Abstract P6-15-06: Establishing the content domain for a patient-reported outcomes measure to evaluate the unique symptom burden of inflammatory breast cancer

Background: Inflammatory breast cancer (IBC) is an aggressive, locally advanced breast cancer with a poor prognosis including a median survival of less than 4 years and a 5-year survival rate of around 60-70%. Symptom monitoring and management has demonstrated improved cancer patient outcomes, including quality of life, resource utilization, ability to continue treatment, and disease-free survival. The use of disease-specific patient-reported outcomes (PROs) is critical for facilitating individualized symptom monitoring and management. While women with IBC likely experience significant and variable symptom burden from diagnosis through treatment and survivorship that may remain under-reported and unmanaged, there is limited description of the symptom burden in this population and no disease-specific valid and reliable instrument for measuring symptom burden in IBC. In addition, because the diagnosis of IBC is based on clinical criteria as opposed to molecular or pathological diagnostic criteria, attention to defining the disease-related symptoms may assist clinicians in making timely and accurate diagnoses. The purpose of this study was to describe the patient experience of IBC and define the content domain for a PRO measure of IBC symptom burden, using patient input to ensure content validity. Methods: This descriptive study is the first stage in development of a PRO IBC symptom burden measure. Twenty patients with IBC across the disease continuum described their experience in single qualitative interviews. Content analysis was used to describe their experience and define the symptom burden content domain. Results: Mean patient age was 52.8 years (range, 30-73 years); 50% with locally advanced and 50% with metastatic disease, with 85% receiving treatment at the time of the interview. Content analysis found 51 symptoms related to both disease and treatment, with 24 symptoms reported at least 20% of participants. Participants reported, on average, 13.1 symptoms (range, 3-23 symptoms). All participants described localized disease-related symptoms that were present at diagnosis, which included breast rash (40% of participants), changes in the texture of the breast (55%), nipple changes (25%), breast pain (40%), breast discoloration (70%), breast lump (55%), breast warmth (10%), and breast swelling (50%). Treatment-related symptoms varied among participants based on modalities received. Patients volunteered ways in which symptoms impacted daily activities and relationships and how symptoms were managed. Conclusions: We have completed our pilot study. Patients with IBC experience numerous symptoms related to disease and treatment, including many localized disease-related symptoms with various treatments resulting in unique symptom burden. Symptoms may result in interference with daily activities, relationships, life plans, treatment adherence, and mood. Well-designed PROs are essential for accurate symptom assessment and management to maintain patient functioning. The content domain for a PRO symptom-burden measure of IBC encompasses the severity and activity interference of common symptoms of IBC and its treatment. Citation Format: Meagan Whisenant, Angela Alexander, Loretta A. Williams, Wendy Woodward, Randa El-Zein, Naoto Tada Ueno. Establishing the content domain for a patient-reported outcomes measure to evaluate the unique symptom burden of inflammatory breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-15-06.