Circulating Tumour Cells: Detection and Application in Advanced Non-Small Cell Lung Cancer.

Non-small cell lung cancer (NSCLC) is one of the deadliest diseases worldwide. Tissue biopsy is the current gold standard for the diagnosis and molecular profiling of NSCLC. However, this approach presents some limitations due to inadequate tissue sampling, and intra- and intertumour heterogenicity. Liquid biopsy is a noninvasive method to determine cancer-related biomarkers in peripheral blood, and can be repeated at multiple timepoints. One of the most studied approaches to liquid biopsies is represented by circulating tumour cells (CTCs). Several studies have evaluated the prognostic and predictive role of CTCs in advanced NSCLC. Despite the limitations of these studies, the results of the majority of studies seem to be concordant regarding the correlation between high CTC count and poor prognosis in patients with NSCLC. Similarly, the decrease of CTC count during treatment may represent an important predictive marker of sensitivity to therapy in advanced NSCLC. Furthermore, molecular characterization of CTCs can be used to provide information on tumour biology, and on the mechanisms involved in resistance to targeted treatment. This review will discuss the current status of the clinical utility of CTCs in patients with advanced NSCLC, highlighting their potential application to prognosis and to treatment decision making.

Role of SIRT-3, p-mTOR and HIF-1α in Hepatocellular Carcinoma Patients Affected by Metabolic Dysfunctions and in Chronic Treatment with Metformin.

The incidence of hepatocellular carcinoma deriving from metabolic dysfunctions has increased in the last years. Sirtuin- (SIRT-3), phospho-mammalian target of rapamycin (p-mTOR) and hypoxia-inducible factor- (HIF-1α) are involved in metabolism and cancer. However, their role in hepatocellular carcinoma (HCC) metabolism, drug resistance and progression remains unclear. This study aimed to better clarify the biological and clinical function of these markers in HCC patients, in relation to the presence of metabolic alterations, metformin therapy and clinical outcome. A total of 70 HCC patients were enrolled: 48 and 22 of whom were in early stage and advanced stage, respectively. The expression levels of the three markers were assessed by immunohistochemistry and summarized using descriptive statistics. SIRT-3 expression was higher in diabetic than non-diabetic patients, and in metformin-treated than insulin-treated patients. Interestingly, p-mTOR was higher in patients with metabolic syndrome than those with different etiology, and, similar to SIRT-3, in metformin-treated than insulin-treated patients. Moreover, our results describe a slight, albeit not significant, benefit of high SIRT-3 and a significant benefit of high nuclear HIF-1α expression in early-stage patients, whereas high levels of p-mTOR correlated with worse prognosis in advanced-stage patients. Our study highlighted the involvement of SIRT-3 and p-mTOR in metabolic dysfunctions that occur in HCC patients, and suggested SIRT-3 and HIF-1α as predictors of prognosis in early-stage HCC patients, and p-mTOR as target for the treatment of advanced-stage HCC.

Bordetella bronchiseptica pneumonia in a patient with lung cancer; a case report of a rare infection.

BACKGROUND: Bordetella bronchiseptica (B.bronchiseptica) is a frequent cause of respiratory infections in animals but rarely causes serious infection in humans. We present a rare case of B. bronchiseptica pneumonia in a patient with lung cancer. CASE PRESENTATION: A 52-year-old white male with non small cell lung cancer developed fever during treatment with nivolumab. A persistent productive cough and a deterioration in his clinical condition led to his hospitalization for evaluation. Bronchoscopy was performed and a diagnosis of B. bronchiseptica pneumonia was made. The infection was successfully managed by antiobiotic therapy. CONCLUSIONS: B. bronchiseptica is a pathogen that can cause serious infection in humans, especially in immunocompromised or immunoincompetent individuals. In our patient it showed unusual resistance to cephalosporins and poor sensitivity to amikacin. To our knowledge this is the first case of such an infection in a lung cancer patient undergoing treatment with nivolumab. When B. bronchiseptica is identified, the possibility of a nosocomial transmission must be considered.

Rare Driver Mutations in Advanced, Oncogene-Addicted Non-Small Cell Lung Cancer: A North Italian, Real-World, Registry Experience.

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.

Clinicopathological Features of Non-Small Cell Lung Carcinoma with BRAF Mutation.

