prostate Cancer; JVIR 2018