Can an annual physical examination really help you “detect cancer early”?

Most people regard routine annual physical examinations as a company benefit with no disadvantages. But in fact, existing data show that this benefit does not bring real benefits to your health, but may bring certain harms, and the so-called "high-end physical examinations" are no exception.

Written by Li Changqing (Doctor of Medicine, practicing physician in the United States)

Routine annual physical examinations have always been treated as an important part of life and are one of the main benefits of many units and institutions. Many people regard annual physical examinations as a must-have service like annual car inspections, believing that annual health examinations can help maintain good health, detect early signs of disease and intervene.

But in reality, statistics show that the benefits of annual wellness exams are unclear.

Weak evidence to support benefits of annual checkups

The idea of ​​annual physical examinations dates back to the 1920s, initially driven by the development of the recruitment and insurance industries, but doubts about its benefits have never ceased.

The landmark event occurred in 2015, when two professors of internal medicine from well-known medical institutions wrote an article in the New England Journal of Medicine, calling for the cancellation of annual physical examinations. Prior to this, another professor of medicine also wrote an article in the New York Times expressing similar views.

Their basis comes from some comprehensive studies, one of which is a systematic review of the Cochrane Database of Evidence-Based Medicine. This review was published in the British Medical Journal in 2012. The authors analyzed 16 randomized controlled studies on people who received regular physical examinations and those who did not, and found that annual physical examinations had no significant effect on the overall health status and mortality of the population. Statistically, this type of study often uses the risk ratio. If the value is 1, it means there is no effect; greater than 1 means increased risk, and less than 1 means reduced risk. Comprehensive analysis shows that the impact of annual physical examinations on overall mortality, cardiovascular disease mortality, and cancer mortality is basically 1. Some studies have also compared data such as disability rate, hospitalization rate, and absenteeism time, and found that whether or not to participate in annual physical examinations has no significant effect.

The above research results may go against the intuition of many people, and there will inevitably be many people who do not believe it, including ordinary people and medical workers. Almost everyone can cite one or two contrary examples, such as someone who was found to have high blood pressure, diabetes or even cancer during an annual physical examination and received timely treatment, and some may have saved their lives. However, the effectiveness of health care measures involving the entire population can never be based on individual experiences, but on statistical data. Maybe some people do benefit from physical examinations, but such events are insignificant compared to the total number of people undergoing physical examinations, and are not enough to significantly change the overall health data.

We can micro-analyze the impact of annual physical examinations on several diseases and causes of death. Cardiovascular and cerebrovascular diseases, which are the leading cause of death, are actually not discovered through physical examinations in asymptomatic people. Professional organizations, including the American Academy of Family Physicians, do not recommend routine electrocardiograms and cardiovascular and cerebrovascular imaging examinations for asymptomatic or non-high-risk patients. Studies have found that compared with non-physical examinees, people who participate in annual physical examinations have a higher diagnosis rate for high-risk factors for cardiovascular and cerebrovascular diseases such as obesity and the three highs (high blood pressure, high blood sugar and high blood lipids), but this has not translated into actual health benefits.

However, some other studies have not found the value of routine physical examinations in detecting high-risk factors for cardiovascular and cerebrovascular diseases. For example, a Danish study involving 1,104 people found no difference in the diagnosis of hypertension, hyperlipidemia and diabetes between the physical examination group and the routine group.

Cancer is the leading cause of death after cardiovascular and cerebrovascular diseases, but annual physical examinations do not play a significant role in reducing cancer deaths. Some cancers are already in the late stages when they are discovered during physical examinations, such as pancreatic cancer. For such patients, physical examinations are just to let them know that they have cancer in advance, and will not increase their life expectancy (for details, see "Some cancer screenings are useless or even harmful" and "Reflections on early cancer screening: Statistical biases "create" exaggerated effects").

There are also some other types of diseases, like most cancers, that lack effective intervention and treatment measures even if they are discovered during physical examinations. For example, Alzheimer's disease-related deaths rank fifth among causes of death in the United States, but there is still a lack of effective treatment options.

There are also some health issues that are clearly not solved by annual physicals. As the New York Times article points out, unintentional injuries are the fourth leading cause of death in the United States, and suicide is the tenth, and deaths from these two causes are obviously impossible to prevent through annual physicals.

Physical examination is also an opportunity for patients and doctors to communicate with each other and for doctors to provide health advice to patients, such as quitting smoking, controlling weight, and exercising properly. However, clinical practice shows that the effect of such communication is very limited. Almost all patients understand and agree on the harm of smoking, but only a small number of them will follow the doctor's advice to quit smoking. The effects of most other health advice are similar.

Considering the huge amount of money and manpower spent on annual physical examinations, this ineffective practice is likely to occupy medical resources from other patients who are in greater need of help.

The overlooked "side effects" of annual physical examinations

The content of annual physical examination generally includes doctor's consultation, physical examination, laboratory tests, and some imaging examinations. Some studies combined with doctors' experience have found that many abnormal results found in people without symptoms are false positives. However, these false positive results often lead to more examinations and unnecessary treatments, even including surgery, and will cause unnecessary additional psychological pressure on people.

