Radiation and anti-PD-L1 synergize by stimulating a stem-like T cell population in the tumor-draining lymph node.

Radiotherapy (RT) and anti-PD-L1 synergize to enhance local and distant (abscopal) tumor control. However, clinical results in humans have been variable. With the goal of improving clinical outcomes, we investigated the underlying synergistic mechanism focusing on a CD8+ PD-1+ Tcf-1+ stem-like T cell subset in the tumor-draining lymph node (TdLN). Using murine melanoma models, we found that RT + anti-PD-L1 induces a novel differentiation program in the TdLN stem-like population which leads to their expansion and differentiation into effector cells within the tumor. Our data indicate that optimal synergy between RT + anti-PD-L1 is dependent on the TdLN stem-like T cell population as either blockade of TdLN egress or specific stem-like T cell depletion reduced tumor control. Together, these data demonstrate a multistep stimulation of stem-like T cells following combination therapy which is initiated in the TdLN and completed in the tumor.

Platinum-based chemotherapy attenuates the effector response of CD8 T cells to concomitant PD-1 blockade.

PURPOSE: Combination of chemotherapy (CT) with programmed cell death (PD)-1 blockade is a front-line treatment for lung cancer. However, it remains unknown whether and how CT affects the response of exhausted CD8 T cells to PD-1 blockade. EXPERIMENTAL DESIGN: We used the well-established mouse model of T cell exhaustion with chronic lymphocytic choriomeningitis virus (LCMV) infection to assess the effect of CT (cisplatin+pemetrexed) on T cell response to PD-1 blockade, in the absence of the impact of CT on antigen release and presentation observed in tumor models. RESULTS: When concomitantly administered with PD-1 blockade, CT affected the differentiation path of LCMV-specific CD8 T cells from stem-like to transitory effector cells, thereby reducing their expansion and production of interferon (IFN)-γ. After combination treatment, these restrained effector responses resulted in impaired viral control, compared to PD-1 blockade alone. The sequential combination strategy, where PD-1 blockade followed CT, proved to be superior to the concomitant combination, preserving the proliferative response of exhausted CD8 T cells to PD-1 blockade. Our findings suggest that the stem-like CD8 T cells themselves are relatively unaffected by CT partly because they are quiescent and maintained by slow self-renewal at the steady state. However, upon the proliferative burst mediated by PD-1 blockade, the accelerated differentiation and self-renewal of stem-like cells may be curbed by concomitant CT, ultimately resulting in impaired overall CD8 T cell effector functions. CONCLUSIONS: In a translational context, we provide a proof-of-concept to consider optimizing the timing of chemo-immunotherapy strategies for improved CD8 T cell functions.

Analysis of the adequacy of control arms in oncology randomised clinical trials published between 2017 and 2021: a meta-research study.

INTRODUCTION: Randomised controlled trials (RCTs) are usually considered the highest level of evidence for clinical practice. Patients assigned to control arm in RCTs should always receive the best available treatments to protect participants while also allowing for proper interpretation and applicability of study results. Here we analysed RCTs published in oncology between 2017 and 2021 to describe the frequency of suboptimal control arms. METHODS: We identified phase III studies testing active treatments in patients with solid tumours among 11 major oncology journals. Each control arm was analysed, and the standard of care was determined according to international guidelines and scientific evidence at accrual beginning and until accrual completion. We identified studies with suboptimal control arm from the beginning (type 1) and studies with an initially optimal control arm which became outdated during the accrual period (type 2). RESULTS: This analysis included 387 studies. Forty-three (11.1%) control arms were judged as suboptimal: 24 (6.2%) type 1 and 19 (4.9%) type 2. These rates were higher in industry-sponsored compared to academic trials: 9.3% versus 1.9% for type 1 (p = 0.003); 7.9% versus 0.6% for type 2 (p = 0.001). Rates of suboptimal control arms were higher in studies with positive results: 8.1% versus 4.0% for type 1 (p = 0.09); 7.6% versus 1.7% for type 2 (p = 0.007). CONCLUSIONS: Many trials have suboptimal control arms, even in journals with high-impact factors, leading to suboptimal treatment of control patients and biased evaluation of trial results.

