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Medical myths: All about cancer
May is National Cancer Research Month, a time to highlight the ongoing work of scientists who dedicate their lives to understanding and treating cancer. Here, we cover 10 myths associated with cancer to help people cut through the maze of misinformation.
In our Medical Myths series, we approach medical misinformation head on. Using expert insight and peer reviewed research to wrestle fact from fiction, MNT brings clarity to the myth riddled world of health journalism.
According to the World Health Organization (WHO), cancer accounted for
In the United States, an estimated
Myths tend to develop around particularly prevalent conditions. It is no surprise, therefore, that people often misunderstand cancer.
“Cancer” is a generic term for a group of diseases that can affect any part of the body. This variety adds fuel to the fire of confusion.
In this article, we hope to dispel some myths and clarify this common and varied group of diseases.
Cancer is not a death sentence. Despite the sobering statistics quoted above, cancer is not always terminal.
As scientists understand cancer better and develop improved treatments, recovery rates continue to improve.
For instance, in January 2019, an estimated
It is also worth noting that survival rates vary significantly depending on the type of cancer. For instance, in the U.K., survival rates for testicular cancer are 98%, whereas survival rates for pancreatic cancer are just 1%.
According to the
“In the United States, the likelihood of dying from cancer has dropped steadily since the 1990s. Now, 5-year survival rates for some cancers, such as breast, prostate, and thyroid cancers, are 90% or better. The 5-year survival rate for all cancers combined is currently about 67%.”
Overall, cancer death rates are slowly declining, although the survival rates of some cancers are increasing more than others. An annual report on the status of cancer in the U.S., which appears in
“[C]ancer death rates decreased 1.5% on average per year during 2001 through 2017.”
This is a myth. Cancer is not contagious. Someone with cancer cannot spread it to others.
However, some sexually transmitted diseases,
As an interesting aside, scientists have
To date, there is no evidence that cell phones cause cancer. One of the reasons this myth developed is that these devices emit radiofrequency radiation (radio waves), a form of non-ionizing radiation. The body absorbs this radiation.
Scientists know that exposure to ionizing radiation, for instance, X-rays, increases the risk of cancer. However, radiofrequency radiation is non-ionizing radiation, which does not increase cancer risk. The
“[A]lthough many studies have examined the potential health effects of non-ionizing radiation from radar, microwave ovens, cell phones, and other sources, there is currently no consistent evidence that non-ionizing radiation increases cancer risk in humans.”
This is also a myth. The extremely low frequency (ELF) magnetic fields produced by power lines are non-ionizing and, therefore, do not cause cancer.
The
“Several large studies have looked at the possible effects of ELF magnetic fields on cancer in rats and mice. These studies expose the animals to magnetic fields much stronger than what people are normally exposed to at home […]. Most of these studies have found no increase in the risk of any type of cancer. In fact, the risk of some types of cancer was actually lower in the animals exposed to the ELF radiation.”
However, the American Cancer Society also explains that some studies have found a slight increase in leukemia risk for children who live close to power lines. However, the reasons for this remain unclear.
Medical News Today spoke with Dr. Joel Newman, a consultant hematologist and specialty lead for pathology at East Sussex Healthcare Trust in the U.K. He puts the risk into perspective:
“We don’t have any real evidence that cell phones or power lines cause cancer, and there are many other things that we do daily that put us at a much greater risk than these ever could, including smoking and alcohol consumption.”
To date, there is
The National Cancer Institute explains why this myth may have arisen:
“Questions about artificial sweeteners and cancer arose when early studies showed that cyclamate in combination with saccharin caused bladder cancer in laboratory animals.”
However, they explain that further studies “have not provided clear evidence of an association with cancer in humans. Similarly, studies of other [Food and Drug Administration (FDA)]-approved sweeteners have not demonstrated clear evidence of an association with cancer in humans.”
Similarly, a
This is only a partial myth. It is true that cancer surgery can cause the cancer to spread, but this is rare. As the
“Advances in equipment used during surgery and more detailed imaging tests have helped make this risk very low.”
A related
There is no evidence that any herbal medicines can cure or treat cancer.
