Cell-Free Circulating Tumor DNA Improves Standard Genotyping of Non-Small-Cell Lung Cancer and Increases Detection of Targetable Alterations in a Selected Hispanic Cohort.

BACKGROUND: Several studies have shown that the non-small-cell lung cancer (NSCLC) genomic background among Hispanics differs from other populations. The finding of low-frequency genomic alterations in cell-free DNA (cfDNA) can increase diagnostic accuracy and could improve treatment in NSCLC. METHODS: Data from 54 Hispanic patients with advanced NSCLC with high clinical suspicion for ALK, EGFR, and ROS1 mutations were collected (including young age, female sex, and non-smokers). cfDNA was extracted from plasma and analyzed using a commercial next-generation sequencing test (Guardant360) which detects genomic alterations in 74 genes. RESULTS: The median age was 56 years (range 31-83). Most patients were female (661.1%) and never smokers (72.3%). Among the patients included, 96% (52/54) had cfDNA detectable alterations with a mean number of 3.37 cfDNA alterations per test (range 1-10). cfDNA was able to detect some genomic alterations previously undetected by tissue biopsy. Among patients with insufficient or unavailable tissue to perform testing, mutations in EGFR and ALK which led to a change in therapy were determined using cfDNA in 28.8 and 3.8% of cases, respectively. Among patients with cfDNA alterations, 46.1% (n = 24) were switched to a targeted therapy with a median progression-free survival of 11.1 months (95% CI 7.6-14.6) and an overall survival of 40.3 months (95% CI 27.1-53.6). Concurrent genetic mutations with TP53 and KRAS negatively impacted the prognosis. CONCLUSIONS: In a selected population of NSCLC Hispanic patients, comprehensive cfDNA analysis allowed a treatment change in 46.1% of the cases. Guardant360 allows the identification of genomic alterations to improve treatment selection and increase prognosis.

Molecular Epidemiology of ALK Rearrangements in Advanced Lung Adenocarcinoma in Latin America.

OBJECTIVE: Latin American countries are heterogeneous in terms of lung cancer incidence and exposure to potential carcinogens. We evaluated the frequency and clinical characteristics of ALK rearrangements (ALKr) in Latin America. METHODS: A total of 5,130 lung cancer patients from 10 Latin American countries were screened for inclusion. ALKr detection was performed by fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to assess method variability. Demographic and clinicopathologic characteristics were analyzed. RESULTS: Among the 5,130 patients screened, 8.4% (n = 433) had nonevaluable FISH tests. Evaluable FISH analyses revealed positive ALKr in 6.8% (320/4,697) of the study population, which included patients from 9 countries. ALKr distribution for each country was: Mexico 7.6% (79/1,034), Colombia 4.1% (10/242), Argentina 6.0% (153/2,534), Costa Rica 9.5% (13/137), Panama 4.4% (5/114), Uruguay 5.4% (2/37), Chile 8.6% (16/185), Venezuela 8.9% (13/146), and Peru 10.8% (29/268). RT-PCR showed high positive (83.6%) and negative (99.7%) predictive values when compared to the gold standard FISH. In contrast, IHC only showed a high negative predictive value (94.6%). CONCLUSIONS: Although there is a clear country and continental variability in terms of ALKr frequency, this difference is not significant and the overall incidence of ALKr in Latin America does not differ from the rest of the world.

Impact of Concurrent Genomic Alterations on Clinical Outcomes in Patients With ALK-Rearranged NSCLC.

INTRODUCTION: ALK tyrosine kinase inhibitors have exhibited promising activity against advanced ALK-rearranged NSCLC. However, co-occurring genetic alterations, such as CDKN2A/B or TP53, may negatively affect the efficacy of targeted therapies. METHODS: From December 2017 to December 2022, this study cohort analyzed next-generation sequencing data of 116 patients with metastatic ALK-rearranged NSCLC from five Latin American cancer centers. Clinicopathologic and molecular features were associated with clinical outcomes and risk of brain metastasis (BrM) in patients with and without concurrent somatic alterations. RESULTS: All patients (N = 116) received a second-generation ALK tyrosine kinase inhibitor, and alectinib was selected in 87.2% of cases. Coalterations occurred in 62% of the cases; the most frequent were TP53 mutations (27%) and CDKN2A/B loss (18%). The loss of CDKN2A/B was associated with an increased risk of BrM, with a cumulative incidence of 33.3% versus 7.4% in the non-coaltered subgroup. Compared with patients without coalterations, patients with concurrent CDKN2A/B loss (n = 21) had a shorter median progression-free survival (10.2 versus 34.2 mo, p < 0.001) and overall survival (26.2 versus 80.7 mo, p < 0.001). In the multivariate analysis, co-occurring CDKN2A/B loss was associated with poorer progression-free survival and OS despite the presence of other somatic coalterations, TP53 mutations, BrM, and Eastern Cooperative Oncology Group Performance Status. CONCLUSIONS: This study confirmed the worse prognostic value, which depicted co-occurring alterations in patients with ALK rearrangement. CDKN2A/B loss was substantially associated with worse outcomes and a higher risk of brain metastases. The evidence presented in our study may help select patients with ALK-positive tumors suitable for treatment escalation and closer brain follow-up.