(1) Background: BRAF mutations affect 4-5% of lung adenocarcinomas. This study aimed to analyze the clinicopathological features of lung carcinomas with BRAF mutations, focusing on V600E vs. non-V600E and the presence of co-mutations. (2) Methods: All BRAF-mutated lung carcinomas were retrieved from a molecular diagnostic unit (the reference unit for four different hospitals). The samples were analyzed using next-generation sequencing. Statistical analyses included log-rank tests for overall survival (OS) and progression-free survival (PFS). (3) Results: In total, 60 BRAF-mutated lung carcinomas were retrieved: 24 (40.0%) with V600E and 36 (60.0%) with non-V600E mutations, and 21 (35.0%) with other co-mutations and 39 (65.0%) with only BRAF mutations. Survival data were available for 54/60 (90.0%) cases. Targeted therapy was documented in 11 cases. Patients with V600E mutations exhibited a better prognosis than patients with non-V600E mutations (p = 0.008 for OS, p = 0.018 for PFS); this was confirmed in PFS (p = 0.036) when considering only patients who received no targeted therapy. Patients with co-mutations displayed no prognostic difference compared to patients carrying only BRAF mutations (p = 0.590 for OS, p = 0.938 for PFS). (4) Conclusions: BRAF-mutated lung carcinomas with V600E (40.0%) had a better prognosis than those without V600E. Concomitant co-mutations (35.0%) did not affect the prognosis.

The Clinical Significance of Circulating Tumor DNA for Minimal Residual Disease Identification in Early-Stage Non-Small Cell Lung Cancer.

Lung cancer (LC) is the deadliest malignancy worldwide. In an operable stage I-III patient setting, the detection of minimal residual disease (MRD) after curative treatment could identify patients at higher risk of relapse. In this context, the study of circulating tumor DNA (ctDNA) is emerging as a useful tool to identify patients who could benefit from an adjuvant treatment, and patients who could avoid adverse events related to a more aggressive clinical management. On the other hand, ctDNA profiling presents technical, biological and standardization challenges before entering clinical practice as a decisional tool. In this paper, we review the latest advances regarding the role of ctDNA in identifying MRD and in predicting patients' prognosis, with a particular focus on clinical trials investigating the potential of ctDNA, the technical challenges to address and the biological parameters that influence the MRD detection.

Identification of palliative care needs and prognostic factors of survival in tailoring appropriate interventions in advanced oncological, renal and pulmonary diseases: a prospective observational protocol.

INTRODUCTION: It is estimated that of those who die in high-income countries, 69%-82% would benefit from palliative care with a high prevalence of advanced chronic conditions and limited life prognosis. A positive response to these challenges would consist of integrating the palliative approach into all healthcare settings, for patients with all types of advanced medical conditions, although poor clinician awareness and the difficulty of applying criteria to identify patients in need still pose significant barriers. The aim of this project is to investigate whether the combined use of the NECPAL CCOMS-ICO and Palliative Prognostic (PaP) Score tools offers valuable screening methods to identify patients suffering from advanced chronic disease with limited life prognosis and likely to need palliative care, such as cancer, chronic renal or chronic respiratory failure. METHODS AND ANALYSIS: This multicentre prospective observational study includes three patient populations: 100 patients with cancer, 50 patients with chronic renal failure and 50 patients with chronic pulmonary failure. All patients will be treated and monitored according to local clinical practice, with no additional procedures/patient visits compared with routine clinical practice. The following data will be collected for each patient: demographic variables, NECPAL CCOMS-ICO questionnaire, PaP Score evaluation, Palliative Performance Scale, Edmonton Symptom Assessment System, Eastern Cooperative Oncology Group Performance Status and data concerning the underlying disease, in order to verify the correlation of the two tools (PaP and NECPAL CCOMS-ICO) with patient status and statistical analysis. ETHICS AND DISSEMINATION: The study was approved by local ethics committees and written informed consent was obtained from the patient. Findings will be disseminated through typical academic routes including poster/paper presentations at national and international conferences and academic institutes, and through publication in peer-reviewed journals.

The Role of TP53 Mutations in EGFR-Mutated Non-Small-Cell Lung Cancer: Clinical Significance and Implications for Therapy.

