Direct treatment of the primary tumor in metastatic prostate cancer appears to significantly prolong survival, a new study shows.
Researchers say the findings, which run counter to the standard approach, have prompted them 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—cancer that is contained within the prostate—has a five-year survival rate of almost 100 percent. But that number drops dramatically if the cancer is metastatic, meaning it has spread beyond the prostate. In that case, five-year survival is only 28 percent.
In the new study, published in European Urology, researchers compared the outcomes of 250 men with metastatic cancer who received direct treatment of the tumor versus the outcomes of 8,000 who received androgen-deprivation therapy without direct treatment.
Five-year overall survival among patients who received a radical prostatectomy, for example, was more than 67 percent, while overall survival of patients who did not receive surgery or radiation therapy was 22.5 percent.
“When we compared their survival, we noted that patients who had definitive treatment of the primary tumor had significantly improved survival compared to those who didn’t,” says urologist Stephen H. Culp of the University of Virginia Cancer Center. “Even when we separated it based on the stage of metastatic disease, you still saw that survival advantage.
More study needed
“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 researchers note in their paper that this is the first large, population-based analysis, to their knowledge, to find that prostatectomy and other primary treatments of the prostate can increase lifespan. The study does not address the best form of direct treatment for extending survival.
The authors stopped short of advocating that direct treatment become the norm, but instead emphasized the need for clinical trials to determine effectiveness and identify the patients most likely to benefit.
They acknowledge there were limitations to their review—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 says. “We need to organize trials to figure out whether this is real.”
Researchers from Eastern Virginia Medical School contributed to the study.
Source: University of Virginia