Novel Lymphocyte-Independent Antitumor Activity by PD-1 Blocking Antibody against PD-1+ Chemoresistant Lung Cancer Cells.

PURPOSE: Antibodies against the lymphocyte PD-1 (aPD-1) receptor are cornerstone agents for advanced non-small cell lung cancer (NSCLC), based on their ability to restore the exhausted antitumor immune response. Our study reports a novel, lymphocyte-independent, therapeutic activity of aPD-1 against NSCLC, blocking the tumor-intrinsic PD-1 receptors on chemoresistant cells. EXPERIMENTAL DESIGN: PD-1 in NSCLC cells was explored in vitro at baseline, including stem-like pneumospheres, and following treatment with cisplatin both at transcriptional and protein levels. PD-1 signaling and RNA sequencing were assessed. The lymphocyte-independent antitumor activity of aPD-1 was explored in vitro, by PD-1 blockade and stimulation with soluble ligand (PD-L1s), and in vivo within NSCLC xenograft models. RESULTS: We showed the existence of PD-1+ NSCLC cell subsets in cell lines and large in silico datasets (Cancer Cell Line Encyclopedia and The Cancer Genome Atlas). Cisplatin significantly increased PD-1 expression on chemo-surviving NSCLC cells (2.5-fold P = 0.0014), while the sequential treatment with anti-PD-1 Ab impaired their recovery after chemotherapy. PD-1 was found to be associated with tumor stemness features. PD-1 expression was enhanced in NSCLC stem-like pneumospheres (P < 0.0001), significantly promoted by stimulation with soluble PD-L1 (+27% ± 4, P < 0.0001) and inhibited by PD-1 blockade (-30% ± 3, P < 0.0001). The intravenous monotherapy with anti-PD-1 significantly inhibited tumor growth of NSCLC xenografts in immunodeficient mice, without the contribution of the immune system, and delayed the occurrence of chemoresistance when combined with cisplatin. CONCLUSIONS: We report first evidence of a novel lymphocyte-independent activity of anti-PD-1 antibodies in NSCLC, capable of inhibiting chemo-surviving NSCLC cells and exploitable to contrast disease relapses following chemotherapy. See related commentary by Augustin et al., p. 505.

Comparing T Cell Subsets in Broncho-Alveolar Lavage (BAL) and Peripheral Blood in Patients with Advanced Lung Cancer.

BACKGROUND: Lung cancer (LC) tissue for immunological characterization is often scarce. We explored and compared T cell characteristics between broncho-alveolar lavage from tumor affected (t-BAL) and contralateral lung (cl-BAL), with matched peripheral blood (PB). METHODS: BAL and PB were collected during bronchoscopy for diagnostic and/or therapeutic purposes in patients with monolateral primary lesion. RESULTS: Of 33 patients undergoing BAL and PB sampling, 21 had histologically-confirmed LC. Most cases were locally-advanced or metastatic non-small cell LC. T cell characteristics were not significantly different in t-BAL vs. cl-BAL. Compared to PB, CD8 T cells in BAL presented features of immune activation and exhaustion (high PD-1, low IFN-g production). Accordingly, regulatory CD4 T cells were also higher in BAL vs. PB. When dichotomizing T cell density in t-BAL in high and low, we found that PD-L1 expression in LC was associated with T cell density in t-BAL. T-BAL with high T cell density had higher %IFN-g+CD8 T cells and lower %T-regs. CONCLUSION: In BAL from advanced LC patients, T cells present features of exhaustion. T cells in t-BAL could be the best surrogate of tumor-infiltrating T cell, and future studies should evaluate T cell phenotype and density as potential biomarkers for cancer immunotherapy outcome.

Squamous cell histological transformation in a lung adenocarcinoma patient (hyper) progressing upon immunotherapy.

