A New Treatment Approach for Relapsing Prostate Cancer

Photo by Siri Stafford - Getty Images
Photo by Siri Stafford - Getty Images. Photo by Siri Stafford - Getty Images

After undergoing prostate cancer surgery or radiation, about 60,000 men a year relapse with the disease; sometimes residual cancer cells are left behind. Generally, a rising PSA after prostate removal surgery is treated with radiation to the prostate fossa, the area of the body where the prostate gland was previously located.  Twenty-five percent of the time the cancer is cured with this approach.

 However, the remaining seventy-five percent of the time the radiation is not curative and treatment with lifelong hormone therapy is needed.

This article discusses a potential alternative to lifelong hormone therapy.

Hormone therapy is considered a standard treatment following relapsed disease. It is very effective, resulting in remission lasting ten or more years. However, quality of life is often poor with this therapy, due to hot flashes, tiredness, joint aches, muscle atrophy and loss of sex drive. 

What about the possibility of doing further radiation? This is a strong consideration because prostate cancer tends to progress in a fairly predictable, stepwise manner.  First, it originates in the prostate gland, gradually enlarging over time.  Second, it often spreads to the pelvic lymph nodes adjacent to the gland.  Lastly, it can spread to the bones.

Since the advent of intensity modulated radiation therapy (IMRT), the possibility of administering radiation to the lymph nodes is much more feasible.

 Previously, crude attempts blanketed the whole pelvis with radiation. A common side effect included frequent damage to the intestines, which created nasty digestive disturbances such as chronic diarrhea and intestinal bleeding.  However, with IMRT, intestinal damage can be circumvented because the radiation beam can be sculpted to target the nodes and avoid the intestines.

IMRT is an exciting new radiation technology, but has been slow to catch on as a preferred treatment.  Due to the intestinal damage from older types of radiation technology, many people fail to realize that IMRT side-steps these problems.  Also, properly sculpting an accurate radiation field to treat the pelvic lymph nodes takes skill and practice.  Administering IMRT to the pelvic nodes is a new skill that many radiation specialists have yet to develop. 

However, the discovery of new imaging technology that can detect cancer in the lymph nodes opens up an opportunity to exploit the potential for lymph-node-directed IMRT.  Lymph node imaging with Combidex and C11 PET scans enabled doctors to detect cancer in the lymph nodes with far greater accuracy than what was previously available. 

Let me illustrate with a story.  Sam was initially diagnosed with prostate cancer in 1992 at the age of 53. He underwent surgery, but 11 years later, in 2003, his PSA started to rise.  He was treated with standard radiation to the prostate fossa only.

 His PSA briefly dropped, but by 2007, in just four short years, it was 1.83.  Only a year after that in 2008, it was 7.3.  A special MRI scan utilizing Combidex detected cancerous lymph nodes extending from the pelvis up through the abdomen all the way to the diaphragm.  He was started on hormone therapy treatment with Lupron and underwent another Combidex scan in June 2009.  It showed substantial improvement but not total resolution of the cancerous nodes.  He was then administered IMRT with a field designed to cover all the cancerous nodes.  Lupron was stopped in June 2009.  In May of 2015 his testosterone was normal at 609 and the PSA was 0.060.

I consider these technologies a stunning success.  Sometimes breakthroughs simply result from repurposing an existing technology to a new capacity.  This durable prostate cancer remission, now lasting more than six years, illustrates how targeted treatment with IMRT coupled with optimal scanning technology can result in durable remissions and a freedom from dependency on lifelong hormonal therapy.

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