Non-Small-Cell Lung Cancer (NSCLC) is the primary cause of cancer-related death worldwide. Oncogene-addicted patients usually benefit from targeted therapy, but primary and acquired resistance mechanisms inevitably occur. Tumor protein 53 (TP53) gene is the most frequently mutated gene in cancer, including NSCLC. TP53 mutations are able to induce carcinogenesis, tumor development and resistance to therapy, influencing patient prognosis and responsiveness to therapy. TP53 mutants present in different forms, suggesting that different gene alterations confer specific acquired protein functions. In recent years, many associations between different TP53 mutations and responses to Epidermal Growth Factor Receptor (EGFR) targeted therapy in NSCLC patients have been found. In this review, we discuss the current landscape concerning the role of TP53 mutants to guide primary and acquired resistance to Tyrosine-Kinase Inhibitors (TKIs) EGFR-directed, investigating the possible mechanisms of TP53 mutants within the cellular compartments. We also discuss the role of the TP53 mutations in predicting the response to targeted therapy with EGFR-TKIs, as a possible biomarker to guide patient stratification for treatment.

Wide Next-Generation Sequencing Characterization of Young Adults Non-Small-Cell Lung Cancer Patients.

Molecular characterization of advanced non-small-cell lung cancer (NSCLC) is mandatory before any treatment decision making. Next-generation sequencing (NGS) approaches represent the best strategy in this context. The turnaround time for NGS methodologies and the related costs are becoming more and more adaptable for their use in clinical practice. In our study, we analyzed a case series of young (under 65 years old) NSCLC patients with a wide NGS gene panel assay. The most frequent altered genes were TP53 (64.55%), followed by KRAS (44.1%), STK11 (26.9%), CDKN2A (21.5%), CDKN2B (14.0%), EGFR (16.1%), and RB1 (10.8%). Tumor mutational burden (TMB) was also evaluated. Considering the cut-off of 10 mut/Mb, 62 (68.9%) patients showed a TMB < 10 mut/Mb, whereas 28 (31.1%) showed a TMB ≥ 10 mut/Mb. STK11 and KRAS mutations were significantly associated with a higher TMB (p = 0.019 and p = 0.004, respectively). Conversely, EGFR and EML4-ALK alterations were more frequently found in tumors with low TMB (p = 0.019 and p < 0.001, respectively). We compared results obtained from this approach with those obtained from a single or few genes approach, observing perfect concordance of the results.

High Levels of Circulating Monocytic Myeloid-Derived Suppressive-Like Cells Are Associated With the Primary Resistance to Immune Checkpoint Inhibitors in Advanced Non-Small Cell Lung Cancer: An Exploratory Analysis.

Background: Immunotherapy has become the standard of care for non-small cell lung cancer (NSCLC) patients. Some patients experience primary resistance to immunotherapy. Currently, we lack a marker of resistance to immunotherapy. Myeloid-derived suppressive-like cells (MDSCs) can reduce tumor response rate and survival outcomes. Methods: This is an exploratory prospective observational study on metastatic NSCLC patients starting immunotherapy. Baseline peripheral blood samples were collected. Monocytic (M)-MDSCs were analyzed by flow cytometry. The main clinical outcomes were tumor response, progression-free survival (PFS), and overall survival (OS). The association between MDSC levels and tumor response was assessed. The association of PFS with OS was investigated using the Kaplan-Meier method and the Cox proportional hazards model. Results: Twenty-two patients were included. The median M-MDSC value was higher in patients with progressive disease than patients with stable disease or partial response, p = 0.045. The median MDSC value in the overall population was 1.9. We found worse PFS (HR = 2.51; p = 0.046) and OS (HR = 2.68; p = 0.042) in patients with M-MDSC values higher than the median. Conclusions: In this exploratory analysis, high M-MDSC levels are strongly associated with primary resistance to immunotherapy. If validated in larger studies, MDSC levels in blood samples could help to select NSCLC patients for higher benefit from immunotherapy.

Prognosis of ALK-rearranged non-small-cell lung cancer patients carrying TP53 mutations.

Non-small-cell lung cancer (NSCLC) is the primary cause of cancer-related death. Gene rearrangements involving the anaplastic lymphoma kinase (ALK) tyrosine kinase identify a clinical and molecular subset of NSCLC patients, who benefit from the monotherapy with ALK tyrosine kinase inhibitors. Nonetheless, responsiveness to TKIs and prognosis of these patients are influenced by several factors, including resistance mechanisms and mutations affecting genes involved in key molecular pathways of cancer cells. In a cohort of 98 NSCLC patients with ALK gene rearrangements, we investigated the role of Tumor Protein (TP53) gene mutations in predicting patients prognosis. TP53 mutations were evaluated in relation to disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS) and overall survival (OS).Results: In patients with available clinical and TP53 mutation information, we found that 13 patients (20.3%) were affected by TP53 mutations. Considered together, even though showing a trend, TP53 mutations were not associated with PFS and OS. Considering the different TP53 mutations by functionality in terms of disruptive and non-disruptive mutations, we observed that TP53 non-disruptive mutations were able to predict worse OS in the overall case series. Moreover, a worse PFS was seen in the subgroup of patients with TP53 non-disruptive mutation, in first-, second-, and third line of treatment. Our results show that mutations affecting TP53 gene, especially non-disruptive mutations, are able to affect prognosis of ALK-rearranged NSCLC patients.

