Understanding Katie Thurston's Treatment Plan
- Former “Bachelorette” star Katie Thurston, 36, who is living with stage 4 breast cancer that spread to her liver, has shared on social media that her liver problems have forced changes to her treatment plan.
- She has paused Kisqali (ribociclib), a CDK4/6 inhibitor, for several months and stopped letrozole, an aromatase inhibitor.
- She is now deciding whether to restart Kisqali or switch to Verzenio (abemaciclib), another drug in the same class.
- A recent PET scan came back “a little gray,” so Thurston will undergo a specialized FES-PET scan on Oct. 13, which is Metastatic Breast Cancer Awareness Day.
- CDK4/6 inhibitors combined with hormone therapy are a standard first-line treatment for hormone receptor-positive metastatic breast cancer. Liver enzyme changes are a known side effect, which is why doctors monitor blood work closely.
The former “Bachelorette,” who was diagnosed with breast cancer in February 2025 and learned a month later that it had spread to her liver, shared a new video update to Instagram explaining that her liver has been struggling with her current medication combination.
Read MoreWalking her followers through her treatment journey, Thurston explained, “Time for another breast cancer update. If you’ve been following in the Booby Broadcast, some of this might be old news to you. If you haven’t, here’s where I’m at now.View this post on Instagram
“So as part of my cancer care, I get injections that suppress my ovaries, an aromatase inhibitor, and a CDK4/6 inhibitor. Basically, I take Kisqali, letrozole, Lupron.”
We’d like to point out that CDK4/6 inhibitors are targeted therapies that block proteins (cyclin-dependent kinases 4 and 6) that drive cancer cell division. They treat hormone receptor-positive, HER2-negative breast cancer, meaning cancer fueled by estrogen and/or progesterone that lacks the HER2 protein and therefore doesn’t respond to HER2-targeted drugs like Herceptin. This subtype is the most common form of the disease, accounting for more than two-thirds of breast cancers.
“Now in that combo, my liver was having issues, and so I had to pause the Kisqali for several months now, and the liver still is not recovering. Then I was able to pause letrozole, and then my numbers dropped significantly. So letrozole, get in the boot,” she continued.
“Kisqali, we’re waiting to see if that’s something I want to go back on, or if I’m going to switch to Verzenio. Both of these are CDK4/6 inhibitors, so technically it is still a first line of treatment.”
View this post on Instagram
Thurston also addressed her medication changes, explaining that shifting treatments is a normal part of living with metastatic disease.
“And if you don’t know, stage 4, you go through a lot of recipes in your lifetime because you’ll be on treatment for your lifetime,” she said. “I do believe that the cure is within my lifetime for breast cancer. I like to think of my future as optimistic, and the future of breast cancer care.”
The Scan That Raised More Questions Than Answers
Thurston also opened up about her most recent PET scan, which didn’t deliver the news she had hoped for.
“I did just have a recent PET scan, and I was really hoping today would be the day that I got no evidence of disease. It’s a little gray, as cancer care tends to be,” she said. “What a PET scan does is it lights up on your body where there’s cancer, but also where there’s inflammation.”
Having a PET/CT Scan? Here’s What to Expect
Thurston noted that a scan taken right after her double mastectomy in April “was lit up on both sides,” which her team attributed to post-surgical inflammation. Her newest scan looked largely the same, except for increased uptake on her right side.
“You’re not supposed to work out before a PET scan, but I didn’t know that, and I finally had just gotten back into volleyball for the last 48 hours prior to that PET scan,” she added. “So it’s very possible all my, like, I don’t know, serving, hitting made that inflammation happen again.”
View this post on Instagram
To get a clearer answer, her doctors ordered an FES-PET scan, which she explained “is going to find anything that any uptake due to estrogen or hormones, because that’s what my breast cancer feeds off of.”
According to GE HealthCare, FES stands for fluoroestradiol, a form of estrogen with a small radioactive tracer that sticks to estrogen-sensitive breast cancer cells so a PET scan can show where they are in your whole body. As per Siemens Healthineers, this helps your doctor see whether all your tumors respond to estrogen, and you may need to pause drugs like tamoxifen beforehand.
“That scan will happen on the 13th, which happens to be Metastatic Breast Cancer Awareness Day. I find that very fitting,”Thurston continued.
“All is well, and all is stable. So that is my update for now. I will keep you posted as soon as I get that PET scan later this month. And then hopefully one day I’ll get to announce no evidence of active disease, which is what anyone with stage 4 strives for.”
Katie’s Ongoing Breast Cancer Treatment Journey
Thurston is living with hormone receptor-positive (HR+) metastatic breast cancer, meaning her cancer cells use estrogen to grow. She underwent a double mastectomy on April 29, 2026, and her systemic treatment has combined three medications that work together to cut off the cancer’s fuel supply and slow its growth:
- Lupron (leuprolide): A monthly or every-few-months injection that shuts down estrogen production in the ovaries, a strategy called ovarian suppression. For premenopausal women like Thurston, this essentially places the body in a temporary menopause so that the next medication can work.