Liquid biopsy in clinical outcomes and detection of T790M mutation in metastatic non-small cell lung cancer after progression to EGFR-TKI.

BACKGROUND: Liquid biopsy (LB) is used to detect epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) and has been demonstrated to have prognostic and predictive value. OBJECTIVE: To associate the rates of EGFR and T790M mutations detected by LB during disease progression after first- or second-generation EGFR-TKIs with clinical characteristics and survival outcomes. METHODS: From January 2018 to December 2021, 295 patients with advanced EGFR mutant (EGFRm) NSCLC treated with first- or second-generation EGFR-TKIs were retrospectively analyzed. LB was collected at the time of progression. The frequency of EGFRT790M mutations, overall survival (OS), and the clinical characteristics associated with LB positivity were determined. RESULTS: The prevalence of EGFRT790M mutation detected using LB was 44%. In patients with negative vs. positive LB, the median OS was 45.0 months vs. 25.0 months (p= 0.0001), respectively. Patients with a T790M mutation receiving osimertinib had a median OS of 44 months (95% CI [33.05-54.99]). Clinical characteristics associated with positive LB at progression extra-thoracic involvement, > 3 metastatic sites, and bone metastases. CONCLUSIONS: Our findings showed that LB positivity was associated with worse survival outcomes and specific clinical characteristics. This study also confirmed the feasibility and detection rate of T790M mutation in a Latin American population.

Modifying factors of PD-L1 expression on tumor cells in advanced non-small-cell lung cancer.

BACKGROUND: Programmed death ligand-1 (PD-L1) expression predicts immunotherapy utility in nononcogenic addictive lung adenocarcinoma (ADC). However, its reproducibility and reliability may be compromised outside clinical trials. This study aimed to evaluate factors associated with PD-L1 expression in lung ADC. METHODS: This observational study assessed 547 tumor samples with advanced lung ADC from January 2016 to December 2020 in a single cancer institution. Tumor samples were stained by at least one approved PD-L1 clone, SP263 (Ventana) or 22C3 (Dako), and stratified in tumor proportion score (TPS) <1%, 1-49%, or ≥50%. RESULTS: Of all the tumor samples, positive PD-L1 staining was higher in poorly differentiated tumors (67.3% vs. 32.7%, p < 0.001). Analytical factors associated with a PD-L1 high expression (TPS ≥ 50%) were the SP263 clone (19.6% vs. 8.2%, p < 0.001), time of archival tumor tissue <12 months (15.3% vs. 3.8%, p = 0.024), whenever the analysis was performed in the most recent years (2019-2020) (19.0% vs. 8.3%, p < 0.001), and whenever the analysis was performed by pathologists in the academic setting (Instituto Nacional de Cancerologia, INCan) (19.9% vs. 11.9%, p = 0.001). In the molecular analysis, EGFR wild-type tumors had an increased proportion of PD-L1 positive and PD-L1 high cases (60.2% vs. 47.9%, p = 0.006 and 17.4% vs.8.5%, p = 0.004). A moderate correlation (r = 0.69) in the PD-L1 TPS% was observed between the two different settings (INCan vs. external laboratories). CONCLUSION: Clinicopathological factors were associated with an increased PD-L1 positivity rate. These differences were significant in the PD-L1 high group and associated with the academic setting, the SPS263 clone, time of archival tumor tissue <12 months, and a more recent period in the PD-L1 analysis.

A high number of co-occurring genomic alterations detected by NGS is associated with worse clinical outcomes in advanced EGFR-mutant lung adenocarcinoma: Data from LATAM population.

