CHICAGO—Giving radiation and chemotherapy before radical prostatectomy (RP) is safe and could reduce the risk of cancer recurrence and mortality in high-risk patients, according to researchers.
“In men with aggressive prostate cancer, standard therapies such as radiation or surgery often fail to eliminate the cancer completely at the site of treatment. When these cancers recur, they are often fatal,” said principal investigator Mark Garzotto, MD, Associate Professor of Urology and Radiation Medicine at Oregon Health & Sciences University in Portland. “Novel approaches are needed if we are to make advances in this disease.”
Previous clinical trials examining the effect of either hormonal therapy or chemotherapy prior to RP have shown little, if any, benefit over prostate removal alone. Multimodality therapy—a combination of radiation, chemotherapy, and surgery—has resulted in improved outcomes in a number of tumor types, but has not yet been studied in prostate cancer, Dr Garzotto noted. The study by him and his colleagues is the first to examine this multimodal treatment in prostate cancer.
He and his colleagues enrolled 12 men with aggressive prostate cancer. All received intensity-modulated radiation therapy and increasing doses of docetaxel for five consecutive weeks, which was followed by RP. All subjects tolerated the treatment well and could undergo surgery without any major complications, a potential concern in this trial.
They also studied the effect of this treatment on serum testosterone levels, as this can affect important oncologic end points. “We didn’t see any changes in the testosterone levels, which are important when interpreting PSA values and surgical margin status,” Dr. Garzotto said. “We didn’t incur any rectal injuries, ureteral injuries, wound complications or deep vein thromboses. The average length of hospital stay was three days, which was average for this type of surgery. The negative surgical margin rate was 75%, which is very positive. Normally, in this patient population you would expect about a 50% [negative] margin rate.” In addition, PSA levels were undetectable after treatment in all 12 patients. This treatment regimen is undergoing further evaluation in an ongoing phase 2 study.
The researchers reported their findings here at the American Society for Radiation Oncology annual meeting.
A Phase 2 study is underway and will include approximately 30 patients. Dr. Garzotto and his colleagues said the current study findings are important and should be of particular interests to urologists who routinely counsel men with high-risk prostate cancer.