TUESDAY, Sept. 27 (HealthDay News) -- A number of recurrent genetic errors common to advanced lethal prostate cancers have been identified by scientists who conducted the first complete genome mapping of these types of cancers.

The team also identified several instances of genetic "hypermutation," an excess of single-letter DNA errors that can give the cancers resistance to therapies commonly used to slow advanced prostate cancer, such as surgical castration and androgen-blocking drugs.

The study by researchers at the Fred Hutchinson Cancer Research Center and the University of Washington in Seattle was published in this week's online edition of the Proceedings of the National Academy of Sciences.

"The most interesting finding to come out of our DNA sequencing project was the discovery of three aggressive tumor types that had 10 times the number of mutations compared to the other advanced prostate cancers we studied," co-corresponding author Dr. Peter S. Nelson said in a research center news release.

"That was very surprising and unusual. We don't know the cause of these hypermutated tumors, but the frequency of the mutations suggests these tumors might evolve very rapidly to develop resistance to therapies," he added.

The discovery of these genetic mutations could help improve understanding of why some prostate cancers are so deadly, and could also lead to improved screening tests or treatments, Nelson suggested.

More information

The American Cancer Society has more about prostate cancer.