Take the tumor markers recommended by many physical examination institutions as an example. If a positive tumor marker is considered to indicate cancer, it will inevitably lead to a radiological examination or a biopsy. A positive result of such an examination will inevitably make the examinee nervous - but in fact, the current test results for tumor markers do not explain anything at all (see "Tumor marker screening is popular in physical examinations, none of which has been approved but has become popular").

Another example is electrocardiogram. Some asymptomatic people's electrocardiogram changes often have no clinical significance, but they may lead to further coronary angiography, which may lead to the discovery of coronary artery stenosis. However, many mild to moderate stenosis do not cause symptoms and do not require treatment. Such examinations are likely to bring only risks but no benefits.

This issue has been studied both at home and abroad (see the literature link at the end of the article for details). A 2014 survey by the University of Missouri in the United States found that in 139 coronary angiography examinations, 62 of them did not find abnormalities due to misinterpretation of the electrocardiogram during the primary examination. This is still the case in cardiology departments that have a relatively strict grasp of the indications for coronary angiography. Some institutions that have just started coronary angiography technology and are eager to increase the number of coronary angiography examinations may have more such cases.

It is not uncommon for normal annual checkups to provide a false sense of security, so that patients do not seek medical attention when they have symptoms.

As an ordinary individual, we can roughly understand the results of big data statistics in this way: if you accept annual routine checkups, there is a small probability that you can find health problems that can be effectively intervened in time, and there is another small probability that you can find diseases that cannot be effectively intervened in advance; at the same time, there is a high probability that you will find "problems" that require you to go for further examinations, and there is also a considerable probability that you will find diseases that you don't need to pay attention to, but once you find them, it is difficult for you to rationally decide to refuse treatment. Of course, there is also a certain probability that you find nothing wrong during the examination, but there are actually problems in your body. In this case, you may be careless because of this false negative result and ignore the initial symptoms that should have caused vigilance.

Do high-end physical examinations really have special “effects”?

The concept of physical examination in maintaining health, detecting early cancer and timely treatment is deeply rooted in people's minds. Capital has also taken a fancy to this market, and some investments are positioned as so-called high-end physical examinations. So what exactly is a high-end physical examination and what is its value? We can analyze it from several aspects.

As a medical practitioner, I do not agree with the concept of high-end physical examinations. It is impossible to distinguish between so-called high-end and low-end in medicine. Even though people’s access to medical and health services is unequal due to social status, economy and culture, this does not negate the principle of fairness in health and medical care. Physical examinations are a special part of health and medical services. An important feature is their popularity. Everyone has the right to undergo a special physical examination at a certain stage, and fairness is even more important for physical examinations. In this sense, the concept of high-end physical examinations goes against the principle of fairness in medical care.

However, in a commercial society, if there are people willing to sell and people willing to buy, as long as it is not illegal, it can be opened. The question is, do the so-called high-end physical examinations really have the value they are advertised for? From a medical and technical perspective, it is very questionable.

First, the concept of so-called high-end physical examination is vague. Like many concepts that have been criticized, high-end physical examination is not a medical concept, but a commercial concept, which cannot be defined from the perspective of medical science. Those institutions that promote high-end physical examination cannot explain what its definition is, and the distinction between high-end physical examination and non-high-end physical examination is not clear.

Judging from some commercial websites promoting high-end physical examinations, the main difference between physical examinations of different "levels" is the physical examination items. Some institutions provide both basic physical examinations and high-end physical examinations. The latter is different from the former only in that it has more blood tests and CT examinations; some have added bone density screening; some have three different levels. Those under 10,000 yuan only have ordinary blood tests and physical examinations, those above 10,000 yuan have imaging examinations, including chest CT and head MRI, those starting at 18,000 yuan have gastrointestinal endoscopy, and those at 30,000 yuan can also do PET-CT; some medical examination institutions for going to Japan define high-end physical examinations as whole-body PET-CT, MRI and ultrasound... There are many different levels.

Such a confusing definition confuses not only ordinary consumers but also doctors, who don’t know where the so-called high-end boundary lies.

More importantly, the value of high-end physical examinations is questionable. Some people choose high-end physical examinations because they don't trust ordinary physical examinations. Many people have heard of people who just had a physical examination and found no abnormalities, but were diagnosed with cancer not long after; or had normal physical examinations every year, but suddenly died of a heart attack, etc. So can high-end physical examinations avoid these tragedies? I'm afraid not, because these additional items also have the problem of false negatives.

The target population for high-end physical examinations is people with higher incomes, better living conditions and stronger health awareness, which means that there is little value in conducting "enhanced" physical examinations on them (in fact, those who need to be examined more are the poor who do not see a doctor for various reasons even if they have certain symptoms).

Not only are they useless, the additional examination items added to high-end physical examinations may be more harmful.

The more items in a physical examination, the better. The selling point of high-end physical examinations is precisely the additional items compared to ordinary physical examinations. For example, tumor markers, imaging examinations including ultrasound, CT and MRI, and endoscopy, etc. Some other high-end physical examinations promote diverse and expensive cancer-related gene tests.

