RWE in oncologia: uso dei database per identificare isottotipi molecolari del cancro mammario metastatico in Italia

Introduction: The use of Real-World Evidence (RWE) is gaining increasing relevance in oncology, offering a complementary
perspective to randomised clinical trials (RCTs). In Italy, administrative databases represent a promising
source to explore treatment patterns and distribution of molecular subtypes in metastatic breast cancer
(mBC). This study was aimed at evaluating the feasibility and accuracy of using administrative data to identify and
characterise molecular subtypes of mBC in a setting of real clinical practice in Italy.
Methods: Retrospective observational study conducted on a sample of about 4 million assisted patients. Data
from different administrative flows were used to identify patients with mBC and to assign them to one of the
three main molecular subtypes (HR+/HER2-, HER2+, TNBC) through the use of proxies based on prescriptions of
drugs and diagnostic codes.
Results: Between January 2019 and June 2023, the observed distribution of subtypes was HR+/HER2- (74%),
HER2+ (15%), and TNBC (11%), in line with the ranges reported in the literature. The model demonstrated a high
concordance with pre-existing epidemiological data.
Conclusions: Administrative data are confirmed as a valid resource to describe the molecular landscape of mBC
in Italy. The RWE emerges as a crucial tool to support clinical and regulatory decisions, promoting the approach
of personalised medicine and the optimisation of healthcare resources.
Keywords: Administrative databases, Metastatic breast cancer, Molecular subtypes of breast cancer, Real-World
Evidence