No abstract

Before the introduction of tyrosine kinase inhibitors (TKIs) for a particular subgroup of patients, despite platinum-based combination chemotherapy, the majority of patients affected by non-small-cell lung cancer (NSCLC) did not live longer than one year. With deeper understanding of tumor molecular biology, treatment of NSCLC has progressively entered the era of treatment customization according to tumor molecular characteristics, as well as histology. All this information allowed the development of personalized molecular targeted therapies. A series of studies have shown that, in some cases, cancer cells can grow and survive as result of the presence of a single driver genomic abnormality. This phenomenon, called oncogene-addiction, more often occurs in adenocarcinoma histology, in non-smokers (except BRAF mutations, also frequent in smoking patients), young, and female patients. Several different driver mutations have been identified and many studies have clearly shown that upfront TKI monotherapy may improve the overall outcome of these patients. The greater efficacy of these drugs is also associated with a better tolerability and safety than chemotherapy, with fewer side effects and an extremely good compliance to treatment. The most frequent oncogene-addicted disease is represented by those tumors carrying a mutation of the epidermal growth factor receptor (EGFR). The development of first, second and third generation TKIs against EGFR mutations have dramatically changed the prognosis of these patients. Currently, osimertinib (which demonstrated to improve efficacy with a better tolerability in comparison with first-generation TKIs) is considered the best treatment option for patients affected by NSCLC harboring a common EGFR mutation. EML4-ALK-driven disease (which gene re-arrangement occurs in 3–7% of NSCLC), has demonstrated to be significantly targeted by specific TKIs, which have improved outcome in comparison with chemotherapy. To date, alectinib is considered the best treatment option for these patients, with other newer agents upcoming. Other additional driver abnormalities, such as ROS1, BRAF, MET, RET and NTRK, have been identified as a target mirroring peculiar vulnerability to specific agents. Oncogene-addicted disease typically has a low early resistance rate, but late acquired resistance always develops and therefore therapy needs to be changed when progression occurs. In this narrative review, the state of art of scientific literature about targeted therapy options in oncogene-addicted disease is summarized and critically discussed. We also aim to analyze future perspectives to maximize benefits for this subgroup of patients.

No abstract

Large-cell neuroendocrine carcinomas of the lung (LCNECs) are rare tumors representing 1–3% of all primary lung cancers. Patients with LCNEC are predominantly male, older, and heavy smokers. Histologically, these tumors are characterized by large cells with abundant cytoplasm, high mitotic rate, and neuroendocrine immunohistochemistry-detected markers (chromogranin-A, synaptophysin, and CD56). In 2015 the World Health Organization classified LCNEC as a distinct subtype of pulmonary large-cell carcinoma and, therefore, as a subtype of non-small cell lung carcinoma (NSCLC). Because of the small-sized tissue samples and the likeness to other neuroendocrine tumors, the histological diagnosis of LCNEC remains difficult. Clinically, the prognosis of metastatic LCNECs is poor, with high rates of recurrence after surgery alone and overall survival of approximately 35% at 5 years, even for patients with early stage disease that is dramatically shorter compared with other NSCLC subtypes. First-line treatment options have been largely discussed but with limited data based on phase II studies with small sample sizes, and there are no second-line well defined treatments. To date, no standard treatment regimen has been developed, and how to treat LCNEC is still on debate. In the immunotherapy and targeted therapy era, in which NSCLC treatment strategies have been radically reshaped, a few data are available regarding these opportunities in LCNEC. Due to lack of knowledge in this field, many efforts have been done for a deeper understanding of the biological and molecular characteristics of LCNEC. Next generation sequencing analyses have identified subtypes of LCNEC that may be relevant for prognosis and response to therapy, but further studies are needed to better define the clinical impact of these results. Moreover, scarce data exist about PD-L1 expression in LCNEC and its predictive value in this histotype with regard to immunotherapy efficacy. In the literature some cases are reported concerning LCNEC metastatic patients carrying driver mutations, especially EGFR alterations, showing targeted therapy efficacy in this setting of disease. Due to the rarity and the challenging understanding of LCNEC, in this review we aim to summarize the management options currently available for treatment of LCNEC.