Current practice of genomic profiling of patients with advanced solid tumours in Italy: the Italian Register of Actionable Mutations (RATIONAL) study

Background: The Italian Register of Actionable Mutations (RATIONAL) is a multicentric, observational study collecting next-generation sequencing (NGS)-based tumour profiling data of patients with advanced solid tumours. Methods: The study enrols patients who had available an NGS-based tumour profiling (Pathway-A) or undergo comprehensive genomic profiling (CGP) with FoundationOne CDx assays within the trial (Pathway-B). The primary endpoint was the rate of actionable mutations identified. Results: Sequencing data were available for 738 patients in Pathway-A (218) and -B (520). In Pathway-A, 154/218 (70.6%) tests were performed using NGS panels ≤52 genes, and genomic alterations (GAs) were found in 164/218 (75.2%) patients. In Pathway-B, CGP revealed GAs in 512/520 (98.5%) patients. Levels I/II/III actionable GAs according to the European Society of Medical Oncology Scale for Clinical Actionability of molecular Targets (ESCAT) were identified in 254/554 (45.8%) patients with non-small-cell lung cancer, cholangiocarcinoma, colorectal, gastric, pancreatic and breast cancer. The rate of patients with level I GAs was similar in Pathways A and B (69 versus 102). CGP in Pathway-B revealed a higher number of patients with level II/III GAs (99 versus 20) and potentially germline pathogenic/likely pathogenic variants (58 versus 15) as compared with standard testing in Pathway-A. In patients with cancer of unknown primary, CGP detected OncoKB levels 3B/4 GAs in 31/58 (53.4%) cases. Overall, 67/573 (11.7%) of patients received targeted therapy based on genomic testing. Conclusion: The Italian Register of Actionable Mutations represents the first overview of genomic profiling in Italian current clinical practice and highlights the utility of CGP for identifying therapeutic targets in selected cancer patients.