INTRODUCTION: In non-small cell lung cancer (NSCLC) histologic transformation upon immune checkpoint inhibitors (ICI) is rare. CASE PRESENTATION: We described the case of a patient with early-stage lung adenocarcinoma who relapsed after surgery. At the time of relapse, he received chemo-radiotherapy, followed by consolidation immunotherapy. After 3 cycles the patient experienced disease hyperprogression for onset of a new lung mass, which resulted in squamous cell carcinoma. The preservation of an atypical mutation in the v-raf murine sarcoma viral oncogene homolog B1 (BRAF) gene in both the primary adenocarcinoma and the new squamous carcinoma suggests histological transformation, likely ICI-related. DISCUSSION: We reviewed similar cases in literature, highlighting common patterns and substantial differences. For a deeper insight into inherent biological mechanisms, re-biopsy in case of atypical ICI response should be encouraged.

NSCLC Biomarkers to Predict Response to Immunotherapy with Checkpoint Inhibitors (ICI): From the Cells to In Vivo Images.

Lung cancer remains the leading cause of cancer-related death, and it is usually diagnosed in advanced stages (stage III or IV). Recently, the availability of targeted strategies and of immunotherapy with checkpoint inhibitors (ICI) has favorably changed patient prognosis. Treatment outcome is closely related to tumor biology and interaction with the tumor immune microenvironment (TME). While the response in molecular targeted therapies relies on the presence of specific genetic alterations in tumor cells, accurate ICI biomarkers of response are lacking, and clinical outcome likely depends on multiple factors that are both host and tumor-related. This paper is an overview of the ongoing research on predictive factors both from in vitro/ex vivo analysis (ranging from conventional pathology to molecular biology) and in vivo analysis, where molecular imaging is showing an exponential growth and use due to technological advancements and to the new bioinformatics approaches applied to image analyses that allow the recovery of specific features in specific tumor subclones.

Descriptive Comparative Analysis of Patients With Cancer Referring to the Emergency Department of an Italian University Hospital Across the Severe Acute Respiratory Syndrome Coronavirus 2 Waves.

PURPOSE: COVID-19 cancer patients (C19-CP) represent a population at high risk for mortality, whose clinical characteristics are still unknown in the second SARS-CoV-2 wave. The aim of this retrospective study was to compare epidemiology and clinical presentation of C19-CP referring to the emergency department (ED) of our institution (San Luigi Gonzaga University Hospital, Orbassano, Turin, Italy), in a 3-week observation period of the first and second COVID-19 waves, starting from the introduction of the corresponding national lockdowns. METHODS: We retrieved ED admissions from March 9 to 29, 2020, for the first wave, and from October 24 to November 13, 2020, for the second wave. We collected clinical characteristics of consecutive patients with molecularly confirmed SARS-CoV-2 infection. We also considered untested or SARS-CoV-2-negative cancer patients referring to the ED in the reference time frames. RESULTS: C19-CP in the second wave exceeded those in the first wave despite the nonsignificant difference (39 of 576 v 8 of 163; P = .5). Compared with nononcological patients, C19-CP were older (median age 70 years [interquartile range 61-77] v 60 years [interquartile range 45-73]; P = .02) and presented more often with ≥ 2 comorbidities (40.4% v 24.3%; P = .02). Compared with nononcological patients, in C19-CP, respiratory failure (29 of 47 v 321 of 692; P = .049) and hospitalization (37 of 47 v 363 of 692; P = .0004) were higher, with comparable frequencies across the waves. Five of 24 and 10 of 27 hospitalized cancer patients in the first and second waves developed SARS-CoV-2 infection during hospitalization. CONCLUSION: C19-CP were a vulnerable population, irrespective of the COVID-19 waves. This highlights the need to prioritize vaccinations in oncological patients to safeguard and guarantee optimal anticancer care.

Predicting immunotherapy outcomes under therapy in patients with advanced NSCLC using dNLR and its early dynamics.

