Study Questions Accepted Treatment for Prostate Cancer
Findings ignite impassioned debate
Contrary to the standard approach to treating metastatic prostate cancer, direct treatment of the primary tumor appears to prolong survival significantly, a new study by researchers at the University of Virginia School of Medicine and the Eastern Virginia Medical School suggests. The surprising findings have prompted the researchers to launch clinical trials that could upend the accepted treatment of the disease.
Prostate cancer is the most common form of cancer in American men and the second-leading cause of cancer death in men. Localized prostate cancer has a 5-year survival rate of almost 100%. But that number drops dramatically if the cancer is metastatic. In that case, the 5-year survival rate is only 28%.
In the new study, the researchers compared the outcomes of 250 men with metastatic prostate cancer who received direct treatment of the tumor with the outcomes of 8,000 men who received androgen-deprivation therapy without direct treatment.
The results, published in European Urology, defied conventional wisdom on how best to treat the disease. Five-year overall survival among patients who received radical prostatectomy, for example, was more than 67%, whereas the overall survival rate in patients who did not receive surgery or radiation therapy was only 23%.
“When we compared their survival, we noted that patients who had definitive treatment of the primary tumor had significantly improved survival compared with those who didn’t,” said Dr. Stephen H. Culp, a urologist at the University of Virginia Cancer Center. “Even when we separated it based on the stage of metastatic disease, we still saw that survival advantage. Based on this, we can formulate the hypothesis that treatment of the primary tumor does affect survival in patients with metastatic prostate cancer, and therefore trials should be initiated to further examine this as an option for metastatic prostate cancer.”
The new findings have ignited an impassioned debate in the medical community, prompting multiple editorials in response.
In their paper, the researchers noted that, to their knowledge, this is the first large, population-based analysis to find that prostatectomy and other primary treatments of the prostate can increase a patient's lifespan. The study did not address the best form of direct treatment for extending survival.
The authors stopped short of advocating that direct treatment should become the norm, but instead emphasized the need for clinical trials to determine its effectiveness and to identify the patients most likely to benefit from it. They acknowledge that their review had limitations — such as a lack of information on whether the patients had other medical conditions that could have affected mortality — that necessitate further investigation.
“We’re not suggesting everyone drop the existing approaches and do this,” Culp said. “We need to organize trials to figure out whether this is real.”
To that end, the University of Virginia has launched a trial to further the pioneering research.
Source: University of Virginia; March 11, 2014.