Do "star drugs" such as statins cause cancer? Don't believe it.

Produced by: Science Popularization China

Produced by: Ho Chu-wai (Health Scholar)

Producer: Computer Network Information Center, Chinese Academy of Sciences

"Statins can cause cancer... You don't need to take them..."

This is a suggestion made by a doctor to a patient in a short video on a certain platform. The author of the video has a certain influence on the online platform. After the video was released, it caused a lot of controversy and many netizens questioned the safety of the drug.

Statins are not unfamiliar to patients with cardiovascular and cerebrovascular diseases. As lipid-lowering drugs, statins have been used clinically for more than 20 years. Many patients who are currently using statins feel panicked when they hear that they cause cancer, fearing that the side effects of "statins causing cancer" will damage their health.

Image source: pixabay

Are statins safe? Do they cause cancer? Can patients with cardiovascular disease continue to take statins?

What kind of “star drug” is statin?

High cholesterol may induce cardiovascular disease. In the mid-20th century, scientists were very curious about the biosynthesis mechanism of cholesterol. Researchers found that hydroxymethylglutaryl coenzyme A reductase is a key enzyme in the cholesterol synthesis process. In other words, if a substance that inhibits this reductase can be found, cholesterol can be controlled and cardiovascular disease can be treated.

Image source: veer gallery

In 1976, Akira Endo of the Japanese medical community successfully isolated and extracted a substance called mevastatin from Penicillium citrinum that inhibits the active ingredient of hydroxymethylglutaryl coenzyme A reductase. This drug did not perform well in clinical trials and also had a clear carcinogenic effect on experimental dogs. However, its discovery still encouraged researchers to explore other statins.

Since then, lovastatin, simvastatin, pravastatin, fluvastatin, and atorvastatin have been launched one after another. In 2008, the sales of statins accounted for 5.5% of the total sales of the global pharmaceutical market, and statins became the "traffic star" in the pharmaceutical industry.

Do statins really cause cancer?

At present, statins are the first-line drugs for the prevention and treatment of cardiovascular diseases. They are cost-effective, well tolerated, and have few side effects. In 2020, the international authoritative medical journal "The New England Journal of Medicine" published a clinical study that found that side effects of statins (such as muscle soreness) were uncommon and were no different from taking a placebo. Although studies have found that statins may slightly increase the incidence of diabetes, their overall health protection effect is still very high, and clinical medication guidelines in various countries list them as the first choice of drugs. At the same time, the clinical research reports on adverse reactions did not mention the "possible carcinogenicity" content. So, is this statement groundless?

In the long-term research, experts have been paying close attention to the safety and effectiveness of statins, and have conducted various special studies on their carcinogenicity. At least, judging from the current research results, the claim that "statins cause cancer" is unreliable, and this claim is likely due to a misunderstanding of the research results.

In 2011, the Chinese Journal of Cardiology published an article titled "No clear evidence suggests that statins increase cancer risk." The article pointed out that concerns about statins causing cancer first came from epidemiological studies and animal experiments. That is, the statins mentioned in the previous article have a clear carcinogenic effect on experimental dogs in clinical trials, but there is no scientific data to support the claim that they increase the risk of cancer in patients. Not only that, because statins can inhibit the production of isoprene products (which can promote cell proliferation), statins theoretically have anti-cancer effects.

In July of the same year, the American Journal of Cardiology published a study finding that statins do not increase the risk of malignant tumors. In this study, scholars conducted a five-year experiment and found that the cancer incidence rates of participants taking statins and those not taking statins were 11.37% and 11.11%, respectively, with no significant difference between the two. Dr. Stanley Rockson, a cardiologist at Stanford University School of Medicine, said that the scale of this study was unprecedented and the conclusions were convincing and definitive.

However, as the saying goes, "All medicines are poisonous", it is very necessary to use medicines correctly and safely under the guidance of a doctor.

Can cardiovascular patients continue to take statins?