BACKGROUND: dNLR at the baseline (B), defined by neutrophils/[leucocytes-neutrophils], correlates with immune-checkpoint inhibitor (ICI) outcomes in advanced non-small-cell lung cancer (aNSCLC). However, dNLR is dynamic under therapy and its longitudinal assessment may provide data predicting efficacy. We sought to examine the impact of dNLR dynamics on ICI efficacy and understand its biological significance. PATIENTS AND METHODS: aNSCLC patients receiving ICI at 17 EU/US centres were included [Feb/13-Jun/18]. As chemotherapy-only group was evaluated (NCT02105168). dNLR was determined at (B) and at cycle2 (C2) [dNLR≤3 = low]. B+C2 dNLR were combined in one score: good = low (B+C2), poor = high (B+C2), intermediate = other situations. In 57 patients, we prospectively explored the immunophenotype of circulating neutrophils, particularly the CD15+CD244-CD16lowcells (immature) by flow cytometry. RESULTS: About 1485 patients treatment with ICI were analysed. In ICI-treated patients, high dNLR (B) (~1/3rd) associated with worse progression-free (PFS)/overall survival (OS) (HR 1.56/HR 2.02, P < 0.0001) but not with chemotherapy alone (N = 173). High dNLR at C2 was associated with worse PFS/OS (HR 1.64/HR 2.15, P < 0.0001). When dNLR at both time points were considered together, those with persistently high dNLR (23%) had poor survival (mOS = 5 months (mo)), compared with high dNLR at one time point (22%; mOS = 9.2mo) and persistently low dNLR (55%; mOS = 18.6mo) (P < 0.0001). The dNLR impact remained significant after PD-L1 adjustment. By cytometry, high rate of immature neutrophils (B) (30/57) correlated with poor PFS/OS (P = 0.04; P = 0.0007), with a 12-week death rate of 49%. CONCLUSION: The dNLR (B) and its dynamics (C2) under ICI associate with ICI outcomes in aNSCLC. Persistently high dNLR (B+C2) correlated with early ICI failure. Immature neutrophils may be a key subpopulation on ICI resistance.

Adoption of multiple primary endpoints in phase III trials of systemic treatments in patients with advanced solid tumours. A systematic review.

BACKGROUND AND AIM: Trial designs using multiple primary endpoints (MPEs) are increasing in phase III cancer trials. Our objectives were to describe the incidence of MPEs in recently published phase III trials testing systemic treatments in patients with advanced cancer; the main characteristics of trials adopting MPEs; the presence of mature results for all endpoints in the primary publication; consistency between results of each endpoint and authors' conclusions. METHODS: Articles of randomised phase III trials conducted in patients with advanced cancer, published between 2017 and 2020, were retrieved from PubMed. The main outcome was the proportion of trials with MPEs. In principle, according to regulatory agencies, we considered two distinct cases: (i) MPEs correspond to 'multiple chances' for the success of experimental treatment, needing adjustment for multiplicity, and (ii) a positive result depends on the success in all MPEs ('co-primary' endpoints). RESULTS: Out of 235 eligible trials, 27 trials (12%) adopted MPE, mostly overall survival (OS) and progression-free survival (PFS). The proportion of trials with MPEs increased over time, from 6% in 2017 to 20% in 2020 (p = 0.025). MPEs were adopted in 16% of for-profit trials versus 4% of non-profit trials (p = 0.006). The proportion of trials adopting MPEs was particularly high with immunotherapy (53%, p < 0.00001). Out of 27 trials with MPEs, 10 (37%) adopted an explicit definition of 'co-primary' endpoints, but only 1/10 declared the positivity of both endpoints critical for interpretation. Most trials (23, 85%) planned correction for multiplicity. Of 21 publications with positive conclusions, only 12 had a statistically significant positive result in both primary endpoints. In four cases (15%), positive conclusions were based on PFS results alone. CONCLUSIONS: Adoption of MPEs in randomised trials in oncology is quite common. Only a minority of trials respect recommendations by regulatory agencies about the adoption of MPEs, definition of 'co-primary' endpoints and correction for multiplicity.

