The most useful thing a cancer patient tells her doctor is usually the thing nobody writes down. Dr. Tiffany Troso-Sandoval spent 25 years as a medical oncologist at Memorial Sloan Kettering. When asked what patients told her that never made it into a chart or a published paper, she said it was everything that mattered most. ”Those answers die in the room. They live in my head, where they helped me better understand my patient and help her personally, yet taught the field nothing.”

Elizabeth Elfenbein has built a company on that loss. On September 12, she launched Under the Sisterhood of Breast Health in San Francisco, a platform drawn from recorded conversations with survivors, previvors, and the clinicians who treat them. She is selling the patterns inside it to health systems, medtech comapniess, and drug makers.

What Doctors Learn And Never Write Down

In Under the Sisterhood’s report, 95% of patients said they had to become the CEO of their own care. Troso, who had not seen the report, described the same failure from the other side of the desk. For years she assumed she was explaining things clearly, until the volume of follow-up calls reported otherwise. “When the hundredth woman asks you the same question, you stop thinking the problem is her,” she stressed.

Her diagnosis is not that the information is missing. It was written, she explained, “in our language, for us as medical professionals,” and nobody was assigned to translate it. That is a delivery failure rather than a knowledge gap, and delivery is cheaper to fix.

Why The Survivorship Cliff Keeps Catching Everyone By Surprise

The survivorship cliff is the point where active treatment ends and structured care stops. In the report, 73% of patients described being abandoned at that moment, and 82% of clinicians independently named the same gap. Neither interview guide asked about it.

Troso supplies the mechanism. Oncology training, she noted, “defines its finish line as the end of treatment, a response rate, a cure. Not the return of a life.” Survivorship programs are required at accredited cancer centers, yet no nationally accredited fellowship exists in the field and, as of 2025, no survivorship-specific billing codes.

“Until survivorship becomes a real subspecialty the way palliative care did, we will keep producing survivors faster than we produce anyone equipped to care for them,” Troso emphasized.

She is not alone. Dr. Fumiko Chino of MD Anderson told CancerNetwork that young patients finishing radiation say “ they felt like they fell off a cliff .”

The Menopause Nobody Warned Them About

That group is growing. Breast cancer incidence climbed 1.4% a year among women under 50 between 2013 and 2022, double the rate in older women, and it is now the leading cause of cancer death in that group.

In the report, 65% mentioned treatment-induced menopause was harder than chemotherapy. Troso, who never saw that figure, put it almost identically: Oncology knows how to treat the tumor, but “it has no plan for the 40 years that follow, and for many women the menopause is harder than the chemotherapy was.”

Dr. Taniqua Miller, a board-certified OB-GYN and certified menopause practitioner, wants that conversation moved earlier. “Informed consent should not simply be ‘this treatment may cause menopause,’” she argued. Published guidance is already on her side, recommending that counseling on ovarian suppression be treated as a fundamental part of survivorship care.

Miller faults the payment model more than the clinicians. “Our healthcare system pays much more reliably for procedures, testing, and treatment than it does for thoughtful longitudinal counseling,” she sighed.

Can An AI Interviewer Get A Woman To Tell The Truth?

Elfenbein is entering a market sprinting the other way. Listen Labs, which uses AI to run customer interviews, reached a $500 million valuation on a $69 million round in January. Salesforce has since held talks about buying it for roughly $2 billion , though nothing is finalized.

Under the Sisterhood uses AI to analyze transcripts, not to conduct interviews. “AI isn’t the source of the intelligence. The women are,” commented Elfenbein.

Breast health is where the company is starting, not where it stops. Under the Sisterhood turned four this year, calls itself the Women’s Lived Experience Company, and says its archive now holds voices from more than 75 countries across six generations, spanning health, identity, leadership, work and culture.

Its women’s health platform is organized by life stage rather than by disease, running from puberty and adolescence through the reproductive years, perimenopause, menopause and post-menopause. Breast health is simply the first condition to get a platform of its own.

The breast health report analyzes 57 fully transcribed conversations, and the library keeps growing as women are recorded. Size is the obvious objection, and the company met it head-on. When the dataset expanded from 51 conversations to 57, every finding held and two grew stronger, the pattern researchers call saturation.

Every conversation was run by Teyonna Bowman, the company’s head of advocacy and engagement and a two-time survivor diagnosed at 35. Her account doubles as the sharpest limit on what the dataset holds. “There were moments when the recording stopped so we could talk about it more deeply or cry together,” she shared.

