Metabolites may indicate aggressive prostate cancer

A panel of metabolites appear to be linked to aggressive prostate cancer, according to researchers from the University of Michigan Comprehensive Cancer Center, Ann Arbor.

The finding could lead to a simple test that would help doctors determine which prostate cancers are slow-growing and which require immediate, aggressive treatment.

“One of the biggest challenges we face in prostate cancer is determining if the cancer is aggressive. We end up overtreating our patients because physicians don’t know which tumors will be slow-growing,” said senior author Arul Chinnaiyan, MD, PhD. “With this research, we have identified a potential marker for the aggressive tumors.”

As reported in Nature (2009; 457:910-15), the researchers looked at 1,126 metabolites across 262 samples of tissue, blood, or urine associated with benign prostate tissue, early-stage prostate cancer, and metastatic prostate cancer. They mapped alterations in metabolites and identified about 10 that were present more often in prostate cancer than in the benign cells and that were present most often in the advanced cancer samples.

One metabolite in particular, sarcosine, appeared to be one of the strongest indicators of advanced disease. Levels of this amino acid were elevated in 79% of the metastatic prostate cancer samples and in 42% of the early-stage cancer samples. None of the cancer-free samples had detectable levels of sarcosine.

In the study, sarcosine was a better indicator of advancing disease than PSA. Sarcosine was detected in the urine, which suggests that eventually a simple urine test could be used. In addition, researchers found that sarcosine is involved in the same pathways that are linked to cancer invasiveness, suggesting sarcosine as a potential target for future drug development.