Many of these tests should not only not be performed on healthy people, but they are not necessarily the first choice even for symptomatic patients. Some tests are not even necessary for patients, such as many tumor markers, whose clinical value is questionable (see "Tumor marker screening is popular in physical examinations, none of which has been approved but has become popular"). So far, genetic testing for tumors has been limited to specific clinical conditions, such as follow-up of confirmed patients after treatment, and testing for family histories of cancer.

More importantly, these additional tests will have false positives. Once a false positive result appears, a considerable number of patients will have to undergo more tests, and individuals and families will bear a serious psychological burden. The psychological pressure on some people will continue to exist, even if subsequent tests confirm that it is a false positive.

In addition, people who undergo high-end medical examinations are more likely to have a false sense of security after receiving normal results. They may be more inclined to ignore symptoms when they occur, which makes it easier to delay diagnosis and treatment.

Whether it is overdiagnosis and overtreatment caused by false positives or delayed diagnosis and treatment due to a false sense of security, there are many cases in reality, which may offset the benefits of physical examinations for a small number of people.

It can be seen from this that high-end physical examinations are at best just high-priced physical examinations, and salesmen cannot truly provide the value of the physical examination, including the principles, significance and limitations of each examination.

What is a valid physical examination?

It should be clear that the ineffective annual physical examinations discussed above are not the same as disease screening in healthcare.

The main difference between the two lies in the target population. Annual physical examinations are aimed at all people, including healthy people without symptoms (before a clear disease is diagnosed, people who do not show obvious symptoms can be assumed to be healthy, and there is no so-called "sub-health" concept in medicine), while disease screening is aimed at specific populations. Disease screening can include those with symptoms, such as prostate disease screening for elderly men with dysuria; including those with bad living habits, such as lung cancer screening for smokers; also includes liver cancer screening for people infected with hepatitis B virus, and specific screening for people with a family history of cancer; health examinations for specific genders and specific ages are also worth recommending, such as examinations for children, pregnant women and the elderly.

Another task that annual physical examinations undertake is also worth maintaining, that is, urging vaccination. Vaccination of children and adolescents goes without saying, and annual influenza vaccination for healthy adults, pneumococcal vaccine and shingles vaccination for the elderly are also very important health care measures.

Regular check-ups for some chronic disease patients do not fall into the category of invalid annual physical examinations mentioned above, such as regular follow-up visits for patients with hypertension and diabetes, and regular follow-up visits for cancer patients.

According to the evidence-based medicine requirement, it can be said that the practice of annual physical examinations has not been proven to be beneficial to health. Based on this, public health agencies in many countries no longer recommend or cancel the requirement for annual physical examinations. For example, Canada canceled the recommendation for healthy people to undergo annual physical examinations as early as 1979. Even in some countries where there is a habit of health examinations, the recommended intervals for physical examinations are inconsistent, some are one year, some are two years, and some are five years.

Although many insurance companies in the United States provide annual physical examination services and family doctors also recommend annual physical examinations, the United States Preventive Services Task Force (USPSTF), the main agency providing public health advice, does not require annual physical examinations for healthy people. On the contrary, the suggestion to cancel annual physical examinations has been responded to by many experts.

Despite this, annual physical examinations are still being practiced. There are vested interests (some medical institutions and doctors are unwilling to give up this profit), but to a large extent it is due to inertia. Many people, including doctors and ordinary people, cannot accept the denial of annual physical examinations.

In addition, some studies have found that annual physical examinations can indeed reduce people's anxiety about health and provide a channel for doctors and patients to communicate, build connections and trust, which is important for patients to seek help in time when they have symptoms or health problems. If annual physical examinations are cancelled, other channels for doctor-patient communication need to be provided.

It is foreseeable that, despite insufficient evidence to support the overall benefits of annual physical examinations for ordinary people, this practice will continue in many countries and regions. It is very difficult to remain rational when it comes to health issues, and personal decisions and choices are influenced by many factors, such as commercial propaganda and persuasion from relatives and friends. Ultimately, it will require the intervention of regulatory agencies and academic organizations to regulate it, as well as responsible media publicity.

Reviewer: Wang Chenguang (PhD in Biology, former professor of Peking Union Medical College)

References

[1] https://www.nytimes.com/2015/01/09/opinion/skip-your-annual-physical.html

[2] https://www.acpjournals.org/doi/full/10.7326/0003-4819-146-4-200702200-00008?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org

[3] https://www.nejm.org/doi/full/10.1056/NEJMp1507485?af=R&logout=true

[4] https://choosingwiselycanada.org/wp-content/uploads/2017/05/Health-check-ups-EN.pdf

[5] https://jamanetwork.com/journals/jama/fullarticle/2780614

[6] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4069980/

[7] Clinical etiology analysis of patients with ischemic changes on electrocardiogram but normal coronary angiography (hebmu.edu.cn)

This article is supported by the Science Popularization China Starry Sky Project

Produced by: China Association for Science and Technology Department of Science Popularization

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.

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