However, some people find certain alternative therapies, such as acupuncture, meditation, and yoga,
As the
“[S]ome studies have shown that kava kava, a herb that some people use to help with stress and anxiety, may cause liver damage. And St. John’s wort, which some people use for depression, may cause certain cancer drugs not to work as well as they should.”
It is important that people with cancer speak with a doctor about supplements and vitamins before taking them.
Although some cancers are passed on genetically through families, they are the minority of cases: an estimated 3–10% of cancers result from mutations inherited from parents.
Because people are more likely to develop cancer as they age, and people today live longer lives, it is not uncommon for people to have some relatives who develop cancer. This might help explain why this myth persists.
Most cases of cancer are due to a buildup of mutations in genes that accumulate over time. As the
“Some types of cancer run in certain families, but most cancers are not clearly linked to the genes we inherit from our parents. Gene changes that start in a single cell over the course of a person’s life cause most cancers.”
To address this question, MNT spoke with Dr. Collin Vu, a medical oncologist and hematologist at MemorialCare Cancer Institute at Orange Coast Medical Center in Fountain Valley, CA. He said:
“Fortunately for all of us, this statement is a myth and entirely not true. The current therapies for cancers are improving to the point where the cure of cancer — that is, treatments that will kill cancer completely — are improving continuously.”
However, he explains that the subject is complicated because “different cancer types have a markedly different ability to be cured, and different cancer types also have different time frames for which a cancer may typically recur. [This] makes it very difficult for patients to know when they may be truly ‘cured’ or when they still have a high risk of cancer recurrence.”
Dr. Vu has great hopes for the future of cancer treatment; he told MNT:
“In the future, with current scientific progress in better treatments for cancer, and improved population awareness of cancer risks and diagnosis, the statement that ‘cancer always comes back’ may become even more of a myth.”
Thankfully, this is also a myth. As medical science delves deeper into the mechanisms behind cancer, treatments steadily grow more effective.
According to Dr. Vu, some cancers, such as testicular and thyroid cancer, have a
Breast, prostate, and bladder also have cure rates of around 50%. Dr. Vu concludes:
“As can be seen by the above data, some cancers can be eradicated, but, unfortunately, not all cancers can be cured completely. There is ongoing optimism that cure rates are increasing given the ongoing focus on screening and better treatments for cancer.”
MNT also spoke with Dr. Anton Bilchik, Ph.D., a surgical oncologist, professor of surgery, chief of gastrointestinal research, and chief of medicine at Saint John’s Cancer Institute at Providence Saint John’s Health Center in Santa Monica, CA. He also leads with a message of hope:
“It is imperative that patients who are diagnosed with cancer, even at an advanced stage, do not lose hope: there are many effective, novel therapies, as well as more effective surgical techniques. A good example is with the use of modern immunotherapy, up to 40% of patients with stage 4 melanoma are curable, and 50% of patients with stage 4 colon cancer metastatic to the liver can be cured with a combination of chemotherapy and surgery.”
In short: although the battle with cancer is ongoing, science is making significant headway.
Fonte: MNT
As informações e sugestões contidas neste blog são meramente informativas e não devem substituir consultas com médicos especialistas.
É muito importante (sempre) procurar mais informações sobre os assuntos
Medical Myths: 15 breast cancer misconceptions
October is National Breast Cancer Awareness Month. With this in mind, the latest edition of Medical Myths focuses on some of the most common misunderstandings associated with breast cancer.
Written by Tim Newman on October 7, 2021 — Fact checked by Ferdinand Lali, Ph.D.
According to the
“As of the end of 2020, there were 7.8 million women alive who were diagnosed with breast cancer in the past 5 years, making it the world’s most prevalent cancer.”
Its prevalence might help explain why there is a wide range of myths attached to it. Here, we will tackle 15 of the most common misunderstandings.
To help us reach the truth, we enlisted the help of three experts:
- Dr. Michael Zeidman: an assistant professor of breast surgery at Icahn School of Medicine at Mount Sinai in New York City.
- Dr. Crystal Fancher: a surgical breast oncologist at the Margie Petersen Breast Center at Providence Saint John’s Health Center and assistant professor of surgery at the Saint John’s Cancer Institute in Santa Monica, CA.
