CONCORDANCE OF HER2-LOW SCORING IN BREAST CARCINOMAS AMONG PATHOLOGISTS

 SAŽETAK

SnježanaTomić1,2, Tatjana Kapicl Ivković3,4, Marija Milković Periša5,6, Duško Đunđerović7,
Maja Jovičić Milentijević8,9, Svetlana Oprić10,11, Slobodanka Mitrović12, Irena Jovanić13,
Savelina Popovska14, Svitlana Bachurska15, DesislavaTashkova16, Kalin Kalchev17,
LjiljanaVučković18, ManuelaAvirović19,20, Emina Babarović19,20, Melita Perić Balja21,
ČednaTomasović22, Jasmina Rajc23,24, Irena Zagorac23,24, Davor Oršolić25 & Toni Čeprnja1,2
The results from DESTINY-Breast 04 and the subsequent introduction of trastuzumab-deruxtecan as
a potential treatement for HER2-low breast cancer necessitated the reevaluation of HER2 scoring.
The discordance in HER2 scoring reported in previous studies led us to initiate a regional ring study
and to assess our data. This ring study involved 61 breast pathology experts from four countries across
the Balkans region. The research comprised 20 samples, including biopsies and surgical specimens,
sourced from the archives of one institution. We amassed a total of 1220 scores. The findings indicate
a significant degree of interobserver agreement among pathologists in scoring individual categories
(scores 0, 1+, 2+, and 3+), with even higher agreement observed when scores 1+and 2+were combined
into a single, HER2-low category. The findings of this study indicate that adequate education,
awareness regarding the therapeutic significance of the HER2-low category, and expertise in breast
pathology facilitate the accurate identification of HER2-low breast cancers. These findings will promote
ongoing training in breast pathology within the region and will provide a reference for subsequent
research efforts.
Keywords Breast cancer, HER2-low, Trastuzumab-deruxtecan
Breast cancers represent a diverse array of tumors characterizide by significant differences in morphology,
molecular profiles, clinical presentations, biological behaviours, and therapeutic responses1
. Treatment decisions
primarily rely on the clinical stage of the disease and the outcomes of conventional biomarker analysss, which
include assessment of estrogen and progesterone receptors, human epidermal growth factor receptor 2 (HER2),
and proliferative marker Ki672.

OTVORI PDF