Breast Cancer Awareness is a massive success, except at generating awareness for complicated cases like Tanya

Every October, the breast cancer conversation turns toward detection, survival rates, and progress. Pink ribbons appear on packaging and stadiums light up to highlight breast cancer awareness and the immense progress we’ve made in treating the disease, especially when it’s caught early. This Breast Cancer Awareness Month, Novellia wants to raise awareness about the multitude of other conditions, including heart disease, diabetes, and depression, among others, that patients with breast cancer contend with each day on top of managing their breast cancer treatment. 

Tanya arrived with more than breast cancer 

To illustrate what a real breast cancer patient in our cohort looks like, I want to share the story of Tanya (name changed to protect her privacy). Tanya is a Novellia patient who consented to share her data, and her story belongs to her. 

Tanya was in her late 20s when she was diagnosed with breast cancer; but at that point she had already spent more than a decade managing sickle cell disease, a hereditary red blood cell disorder that causes episodes of severe pain, organ damage, and chronic anemia. Tanya’s medical record already told a decade-long story pre-cancer: recurrent vaso-occlusive crises requiring hospitalization, acute chest syndrome, a pulmonary embolism, transfusions, and chronic pain managed on long-acting morphine and oxycodone. She had also cycled through multiple therapies, hydroxyurea, L-glutamine, crizanlizumab, and voxelotor, before her breast cancer diagnosis arrived.

One month after she was diagnosed with breast cancer, she had a lumpectomy. The hardest part came when chemotherapy started. After her first cycle, she was hospitalized in a sickle cell pain crisis. A blood transfusion meant to help triggered a serious reaction; fever, worsening breathing, and she ended up in the ICU requiring an exchange transfusion. Even finding compatible blood was its own ordeal: over a decade of transfusions had left her body sensitized to donor blood, and with 11 antibodies on file, matched units were hard to come by.

Tanya is the type of patient that clinical trials are not built around. Her chronic anemia, her history of blood clots, her anticoagulation, her organ complications; any one of these would likely have been grounds for exclusion from a standard breast cancer protocol. Her data also spanned multiple specialties, bridging together a care team across oncology and hematology. 

Most Patients Arrive with More Than Cancer

A patient like Tanya is more common than you think. Before a breast cancer patient receives their first diagnosis, they are often already carrying a significant disease burden. Data from Novellia's patient-mediated EHR cohort shows that 56% of patients had two or more chronic conditions prior to their diagnosis. The most common were depression or anxiety (56%, including antidepressant use), obesity (44%), hypertension (43%), hyperlipidemia (40%), and diabetes (21%). The most frequent comorbid pair was hypertension with hyperlipidemia (19%).

Yet the clinical trials generating this evidence, the ones whose results become drug labels, reimbursement decisions, and clinical guidelines, are designed around less comorbid patients with fewer variables. Cardiovascular disease is one of the most prevalent comorbidities in breast cancer patients at 39%. Yet across landmark trials, patients with cardiac histories, renal impairment, or hepatic dysfunction are systematically screened out.

For example, DESTINY-Breast03 and DESTINY-Breast04, two landmark trials that reshaped the HER2-positive and HER2-low treatment landscape, both excluded patients with a history of clinically significant interstitial lung disease (ILD) or pneumonitis, uncontrolled cardiovascular disease, symptomatic heart failure (NYHA Class II–IV), prior myocardial infarction within six months, and QTc prolongation beyond defined thresholds. Adequate hepatic and renal function were required as inclusion criteria, ruling out patients with even moderate organ impairment. monarchE, the pivotal adjuvant trial for abemaciclib, similarly excluded patients with a history of ventricular arrhythmia, sudden cardiac arrest, or venous thromboembolism, and required ECOG performance status ≤1.

How Real World Data Informs Breast Cancer Studies

The FDA has explicitly signaled interest in broadening eligibility criteria in oncology trials, and its Oncology Real-World Evidence Program, established under the 21st Century Cures Act, now accepts RWE for label expansions, post-marketing surveillance, and external control arms. Approximately 23–28% of drug approvals between 2022-2024 included RWE submissions, with oncology representing the largest single therapeutic area. 