- Dr. Richard Reitherman, Ph.D.: the medical director of breast imaging at MemorialCare Breast Center at Orange Coast Medical Center in Fountain Valley, CA.
“Injury to the breast cannot cause breast cancer,” explained Dr. Zeidman, “however, it can cause changes in the breast that may mimic breast cancer on imaging.”
“This process is called ‘fat necrosis,” he continued, “and it can look like an irregular mass with jagged edges on a mammogram, much like the appearance of a new breast cancer. The best way to distinguish cancer from fat necrosis is with a needle biopsy.”
Although underwire bras do not increase breast cancer risk, Dr. Zeidman always recommends bras without a wire. He explains:
“The wire can irritate the skin under the breast, which can lead to skin breakdown. This breakdown may allow bacteria to enter the breast causing infection, [an] abscess, [or both].”
3. IVF increases the risk of breast cancer
As part of the in vitro fertilization (IVF) procedure, doctors often prescribe drugs that stimulate the ovaries to produce eggs. These drugs mimic the activity of estrogen.
Because of this, some experts wondered whether they might encourage the growth of estrogen receptor-positive breast cancer. As the name suggests, these cancer cells have estrogen receptors on their membranes.
“While there are no randomized controlled trials looking to answer this question,” explained Dr. Zeidman, “a recent meta-analysis of all observational studies over the past 30 years concluded that there is no increase in breast cancer risk for women who received ovarian stimulation drugs compared with the general population.”
This is a myth that Dr. Zeidman is familiar with, he told Medical News Today: “It is very common for [people] with a new breast cancer diagnosis to tell me how shocked they are considering that they have no family history.”
“I then respond by stating that the vast majority of [people who] I see with a new breast cancer have no risk factors. In fact, the most significant risk factor for developing breast cancer is being a woman. In the United States, 1 in 8 women will develop breast cancer over their lifetime.”
As Dr. Fancher explained to us, “only about
Because family history is only one factor in the risk of breast cancer, screening is important. As Dr. Reitherman explained:
“The message is that every woman starting at 40 years of age should have a yearly mammogram regardless of a family history of breast cancer. Those women with a family history of breast or ovarian cancer should be evaluated by a genetics counselor by the age of 30. This group of women may need to begin breast cancer screening prior to the age of 40.”
Dr. Zeidman takes the opportunity to stress the importance of checkups:
“If you are a woman and at least 40 years old, please get your screening mammograms!”
With the ever-present stresses of modern life, it is no surprise that people are concerned about how stress might impact health.
However, as Dr. Zeidman told us, “There is absolutely no evidence to support a link between stress and breast cancer. In fact, there is evidence to support that stress does not increase breast cancer risk.”
That is not to say that stress cannot impact health at all, however. He goes on: “Part of being human is finding effective ways to deal with the stress we all will inevitably face. This can have profound health benefits both mentally and physically, but will do nothing to mitigate breast cancer risk.”
“While it is true that postmenopausal women who are overweight are at an increased risk of developing breast cancer, there is nothing that a woman can do to eliminate breast cancer risk,” explained Dr. Zeidman.
“Even women who undergo bilateral mastectomy are still at risk of developing a new breast cancer.”
However, he is not suggesting anyone starts “smoking and eating fast food every day.”
More generally, he believes that “it is of the utmost importance to take care of your body because you only get one. But even world class athletes have been diagnosed with breast cancer.”
“While it is true that breast cancer risk increases as women age, and the average age of a new breast cancer diagnosis is 61 years, breast cancer can occur much earlier,” Dr. Zeidman told MNT.
“About 5% of new breast cancer diagnoses are in women under the age of 40 years. There, unfortunately, have been reports of women in their early 20s and even teens who were diagnosed. There is typically a strong family history in these young women.”
“If you have a significant lifetime breast cancer risk based on a strong family history, then you may qualify for genetic testing and early screening starting at age 25.”
Dr. Fancher explains that, although breast cancer is rarer in younger people, she encourages people to “bring any concerning findings in your breast to your doctor’s attention and follow their recommended screening guidelines.”
This is a myth — not all lumps in the breast are cancer. Dr. Zeidman explained that the
However, Dr. Zeidman made it clear that any new lump should be “evaluated by a healthcare professional.”