Real-World Outcomes and Treatments Patterns Prior and after the Introduction of First-Line Immunotherapy for the Treatment of Metastatic Non-Small Cell Lung Cancer.

BACKGROUND: This study provides insights into the treatment use and outcomes of metastatic non-small cell lung cancer (NSCLC) patients in a real-world setting prior to and after the availability of immuno-oncology (IO) regimens in the first line (1L). METHODS: Metastatic NSCLC patients, who initiated systemic 1L anticancer treatment from 2014 to 2020, were identified from health records. Patients were grouped into Pre-1L IO and Post-1L IO, according to the availability of pembrolizumab 1L monotherapy at the date of initiating 1L systemic anticancer treatment. Patient characteristics, treatment patterns and outcomes were assessed by the cohort. Overall survival (OS) and real-world progression-free survival (rwPFS) were calculated using the Kaplan-Meier method. RESULTS: The most common 1L treatment was platinum-based chemotherapy regimens in both groups (≥46%), followed by single-agent chemotherapy (27.0%) in Pre-1L IO and pembrolizumab (26.0%) in Post-1L IO. Median OS was 6.2 (95% CI 5.5-7.4) in Pre- and 8.9 months (95% CI 7.5-10.6) in Post-1L IO, while rwPFS was 3.7 (95% CI 3.3-4.2) and 4.7 months (95% CI 3.9-5.7), respectively. CONCLUSIONS: Even if a small proportion of patients received a 1L IO, the data showed an improved survival outcomes in the Post-1L IO group.

Brigatinib in the first-line treatment of ALK+ metastatic NSCLC: safety and efficacy.

Introduction: Among the oncogene-addicted non-small cell lung cancer patients, those bearing ALK rearrangement can be currently treated with next-generation ALK inhibitors. Brigatinib was first used to treat Crizotinib-resistant patients because it can target resistance mutations in ALK fusion protein. Recently, Brigatinib was also studied as upfront treatment of newly diagnosed ALK-positive patients.Areas covered: We outline the drug profile of Brigatinib as first-line treatment and compare it with other ALK inhibitors available. The context of ALK-rearranged non-small cell lung cancer and pharmacological aspects of Brigatinib are reviewed before the analysis of the results from the study ALTA-1 L in terms of efficacy and safety.Expert opinion: The superior efficacy of Brigatinib over Crizotinib as first-line treatment is undoubted. Consequently, Brigatinib is a new option in untreated ALK+ metastatic NSCLC patients, among the other drugs available for this indication, such as Ceritinib and Alectinib. Each of these ALK inhibitors has a specific tolerability profile, so that the choice may be also guided by patient preference according to potential side effects. In the future other factors could impact treatment choice, for instance the kind of resistance ALK mutations develop under treatment could influence the sequence of ALK inhibitors.

Liquid Biopsy for EGFR Mutation Analysis in Advanced Non-Small-Cell Lung Cancer Patients: Thoughts Drawn from a Real-Life Experience.

BACKGROUND: Liquid biopsy analysis for EGFR detection in cell-free DNA (cfDNA) from NSCLC patients has become routine. The aim of this study was to explore its applicability in clinical practice. METHODS: We collected data of EGFR-mutated NSCLC patients with liquid biopsy analysis. Data included test timing, concomitant tissue re-biopsy, therapy change, histology, stage, smoking habits, gender and age. All analyses were performed via a real-time PCR method to analyze EGFR mutations at exons 18, 19, 20 and 21. Variant allele frequency was performed for patients with available sequential EGFR mutation analysis in cfDNA. Overall survival was analyzed through the Kaplan-Meier method. We designed flow charts to show the real-life application of liquid biopsy. RESULTS: We found that liquid biopsy is used in treatment-naïve patients as an alternative to EGFR detection in tumor tissue, and in patients with positive or negative EGFR from tumor biopsy. The majority of liquid biopsy analyses were performed in NSCLC patients who were disease progressive during TKI therapy. The presence of EGFR mutation in cfDNA was associated with a worse prognosis. In two patients, VAF of EGFR mutations in cfDNA was concordant with tumor volume changes. CONCLUSION: These findings suggest that liquid biopsy for EGFR detection can continue to be useful.

