Katie Thurston was diagnosed with breast cancer in February 2025 at the age of 34.
“I had a small lump in my breast around the 10’oclock [sic] spot,” the former Bachelorette wrote via her Instagram Stories that same month. “I discovered it myself. Thought maybe it was my period [or] maybe it was muscle soreness from working out. But, eventually, this lump never went away.”
Thurston subsequently visited her doctor for a mammogram, which indicated the presence of cancerous tissue. She later underwent a biopsy to learn more about the type of cancer.
“Good news! My cancer hasn’t metastasize[d],” Thurston shared via her Instagram Stories on February 21, 2025, noting the malignant tissue was confined in her lymph nodes. “Two more appointments left in LA before officially moving to NYC [on] March 1st. The anticipated order of things is fertility (egg/embryo freezing), chemo, then surgery.”
Katie Thurston Diagnosed With Breast Cancer: ‘Ready to Fight This’
Ahead of her cancer treatment, Thurston moved to the Big Apple with her now-husband, Jeff Arcuri. (Thurston and the comedian got engaged in late 2024 and married in March 2025.)
“I’m so thankful for my family, friends, and community here for helping me make it to my current stage [sic] of mind,” she added. “Today I feel calm, less scared, and ready.”
Keep scrolling for a full timeline of Thurston’s cancer battle:
November 2024
Thurston discovered a lump in her breast in late 2024, noting the following February on her Instagram Stories that the pain continued for “three [or] four months.”
“My first lump [which was a benign cyst] felt like a pea or marble [and] hard, unnatural, but didn’t cause me discomfort. The second felt larger,” she recalled in February 2025. “The pain initially came and went, but maybe after 3-4 months of it not going away or improving, I got nervous and saw my doctor.”
Thurston had a breast ultrasound, a mammogram and multiple biopsies, which confirmed the presence of cancer.
February 2025
Thurston was diagnosed shortly before Valentine’s Day, revealing the news publicly several hours later.
“Yesterday I saw all the couples post their Valentine’s Day celebrations. I felt envious if I’m being honest. Jeff took me to Hawaii and after, we were going to travel the world before planting roots together in NYC finally,” she wrote via Instagram on February 15. “But instead, my Vday was spent coordinating a place to live as I have to go back to LA for more testing and treatment.”
She added, “I used my morning to figure out insurance for NYC and laws on preexisting conditions. I scheduled appointments for another biopsy, fertility, mental health, surgery, as well as meeting with my team to discuss the overall treatment plan, which will include chemo.”
‘Bachelorette’ Star Katie Thurston Gives Update on Breast Cancer Diagnosis
Thurston had another biopsy, this time on her lymph nodes, on February 19.
“Finished biopsy. Went much better this time,” Thurston wrote via her Instagram Stories. “Took lorazepam, explained my last appt struggles and asked for more numbing, and they allowed Jeff to be there holding my hand.”
The biopsy indicated that Thurston’s cancer hadn’t metastasized further.
March 2025
At the start of the month, Thurston moved to NYC full-time before she started fertility treatments. The reality star opted to freeze embryos before undergoing chemotherapy.
“One day you think you don’t want kids,” she wrote on March 9. “Then one day you meet the man of your dreams and would do anything to make sure we can start a family in the future.”
Throughout March, Thurston continued planning her treatment protocol.
“I opted in for the I-Spy breast cancer trial instead of the standard of care,” she wrote on March 13. “The goal is to match treatments to patients used on the molecular and genetic characteristics of their tumors instead of a ‘one size fits all’ route. This all means I’ll have extra testing done in advance and during.”
That same day, she had an optometry appointment to “get [her] eyes checked out” to check if she still qualifies for the I-Spy clinical trial. One day later, Thurston underwent an egg retrieval.