“The reason this question comes up is because we know that breast cancer risk is directly related to estrogen exposure,” Dr. Zeidman told us, “and abortion interrupts the normal hormonal cycle of pregnancy.”
“While we can never perform a randomized controlled trial to address this question, there was a very large observational
study in Denmark that included 1.5 million women and found no link between abortion and breast cancer.”
Aside from this analysis, he explained that there have also “been several other large-scale studies that came to the same conclusion.”
According to Dr. Zeidman: “There is no evidence to support that cell phones cause cancer, period.”
“However, we do not have any long-term studies, so we may find this to be the case in the future. For now, why can’t you just put your phone in your pocket or bag?”
Dr. Zeidman told MNT that this is a myth — nipple piercings do not increase breast cancer risk.
“However,” he elaborated, “they can lead to complications, such as infection, abscess, difficulty breastfeeding due to blocked ducts from scar tissue, nerve damage, keloids, cysts, and more rare but serious illness from HIV and hepatitis B and C.”
“For these reasons,” he said, “I always recommend against nipple piercing. If the deed is done, I recommend removing it.”
Dr. Zeidman maintains a firm stance on sugar: “Sugar should be avoided in general. It is addictive.”
“It can cause mood swings,” he continued, “It leads to spikes in insulin, which puts the body in a pro-inflammatory state. This, in turn, can lead to heart disease, diabetes, and other chronic inflammatory diseases.”
“Too much sugar can result in obesity, which is a risk factor for breast cancer.”
However, he explained that studies investigating links between sugar and breast cancer have been “mixed and inconsistent.”
While discussing sugar, it is worth busting a related myth: that sugar helps tumors grow. This myth arose because cancer cells divide rapidly and, therefore, need a lot of energy.
“While there is no concrete evidence to support this,” stated Dr. Zeidman, “I still recommend abstaining from added sugar as much as possible for overall well-being.”
“Men have breasts… so yes, they too get breast cancer,” said Dr. Zeidman. “In fact,
According to the Centers for Disease Control and Prevention (CDC), there were 2,300 new cases of male breast cancer in 2017 and 500 deaths.
“While breast cancer is more common in women than men, there are still men who get breast cancer,” explained Dr. Fancher, “It’s important for men also to be aware of any changes in their breast since there are no recommended screening guidelines for men.”
“Any lump, pain, or changes should be brought to your doctor’s attention, even if you don’t have a strong family history.”
– Dr. Fancher
Dr. Reitherman added, “Men are diagnosed with breast cancer rarely […] the most common risk factor is a family history of breast cancer. The
“This is a common misconception that I hear from my patients,” Dr. Zeidman told us.
“The thinking is that squeezing the cancer with compression during mammography, or performing a needle biopsy on the cancer, will cause the cancer to seed other parts of the breast.” However, he confirms:
“There is absolutely no evidence to support this.”
Dr. Reitherman agrees: “There is absolutely no evidence that mammograms cause breast cancer. The performance of a mammogram uses a very low dose of radiation and compression and has no documented or theoretical relationship to causing breast cancer.”
“If this were true, then we would not need mammograms,” said Dr. Zeidman. “Mammograms have been proven to save lives because they allow us to catch the cancer before it becomes palpable,”
In this context, “palpable” means that a person can feel the lump with their fingers.
“If we diagnose and treat a breast cancer while it is stage 1, survival approaches 100%. Survival drops as the stage advances. In fact, the cancer may never be palpable and still spread to other parts of the body,” Dr. Zeidman added.
According to Dr. Fancher, “Many breast cancers are found on screening mammograms and may not be felt. This is especially true for noninvasive breast cancer or ductal carcinoma in situ, which may only show up as calcifications on a screening mammogram.”
Breast cancer is common, and while a healthy lifestyle might reduce the risk to a certain extent, vigilance is key. The earlier a doctor catches breast cancer, the higher the chances of surviving it.
Fonte: MNT
As informações e sugestões contidas neste blog são meramente informativas e não devem substituir consultas com médicos especialistas.
É muito importante (sempre) procurar mais informações sobre os assuntos