Indigo Overview
Over 50,000 men relapse after surgery or radiation each year. The characteristics of Indigo are: previous treatment with surgery, radiation or cryotherapy, a clear bone scan, a normal level of testosterone in the blood, and one or more of the following:
- A rising PSA due to progressing cancer.
- Residual disease after surgery noted on a pathology report, such as a positive margin or seminal vesicle invasion.
- Residual disease after radiation or cryotherapy detected by imaging or biopsy.
- Surgically-detected or scan-detected cancer in the pelvic lymph nodes.
Low-Indigo is the situation where microscopic lymph node metastases are very unlikely. Basic-Indigo is when microscopic pelvic lymph node disease is more likely. High-Indigo means that node metastases are unequivocally confirmed by surgery or scans.
The traditional approach to Low-Indigo utilizes a sequential, one-treatment-at-a-time policy. It begins with radiation administered to the prostate fossa alone. If the cancer later resurfaces, the next step has traditionally been to start testosterone inactivating pharmaceuticals (TIP). Indigo can be controlled for a decade or more in this manner using ongoing TIP given either intermittently or continuously.
Over the last 5 to 8 years, due to improvements in radiation technology, it has become feasible to safely extend the radiation field to cover the pelvic nodes. Therefore, men with Basic-Indigo or High-Indigo are now candidates for a multimodality approach that relies on extended radiation fields, supplemental TIP, and possibly chemotherapy to improve cure rates.
ABOUT THE AUTHOR
Mark Scholz, MD is the Executive Director of the Prostate Cancer Research Institute. He is also the Medical Director of Prostate Oncology Specialists Inc. He received his medical degree from Creighton University in Omaha, NE. Dr. Scholz completed his Internal Medicine internship and Medical Oncology fellowship at University of Southern California Medical Center. He is co-author of Invasion of the Prostate Snatchers. He has authored over 20 scientific publications related to the treatment of prostate cancer.