Nationwide analysis of the breast cancer guidelines adherence in Bulgaria

The diagnosis and treatment of breast cancer have tremendously changed in the last decades improving the survival and quality of life of the patients. Adherence to clinical practice guidelines in oncology significantly improves patients' recurrence-free and overall survival. Nowadays, no national registry/database for breast cancer patients is available. This study aims to perform a nationwide analysis of the breast cancer guidelines adherence in Bulgaria, in particular regarding the diagnostic methods for histological confirmation and the types of radical surgery performed using an artificial intelligence (AI) powered software. We analyzed data from January 2019 to August 2023 nationwide using the platform with access to anonymized medical information from Bulgaria's leading territorial oncology hospitals. A total of 13,790 patients met the inclusion criteria. The gold standard diagnostic tool, CNB, was done in 5 427 patients (39.35%), an intraoperative frozen section was performed as a method for confirmation of breast cancer in 6 257 patients (45.37%) and the standard technique for lymph node evaluation, sentinel lymph node biopsy, was done in 357 patients (2.99%). In Bulgaria, there are still difficulties in achieving comparable rates of core-needle biopsy for the diagnosis of breast cancer and we have demonstrated unacceptably high rates of frozen section use for intraoperative diagnosis of breast cancer. Breast-conserving surgery is widely accepted and available, but still, the rates are lower than usual for developed countries. The rates of sentinel lymph node biopsy, however, are unreasonably low.