Prostate cancer may be the most common cancer in American men, but its course remains difficult to predict. In some men, the disease lies dormant for many years, never displaying ill effects, while in others, tumors rage in spite of treatment, spreading to the bones, where a cure is exceedingly rare.
Identifying new, more precise ways to individualize care for the disease's varied forms is one of the major challenges confronted by the Hutchinson Center's Dr. Peter Nelson.
"Does a man have the kind of cancer that is lethal versus the kind of cancer where you say, 'Well, we found a cancer, but you don't need to worry about this?'" said Nelson, who also serves as principal investigator of the Pacific Northwest Prostate Cancer SPORE, a multicenter research consortium.
Studies have shown that if a man lives long enough, he is almost certain to develop prostate cancer. But in the vast majority of men, these cancers turn out to be the indolent kind, Nelson said. For these men, traditional treatment that may cause incontinence or impotence may not be the best course of action.
By working to identify genetic or molecular hallmarks of prostate tumor cells, Nelson and his colleagues hope to determine which patients would benefit simply from close observation, and which patients require more aggressive treatment.
After observing that many clinical trials don't address specific reasons why treatment approaches fail, Nelson sought to fill that gap by delving into the makeup of tumor cells. Through this analysis, he aims to determine why prostate cancers develop, why therapies often become ineffective over time, and why there's so much variability in responses among patients. He's also working to better understand the role of aging and male hormones, such as testosterone, in prostate cancer development.
"Not every tumor looks the same," Nelson said. 'There are many ways for a normal prostate cell to evolve to become a cancer cell and ultimately develop resistance to therapy."
One major goal is to identify molecular markers in the body that indicate which prostate tumors are destined to be aggressive. Known as biomarkers, these molecules could one day form the basis for a more precise early cancer detection test.
Nelson's lab has already identified some promising biomarker candidates through clinical trials in men diagnosed with lower-risk cancers. He plans to expand these studies to include other factors, such as dietary and lifestyle changes and drug interventions, that may also influence the disease's progression.
"From just about every angle prostate cancer is a fascinating disease to study," Nelson said. "It also has major societal implications because it's so common."