The Interplay Between Programmed Death Ligand 1 and Vimentin in Advanced Non-Small-Cell Lung Cancer.

BACKGROUND: Current therapy for non-small-cell lung cancer (NSCLC) frequently includes immune checkpoint inhibitors, such as pembrolizumab, and programmed death ligand 1 (PD-L1) positivity is mandatory for its use in this setting. Vimentin plays a role in carcinogenesis through the activation of the epithelial-to-mesenchymal transition (EMT) process. Its prognostic impact in NSCLC has been investigated in numerous studies but little data are available on its relation with PD-L1 expression. PATIENTS AND METHODS: We retrospectively retrieved data on patients with advanced NSCLC consecutively enrolled in a clinical trial at our institute. PD-L1 and vimentin expression were determined by immunohistochemistry. Correlations between variables were assessed using the Spearman correlation coefficient. The Kaplan-Meier method was used to estimate overall survival (OS) and the Log-rank test was used to compare survival curves. The association between demographic, clinical and biomarker information and survival was investigated with the Cox model. RESULTS: Fifty-three patients were included in the study. A weak positive correlation was observed between the PD-L1 and vimentin (ρ=0.41, P=0.003). Patients with PD-L1 values <1% showed a slightly better OS than those with higher values (HR=2.07; 95% CI: 0.92-4.65), but the difference was not significant (P=0.080). No difference in overall survival (OS) was observed on the basis of vimentin expression (HR=1.25; 95% CI: 0.59-2.66; P=0.554). Patients harboring both vimentin and PD-L1 negative expression (<1%) showed a trend towards better survival than those with ≥1% expression (HR=2.31; 95% CI: 0.87-6.17, P=0.093). No significant associations were observed between gender, age at diagnosis, stage at diagnosis, histology, KRAS or EGFR status, radical surgery or immunotherapy and OS. CONCLUSIONS: The weak positive association between PD-L1 and vimentin suggests a potential interplay between these biomarkers. Further research is warranted to evaluate EMT and immune escape as two components of the same process.

Impressive clinical response to anti-PD-1 therapy in epithelioid mesothelioma with high clonal PD-L1 expression and EML4-ALK rearrangement.

OBJECTIVES: Treatment options for malignant pleural mesothelioma (MPM) are limited but some studies on immune checkpoint inhibitors (ICIs) in MPM have reported antitumor activity. Very little is known about immune-related predictive factors. MATERIALS AND METHODS: Here we report the case of a 45-year-old woman presenting with dyspnea and evidence of pleural effusion. She was diagnosed with malignant epithelioid pleural mesothelioma with brain metastasis and peritoneal carcinosis, refractory to initial standard chemotherapy treatment. Because of high PDL1 expression (100 %), she was treated with the anti-PD1 agent, pembrolizumab. RESULTS: Chemotherapy with cisplatin and pemetrexed was started, imaging studies showing stable disease after 3 treatment cycles. The patient underwent pleural decortication but rapidly progressed and thus started chemotherapy with carboplatin and gemcitabine. After 2 cycles she experienced seizures caused by a brain metastasis. This secondary lesion was surgically removed and confirmed as a metastasis from mesothelioma. Samples from both the primary tumor and the metastasis were molecularly characterized, the pleural sample proving ALK-positive and the brain sample, ALK-negative. PD-L1 was positive in 10 % of tumor cells in the pleural biopsy and 100 % in the brain lesion. Next generation sequencing analysis was negative for both samples. It was decided to start alectinib. Disease progression (peritoneal carcinosis and liver metastases) was documented after one month followed by complete bowel obstruction and recurrence in the site of the brain surgery. Alectinib was stopped and supportive care begun with parenteral nutrition via nasogastric tube. Pembrolizumab was started and after 15 days the patient's condition had significantly improved, enabling recanalization and restoration of enteral nutrition. Imaging displayed complete response of the brain metastasis, peritoneal carcinosis, bone lesions and mediastinal nodal metastases. A partial response was documented in the pleural and pulmonary nodules, with stable liver metastases. The patient is still undergoing immunotherapy and has no cancer-related symptoms. CONCLUSIONS: Our findings indicate that the use of immunotherapy in MPM warrants further investigation. Furthermore, the impressive clinical response obtained by our patient suggests that immune checkpoint inhibitors could help in the management of the disease after the failure of other treatments.