Real-world data on comorbid subgroups directly supports market access. Payers making formulary decisions want evidence of effectiveness in the patients they are actually covering: patients with hypertension on ACE inhibitors, patients with diabetes on GLP-1 agonists, patients with histories of cardiac events. Beyond formulary, comorbidity-aware RWE supports clinical differentiation. If two drugs have comparable trial-derived data, but one has published outcomes data in HER2-low patients with baseline cardiovascular disease—the population a cardiologist and oncologist are co-managing together—that evidence matters to the clinician making the prescribing decision.

But this kind of evidence only exists if you can see the whole patient. A payer claim will show a drug dispensed, an oncology EHR shows a dose modified, and a cardiology clinical note may explain why. When those records live in separate systems and never speak to each other, the picture is incomplete. For a patient like Tanya, her breast cancer care and her sickle cell care were inseparable. But in a standard data environment, they would appear as two unconnected stories. Longitudinal, multi-system records don't just add data points, but they change what questions are even askable.

Does Your Data Show the Complete Picture?

The breast cancer patient who arrives in the clinic in 2026 is not always the patient built into a clinical trial population. She is managing her cancer alongside other conditions, often several of them, that shape her treatment tolerance, her adherence, her risk of treatment-emergent toxicities, and the durability of her response.

Clinical trials are designed the way they are for good reasons: Tight eligibility criteria protect patient safety, reduce confounding, and give regulators a clean signal on which to base an approval decision. That scientific rigor is the foundation the field is built on. RWE doesn't replace that foundation, but it extends it into populations, care settings, and comorbidity profiles that trials can't follow patients into. If you work in life sciences, take a close look at your evidence base. Does your data reflect the patients who receive your therapy? Does it follow them across years of care, through comorbid conditions and treatment changes? Teams that pair trial data with longitudinal real world data gain a fuller understanding of how their drugs perform in practice. Start by mapping which patients your current data covers, then extend that coverage.

The breast cancer cohort referenced in this post was refreshed September 2026 (N = 1,770).

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References

AstraZeneca & Daiichi Sankyo. (2022). DESTINY-Breast03: A study of DS-8201a versus T-DM1 for HER2-positive metastatic breast cancer (NCT03529110). ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT03529110

AstraZeneca & Daiichi Sankyo. (2018). DESTINY-Breast04: DS-8201a versus investigator's choice for HER2-low breast cancer (NCT03734029). ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT03734029

Deng, Y.-F., Girman, C. J., & Ritchey, M. E. (2025). Real-world evidence in FDA approvals for labeling expansion of small molecules and biologics. Therapeutic Innovation & Regulatory Science, 59, 982–992. https://doi.org/10.1007/s43441-025-00816-9

Johnston, S. R. D., Toi, M., O'Shaughnessy, J., Rastogi, P., Campone, M., Neven, P., et al. (2023). Abemaciclib plus endocrine therapy for hormone receptor-positive, HER2-negative, node-positive, high-risk early breast cancer (monarchE): results from a preplanned interim analysis of a randomised, open-label, phase 3 trial. The Lancet Oncology, 24(1), 77–90. https://doi.org/10.1016/S1470-2045(22)00694-5

Laberge, M., Lapointe, I., Maheu, C., Lambert, S., Lebel, S., & Paquette, M. (2021). Patterns of comorbidities in women with breast cancer: A Canadian population-based study. Cancer Causes & Control, 32(9), 981–993. https://pubmed.ncbi.nlm.nih.gov/31280456/

Unger, J. M., Vaidya, R., Hershman, D. L., Minasian, L. M., & Fleury, M. E. (2019). Systematic review and meta-analysis of the magnitude of structural, clinical, and physician and patient barriers to cancer clinical trial participation. JNCI Cancer Spectrum, 3(4), pkz52. https://pmc.ncbi.nlm.nih.gov/articles/PMC6649727/

U.S. Food and Drug Administration. (2023). Advancing real-world evidence program. https://www.fda.gov/drugs/development-resources/advancing-real-world-evidence-program

U.S. Food and Drug Administration. (2024). FDA eliminates major barrier to using real-world evidence in drug and device application reviews [Press release]. https://www.fda.gov/news-events/press-announcements/fda-eliminates-major-barrier-using-real-world-evidence-drug-and-device-application-reviews

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