Might Statin Use Lower the Risk of Death from Prostate Cancer?

By Scott Baltic

NEW YORK (Reuters Health) - In patients with prostate adenocarcinoma, postdiagnosis statin use was associated with reduced mortality both from prostate cancer (PC) and from all causes, according to a nationwide registry study from Denmark.

The researchers identified 31,790 patients with PC (median age at diagnosis, 70); 21% used statins during the first year after diagnosis.

During a median follow-up of 2.8 years, 7,365 patients died of PC and 11,811 died of other causes, according to the online August 14 report in the Journal of Clinical Oncology.

Men who used statins after PC diagnosis had a 17% lower risk for PC mortality and a 19% lower risk for all-cause mortality, compared with nonusers of statins. Both differences were statistically significant.

No evidence of a dose-response relationship between post-diagnosis statin use and mortality risk was found.

The authors conclude that the study “adds to the increasing evidence that statin use is associated with reduced PC mortality,” but they caution that no causal association has been established.

“Our study is the largest registry-based study investigating the association between statin use and prostate cancer mortality,” using data on all Danish PC patients diagnosed from 1998 to 2011, corresponding author Dr. Signe Benzon Larsen, of the Danish Cancer Society Research Center, Copenhagen, told Reuters Health by email.

The authors mention in their report that there is less use of PSA testing in Denmark, so that Danish PC patients “likely presented with, on average, greater tumor burden than patients in other Western countries.” Nevertheless, they “observed substantial reductions in PC-specific mortality, which may strengthen the assumption that statin use may have a beneficial influence on the outcome of PC.”

Dr. Benzon Larsen noted that statins can affect cancer growth in many ways, mainly by lowering the level of cholesterol, a building block for androgens. A lower androgen level could affect the growth of tumor cells, especially in hormone-sensitive organs like the prostate.

Given this connection, she added, “We need to look deeper into the effect of statins in well-defined groups of prostate cancer patients to explore who would benefit the most by adding statins to primary treatment.”

If statins are ultimately shown by clinical trials to have an effect, Dr. Larsen concluded, “they would most likely be introduced in clinical practice, because they are cheap, have few side effects, and are already approved by the health authorities.”

In an editorial accompanying the report, Dr. Lorelei A. Mucci, of the Harvard T.H. Chan School of Public Health, Boston, and Dr. Philip W. Kantoff, of Memorial Sloan Kettering Cancer Center, New York, praised the study’s “considerable statistical power.”

This study and earlier ones with similar findings, they write, “point toward a substantial salutary effect associated with statins,” especially in view of the cost and toxicity of other drugs used to treat advanced PC.

Mucci and Kantoff note that the consistency of the statin-PC association across populations in multiple epidemiologic studies means that “chance as an explanation of the findings can likely be ruled out.”

This study “is large and well-designed, and the finding of lower risk of cancer death among prostate cancer patients who used statins has been reported in some previous studies,” Eric Jacobs, strategic director of pharmacoepidemiology at the American Cancer Society, Atlanta, told Reuters Health by email. “However,” he added, “this study does not provide enough evidence to recommend that men with prostate cancer use statins specifically to lower their risk of dying from prostate cancer.”

Because the study was not randomized, he said, “It is difficult to determine with confidence whether statins actually prevented some deaths, or whether prostate cancer patients taking statins had a lower risk of dying for some other reason.”

“Evidence from a randomized trial will be needed before statins can be recommended as therapy for prostate cancer,” Jacobs concluded. “The new Danish study provides additional justification for starting such a trial.”

SOURCE: https://bit.ly/2xwM1qO

J Clin Oncol 2017.

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