Researchers behind a new genetic study led by the University of Pittsburgh School of Medicine, PA, suggest their findings will lead to a more accurate test for aggressive prostate cancer and new ways to treat it.
Writing about their work in the American Journal of Pathology, the team explains how they found prostate cancer patients with certain genetic mutations have a 91% chance of their cancer coming back.
Senior author Jian-Hua Luo, a professor of pathology at Pitt School of Medicine who specializes in researching the genome and gene expression of cancers, and particularly how prostate cancers become invasive, says:
He suggests eventually such a finding could lead to a genetic therapy that cures prostate cancer, and adds:
“With this discovery, we’re at the tip of the iceberg in terms of possibilities for improving patient outcomes.”
Prostate cancer treatment can be worse than the disease
Prostate cancer is the second most common cancer in men (after skin cancer) and the second leading cause of cancer death in American men, behind only lung cancer.
According to the American Cancer Society, about 1 man in 7 will be diagnosed with prostate cancer during his lifetime.
However, despite this high rate of disease, few men diagnosed with it develop the aggressive type that spreads, which poses a problem for treatment, as Prof. Luo explains:
“In some cases, this can make the treatment more dangerous than the disease, so doctors need more accurate tests to tell them which patients would most benefit from aggressive therapies, such as surgery, radiation and chemotherapy.”
Study found 8 ‘hybrid genes’ or ‘fusion transcripts’ strongly linked to prostate cancer
For the study, the team sequenced the genomes of tissue samples taken from the prostates of five men whose prostate cancer recurred, and compared them with the genomes of tissue samples from men without cancer.
In the tissue of the men with prostate cancer recurrence, they found 76 hybrid genes that are often linked to cancer. After further tests, 8 of these hybrid genes were found to be strongly linked to prostate cancer.
The hybrid genes are known as “fusion transcripts” that are formed from previously separate genes. These are often linked to cancer.
The team then looked for the 8 hybrid genes in 289 prostate tissue samples from men treated at three centers, with clinical follow-up ranging from 1 to 15 years after surgery.
The analysis showed that 91% of the patients (69 out of 76) who tested positive for any of the hybrid genes experienced prostate cancer recurrence, metastases, and/or died of prostate cancer after surgery. Also, three of the hybrid genes were only found in tissue samples from patients who experienced recurrence or died from prostate cancer.
However, of the prostate cancer patients who did not carry any of the genes, only 37% (58 out of 157) experienced recurrence, metastases or died of prostate cancer.
The researchers say the findings suggest formation of the hybrid genes may underlie the aggressive behavior of prostate cancer.
Subject to successful clinical trials, Prof. Luo expects the test to be available to patients in a few years. He says there are also plans to further investigate the hybrid genes most strongly linked to prostate cancer. This could one day lead to treatments that stop the cancer by changing or stopping the mutations.
Funds for the study came from the National Institutes of Health, the American Cancer Society and the University of Pittsburgh Cancer Institute.
Meanwhile, in May 2014, Medical News Today learned about research from the University of Tampere in Finland that established the feasibility of diagnosing prostate cancer using an eNose. The team found the eNose results were comparable to those obtained from prostate specific antigen tests.
Written by Catharine Paddock PhD