Among all the recurrence and metastasis sites of breast cancer, brain metastases are relatively the most difficult to treat and the most need to be prevented. There are three reasons for this:
Brain metastases basically do not show any symptoms in the early stage [1-2] (dizziness and headache may appear only when there are more brain tumors), which is easily ignored by breast cancer patients themselves, it is difficult for drugs to cross the blood-brain barrier to act on brain metastases and kill cancer cells, and the prognosis of breast cancer patients after brain metastases is relatively poor, and if they are not intervened in time, their natural course is only 1~3 months [3].
What is the most useful test to prevent brain metastases? Magnetic resonance examination, that is, MRI examination, is about 600 yuan for one time, including noncontrast and enhancement. It can detect tumors as small as about 1 mm, and is more sensitive to the identification of edema and meningeal metastases, and is the preferred imaging examination method for the diagnosis of brain metastases.
Unfortunately, many breast cancer sisters do not pay attention to MRI due to various factors (or fear of radiation, or have passed the 5-year survival period, and are not so vigilant about cancer cells). As everyone knows, there is no radiation in MRI examinations, and there are several breast cancer patients who are "favorites" of brain metastases!
01 These 5 types of breast cancer patients are more preferred by brain metastases
1) Patients with HER2-positive breast cancer
Data show that the proportion of central nervous system metastasis in HER2-positive breast cancer patients is 30%~55%[4]—HER2 overexpression or abnormal amplification makes breast cancer cells more aggressive, thus more easily metastasized to the brain, and the central nervous system may become a "safe haven" for HER2-overexpressing breast cancer cells due to its biological specificity (i.e., the existence of a blood-brain barrier that can increase the difficulty of anticancer drugs entering brain metastases) [5].
2) Triple negative breast cancer patients
Brain metastases occur in 25%-46% of patients with triple-negative breast cancer with the shortest metastasis interval, and even the first intracranial metastasis is in the meninges [6] (brain metastases include brain parenchymal metastases and meningeal metastases, the former has clinical manifestations of increased intracranial pressure and neurological dysfunction, such as headache, vomiting, and optic nerve disc edema, etc., while the latter mostly manifests as symptoms of meningeal irritation, such as headache, vomiting, nuchal rigidity, cognitive impairment, confusion, etc.).
It is important to emphasize that the meninges are a layer of membranous structure that wraps around the outside of the brain, and once it metastasizes, breast cancer patients will have unbearable severe headaches.
3) Breast cancer patients who have developed extracerebral metastases
Including but not limited to, breast cancer patients who have metastasized to the liver, lung, bone, lymph nodes, etc., and the more metastasis sites and the greater the burden, the higher the risk of intracerebral dissemination.
4) Breast cancer patients who have metastases to axillary lymph nodes at the time of surgery, and the number of metastases is relatively large
That is, a large number of breast cancer patients who have undergone radical mastectomy but have developed axillary lymph node metastasis at the time of surgery. In terms of stage, they are intermediate or locally advanced, and the risk of brain metastases in recurrence and metastasis is relatively high (the later the stage, the faster the brain metastases, about 54.2% of which are multiple brain metastases [7]).
5) Breast cancer patients aged < 50 years
Younger breast cancer patients are more likely to develop brain metastases (higher histologic grade, higher proportion of Ki-67 expression, higher proportion of vascular invasion, and higher proportion of triple-negative breast cancer) than older breast cancer patients [8]).
If the breast cancer patient is a young HER2-positive breast cancer patient or a triple-negative breast cancer patient, and the stage at the time of surgery is intermediate or advanced, and there are extracerebral metastases with a large number of metastases, they are considered high-risk patients with brain metastases (or high-risk among high-risk patients), and regular follow-up examinations related to brain metastases must be performed.
If a breast cancer patient has no symptoms of brain metastases and is still a hormone receptor-positive breast cancer patient, it is likely that MRI of the brain will not be recommended, because currently major guidelines do not recommend routine imaging monitoring in the absence of symptoms. However, it is still not to be taken lightly, taking hormone receptor-positive breast cancer patients as an example, the incidence of brain metastases is only relatively low, but not 0, and there are about 10%-15%.
02 These 4 magnetic resonance minefields Breast cancer patients must not step on them
✦ When you do an MRI, you should have banknotes in your pocket
Because the wires inside the banknote have an effect on the uniformity of the magnetic field. When the correlation sequence is scanned, artifacts are produced that affect image quality. Therefore, breast cancer patients must not only empty the metal items they carry with them before having an MRI examination, but also take away the banknotes on their bodies in advance.
