Abstract 225P
Background
Prognosis and treatment of breast cancers are associated with clinico-pathologic and biological characteristics of the tumor, which vary due to the heterogeneous nature of breast cancers. The aim of this study was to assess the frequency and prognostic parameters of luminal breast cancers among Croatian breast cancer population.
Methods
A large retrospective cross-sectional study including 1248 cases of primary breast cancer treated at Osijek University Hospital was conducted during 2016–2020. The clinico-pathologic and immunohistochemical (IHC) and in situ hybridization (ISH) data were extracted from pathology reports to study the luminal subtypes A and B. The cross-tabulated statistics of the observed characteristics were performed between the two subtypes.
Results
Luminal cancers comprised 89% (1006/1130) of the total number of cases. Of 1006 cases of luminal cancers, 717 cases (71.3%) were luminal B, while 289 (28.7%) were luminal A. Age profile of Luminal A and B cancers were similar (62.8 vs 62.7 years). Luminal B cancers were associated with higher grade (22.9% grade III in luminal B compared to 6.6% in luminal A), micorpapillary and metaplastic histology, and high frequency of nodal metastasis (39.8% in luminal B compared to 23.3% in luminal A).
Conclusions
Luminal B is the most frequent subtype of breast cancer in Croatian patients. They were associated with adverse clinico-histologic parameters such as higher grade and nodal metastasis. Our findings suggest that, despite lack of molecular studies in routine practice, IHC/ISH-based typing are sufficient for prognostic and therapeutic stratifications in breast cancers in Croatia.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.