How to do the research for your own bio-individuality when it comes to cancer recurrence risk.
When I was diagnosed last August with breast cancer, I met with my surgeon so she could outline my personalized treatment plan. The plan was based on various factors such as my cancer’s stage, type, and hormone receptor status. For my Triple+ breast cancer I would have surgery first, 6 rounds of chemo, HER2+ targeted therapy for a year, radiation for 3 weeks + 1 day, and tamoxifen for 5 years starting mid-treatment (after chemo ended). At the time of my diagnosis, I knew very little about breast cancer and how it was treated. I was scared and just wanted the cancer gone. The surgery date could not come quick enough. Research at the beginning of my journey was not something I could do. I was overwhelmed by the initial diagnosis and the speed at which they ask you to consent to the treatment plan, so I let go and surrendered to the process.
Once my pathology report came back and the margins looked clear, I started to be able to breathe again. I was able to think about my cancer as a localized disease that could be managed instead of an instant death sentence. I moved out of my fear based mindset and became committed to approaching this journey with curiosity. As I took a deeper dive into my disease, all my research kept leading back to hormones – particularly estrogen and the important role it plays in women’s health. And how quickly it becomes demonized when the topic of breast cancer comes up.
But let me digress for a moment. When I was diagnosed last year at 43 years old, I was already starting to explore my hormones. I had been experiencing perimenopausal symptoms for about a year before my cancer discovery – sleep disruption, easy to rage, low stress tolerance, low libido – and I was beginning to realize how little I actually understood about what was happening inside my body.
Because I run a yoga studio for women, the topic of hormones comes up often, whether we are talking about shifts during pregnancy, the perinatal year, or the menopausal transition. I had been meaning to book an appointment with my GP to talk about my hormonal health but life and responsibilities kept getting in the way. When I found a lump in my breast, it seemed like a good excuse to make an appointment. Hormonal curiosity was what ultimately got me to the doctor and that appointment led to the early detection of my invasive breast cancer.
Looking back, it feels like a strange kind of serendipity that my curiosity about hormones ended up being the reason I caught my cancer early. I had no idea then that estrogen would become my primary focus for the next year as I worked to understand what it means to have hormone-positive breast cancer. I found myself deep in research, trying to make an informed decision about whether or not adding Tamoxifen, an endocrine blocker, to my treatment regime was the right decision for me. And I was doing it largely on my own, because most conventional doctors are not trained in hormonal health. The well known narrative at the moment is that if you have hormone-positive breast cancer, then you should reduce or block estrogen in your body. My doctors all know how to prescribe medicine that blocks estrogen receptors, but not how to talk about its many roles in the body or how to support someone navigating its complexities in the context of cancer and long-term wellness.
When I spoke with my oncologist about my concerns for my quality of life post treatment, she assured me that she could prescribe many drugs to mitigate hot flashes, bone loss, high cholesterol, depression, anxiety, vaginal dryness – all side effects of tamoxifen (and menopause). The problem with the conventional Western medical paradigm is that an oncologist is trained to treat cancer. Not to worry about long-term, whole-body health. My oncologist (who I like very much) was focused on getting me through treatment and reducing my recurrence risk, not to consider what could happen to my body over the next 50 years without estrogen. And as I was learning, estrogen is not just a reproductive hormone, it plays a critical role in protecting your bones, heart, brain, and sex life. When it’s abruptly removed or suppressed, as it often is during breast cancer treatment, the long-term consequences can be profound. Women who go through treatment and are left estrogen-depleted face significantly higher rates of osteoporosis and bone fractures, cardiovascular disease, cognitive decline and dementia, sexual dysfunction, and even divorce. These are not rare side effects. They are common realities of living without estrogen. And yet these risks are rarely part of the treatment conversation.
So I kept reading and researching. Assessing my actual risk factors and gathering objective data about estrogen so I could make an informed decision that was not fear based. Because if one thing was clear from the very beginning of my research – there is a lot of fear and confusion surrounding estrogen and cancer.