In addition to banknotes, items such as wallets (containing coins and bank cards), mobile phones, watches, keys, coins, card hairpins, necklaces, lighters, dentures, and other items containing metal[9], as well as magnetic items such as refrigerator magnets, are not permitted. Because the magnetic field strength of the magnetic resonance machine is tens of thousands of times that of the earth, if a breast cancer patient or an accompanying person accidentally brings a magnetizable object into the MRI room, it may be ejected, causing accidental injury.
✦ During the MRI examination, the body moves around
As with photographs, MRI can be reported as if the person being examined is physically moved, and the reported images are prone to double vision and are not clear (approximately 58 percent of MRI images contain motion-related artifacts [10]).
It is recommended that breast cancer patients: before the examination, understand the precautions of magnetic resonance examination (for example, the upper limit of human ear comfort is about 75 decibels, and the noise generated during MRI examination can reach 65-92 decibels, which may sometimes cause auditory discomfort, which is normal, do not panic, and earplugs are generally equipped to reduce noise during the examination);
✦ At the time of the MRI examination, there are cosmetics containing metal ingredients on the face
For example, lipstick, magnetic eyelashes, etc., the metal components in these items may react with the magnetic field during the inspection process, causing interference with the magnetic field, which is not conducive to the normal progress of the examination. Heavy metal salts contained in hair dye may also adhere to the body, causing interference and artifacts in the image.
✦ Body temperature over 39°C at the time of MRI
Patients with high fever are already in the situation of increased thermogenesis and decreased heat dissipation, and if an MRI is performed at this time, their body temperature will rise further, and there is a risk of convulsive syncope shock.
1) Breast cancer patients with stroke, brain tumor and intracranial hypertension should take measures to lower intracranial pressure first to avoid vomiting and related accidents during magnetic resonance examination.
2) Breast cancer patients with metal objects in their bodies are not allowed to undergo magnetic resonance examination, including but not limited to: breast cancer patients with pacemakers, nerve stimulators, breast cancer patients with artificial metal heart valves, metal joints, fixed steel plates, steel needles, etc., breast cancer patients with aneurysm clips (except for non-paramagnetic materials such as titanium alloys), etc.
Write at the end
In addition to regular re-examinations (it is recommended to read "5 "Unspoken Rules" for Going to the Hospital for Re-examination, Breast Cancer Patients Don't Know It's a Big Loss!), there are also these effective measures for breast cancer patients to prevent brain metastases:
After surgery, cooperate with long-term treatment, adhere to moderate exercise (such as slow walking, walking, tai chi, etc.), maintain a reasonable diet (i.e., rich in vegetables and fruits, whole grains, poultry and fish), develop a healthy lifestyle (such as not staying up late), and be emotionally stable. If you have other prevention experiences for breast cancer, please share them in the comment area so that more sisters can benefit.
What other questions do you want to know about the review? Welcome to leave a message in the comment area!
Warm reminder: The purpose of this article is to convey disease knowledge, and it is not used as a recommendation for diagnosis and treatment plans and medical basis.
Cover image source: photo.com
Editor in charge: Mijian Mutual Aid Jun
Bibliography:
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[3] Zhong Yihong, Yang Qian, Liu Zhou, et al. Value of magnetic resonance imaging in the diagnosis of brain metastases by noncontrast and diffusion-weighted imaging[J]. Chinese Journal of Oncology, 2021, 43(4):466-471.
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[5] Stavrou E, Winer EP, Lin NU. How we treat HER2-positive brain metastases. ESMO Open. 2021 Oct; 6(5):100256.
[6] Management of breast cancer brain metastases[J]. Chin Clin Oncol
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[8] Breast Cancer Expert Committee of Chinese Society of Clinical Oncology, Breast Cancer Professional Committee of Chinese Anti-Cancer Association, Breast Surgery Group of Chinese Society of Surgery. Expert consensus on the diagnosis and treatment of young breast cancer in China (2022) [J] . Chinese Medical Journal, 2023, 103(6) : 387-403.
[9] Chinese Medical Association Imaging Technology Branch, Medical Technologist Professional Committee of Chinese Medical Doctor Association.Chinese Expert Consensus on Magnetic Resonance Imaging Safety Management (2017)[J] . Chinese Journal of Radiology, 2023, 57(9): 955-961.
[10] Yang Zhenghan, Feng Feng, Wang Xiaoying. Guidelines for Magnetic Resonance Imaging Techniques: Examination Specifications, Clinical Strategies and New Techniques (Revised)[J]. Chinese Journal of Medical Imaging, 2010, 04(v.18; No.89):26-26.