Treatment and Other Healthcare Use of Breast Cancer Patients With a Previous Cancer Diagnosis

Background/Aim: To quantify the association between a previous cancer diagnosis and healthcare use among breast cancer (BC) patients, and estimate five-year recurrence-free survival (RFS). Patients and Methods: Women with BC were classified according to a previous cancer diagnosis (BC or other). Healthcare use during the first year and five-year RFS were obtained through clinical and administrative records. Adjusted odds ratios and hazard ratios (HR) were estimated. Results: Among 681 BC patients, 21 had a previous BC and 32 a previous non-BC. The latter were less likely to receive anthracycline-based combination chemotherapy. The former had higher odds of mastectomy and genetic testing. Five-year RFS HRs (95% confidence interval) were 2.75 (0.79-9.52) and 0.52 (0.07-3.89) for previous BC and non-BC, respectively. Conclusion: Previous cancer was associated with less anthracycline-based combination chemotherapy, and patients were more likely to undergo mastectomy and genetic testing. These findings highlight the need for assessment of previous treatments, personal genetic risk and current BC characteristics. This study was funded by FEDER through the Operational Programme Competitiveness and Internationalization and national funding from the Foundation for Science and Technology – FCT (Portuguese Ministry of Science, Technology and Higher Education), under the project “A five-year prospective cohort study on the neurological complications of breast cancer: frequency and impact in patient reported outcomes” (POCI-01-0145-FEDER-016867; ref. PTDC/DTP-EPI/7183/2014), and the Unidade de Investigação em Epidemiologia – Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (POCI-01-0145-FEDER-006862; ref. UID/DTP/04750/2019). SM and LC were also funded under the scope of the project "NEON-PC -Neuro-oncological complications of prostate cancer: longitudinal study of cognitive decline" (POCI-01-0145-FEDER-032358; ref.PTDC/SAU-EPI/32358/2017). Individual grants attributed to ARC (SFRH/BD/102181/2014) and NA (SFRH/BD/119390/2016) were co-funded by FCT and the Programa Operacional Capital Humano (POCH/FSE). Data management activities up to the first year of follow-up were supported by the Chair on Pain Medicine of the Faculty of Medicine, University of Porto and by the Grünenthal Foundation – Portugal.