Incidence of palliative treatment among breast cancer patients undergoing neoadjuvant therapy: an analysis of the Brazilian public health system.

Breast cancer is the leading cause of cancer-related deaths among women globally, including Brazil. This study assesses neoadjuvant treatment patterns, the impact of new therapies, and factors determining palliative care for patients who failed initial treatments. A historical cohort study using secondary data from DATASUS (2008-2017) focused on women aged 18-90 with stages II and III breast cancer who received neoadjuvant treatment. Data on chemotherapy, hormonal therapy, and anti-HER2 treatment were analyzed. The Palliative Treatment Rate (PTR) was calculated by cross-referencing neoadjuvant treatment records with subsequent palliative care records, indicating cases where the initial curative intent was not achieved. The study included 71,181 patients, with a mean age of 51.5 years. Most were diagnosed at Stage III (85%). Anti-HER2 therapy was introduced in 2013, with 10.5% receiving it. The 5-year PTR decreased from 44% (2008-2012) to 36% (2013-2017). The combination of chemotherapy, endocrine therapy, and anti-HER2 therapy had the lowest PTR. Logistic regression identified younger age, higher histological grade, Stage III disease, and compromised lymph nodes as factors increasing the likelihood of needing palliative care, while HER2 positivity and hormonal therapy reduced it. Regional disparities were observed, with patients from the Southeast more likely to receive palliative care. Early diagnosis and access to anti-HER2 therapy significantly reduce palliative care needs. Socio-economic and regional disparities in treatment highlight the need for equitable access to diagnostic tools and therapies to improve survival outcomes in Brazil's public healthcare system.