LOS ANGELES – Men who were on statins when given radiotherapy for prostate cancer were significantly more likely to be disease free 10 years later, said researchers who reviewed 871 patients treated from 1994 to 2000 at a New York City cancer center.
Based on prostate-specific antigen levels, 76% of statin users, but only 66% of men who did not take the cholesterol-lowering drugs, were relapse free, Dr. Michael J. Zelefsky, lead author, reported at the annual meeting of the American Society for Therapeutic Radiation and Oncology.
The greatest benefit was seen in 221 men with high-risk disease, who were threefold more likely to have long-term biochemical control and to be free of distant metastases if they used statins.
“These results … will have to be tested carefully,” cautioned Dr. Zelefsky, a radiation oncologist at Memorial Sloan-Kettering Cancer Center, where the study was conducted. “We still don't know … the appropriate duration of taking these medications, or the appropriate dose, or which particular statin is more beneficial.”
That statins can lower risk of heart disease is well established. Dr. Zelefsky said the team conducted the retrospective study because published studies had suggested statins also may have an apoptotic effect, may act as a radiation sensitizer, and may reduce cancer risk.
They selected patients with T1c-T3 prostate cancer who received high-dose radiotherapy, 75.6-86.4 Gy, at Memorial Sloan-Kettering during the study period. A records review determined that 168 men, 19%, used statins and 703 men, 81%, did not. The population had been followed for a median of 7 years. PSA relapse was defined as nadir +2.
Overall survival was not significantly different at 10 years, with 78% of the statin users and 71% of the nonusers still alive. All told, 72% of the entire population lived 10 years.
Introducing Dr. Zelefsky at a press briefing, Dr. Anthony Zietman, professor of radiation oncology at Harvard Medical School, Boston, said cancer treatment is “not just about the therapy and the cancer–it's about the environment. … We are treating the patients with whatever they are putting inside their body. By the time a man gets to 70 years of age, he is almost certainly taking at least one prescription medication. That prescription medication interacts with our therapy.”
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