Bowman also disagrees with her own report. It argues survivors speak in borrowed advocacy language until the official phrases run out. “What struck me the most is not the borrowed language but what it meant in real life,” she countered, translating “advocate for yourself” into the work of convincing a surgeon. The company’s brief concedes there is no sampling frame, and that women who never found community are missing.

Who Gets Paid When A Story Becomes A Data Asset

Elfenbein built the platform as a pitch to the president of a medtech division at a large multinational corporation. After months of meetings, it did not align with their strategic imperatives, so she paid for it herself.

Her commercial case is adherence. Between 30% and 70% of women stop endocrine therapy before completing five years. A meta-analysis of 37 studies covering 104,777 patients found women under 50 less adherent than older ones, with menopausal symptoms the leading reason. 1 Records capture that women quit. They never capture why.

What The Rest Of The Sector Can Do With It

The buyers vary by what they need. Drug makers want the reasons behind adherence numbers they already track. Medtech wants what women say about screening, imaging and reconstruction. Health systems want language and program design, while advocacy groups and public agencies want to see where care breaks down before setting priorities.

Each can put custom questions to the database, commission a report around a single question, or fund the next wave of interviews. A government agency, she suggests, could surface “where women are experiencing delays, what they don’t understand, where communication breaks down.”

Which raises the harder question of who owns the answer. Participants recorded for nothing. Elfenbein has committed to paying them retroactively, roughly $250 to $500 apiece, once a partner pays her. “I feel strongly that if lived experience is valuable enough for companies, researchers, and institutions to learn from, then the people contributing that experience should be valued as well,” she said.

Oncology Already Proved This Works And Never Scaled It

Troso’s last answer complicates the entire enterprise. A version of this already existed, at her own institution. Patients randomized to report symptoms weekly had better quality of life and fewer emergency room visits. 2 A larger multicenter follow-up found no survival difference but confirmed the rest. 3

A decade later, it still is not standard care. A bill now before the Senate would set a minimum standard for survivorship and direct a payment model to fund it. 4 Until something like this passes, the record of what women actually endure after treatment is being built privately, on one founder’s money, and sold to whoever will buy it.

1. Wang X, Jia R, Xiang G, Zhang D, Wang Y, Xu H. Influencing Factors of Adherence to Adjuvant Endocrine Therapy in Breast Cancer Patients: A Meta-Analysis. Health Sci Rep. 2025 Jun 18;8(6):e70934. doi: 10.1002/hsr2.70934. PMID: 40535520; PMCID: PMC12174669.

2. Basch E, Deal AM, Kris MG, Scher HI, Hudis CA, Sabbatini P, Rogak L, Bennett AV, Dueck AC, Atkinson TM, Chou JF, Dulko D, Sit L, Barz A, Novotny P, Fruscione M, Sloan JA, Schrag D. Symptom Monitoring With Patient-Reported Outcomes During Routine Cancer Treatment: A Randomized Controlled Trial. J Clin Oncol. 2016 Feb 20;34(6):557-565. doi: 10.1200/JCO.2015.63.0830. PMID: 26644527; PMCID: PMC4872028. (ascopubs.org)

3. Basch E, Schrag D, Jansen J, Henson S, Ginos B, Stover AM, Carr P, Spears PA, Jonsson M, Deal AM, Bennett AV, Thanarajasingam G, Rogak L, Reeve BB, Snyder C, Bruner D, Cella D, Kottschade LA, Perlmutter J, Geoghegan C, Given B, Mazza GL, Miller R, Strasser JF, Zylla DM, Weiss A, Blinder VS, Wolf AP, Dueck AC. Symptom Monitoring With Electronic Patient-Reported Outcomes During Cancer Treatment: Final Results of the PRO-TECT Cluster-Randomized Trial. Nat Med. 2025 Apr;31(4):1225-1232. doi: 10.1038/s41591-025-03507-y. PMID: 39920394; PMCID: PMC12184200. (nature.com)

4. Klobuchar A, Alsobrooks AD. Lainie Jones Comprehensive Cancer Survivorship Act of 2026. S. 5052, 119th Cong., 2nd Sess. Introduced July 21, 2026. Referred to the Senate Committee on Finance. U.S. Congress. Available at: Congress.gov.