The real-world, retrospective, NEROnE registry investigated the impact of next-generation sequencing (NGS) in advanced non-small-cell lung cancer (NSCLC) patients (pts) at three oncology units in the north of Italy between January 2020 and December 2022. We focused on the clinical characterization and outcomes of NSCLC with rare molecular alterations: EGFR exon 20 insertion, non-activating EGFR mutations, BRAF V600E and non-V600, ROS1 and RET rearrangements, MET, ErbB2, and FGFR mutations. Overall, these represented 6.4% (62/970) of the pts analysed with NGS in the daily practice. The most heavily represented rare alterations were ROS1 rearrangement (15 pts—24%) and MET exon 14 skipping mutation (11 pts—18%). No associations were found with the demographic and clinical features. Forty-nine pts received targeted therapies, of which 38.8% were first- and 9.8% were second-line. The remaining pts received chemotherapy and/or immunotherapy. In terms of the clinical outcomes, although not statistically significant, a tendency toward shorter OS was seen when therapies other than specific targeted therapies were used (HR: 1.84, 95% CI: 0.79–4.33, p = 0.158). The pts with co-mutations (19.4%) seemed to receive an advantage from the front-line chemotherapy-based regimen. Finally, an NLR score (a well-known inflammatory index) ≥ 4 seemed to be related to shorter OS among the pts treated with immunotherapy alone or in combination with chemotherapy (HR: 2.83, 95% CI: 1.08–7.40, p = 0.033). Prospective evaluations need to be performed to clarify whether these indexes may help to identify patients with oncogene-addicted NSCLC who could benefit from immunotherapy.
