New Marker Identified for Staging Prostate Cancer

Clinicians soon may have a new tool for staging prostate cancer and predicting survival. Investigators at Indiana University School of Medicine are reporting in the May 14, 2015 online edition of the journal Cancer Cell, that the protein transforming growth factor beta (TGF-beta) is involved in metastatic prostate cancer. In addition, they have found that the transforming growth factor beta receptor 1 (TGFBR1) inhibitor SD208 may effectively reduce prostate cancer bone metastases.^{1, 2}

The researchers report that TGF-beta upregulates in prostate cancer cells a set of genes associated with cancer aggressiveness and bone metastases. They also report that the most upregulated gene is prostate transmembrane protein, androgen induced 1 (PMEPA1). To investigate the clinical significance of PMEPA1, the researchers compared its presence in normal tissue to primary tumors. They found the gene was active in prostate, breast, and lung cancer tumors. The opposite was true of TGF-beta, which led the researchers to determine that the presence of TGF-beta regulates the activity of PMEPA1.

Senior study author Theresa Guise, MD, who is with Indiana University School of Medicine in Indianapolis, said when comparing data on patients with prostate or breast cancer, the team found those with low amounts of PMEPA1 developed metastases faster and had shorter survival. She said by inhibiting TGF-beta, it may be possible to stop the spread of prostate cancer to the bone and increase survival.  In addition, Dr. Guise said the presence of PMEPA1 may serve in the future as a diagnostic tool to predict the likelihood of prostate cancer metastases and serve as an indicator of survival, similar to the Gleason score and prostate-specific antigen (PSA) levels.

Lead study author Pierrick Fournier, PhD, who is with the Center for Scientific Research and Higher Education at Ensenada (CICESE), Baja California, México, said these new findings could make a difference in how prostate cancer is treated in the future. He said the unknown qualities of prostate cancer frequently lead to aggressive treatments that are unnecessary. However, Dr. Fournier said this new marker could help better guide treatment and help improve patients’ quality of life.

Prostate cancer is the second most common cancer among men, according to the American Cancer Society. It estimates that 220,800 new cases of prostate cancer are diagnosed annually in all age groups and that 27,540 men succumb to the disease each year. When diagnosed in the early stages, prostate cancer is often successfully treated. However, in advanced stages, metastasis to the bone is common and often incurable.³

References:

• Indiana University School of Medicine. (2015). Researchers focus on potential tool for predicting survival, staging prostate cancer in Cancer Cell.
• Fournier P, Juarez P, Jiang G, et al. (2015). The TGF-β Signaling Regulator PMEPA1 Suppresses Prostate Cancer Metastases to Bone. Cancer Cell.
• American Cancer Society. (2015). What are the key statistics about prostate cancer?