About 40 million US adults take statins to lower their cholesterol levels and reduce their risk of heart disease. But, these drugs may come with an added beneficial effect: protection against cancer.
Although initial animal studies indicated that statins might increase the risk of cancer, current research is showing the opposite. In a large systematic review and meta-analysis, for example, researchers showed that patients who took statins before their cancer diagnosis had a 21% lower risk of all-cause mortality and a 31% lower risk of cancer-specific mortality.
While researchers haven’t found that statins reduce the incidence of most types of cancer, statins do appear to prevent recurrence and increase survival in many cancer types. Here’s a roundup of recent research that provides evidence of statins’ preventative effect against cancer.
People with colorectal cancer tend to have improved overall survival if they’re already taking statins, researchers found. In preliminary research, investigators analyzed the medical records of 29,498 veterans with colorectal cancer. After about 5 years of follow-up, those taking statins at the time of their cancer diagnosis were 38% less likely to die from colorectal cancer and 31% less likely to die from any cause compared with those not taking statins. These benefits remained even after adjusting for factors like cancer stage and location.
Interestingly, the researchers showed that statins may work better at protecting against colorectal cancer death than against statins’ usual targets: heart attack and stroke. For instance, taking statins lowered the risk of heart attack by 9% and stroke by 23%, but reduced death from colorectal cancer by nearly 40%.
Statin use in patients with breast cancer is associated with 30% improved cancer‐specific survival, 34% improved overall survival, and 36% improved recurrence‐free survival, according to the authors of a systematic review and meta‐analysis.
However, these benefits occurred primarily with the use of lipophilic statins, not hydrophilic statins. Lipophilic statins include cerivastatin, lovastatin, simvastatin, and fluvastatin, while hydrophilic statins include atorvastatin, pravastatin, and rosuvastatin.
Why do lipophilic statins produce much greater benefits against breast cancer than hydrophilic statins? It may depend on whether statins have a direct effect on cancer cells or an indirect effect by improving cholesterol levels. Authors of another article on statins and breast cancer speculate that it’s the former mechanism: “[T]he findings that the most beneficial effects of statins accrue to those on lipophilic statins suggest direct effects on the tumor cells.”
Taking statins is associated with significantly improved survival in patients with lung cancer, researchers have reported. Specifically, statin use was significantly associated with 21% improved overall lung cancer survival, 17% improved cancer-specific survival, and 15% improved recurrence-free survival, according to the authors of a meta-analysis that included 13 studies with data from more than 99,000 individuals. Also, patients with non-small cell lung cancer who took statins had increased survival benefits than those who didn’t take statins. Moreover, statins were associated with more survival benefits in patients with stage IV lung cancer than in mixed stage (I–IV or I–III) patients.
As with other cancer types, researchers haven’t yet found a clear mechanism for how statins reduce lung cancer mortality. But, they have seen (through in vitro studies) an increase in apoptosis as well as reductions in proliferation and migration of lung cancer cells treated with statins.
Up until recently, statins have shown mixed results (or no results) in improving prostate cancer risk. But, in an analysis of medical data from more than 13,000 men, researchers found that those who took statins had a 20% lower overall prostate cancer risk compared with those who didn’t.
This association held true both for men with low-grade prostate cancer (Gleason score < 7) and high-grade prostate cancer (Gleason score ≥ 7), but men with higher Gleason scores had more pronounced reductions in prostate cancer risk. Also, the association only occurred in men who had taken statins for a relatively longer duration (≥ 11 months) or at a higher dose (≥ 121 defined daily doses). In fact, short‐term statin use (1‐10 months) was actually associated with an increased risk of prostate cancer.
As with breast cancer, only lipophilic statins were protective against prostate cancer, not hydrophilic statins.
Researchers have shown encouraging results among all statin users for the reduced risk of liver cancer. In a very recently published meta-analysis, researchers reported that people who take statins have a significantly reduced risk of hepatocellular carcinoma (HCC), the primary form of liver cancer.
This analysis included 24 studies with data from over 59,000 patients with HCC. Compared with patients not taking statins, those who did take statins had a 46% lower risk of developing HCC. The researchers also reported on patients with high-risk factors, including diabetes and liver cirrhosis. Statins were associated with a 56% reduced risk of HCC in patients with diabetes and a 64% reduced risk in patients with liver cirrhosis compared with patients not taking statins.
Notably, the researchers found that higher cumulative doses of statins were associated with greater risk reductions than lower cumulative doses of statins. Also, certain statins—fluvastatin, lovastatin, and rosuvastatin—were associated with greater reductions in HCC risk than other statins.
Ready for prime time?
Are statins ready to be prescribed as a primary drug to counter the risk of certain cancer types?
Not just yet, wrote the authors of all these articles. For now, researchers consider statins to have a beneficial side effect of cancer risk reduction. What’s needed, they say, are large, randomized, placebo-controlled clinical trials that can authoritatively determine whether statins truly prevent cancer—and to what extent and in which patients.