Advancing HER2-low breast cancer management: enhancing diagnosis and treatment strategies.

Background: Recent evidence brought by novel anti-human epidermal growth factor receptor 2 (HER2) antibody-drug conjugates is leading to significant changes in HER2-negative breast cancer (BC) best practices. A new targetable category termed 'HER2-low' has been identified in tumors previously classified as 'HER2-negative'. Daily practice in pathology and medical oncology is expected to align to current recommendations, but patient access to novel anticancer drugs across geographies might be impeded due to local challenges.

Materials and methods: An expert meeting involving ten regional pathology and oncology opinion leaders experienced in BC management in four Central and Eastern Europe (CEE) countries (Bulgaria, Croatia, Serbia, Slovenia) was held. Herein we summarized the current situation of HER2-low metastatic BC (mBC), local challenges, and action plans to prevent delays in patient access to testing and treatment based on expert opinion.

Results: Gaps and differences at multiple levels were identified across the four countries. These included variability in the local HER2-low epidemiology data, certification of pathology laboratories and quality control, and reimbursement conditions of testing and anticancer drugs for HER2-negative mBC. While clinical decisions were aligned to international guidelines in use, optimal access to testing and innovative treatment was restricted due to significant delays in reimbursement or limitative reimbursement conditions.

Conclusions: Preventing delays in HER2-low mBC patient access to diagnosis and novel treatments is crucial to optimize outcomes. Multidisciplinary joint efforts and pro-active discussions between clinicians and decision makers are needed to improve care of HER2-low mBC patients in CEE countries.