Abstract PO4-16-09: Enhancing Research on Inflammatory Breast Cancer through Count Me In: Assessing the Accuracy of Self-Reported Diagnoses

Abstract Background: Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer that relies on clinical identification of specific breast changes for diagnosis, in addition to pathological confirmation of invasive breast cancer. There is a clear need to increase participation of patients with IBC in research to better understand its clinical course and optimal treatment strategy. Count Me In (CMI) is a nonprofit research initiative that enables patients across the United States and Canada to accelerate cancer research by sharing their clinical data and biospecimens. The Metastatic Breast Cancer Project (MBCProject) was the first CMI initiative and is a prospective longitudinal cohort designed to capture these data from patients with metastatic breast cancer. Methods: We reviewed available medical records of patients participating in the MBCProject and who self-reported as having IBC. Records were reviewed by a study team member to identify documentation by a provider of an IBC diagnosis. For records without a documented IBC diagnosis, the clinical symptoms were assessed using a novel quantitative IBC scoring system (Mason G et al. BCRF 2022) currently being validated. Finally, records were also assessed by a physician for final determination of an IBC diagnosis. Records were classified as “concordant” or “not concordant”. Concordant is defined as “review of medical records confirms IBC using the unifying set of specific diagnostic criteria”. We desired the rate of concordant cases to be ≥90%; if ≤ 85% it would be considered as unacceptable to rely solely on patient self-report of IBC diagnosis in future research. Results: We reviewed records of 79 patients participating in the MBCProject who self-identified as having IBC and had medical records collected. Of these, 51 (64.5%) had IBC stated in providers’ notes. Of the remaining 28 patients, 6/28 met criteria for IBC using the new IBC diagnostic criteria, 17/28 didn’t have evidence of IBC based on the records available and 6/28 we were unable to make a final determination due to lack of records at the time of initial diagnosis. In total, 57/79 (72%; 95% CI 61-82%) patients had a concordant diagnosis. Conclusion: Patient self-report registries such as CMI are invaluable for the collection of clinical information and biospecimens for research of patients with rare diseases, however, a self-reported diagnosis of IBC may not be reliable. To improve the accurate identification of IBC, optimization of the questions asked to patients on these registries is warranted. This may include additional screening questions such as specific skin findings and timing of onset of symptoms. Focusing on patients with stage III IBC may also provide a better patient population to test this strategy. Citation Format: Elizabeth Troll, Sean Ryan, Virginia (Ginny) Mason, Mariesa D. Powell, Aditi Hazra, Nikhil Wagle, Mary McGillicuddy, Sara Tolaney, Meredith Regan, Filipa Lynce. Enhancing Research on Inflammatory Breast Cancer through Count Me In: Assessing the Accuracy of Self-Reported Diagnoses abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-16-09.