Cancer patients taking cholesterol-lowering statin drugs were 15 percent less likely to die of cancer, or of any other cause, than patients who were not on the popular medications, according to a Danish study.
The study, which appeared in the New England Journal of Medicine, did not look at whether the statins can prevent cancer, only at what happens once cancer is diagnosed.
But the pattern held regardless of a person's age, cancer type, tumor size or whether it had spread. Only patients who had received chemotherapy showed no apparent benefit from taking statins, the most commonly-prescribed drugs in the world.
"Statin use in patients with cancer is associated with reduced cancer-related mortality," wrote study leader Stig Bojesen, of the University of Copenhagen, and colleagues.
Using multiple registries containing data on cancer, drug use, population characteristics and deaths for the nation of Denmark, the research team analyzed the cancer cases of 18,721 people over 40 who were diagnosed between 1995 and 2007.
All were taking statins regularly before their cancer was discovered, and the study compared them to 277,204 people who had not regularly taken the drugs before getting cancer treatments.
Overall, the cancer death rate among statin users was 15 percent lower, and so was the rate of death from any cause.
The appearance of a benefit from taking statins was strongest for 13 cancer types in particular, ranging from an 11 percent lower death rate among pancreatic cancer patients to a 36 percent lower rate among cervical cancer patients. For 14 other tumor types, the results were less clear-cut.
"The benefit of receiving chemotherapy versus not receiving chemotherapy is 15 percent to 20 percent, depending on cancer type," Bojesen told Reuters Health. "What we see (in the new study) is comparable to that. That's really something."
The fact that the seeming benefit from statins was not seen in people taking chemotherapy doesn't mean that people should avoid chemotherapy treatment and turn to statins instead, Bojeson stressed.
Rather, he thinks therapeutic use of statins might be considered when no good chemotherapy option is available for a certain cancer type.
Bojesen speculates that the drugs may be robbing cancer cells of an important building block of cell membranes, thereby slowing tumor growth.
"Our hypothesis is that by reducing cholesterol, you steal cholesterol from the proliferating cancer cells ... improving survival," he said.
But there is cause for skepticism. People who took less than the recommended dose of a statin had a higher rate of survival than those who took higher doses.
Other researchers said there was no information in the study about things such as smoking, as well as no information on treatment with radiation and chemotherapy for 72 percent of the people taking statins. They also note there could have been other causes for increased survival than the statins.
Eric Jacobs, a researcher at the American Cancer Society who was not involved in the study, called it "intriguing and exciting" but added that they "do not mean that people with cancer should start using statins in hopes of improving.