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Dr. Drauzio Varella’s Clarification on Mammography and Thyroid Cancer – 07/07/2016
Drauzio Varella, the most popular doctor in Brazil, is very upset. One day before speaking with BBC Brazil, he received, via WhatsApp, several copies of a video that cites his name. “It’s one of those horrible conspiracy theories! What a horror!” He says.
In the video, which also circulates on Facebook, an unidentified woman says that according to Varella, cases of thyroid cancer in women would be increasing because of mammograms and dental radiographs.
She also criticizes health care providers who perform such tests for failing to provide patients with lead protectors for the throat – a part of the body that houses the thyroid gland.
The same text was already circulated by email in 2013, when it came to be denied by “gaggle” sites. At the time, the claims were attributed to the American TV program The Dr. Oz Show, commanded by the physician Mehmet Öz.
Between 2014 and 2015, a version happened to circulate in WhatsApp, already attributed to Drauzio Varella.
The novelty of 2016 is the video, whose circulation exploded precisely in the “October pink”, month of awareness about the diagnosis of breast cancer.
Attention: X-rays do not increase the risk of thyroid cancer
“I’m getting in touch with an internet lawyer to take action. We’ve spent so many years insisting that women get mammograms every year from the age of 40, and an unfortunate person uses my name to scare women,” says the doctor.
“A patient of mine who had breast cancer and today does a mammogram a year to follow came to ask me if I should stop doing it because of that, imagine!”
BBC Brazil has asked questions and answers to clarify what is wrong with the video message. Check below.
Was there really a rise in thyroid cancer cases?
According to the National Cancer Institute (Inca), the incidence rate of this type of cancer has increased about 1% per year in most countries of the world.
But this is due to the fact that the examination that detects a tumor is being performed more frequently.
“One possible explanation for the trend towards increased incidence rates is increased use of ultrasound and imaging guided biopsy to detect subclinical disease,” the institute said in a statement to the BBC.
The mortality rate of thyroid cancer, however, is declining in most countries, says the Inca, probably because of improved treatment.
In Brazil, the institute estimates that 6,960 new cases will be diagnosed this year – 1,090 in men and 5,870 in women.
Cited as the source of the rumor, Drauzio Varella says he is talking to a lawyer to take action
In a video published a year ago, Drauzio Varella cites a study that was conducted in South Korea and reached similar conclusions.
“What happens is that often the thyroid ultrasound shows lumps that would never manifest, and it scares people with problems that are not serious. But that’s it, I did not even touch the word mammography,” the doctor tells the BBC. Brazil.
The incidence of benign nodules and thyroid cancer is two to three times higher in women than in men. According to the Inca, hormonal factors can explain this difference. “But that was always so, long before there was mammography,” explains Varella.
“If you do thyroid ultrasound in 100 women, about 60 will have benign thyroid nodules, but it’s important to remember that having thyroid nodules does not mean having cancer, the disease is more rare.”
This type of cancer, says the Inca, accounts for 2% to 5% of female cancers and less than 2% of male cancers.
Are Mammograms and X-Rays at Risk for Cancer?
Also in 2015, when the written version of the rumor began circulating on the networks, the National Mammography Commission – formed by the Brazilian College of Radiology, the Brazilian Society of Mastology and the Brazilian Federation of Gynecology and Obstetrics Associations – issued a note stating that “the risk of induction of thyroid cancer after a mammogram is insignificant.”
According to the note, this is less than 1 case for every 17 million women between 40 and 80 who perform mammography annually.
“The radiation dose to the thyroid during a mammogram is extremely low (less than 1% of the dose received by the breast). This is equivalent to 30 minutes of exposure to radiation received from natural sources.”
In the site of Drauzio Varela, a text on thyroid cancer lists, among the risk factors, the “radiation in the neck region for treatment of previous diseases.” He clarifies, however, that this refers to radiotherapy treatments, in which the patient receives higher doses of radiation.
“If you do radiotherapy in the neck, the thyroid gets radiation, so much so that we have to keep up with all the patients who undergo this with care, but then say that a mammogram or a dental x-ray can provoke such a process is absurd “he explains to BBC Brazil.
The dose of radiation to which the patient is exposed on a dental x-ray is more than 100 times lower than on a mammogram.
Woman, who does not identify herself, repeats rumor text that had circulated on social networks for about three years
Why is the thyroid protector not used by patients who do these tests?
In her note, the National Mammography Commission states that it does not recommend the use of the thyroid shield because it “may interfere with breast positioning and generate overlap – factors that may reduce image quality, interfere with diagnosis and lead to the need for exams “.
The ruling, according to the statement, is in line with the position of the UN’s International Atomic Energy Agency (IAEA).
An IAEA document, published in 2011, states that “in modern mammography, there is negligible exposure to sites other than the breast” and that the shields can be provided at the request of patients, but have “psychological” value.
The body also says that the protector should not be exposed in the room where the examination takes place to prevent patients from finding it necessary.
Clarification on Mammography and Thyroid Cancer – Brazilian College of Radiology – 03/30/2012
Several studies have confirmed the importance of mammography in reducing breast cancer mortality. On the other hand, there is concern about the effects that ionizing radiation can bring to the body. In particular, a discussion of the rise in thyroid cancer in patients undergoing mammography screening has been circulating on the internet recently, causing anxiety among women. On this, some points must be clarified:
The allusion to the effect of mammography on increasing the incidence of thyroid cancer is made without scientific basis, as there are several published studies showing that mammography does not expose the thyroid at doses considered harmful.
Here is the translation of the original text on the use of mammography shields from the Quality Assurance Program for Digital Mammography – IAEA Human Health Series No. 17, page 139, published by the International Atomic Energy Agency (IAEA) in 2011:
“In modern mammography, there is an insignificant exposure to other radiation-sensitive sites other than the breast. The main value of using radiation protection clothing is psychological. If such clothing is to be provided, it should only be done at the request of the patient The clothing should not be kept on display in the examination room.The presence of the aprons and necklaces in the mammography room may suggest that their use is an acceptable practice, which is not the case.
“Both calculations and measurements show that the amount of radiation reaching the thyroid during mammography is insignificant.” The amount of radiation reaching the ovaries is even smaller, due to the attenuation by the breast support tray and the overlying tissue. X-rays are blocked by the breast and the breast support tray in the mammograph, only an extremely small fraction of dispersed radiation reaches other parts of the human body.The calculated thyroid dose for a four-incident examination is less than 0, 03 mGy.This is about 1% of the dose that would be received by the breast during the examination and is equal to the dose that would be received by the thyroid for three days of natural background radiation (note of translation: the natural background radiation comes from the space extraterrestrial and radioactive materials in the earth’s crust.) In other words, this would be equivalent to receiving 368 days of natural radiation from fun rather than the 365 days of background radiation that would have been received without the examination. Natural background radiation varies from location to location much larger than this. ”
Therefore, according to the International Atomic Energy Agency, the use of the thyroid protector on mammography is not recommended in the routine and should be used only in cases where the patient requests it. It is important to always inform that the use of the protectors can even disrupt the examination, because if it is not well placed in the patient, it can be the cause of repetition in cases in which its image overlaps the image of the breast.
Dr.a Linei Augusta Brolini Delle Urban
Coordinator of the National Commission of Quality in Mamography of the CBR
Text taken in full from issue 288 of the Bulletin of the Brazilian College of Radiology – March 2012.
Bulletin available on the College website: http://www.cbr.org.br/ in Publications> Bulletin> Previous Editions
