Abstract PO2-06-01: Validity of patient-reported data from long-term survivors of metastatic breast cancer
Authors: Gallagher Meredith , Burkard Mark 
Published: May 2024

Background: Metastatic Breast Cancer is incurable, with 5-year survival of ~30%. The Outliers Study recruited participants with metastatic breast cancer to fill out an extensive survey to better elucidate how clinical, social, and genetic factors affect metastatic breast cancer survivorship. Patient-reported surveys can be a valuable source of data for research studies and cancer registries to further our understanding of disease, but concerns regarding the validity of patient reporting remain. Beatty et al. (2022) suggest that patients with early stage breast cancer are reliable reporters of disease recurrence (79% accuracy rate), but no study to our knowledge has evaluated the validity of reporting regarding metastases, or those who are long-term survivors. In this study, over 1000 women with metastatic breast cancer filled out an extensive survey. We compared the medical records with self-reported data on clinical history to assess concordance.

Objective: To determine the validity of patient-reported data pertaining to a wide variety of oncologic information, including but not limited to primary diagnosis date, stage, hormone status, metastatic date, site, and post-metastatic chemotherapy regimens, in long term survivors of metastatic breast cancer.

Methods: Patients with metastatic breast cancer were recruited for the nation-wide Outliers Study to fill out an extensive survey on their oncologic history. Of &gt;1000 participants enrolled in the Outliers Study, we identified a subpopulation of those who had lived the longest with metastatic disease and named this cohort “Long Term Survivors” (LTS). We acquired either partial or complete oncologic medical records from 31 LTS in order to determine the validity of patient-reported survey responses. Table 1 describes the details of this LTS cohort (n=31). We then compared each LTS survey to the medical record to verify responses and identify any inaccuracies. We also assessed accuracy to compare those who did and did not consult their medical records while responding to the survey.

Results: Of the verifiable survey responses, we identified 592 accurate responses and 5 inaccuracies, yielding a 99.2% accuracy rate of patient-reported oncologic data. The identified errors included 2 minor discrepancies in clinical detail, 2 false-negative reports and 1 false-positive report. Specifically, there were minor discrepancies regarding biopsy type (i.e. core biopsy reported instead of fine needle) and site of radiation (e.g. “chest wall” instead of T12 vertebrae). The false-negative reporters failed to report 1) a positive history for surgery distant from breast for metastatic disease and 2) a positive history of biopsy for disease distant to the breast. The false positive error was a report of “surgery on distant metastasis” for a history of bone marrow biopsy. Each error identified was made by a separate participant and we found no association between patients who were reporting from memory and patients who reported an inaccurate response. Of note, there were no inaccurate responses identified pertaining to the topics of initial diagnosis date, stage, and histologic type, breast surgical history, hormone and HER2 receptor status of initial and metastatic disease, date and site of metastatic disease, BRCA mutation status, date and regimens of chemotherapy, and date of radiation history.

Conclusion: Long term survivors of metastatic breast cancer report clinical data spanning a wide range of oncologic topics with high accuracy. The majority of errors identified in patient reported survey responses were minor and suggested misunderstandings of medical nomenclature (surgery vs biopsy; core vs FNA) and anatomic specificity. The topic of biopsy was most prone to error. Notably, we found no association between errored responses and patients who reported from memory without referencing their medical records.

Table 1

Citation Format: Meredith Gallagher, Mark Burkard. Validity of patient-reported data from long-term survivors of metastatic breast cancer [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 PO2-06-01.