Italian survey on the clinical management of non-small cell lung cancer patients during the COVID-19 pandemic: A lesson for the second wave.

This study investigated the clinical management of non small cell lung cancer (NSCLC) patients during the first wave of coronavirus disease 2019 (COVID-19) outbreak in Italy. A 29-questions survey was sent to 95 Italian thoracic oncologists, with 77 % of them declaring significant changes in the outpatients management and treatment. The results of this survey pointed out a significant delay of lung cancer diagnosis along with a relevant reduction of patients' accrual within clinical trials. Telemedicine emerged as a valid support for patient-healthcare interactions. Therapeutic indications followed the guidelines for adjuvant chemotherapy and concurrent chemo-radiation. Clinical indications to first-line therapies were largely confirmed, while major changes regarded the selection of second line treatment options as well as the management of elderly population. This work may represent a valid source of information to improve the clinical management of NSCLC patients during second wave of COVID-19 pandemic.

SARS-CoV-2 Infection in Cancer Patients: A Picture of an Italian Onco-Covid Unit.

Background: The world, and Italy on the front lines, has experienced a major medical emergency due to the novel coronavirus outbreak. Cancer patients are one of the potentially most vulnerable cohorts of people, but data about their management are still few. Patients and Methods: In this monocentric retrospective study we included all SARS-CoV-2 oncological patients accepted, between March 27th and April 19th 2020, at the Onco-COVID Unit at San Luigi Gonzaga Hospital, one of the few Italian oncological-COVID wards. Data were obtained from medical records. Results: Eighteen cancer patients with COVID-19 were included. The mean (±SD) age of patients was 67 ± 14 years, 89% were men. Seven (39%) developed infection in communities and 11 (61%) during hospitalization. Lung cancer was the most frequent type of cancer (10, 56%). Seven patients (39%) were symptomatic for COVID-19 at the time of diagnosis and symptoms began 2 (±2) days before. The most common were shortness of breath and diarrhea. Fever was present in 5 patients (28%). Among the 11 asymptomatic patients, 8 (73%) became symptomatic during the hospitalization (mean time of symptoms onset 4 days ±4). Six patients (33%) were on active anti-tumor treatment: 2 (33%) received anti-tumor therapy within 2 weeks before the infection diagnosis and 2 (33%) continued oncological treatment after SARS-CoV-2 positivity. Eight (44%) patients died within a mean of 12 days (±8) from the infection diagnosis. Conclusions: Our series confirms the high mortality among cancer patients with COVID-19. The presence of asymptomatic cases evidences that typical symptoms and fever are not the only parameters to suspect the infection. The Onco-Covid unit suggests the importance of a tailored and holistic approach, even in this difficult situation.

Double immune checkpoint blockade in advanced NSCLC.

Immunotherapy-based options for patients with advanced non-small cell lung cancer (NSCLC) are increasing at an unprecedented pace, carrying the promise to prolong survival of this deadly disease. To maximize responses and extend benefit to a larger portion of patients, immunotherapy combination strategies are currently under investigation, with chemo-immunotherapy already in use. Combinations of programmed death-1/ligand-1 (PD-1/L1) and cytotoxic T lymphocytes antigen-4 (CTLA-4) were developed with the rationale of targeting complementary pathways involved in T cell activation, and already showed to be highly active in other malignancies. Recently, the phase III Checkmate 227 trial showed that combination of nivolumab and ipilimumab provided survival benefit in untreated advanced NSCLC patients. However, accurate patients' selection and appropriate sequencing of different immunotherapy-based approaches remain unsolved. In this review, we provide an overview of the currently available evidence on double immune checkpoint inhibition (ICI) for NSCLC treatment and discuss current issues and future perspectives.

Quality of life assessment and reporting in colorectal cancer: A systematic review of phase III trials published between 2012 and 2018.