Days after Us Weekly exclusively confirmed that Thurston and Arcuri tied the knot on March 22, they discovered multiple spots had been found on the former Bachelorette’s liver. Afterward, Thurston underwent biopsies on her breast, lymph nodes and liver to discover when to start her treatment. She also had a port placed.
On March 28, Thurston confirmed that the spots found on her liver were cancerous.
“After days of waiting, unfortunately, I did find out today that my breast cancer has spread to the liver,” she said in an Instagram video. “It is fairly small, however it does put me at stage four.”
Thurston shared that she would start treatment the following week.
April 2025
As Thurston packed her hospital bag on April 3 to start chemotherapy the next day, she received a call from her doctors to pause her plans.
“I got the call that my pathology results on my liver, breast and lymph nodes all came back as HER2 Negative, even though my original samples as Kaiser were HER2+,” Thurston wrote via Instagram on April 4. “I was minutes away from taking my steroid for chemo prep. Instead, I am headed to my doctor to discuss how this happened, what testing is needed and what this means for my new treatment plan. Sounds like chemo is off the table now.”
She confirmed on April 10 that her cancer was HER2-negative. “What this means is no chemo,” she explained via Instagram Story, before breaking down her new treatment plan.
“Instead I’ll be on Letrozole + Kisqali + Zoladex as my first line of treatment,” she wrote. “This is a custom plan based on being [/] having HER2-negative, Luminal B, hormone-positive breast cancer. Letrozole to block estrogen, Kisqali to stop cancer cells from growing, and Zoladex to shut down my ovaries.”
However, chemo is “not completely off the table,” she explained, saying, “If this treatment stops working or if the cancer grows again, it’s an option we’ll revisit. We will closely monitor the treatment plan and make sure it’s working for my body.”
On April 12, Thurston further broke down her treatment plan, adding that she’ll have “monthly” appointments to “monitor my heart and do blood draws.” She added, “I think my first scan from now is in three months.”
June 2025
Thurston shared via Instagram on June 1 that she finished her second month of treatment and noticed a few changes to her body.
“Right now, after finishing two months of my medication, my hair is coming out in an unnatural amount of clumps. Working on that,” she said. “I’m losing my memory. That’s great. Going through customs and them being like, ‘Where are you coming from?’ And I looked at him and was like, ‘I don’t remember. I don’t remember.’”
Thurston explained that she’s making “big decisions” about how to treat her liver, whether that be radiation, ablation, histotripsy — which she shared is what she’s going to do with NYU. She noted that zoladex didn’t work, leading her to get her period. Thurston explained that she’s switching to lupron, and if that doesn’t work, she claimed her ovaries might need to be taken out.
Weeks later, Thurston got candid about the cost of her ongoing treatment. She shared a screenshot of an insurance claim via her Instagram Story, which showed that her doctors were billed $320,325.57, while she paid $22,420.40 out of pocket.
“Thank you to the brands I have the opportunity to work with and the people who support me,” Thurston wrote. “Shoutout to the $1300/month I pay to help with my medical bills that I’ll have the rest of my life as a stage 4 patient.”
July 2025
After vacationing in Greece with her husband, Thurston returned home for her “three month scan check in.”
“We will find out if the tumors are stable (no growth) or even possibly shrinking! As long as my scans are good, I can continue this treatment plan,” she wrote via her Instagram Story at the time. “As a stage 4 girly, I’ll be on a treatment plan for life, so it’s a win when something is working. It’s also why funding is so important for breast cancer research, because some of us run out of options for treatment.”
September 2025
Thurston gave an update on her plans for treatment. After some scans came back “a little concerning,” her doctor lowered her medication dosage from three pills to two a day.
“That has worked for my liver enzymes, meaning I don’t need to pause my treatment, I can continue my treatment,” she said in a July 2025 Instagram video. “The bigger test on if this is working still, is next month I will get rescanned to see how much the tumor has shrunk.”
If her next round of scans comes back good, Thurston will be able to undergo a double mastectomy in November.