Let's talk about the effectiveness of statins. In 2016, the U.S. Preventive Task Force published a systematic review report on statins. This report conducted a meta-analysis of data from 71,344 cardiovascular and cerebrovascular patients aged between 51 and 66 years old. The results of the study showed that statins can effectively reduce the mortality rate of patients with cardiovascular disease. The results of this study provide strong data support for the therapeutic effect of statins.

The efficacy and safety of statins are of particular concern to the elderly due to the higher risk of treatment. In February 2019, The Lancet published a study of 14,483 participants aged 75 and over, which found that for every 1.0 mmol/L reduction in LDL cholesterol caused by statins, the probability of major cardiovascular events was reduced by 24%. This proportion decreases slightly with age, but the research data still supports the efficacy of statins. Experts also found that statin treatment had no effect on cancer mortality or cancer incidence.

Statins are also widely used in the primary, secondary, and tertiary prevention of cardiovascular diseases. The efficacy of statins has been scientifically proven in long-term research and clinical practice.

This is not the first time that statins have been questioned. In 2013, BMJ published two articles on the possible adverse effects of statins in low-risk groups. Within 6 months of the publication of the articles, more than 200,000 patients panicked about these remarks and chose to stop taking statins. These patients need to take statins as directed by their doctors to control low-density lipoprotein cholesterol (lower blood lipids). Some scholars predict that if these patients stop taking statins, 2,000 patients may suffer cardiovascular events in the next 10 years due to failure to effectively control blood lipids.

Afterwards, the authoritative journal The Lancet published a scientific review, arguing that the two papers published by BMJ exaggerated the side effects of statins and "vindicated" them. The British independent investigation team eventually asked BMJ to withdraw the article, and the article was published again after revision.

In recent years, the number of people suffering from cardiovascular diseases in China has increased, and the mortality rate has remained high. A research report estimates that the number of people suffering from cardiovascular diseases in my country has reached 330 million in 2019. Patients have an increasing demand for drugs to treat cardiovascular diseases, and they are paying more and more attention to the safety of drugs.

Changes in cardiovascular disease mortality among urban and rural residents in China from 1990 to 2017

Image source: China Cardiovascular Health and Disease Report 2019

With the popularization of the Internet, people have more ways to access information, but the reliability of information sources has been greatly reduced. The public needs to be vigilant about the one-sided and arbitrary interpretation of information on the Internet, believe in scientific research results, and use medicines correctly and safely under the guidance of doctors.

It is also very important for professionals to be cautious in their communications and avoid causing misunderstandings among the public.

References

[1]. China Cardiovascular Health and Disease Report 2019[J]. Journal of Cardiopulmonary and Vascular Diseases, 2020, 39(10): 1157-1162.

[2]Golder Su, O'Connor Karen, Hennessy Sean, Gross Robert, Gonzalez-Hernandez Graciela. Assessment of Beliefs and Attitudes About Statins Posted on Twitter: A Qualitative Study.[J]. JAMA network open, 2020, 3(6).

[3] Cholesterol Treatment Trialists' Collaboration. Efficacy and safety of statin therapy in older people: a meta-analysis of individual participant data from 28 randomized controlled trials[J]. Lancet, 2019,393(10170): 407-415.

[4]Fiona Godlee. Lessons from the controversy over statins[J]. The Lancet,2017,389(10074).

[5] R. Chou, T. Dana, I. Blazina, M. Daeges, TL Jeanne. Statins for Prevention of Cardiovascular Disease in Adults: Evidence Report and Systematic Review for the US Preventive Services Task Force[J]. Journal of Vascular Surgery, 2017, 65(3).

[6]Iwere RB, Hewitt J. Myopathy in older people receiving statin therapy: a systematic review and meta-analysis. Br J Clin Pharmacol 2015; 80: 363–71

[7] Chen Hong, Ren Jingyi. There is no definitive evidence that statins increase the risk of cancer [J]. Chinese Journal of Cardiovascular Diseases, 2011(03):196-198.