Myths about cancer prevention

How we ruin ourselves

Zinaida Belova, Metro

Oncologist Ilya Fomintsev, executive director of the Cancer Prevention Foundation, told Metro why cancer markers are useless for the diagnosis of early cancer and whether it is worth relying on modern medicine in everything.

– We conducted a study. Three thousand users answered our question: which of the presented diagnostic methods do you consider appropriate for a general examination for cancer?

"Blood test for cancer markers" – consider more than 70% of respondents, "Computed tomography of the whole body" – almost 15%, "MRI of the whole body" – 33%, "Ultrasound of all organs" – 42%, oncologist consultation – 64%. The option "I think that a general examination for cancer is impractical" was chosen by only 6.8% of users. And this is the right answer. People think that there is some kind of general examination that you did – and they told you whether there is cancer or not. But this is a mistake. Moreover, all examination methods have their own balance of harm and benefit. Any medical intervention has potential harm. It is unlikely, nevertheless it is there. Each type of cancer has its own diagnostic method, which has few false positive and false negative results.

– If there are symptoms of cancer, then it is more or less clear how to examine a person. And when they are not – what are the indications for the examination?

– Risk of cancer. If the probability of benefit exceeds the probability of harm from screening.

– What is screening?

– Cancer screening is a mass event aimed at the same population group with controlled coverage, quality, controlled intervals and measurement of mortality in this group. The effectiveness of screening is calculated by mortality: if it does not fall, then something is going wrong.

– Your survey showed that the majority of respondents consider a study on cancer markers appropriate.

– Yes, most often people believe that a set of cancer markers should be made for early detection of cancer. This is completely wrong. There is a solid evidence base that suggests that cancer markers are not applicable for the early manifestation of cancer. They give a huge number of false positive and false negative results. In cases of false positive results, people undergo completely unnecessary operations, ovarian biopsy, and so on. This leads to complications, and sometimes to death.

– Why is there such a large percentage of trust?

– Since the nineties, private clinics have actively advertised cancer markers as a way to detect early cancer. Moreover, some large laboratory networks are still doing this. Why? The answer is simple: money. Even about half of the doctors in the Russian Federation are confident in the correctness of the use of cancer markers. The only question is, what kind of specialists are they? In outpatient networks, in private low-level clinics, doctors are often illiterate. They rely only on the information that the medical representative brings to them "in a beak". They cannot read the literature on their own, they cannot disassemble the article, since they often simply do not know English, not to mention the fact that even knowing it, it is necessary to be able to read articles. Outright "paramedicism" is flourishing among doctors now.

I may say a seditious thing: if a doctor prescribes cancer markers to detect early cancer, it means that he is either lying or illiterate – and you'd better change him. If the clinic admits such an employee in its staff, it means that the clinic is of poor quality.

Cancer markers are an applicable thing, but to monitor the course of treatment of an existing tumor.

We are currently working with a number of major laboratory networks to prepare their official open position on the use of cancer markers for early detection of cancer. This myth must be killed by the whole world.

– What other diagnostic methods are not suitable?

– The widespread ultrasound method is also not suitable for detecting cancer. As the primary method of examination, it gives many false positive results. And it's quite low-sensitivity. For example, when detecting breast cancer, ultrasound does not see very small tumors. This is the first. Second: ultrasound is often followed by an unnecessary breast biopsy. That is, something is visible, but it is not clear, let's do a biopsy. Naturally, the woman is scared, she's been biting her nails for a week. Gnawing up to the elbows, and why should we deprive a woman of her hands? Don't need it. Therefore, the International Agency for Research on Cancer does not recommend ultrasound as a method for early detection of the disease.

– What is the alternative?

– For the breast – X-ray mammography. The average risk group is from the age of 50 in the absence of significant risk factors. It is a very common misconception among doctors that mammography can be done after 40 years, and before that – ultrasound. Ultrasound can and should be prescribed only according to indications, if there are any complaints, pain, etc. The screening indication of ultrasound, that is, simply by risk factors, does not matter. Because there will definitely be something: a cyst, some kind of benign node.

– When should breast cancer screening be performed?

– At the age of 30-40 years, the benefits of screening are low, because the probability of cancer is very low. And in general, not every early detection of cancer leads to a reduction in mortality. So at a young age, it is not necessary to give any one general recommendation - this will lead to unnecessary biopsies, hassle. Hundreds of thousands of women will suffer for the sake of one or two whom this screening will help, and even then not radically.

– What should I do?

– In general, the main myth is that people believe too much in medicine, greatly overestimate its impact on reducing mortality. Medicine can do a lot now, but not everything. There are risk factors proven in large studies that increase the possibility of developing cancer. There are criteria and indications for cancer screening that allow reducing mortality in this group. If we talk about screening, then we are dealing with asymptomatic patients. Risk is the only criterion by which an examination can be prescribed. Risk factors can be very diverse: age, gender, smoking, heredity. So their combination is the criterion for determining the group that needs to be screened. Real screening is a very inexpensive thing, because these groups are quite narrow, and the methods used are quite cheap.

Example: cervical cancer screening, which is aimed at detecting not even cancer, but a precancerous condition. It is reasonable to use it from 25 to 65 years. At another age, it doesn't make sense to do it. I'll explain why.

Cervical cancer develops only in the presence of human papillomavirus, and this process takes 10-15 years. The virus can get to the cervix only as a result of sexual intercourse. Therefore, if cervical cancer develops for 10-15 years, does it make sense to check an 18-year-old girl? And our gynecologists recommend starting cervical cancer screening from the age of 18 or at the beginning of sexual life. Once every three years, it is enough to do a cytology of the cervix. And we recommend it often every six months. What for? After all, there is harm from it too. The procedure itself is harmless, but there may be problems if a positive diagnosis is made. Suppose a patient has cervical dysplasia, which at a young age in 80% of cases degenerates by itself, without medical intervention. Conization is very often prescribed in our country, part of the cervix is removed, and a woman risks not being able to endure pregnancy, problems with conception and so on may arise. Question: why do all this? Not only did they torture a woman every six months, they also made it so that she could not give birth. That is, such a recommendation killed thousands of fruits across the country. This is not a joke. Therefore, it is necessary to be very careful when mass recommendations are formed. Any recommendation given to a hundred thousand people will kill at least one. And here's a strange thing: you still need to give it, even knowing the consequences, if the recommendation saves more people than it kills. This fact must be absolutely justified by research.

– What can the Cancer Prevention Foundation offer?

– We have created a SCREEN system that determines the indications for screening in a particular person. It evaluates the balance of harm and benefit from screening for a certain set of risk factors based on studies, meta-analyses, recommendations from WHO and other reputable organizations. It is impossible to give all people one recommendation, for someone it will be true, and for someone it will not. But we can give everyone one link by which everyone will determine their recommendations. In order to find out if you have an increased risk of some type of cancer and what type of diagnosis you should do regularly, take a simple test on our foundation's website.

Household myths:
There are a lot of household myths: for example, there is an opinion that smoking does not affect the formation of cancer. It affects, and yet how. These are obvious things. Smoking is a very serious risk factor for cancer not only of the lungs, but also of the esophagus, stomach and several other fairly frequent localizations. Therefore, in fact, they are frequent.
Many people think that cancer is contagious. There are virus-dependent cancers. For example, cervical cancer. Cancer itself is not transmitted, but the virus that causes its development is. Hepatitis C is an increased risk of liver cancer.

Portal "Eternal youth" http://vechnayamolodost.ru  11.05.2016