Background

Bulgaria is one of the countries with the lowest breast cancer (BC) survival in Europe. We investigated the impact of the adherence to EUSOMA recommendations for diagnosis and treatment of breast diseases on treatment outcomes.

Methods

This retrospective study includes 6699 women with single-sided invasive BC, who lived longer than 1 month after diagnosis. All patients were diagnosed with a single primary tumor and were registered at the Bulgarian National Cancer Registry (BNCR) in 2012 and 2013. We investigated the distribution of the EUSOMA quality indicators (QI) among patients; the median overall survival (OS) in subgroups according to the status of those QI and the difference in OS between the subgroups. Patients were followed up until November 2020. The Kaplan Meier method and log rank test were applied. Information for tumor size was available only according to T category of TNM.

Results

Analysis could be performed for only four QI. Their distribution among patients (pts) and the significance of the survival differences between subgroups is shown in the table. The median OS in most of the subgroups was not reached. The observed 5-year survival rate among all included patients was 74.2%. There was a significant difference in OS between all pairs of subgroups in favor of patients who received the required treatment and had known tumor characteristics, except between HER2+ (T > 2 cm or N+) women who received chemotherapy and were treated or not with adjuvant trastuzumab. Table: 173P

Distribution of EUSOMA QI and significance of the survival difference between the patients' subgroups

Conclusions

The low adherence to EUSOMA recommendations, according to data from BNCR, the observed low overall survival outcomes and the significant differences in survival between investigated subgroups raise the question of whether the patient’s registration process is insufficient or diagnostic procedures and treatments are suboptimal. Wider implementation of the international standards of diagnosis and treatment of BC on a national level is needed.

Legal entity responsible for the study

Mariela Vasileva-Slaveva.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.