BACKGROUND: In this study, our aim was to describe quality of life (QoL) prevalence and heterogeneity in QoL reporting in colorectal cancer phase III trials. METHODS: We included all phase III trials evaluating anticancer drugs in colorectal cancer patients published between 2012 and 2018 by 11 major journals. RESULTS: Out of the 67 publications identified, in 41 (61.2 %) QoL was not listed among endpoints. Out of 26 primary publications of trials including QoL among endpoints, QoL results were not reported in 10 (38.5 %). Overall, no QoL data were available in 51/67 (76.1 %) primary publications. In particular, in the metastatic setting, QoL data were not available in 12/18 (66.7 %) trials with primary endpoint overall survival, and in 20/29 (69.0 %) trials with other primary endpoints. CONCLUSIONS: QoL was absent in a high proportion of recently published phase III trials in colorectal cancer, even in trials of second or further lines, where attention to QoL should be particularly high.

Quality of life analysis in lung cancer: A systematic review of phase III trials published between 2012 and 2018.

OBJECTIVES: We previously reported that quality of life (QoL) is not included among trial endpoints and QoL results are underreported in a significant proportion of phase III oncology trials. Here we describe QoL adoption, reporting and methodology of QoL analysis in lung cancer trials. MATERIALS AND METHODS: We selected all primary publications of lung cancer phase III trials assessing anticancer drugs published between 2012 and 2018 by 11 major journals. RESULTS: 122 publications were included. In 39 (32.0%) publications, QoL was not listed among endpoints: in 10/17 (58.8%) early stage/locally advanced NSCLC, in 15/54 (27.8%) first-line of advanced NSCLC; in 10/41 (24.4%) second and further lines of advanced NSCLC, in 4/10 (40.0%) SCLC. Proportion of trials not including QoL was similar over time: 32.9% publications in 2012-2015 vs. 30.6% in 2016-2018. Out of 83 trials including QoL among endpoints, QoL results were absent in 36 primary publications (43.4%). Proportion of trials without QoL results in primary publication increased over time (30.6% 2012-2015 vs. 61.8% 2016-2018, p = 0.005). Overall, QoL data were not available in 75/122 (61.5%) primary publications, due to the absent endpoint or unpublished results. QoL data were lacking in 48/68 (70.6%) publications of trials with overall survival as primary endpoint, 27/54 (50.0%) with other primary endpoints and 28/54 (51.9%) publications with a positive result. For trials including QoL among endpoints but lacking QoL results in primary publication, probability of secondary publication was 6.3%, 30.1% and 49.8% after 1, 2 and 3 years respectively, without evidence of improvement comparing 2012-2015 vs. 2016-2018. CONCLUSION: QoL is not assessed or published in many phase III lung cancer trials, a setting where QoL value should be highly considered, due to high symptom burden and generally limited life expectancy. Timely inclusion of results in primary publications is worsening in recent years.

Women With Synchronous or Metachronous Lung and Ovarian Cancer: A Multi-Institutional Report.

BACKGROUND/AIM: Double diagnosis of lung cancer (LC) and ovarian cancer (OC) is rare. Here, we describe patients with synchronous/metachronous LC and OC to identify common clinical and pathological patterns. PATIENTS AND METHODS: Clinical, pathological and molecular data of patients diagnosed and treated at 30 European Institutions from 2008 to 2018 were retrieved and analysed. Whenever tissue was available, centralized pathology revision was performed. RESULTS: A total of 19 cases were found; one was excluded at pathology revision. Most LCs were adenocarcinomas (15/18) and most OCs were high-grade serous (15/18) carcinomas. Of the 9 patients analysed, 7 carried oncogene-addicted LC (4 EGFR, 1 B-RAF and 2 ALK) and five out of 7 carried BRCA mutations. One patient with a germline-BRCA1 mutation received olaparib, resulting in a durable response of both malignancies. Median overall survival was 33 months. CONCLUSION: In our series, most synchronous/metachronous LCs and OCs showed genetic alterations. Further analyses with wide NGS panel could shed light on the biological mechanisms driving their occurrence.

