Less invasive approaches may benefit men with prostate cancer

On behalf of her team, Sherry Chow, PhD, presented the preliminary findings from a clinical trial funded by the National Cancer Institute through the University of Arizona Cancer Prevention Clinical Trial Network (UA CP-CTNet) during the I-SCORE NCI/DCP meeting. 

The trial is examining if apalutamide, a non-steroidal androgen inhibitor medication, given at low doses to patients with clinically localized prostate cancer could lead to favorable clinical outcomes. 

Juan Chipollini, MD, leads this clinical trial in partnership with four other major centers: Johns Hopkins, University of Southern California, NCI Clinical Center, and George Washington University.  

Clinically localized prostate cancer is primarily treated through surgery or radiation therapy. Population studies suggest that a substantial proportion of men diagnosed with localized prostate cancer in the U.S. are overtreated.  

“This public health problem—unnecessarily aggressive treatment of tens of thousands of men each year who subsequently suffer chronic side effects—challenges us to develop innovative therapeutic models to refine treatment paradigms within this patient population,” Chow said.  

In recent years, active surveillance has increasingly garnered attention as an alternative, less morbid invasive approach to surgery or radiation in men with clinically localized, low-risk prostate cancer. Follow-up assessments in patients on active surveillance include serial PSA (Prostate Specific Antigen) measures, repeat prostate biopsy, and increasingly, prostate MRI.  

Most men on active surveillance followed for up to 15 years would not require treatment. However, up to one-third of active surveillance patients will undergo treatment within two to five years of initiating surveillance.  

The development of intervention strategies to prevent disease progression in patients on active surveillance thus represents a critical area of prostate cancer chemoprevention. 

“Given the critical role of androgen receptor signaling in the pathophysiology of prostate cancer, treating patients on active surveillance with an androgen receptor inhibitor may be a potential approach to prevent disease progression,” Chow said. “However, long-term, full-dose treatment may cause too many side effects.” 

The study has completed testing the apalutamide dose level that is 1/10th of the standard dose and shows that short-term intervention at this dose level leads to a significant decline in PSA levels. This dose level did not lead to significant side effects or alter the quality of life of study participants.  

The study team is enrolling participants to test the dose level 1/30th of the standard dose to determine its clinical activity. The study will help develop intervention strategies to prevent disease progression in patients with localized prostate cancer undergoing active surveillance.