HER2 Brain Mets Risk
With newer advancements in the care of HER2 affected women, more are living past issues with systemic disease and it is cause for celebration. It does bring to the forefront the risk of our mutation migrating, unchallenged, into the central nervous system where it can grow without challenge.
Targeted therapies are larger particles and most of the time they are unable to pass through the blood-brain barrier to do their good works against our excessive growth receptor mutations.
"Amongst 242 BC patients with brain metastases, 18 (7,4%) had cerebellar metastases. In that subgroup, Her2 over-expression was higher than expected (13/18;72,2%). Compared to all Her2 3+BC (73/242;30%) from our data base, cerebellar metastases were diagnosed in 17,8% (13/73), and only in 3% (5/169) of patients with Her2 negative BC. Majority (11/18; 61%), developed cerebellar metastases as a resectable, first metastatic site, and 73% (8/11) of these patients had Her2 3+ BC, treated with trastuzumab."
"On a positive note, metastasis of breast cancer to the brain is no longer a clinical diagnosis for which therapeutic options and clinical trials are lacking. Improvements in systemic therapies and CNS-directed local therapies have likely improved patient outcomes, even after the development of CNS recurrence, and particularly in the HER2-positive subtype"
Brain cancer, should our cancer progress, is a real risk -- but for HER2 patients it is a real thing and there are options that weren't there before that area still experimental such as intrathecal therapy to put the targeted therapies in through the blood-brain barrier.
About 20% of the time neurosurgeons will see cerebullar disease, aligning with breast cancer mets. The cerebellum is the back part of the brain, responsible for motor coordination, balance, movement. It isn't as critical an area who can be good treatment-wise and tumors in this area are easily excised via craniotomy. They tend to be single lesions when they show up in the cerebellum.
Removal of the bulk of disease quickly is important to delicate brain structures. Typical treatment follows up with 6 weeks of radiation to the tumor bed, causing local inflammation which Dexamethasone will help manage.
If this could develop in me, even thought I sought medical care along the way and everyone of them missed it, it could happen to you also. I want you to understand what and how it progressed in me that you can seek imaging sooner.
3 months ago I started feeling dizzy. I saw my GP after a couple weeks because I thought I thought I was having blood pressure issues post-chemo. He diagnosed a vestibular issue, perhaps from allergies.
A couple weeks later my right neck and shoulder started aching. I've never injured that area before do this was perplexing to me. Was it my reactivated whiplash from rads or my rerouted lymphatic flow that were causing the pain? Had no idea.
Two more weeks went by and I was in a lot of pain in my torso. I saw my RO and MO for post treatment follow-up after my mammogram and mentioned the pain and neither paid notice. I saw my GP the next day and he thought I developed costochondritis, swelling of the chest wall from rads, and a pinched nerve in my neck. He got me a script for Amitriptyline which would knock me out and make it hard to help my young kids in the morning.
I started having difficulty walking and was wearing a neck brace because holding my head neutral was important. My GP was on vacation when I emailed and his office dropped the ball. I got progressively worse over the next month with excruciating headaches that came out of nowhere. I started vomiting. I saw a different GP and he just gave me a script for Gabapentin. No one offered an MRI to figure out the cause. Stories I had read online of pinched nerves didn't get much worse like mine did, and they weren't constant.
I finally sent an email to my breast surgeon begging for help and she admitted me to the hospital. I had a partial brain MRI that revealed the mass on Monday, and Tuesday we learned it was 3.5 x 5 cm in my right cerebellum. It was quite large and amazing that my symptoms were so limited. I had a craniotomy two days later and it's going to be more months of recovery, treatment, monitoring and uncertainty.
It is not unheard of for HER2 disease to do this so don't be caught unawares. There is room for hope and it is a chilling advancement in my care as well. Going to heal and press for full recovery once again, perhaps with experimental therapies
Reminder to us all- in any oncology patient, symptoms which continue to get worse and are unexplained need to get evaluated for CNS disease as soon as possible. Lie if you have to, get peace of mind or catch something early.