Much of that fear, especially in the context of breast cancer, can be traced back to the Women’s Health Initiative (WHI) study published in 2002. The media quickly focused on one headline: that estrogen (specifically when combined with progestin) increased the risk of breast cancer. After that, HRT prescriptions declined dramatically , and estrogen became known as a dangerous hormone to be avoided at all costs. What did not make the headlines were all the other details of the study. The increased risk was mainly linked to synthetic hormones, especially the combination of estrogen and progestin. A group of women in this study were also given just estrogen which did not increase breast cancer risk. In fact, in long-term follow-up, those women actually had a lower risk of breast cancer and breast cancer death. It also appeared to have protective effects on heart health, particularly for women who started estrogen within 10 years of menopause. And more importantly, the risk is not one-size-fits-all. It depends on your genetics, age, and overall health. But all of that got lost in the fear. A deep mistrust of estrogen took hold among women and even more so in the medical system. And that mistrust was what I kept coming up against as I tried to have conversations with my doctors about estrogen and the long term consequences of Tamoxifen.
So my self-study continued, and I came to understand that estrogen does not create disease in the body, it is actually how you personally metabolize and detoxify it. Once estrogen has done its job in the body, whether supporting brain function, bone density, skin elasticity, or reproductive health (because all of those organs have estrogen receptors on them) it heads to the liver to be broken down. The liver then transforms it through a three-phase detoxification process. In Phase I, estrogen is broken down into various metabolites, some of which are protective, and others that are potentially harmful and damaging if it builds up. Phase II is where these metabolites are neutralized when molecules are attached to the metabolites to make them safe and water-soluble. Which is an important step because you need them water-soluble to be able to excrete them in Phase III, through urine, sweat, or poop. And all of these phases can be positively and/or negatively influenced by certain genes and other factors like stress, nutrient deficiencies, alcohol, or lack of sleep.
The takeaway? If you want to stay cancer free, make sure you are pooping daily! Could it really be that simple? Maybe for some of us. But after going down the hormone detoxification rabbit hole, I was now on a mission to understand my own genetics as there are a few important methylation pathways we can all be tested for.
To truly understand how my body was managing estrogen, I started with genetic testing. The Nutritional Genome test was recommended to me and I also combed through some raw data from a 23andMe test I took years back so that I could identify variations that influence hormone metabolism and detoxification (like those in the CYP1B1 and COMT genes). I took a DUTCH test, which showed me exactly how my body was breaking down estrogen in real time. Were my detox systems keeping up? Was I mostly breaking down estrogen into harmful or protective metabolites? This information proved to be invaluable when I was evaluating the risk around Tamoxifen for my body.
What I came to understand through this research is that your genes do matter, but your lifestyle matters more. Even if you have great genes for estrogen metabolism, your lifestyle still determines how well your detox pathways work. When you are stressed, not sleeping well, drinking alcohol, eating processed food, skipping movement, or regularly exposed to xenoestrogens (from plastics, fragrances, and pesticides), your body struggles to clear estrogen effectively. Instead of being excreted, estrogen can be reabsorbed into the bloodstream, recirculating and potentially fueling imbalance, inflammation, or disease. Learning this made me realize that hormone health is not just about what treatments we say yes or no to. It is about how we live every single day.
After gathering all of this information and immersing myself in understanding my bio-individual risk, I decided to say no to Tamoxifan. A drug that could negatively impact my quality of life, not just for the 5 years I was taking it, but forever. I have instead embraced lifestyle changes that can support my healing. I am not drinking. I am exercising every day. I am eating real food like broccoli, sprouts, salmon, chickpeas, sunflower seeds, eggs, almonds, sweet potatoes, garlic, onions, beets, and avocado. All foods that will support my unique detoxifying pathways. I am meditating and practicing mindfulness. I am protecting my energy and intentionally carving out time in my life for deep rest. These are not the kinds of practices often included in clinical research on breast cancer recurrence. But what I have come to understand is this: Your body wants to heal. It wants to stay healthy. And when you create a safe, supportive environment for your cells, they thrive.
This was not a decision I took lightly. It took time, effort, energy, and deep reflection. But now, I feel a profound sense of agency in my health and wellness journey. This choice was not made out of fear and because of that, I have zero anxiety about it. Instead, I feel empowered. The knowledge I have gained has given me the confidence to move forward with clarity and trust in my body.
