Identifying breast cancer recurrence histories via patient-reported outcomes

To test accuracy of patient self-report of breast cancer recurrence for enhancing standard population-based cancer registries that do not routinely collect cancer recurrence data despite the importance of this outcome.

Potential research subjects were identified in the Breast Cancer Research Database (BCRD) of the Swedish Cancer Institute (SCI). The BCRD has collected data within 45 days of each medical encounter on new primary breast cancer patients receiving all or part of their initial care at SCI. Females diagnosed with a new primary breast cancer 2004-2016, Stages I-III, and alive at the time of study initiation (2018) were identified. Recurrent breast cancer patients were matched 1:1 to surviving non-recurrent patients by patient age, date of diagnosis, and single or multiple primary tumors. Consented research subjects were surveyed about their initial and subsequent diagnostic, therapeutic, and recurrent events. PRO survey responses were compared with BCRD information for each individual participant. Discrepancies were reviewed in medical records.

A matched sample of 88 recurrent and 88 non-recurrent patients were used in analyses. Respondents correctly identified the date of diagnosis of first primary breast cancer within 1 year 94% (165/176). Recurrence was reported by 97% (85/88) of recurrent patients. No recurrence was reported by 100% (88/88) of non-recurrent patients. Recurrence date within 1 year was correctly identified in 79% (67/85). Recurrence site was correctly identified in 82% (70/85). Medical record review of survey-registry discrepancies led to BCRD corrections in 4.5% (8/176) of cases.

Breast cancer patients can accurately report their disease characteristics, treatments, and recurrence history. Patient-reported information would enhance cancer registry data.