- Letrozole (Femara): An aromatase inhibitor that blocks the body’s remaining estrogen production outside the ovaries. Aromatase inhibitors are typically used in postmenopausal women, which is why premenopausal patients take them alongside ovarian suppression. Thurston has now paused letrozole after her liver numbers improved without it.
- Kisqali (ribociclib): A targeted therapy known as a CDK4/6 inhibitor, first approved by the FDA in 2017 and later expanded to include premenopausal women. Taken with hormone therapy, it blocks proteins that help cancer cells divide. Studies have shown this combination can extend survival compared with hormone therapy alone, making it a standard first-line option for HR+ metastatic breast cancer. Because Kisqali can raise liver enzymes, doctors monitor liver function with regular blood tests. Thurston has had Kisqali on hold for several months.
Remember, although stage 4 breast cancer is not curable, several treatment options exist that can extend the life of patients.
RELATED: Early Menopause Comes as a Shock to Cancer Survivor Araceli Rubi
Treatment options depend on the stage, type of primary breast cancer, and whether hormone receptors are positive.
Treatment can include a combination of:
- Chemotherapy: Oral or IV medications that are toxic to tumor cells
- Hormonal therapies: Drugs that lower estrogen levels or block estrogen receptors from allowing the cancer cells to grow
- Targeted therapies: Drugs that target your tumor’s specific gene mutations
- Immunotherapy: Medications that stimulate your immune system to recognize and attack cancer cells
- Radiation: The use of high-energy rays to kill tumor cells and shrink tumors
- Surgery: To remove a cancerous tumor or lymph nodes (uncommon with stage IV; more common in stages I, II, and III)
- Clinical trials: Studies of new medications, treatments, and other therapies offer hope for better outcomes.
View this post on Instagram
Understanding CDK4/6 Inhibitors
CDK4/6 inhibitors are a key treatment for HR+, HER2-negative metastatic breast cancer. They block CDK4/6 proteins, which can become overactive in breast cancer and drive uncontrolled cell growth, slowing or even stopping the cancer.
Three are approved:
- Ibrance (palbociclib),
- Kisqali (ribociclib)
- Verzenio (abemaciclib).
All three are pills. Ibrance and Kisqali are taken with hormone therapy for three weeks, followed by a week off, while Verzenio is taken daily, alone or with other treatments.
The drugs haven’t been compared head to head, but doctors consider them equally effective. Their side effects differ, though.
Dr. Eleonora Teplinsky, a medical oncologist at Valley Health System, previously told SurvivorNet that Verzenio causes more diarrhea, while Kisqali requires heart monitoring during the first few doses. Other side effects can include low white blood cell counts, nausea, fatigue, hair loss and headache, and patients need regular blood and liver function tests.
That’s why Thurston can switch drugs and still call it “a first line of treatment.” When side effects become too much, doctors may lower the dose, which Dr. Teplinsky says can be done safely without sacrificing effectiveness, or move to another CDK4/6 inhibitor.
Why PET Scans Can Be ‘Gray’ and What an FES-PET Scan Adds
A PET scan uses a small, safe amount of a radioactive tracer, often one similar to sugar. Cancer cells are more metabolically active than healthy cells, so they absorb more of it and light up.
But as Thurston noted, inflammation can light up too. Her team attributed the bright spots on her post-mastectomy scan to surgical healing, and her volleyball sessions may have affected her latest one.
That’s where the FES-PET scan comes in. As Thurston explained, it looks specifically for estrogen-driven activity, which could help her doctors tell whether the spot on her right side is cancer or inflammation.
Questions to Ask Your Doctor
If you’re deciding how to navigate a cancer diagnosis, it can be helpful to go into the conversation with your doctor prepared. Here are some key questions to ask as you weigh your options. SurvivorNet’s proprietary AI tool, “My Health Questions,” can also support you along the way by providing evidence‑based answers aligned with cancer treatment guidelines and informed by oncologists across multiple specialties.
Guidance on Coping With a Breast Cancer Diagnosis
Receiving a breast cancer diagnosis is undoubtedly one of the most challenging moments in a person’s life. It’s essential to remember that you are not alone. Many resources and support systems are available to help you cope with this diagnosis and navigate your treatment journey.
Here is some practical guidance on how to move forward from SurvivorNet’s experts:
- Seek Support: Reach out to support groups, both in-person and online. Connecting with others who are going through similar experiences can provide comfort and practical advice.
- Communicate with Your Healthcare Team: Your doctors, nurses, and other healthcare professionals are there to help you. Don’t hesitate to ask questions, express your concerns, and discuss your treatment options. Understanding your treatment plan can empower you and alleviate some of your anxiety.
- Take Care of Your Mental Health: Coping with cancer is not just a physical battle but an emotional one as well. Consider speaking with a counselor or therapist who specializes in cancer care. Practices such as mindfulness, meditation, and gentle exercise can also help manage stress and improve your overall well-being.
- Educate Yourself: Knowledge is power. Educate yourself about your specific type of breast cancer and the treatments available. Reliable sources of information can include your healthcare team, reputable cancer organizations, and medical literature.
- Lean on Loved Ones: Your family and friends want to support you. Let them know how they can help, whether it’s accompanying you to appointments, helping with daily tasks, or simply being there to listen.
Contributing: SurvivorNet Staff
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