Quality-of-Life Assessment and Reporting in Prostate Cancer: Systematic Review of Phase 3 Trials Testing Anticancer Drugs Published Between 2012 and 2018.

Quality of life (QoL) is not included among the end points in many studies, and QoL results are underreported in many phase 3 oncology trials. We performed a systematic review to describe QoL prevalence and heterogeneity in QoL reporting in recently published prostate cancer phase 3 trials. A PubMed search was performed to identify primary publications of randomized phase 3 trials testing anticancer drugs in prostate cancer, issued between 2012 and 2018. We analyzed QoL inclusion among end points, presence of QoL results, and methodology of QoL analysis. Seventy-two publications were identified (15 early-stage, 20 advanced hormone-sensitive, and 37 castration-resistant prostate cancer [CRPC]). QoL was not listed among study end points in 23 studies (31.9%) (40.0% early stage, 40.0% advanced hormone sensitive, and 24.3% CRPC). QoL results were absent in 15 (30.6%) of 49 primary publications of trials that included QoL among end points. Overall, as a result of absent end point or unpublished results, QoL data were lacking in 38 (52.8%) primary publications (53.3% early stage, 55.0% in advanced hormone sensitive, and 51.4% in CRPC). The most commonly used QoL tools were Functional Assessment of Cancer Therapy-Prostate (FACT-P) (21, 53.8%) and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) (14, 35.9%); most common methods of analysis were mean changes or mean scores (28, 71.8%), time to deterioration (14, 35.9%), and proportion of patients with response (10, 25.6%). In conclusion, QoL data are lacking in a not negligible proportion of recently published phase 3 trials in prostate cancer, although the presence of QoL results is better in positive trials, especially in CRPC. The methodology of QoL analysis is heterogeneous for type of instruments, analysis, and presentation of results.

Anaplastic lymphoma kinase tyrosine kinase inhibitors in non-small cell lung cancer.

Lung cancer still represents the leading cause of cancer-related mortality. However, the recent advent of tyrosine kinase inhibitors (TKI), pioneering drugs against targetable mutations, have dramatically improved prognosis of advanced non-small cell lung cancer (NSCLC) patients. Anaplastic lymphoma kinase (ALK) gene rearrangements, identified in 3-7% of NSCLC cases, reflects in the constitutive activation of downstream signalling pathways, stimulating tumour cell proliferation, differentiation and survival. To accurately detect the wide spectrum of ALK rearrangements, the introduction of innovative techniques, like reverse transcriptase polymerase chain reaction (RT-PCR) or next generation sequencing (NGS) now allows for a more precise detection of variants and a more objective reading assessment, compared to the traditional diagnostic approaches. In some occasions, these new tools may dynamically monitor tumor evolution and even guide the choice of the most appropriate ALK inhibitor. In fact, among ALK TKIs available, crizotinib was the first to receive FDA accelerate approval for ALK rearranged NSCLC patients. Notwithstanding its response rate, ranging from 57% to 74%, the majority of patients progress within the first year of drug administration, due to acquired resistance. Both ALK-dependent and independent mechanisms of acquired resistance to TKIs have been identified. If the activation of multiple bypass signaling pathways constitutes the most common ALK-independent mechanism of resistance and one of the most difficult to overcome, ALK-dependent escape strategy mainly consists of mutations in the kinase domain, where the type of mutation largely depends on the TKI administered. Second and third generation TKIs are now available and are demonstrating high systemic and central nervous system (CNS) efficacy in clinical trials. Even though appropriate timing and sequencing of these compounds are still unclear, the large number of ALK inhibitors is now a precious resource aiming to prolong progression-free survival (PFS) and finally overall survival (OS). Here Authors provide an overview of the current approaches in the clinical management of advanced NSCLC patients harboring ALK rearrangement and discuss future perspectives to address current issues, highlighting the perception that ALK-rearranged advanced NSCLC patients benefit from maintained ALK inhibition for as long as possible.