Role of liquid biopsy in oncogene-addicted non-small cell lung cancer.

The discovery of actionable oncogene in non-small cell lung cancer (NSCLC) allowed the identification of a subgroup of patients who benefit from targeted tyrosine kinase inhibitors more than others. Mutations in the epidermal growth factor receptor (EGFR), translocations in the anaplastic lymphoma kinase (ALK) and rearrangements in the ROS proto-oncogene 1 (ROS1) must be identified in tumor tissue to guide the proper treatment choice. Liquid biopsy is based on the analysis of tumor materials released in the circulation. Liquid biopsy can be complementary to tissue biopsy, both at baseline and at progression, especially in the detection of somatic gene alterations emerging during the treatment with tyrosine kinase inhibitors (TKIs). Particularly, circulating DNA is used to find mutations in driver oncogenes, while circulating tumor cells, extracellular vesicles (EVs) and cell-free microRNAs (cfmiRNAs) are still under investigation. To help the unbiased use of liquid biopsy in the choice of the appropriate therapy, some recommendations were delivered by expert panels. Currently, analysis of EGFR mutations in cell-free DNA (cfDNA) is recommended at baseline when tissue biopsy harbors scarce tumor cells, and at progression before performing tissue biopsy; liquid biopsy analysis for other oncogenic drivers is not indicated in the clinical practice.

Targeting RET-rearranged non-small-cell lung cancer: future prospects.

Non-small-cell lung cancer (NSCLC) patients with mutated or rearranged oncogene drivers can be treated with upfront selective inhibitors achieving higher response rates and longer survival than chemotherapy. The RET gene can undergo chromosomal rearrangements in 1%-2% of all NSCLC patients, involving various upstream fusion partners such as KIF5B, CCDC6, NCOA4, and TRIM33. Many multikinase inhibitors are active against rearranged RET. Cabozantinib, vandetanib, sunitinib, lenvatinib, and nintedanib achieved tumor responses in about 30% of these patients in retrospective studies. Prospective phase II trials investigated the activity and toxicity of cabozantinib, vandetanib, sorafenib, and lenvatinib, and did not reach significantly higher response rates. VEGFR and EGFR inhibition represented the main ways of developing off-target toxicity. An intrinsic resistance emerged according to the type of RET fusion partners, as KIF5B-RET fusion is the most resistant. Also acquired mutations in rearranged RET oncogene developed as resistance to these multikinase inhibitors. Interestingly, RET fusions have been found as a resistance mechanism to EGFR-TKIs in EGFR-mutant NSCLC patients. The combination of EGFR and RET inhibition can overcome this resistance. The limitations in terms of activity and tolerability of the various multikinase inhibitors prompted the investigation of new highly selective RET inhibitors, such as RXDX-105, BLU-667, and LOXO-292. Some data emerged about intracranial antitumor activity of BLU-667 and LOXO-292. If these novel drugs will achieve high activity in RET rearranged NSCLC, also these oncogene-addicted tumors can undergo a significant survival improvement.

New generation anaplastic lymphoma kinase inhibitors.

Anaplastic lymphoma kinase (ALK) gene translocations are pro-tumoral driver alterations that encompass 3-7% of non-squamous non-small cell lung cancer (NSCLC) with specific, clinic and histologic features. The therapeutic strategy depends on anti-ALK tyrosine kinase inhibitors (TKIs) of which crizotinib was the first approved for clinical use. Despite its use improved significantly progression-free survival, overall response rate and duration of response of this illness, after a median period of 10.9 months all patients progress due to the development of acquired resistance mutations in the ALK tyrosine kinase domain in approximately one third of patients. Moreover, 60-90% of patients treated with crizotinib has a progression in the central nervous system (CNS) in absence of extracranial worsening of the disease. This is primarily attributed to poor CNS penetration by crizotinib as many pre-clinical and clinical models suggest. For instance, in order to overtake acquired resistance to crizotinib, prolong the control of the disease and manage CNS localizations, several II and III generation TKIs have been developed. Some of them were approved after the failure of crizotinib (ceritinib, alectinib, brigatinib and lorlatinib) and in first line setting (ceritinib, alectinib and brigatinib) while others are still under evaluation for TKI-naive patients such as lorlatinib, ensartinib and entrectinib. In this review we will discuss the most recent results of new TKIs in order to describe a fast growing therapeutic landscape in this setting.