BACKGROUND: Co-occurring genomic alterations identified downstream main oncogenic drivers have become more evident since the introduction of next-generation sequencing (NGS) analyses at diagnosis and progression. Emerging evidence has stated that co-occurring genomic alterations at diagnosis might represent de novo and primary resistance mechanisms to tyrosine kinase inhibitors (TKIs) in advanced EGFR-mutant (EGFRm) non-small lung cancer (NSCLC). In this study, we assessed the prognostic role of co-occurring genomic alterations in advanced EGFRm NSCLC. METHODS: A cohort of 111 patients with advanced NSCLC harboring EGFR-sensitive mutations detected by PCR was analyzed in 5 Latin American oncological centers from January 2019 to December 2020. All eligible patients received upfront therapy with EGFR-TKI. Co-occurring genomic alterations were determined at diagnosis in every patient by the NGS (FoundationOneCDx) comprehensive platform, which evaluates 324 known cancer-related genes. RESULTS: EGFR exon19 deletion was the most frequent oncogenic driver mutation (60.4 %) detected by NGS. According to the NGS assay, 31 % and 68.3 % of patients had 1-2 and ≥ 3 co-occurring genomic alterations, respectively. The most frequent co-occurring genomic alterations were TP53 mutations (64.9 %) followed by CDKN2AB alterations (13.6 %), BRCA2 (13.6 %), and PTEN (12.7 %) mutations. Baseline central nervous system disease was present in 42.7 % of patients. First- or second-generation EGFR TKIs (gefitinib, afatinib, or erlotinib) were the most common treatment in 67.5 % of patients, while osimertinib was administered in 27.9 % of cases. The median PFS in all evaluated patients was 13.63 months (95 %CI: 11.79-15.52). Using ≥ 3 co-occurring alterations as the cut-off point, patients with ≥ 3 co-occurring genomic alterations showed a median PFS, of 12.7 months (95 %CI: 9.92-15.5) vs 21.3 months (95 %CI: 13.93-NR) in patients with 2 or less co-occurring genomic alterations [HR 3.06, (95 %CI: 1.55-5.48) p = 0.0001]. Also, patients with a TP53 mutation had a shorter PFS, 13.6 (95 %CI: 10.7-15.5) vs 19.2 months (95 %CI: 12.8-NR); in wild type TP53 [HR 2.01 (95 %CI: 1.18-3.74) p = 0.12]. In the multivariate analysis, the number (≥3) of concurrent genomic alterations and ECOG PS of 2 or more were related to a significant risk factor for progression [HR 2.79 (95 %CI: 1.49-5.23) p = 0.001 and HR 2.42 (95 %CI: 1.22-4.80) p = 0.011 respectively]. CONCLUSION: EGFR-mutant NSCLC is not a single oncogene-driven disease in the majority of cases, harboring a higher number of co-occurring genomic alterations. This study finds the number of co-occurring genomic alterations and the presence of TP53 mutations as negative prognostic biomarkers, which confers potentially earlier resistance mechanisms to target therapy.

Clinicopathological and Prognostic Significance of CD47 Expression in Lung Neuroendocrine Tumors.

BACKGROUND: Lung neuroendocrine tumors account for approximately 15% of all lung cancer cases. LNET are subdivided into typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC), and small-cell lung cancer (SCLC). The Ki-67 index has been used for decades to evaluate mitotic counts however, the role of Ki-67 as a biomarker for assessing prognosis and guiding therapy in metastatic LNET still lacks feasible clinical validation. Recent clinical trials have indicated that inhibition of CD47 with anti-CD47 antibodies exerts a promising antitumor effect against several human malignancies, including NSCLC, melanoma, and hematologic malignancies. However, the clinical relevance of CD47 expression in LNET has remained unclear. METHODS: We performed a retrospective study in which we analyzed tumor biopsies from 51 patients with a confirmed diagnosis of LNET that received treatment at our hospital. Then, we analyzed if there was any correlation between CD47 expression with any clinical or pathological characteristic. We also analyzed the prognostic significance of CD47, assessed as progression-free survival and overall survival. RESULTS: A total of 51 patients with LNET were enrolled in our study. The mean age at diagnosis was 57.6 (±11.6) years; 30 patients were women (59%). 27.5% of patients were positive for CD47 expression, and 72.5% of patients showed a CD47 expression of less than 1% and were considered as negatives. In patients with high-grade tumors (this time defined as Ki-67 > 40%), the positive expression of CD47 was strongly associated with an increased PFS. Albeit, these differences did not reach statistical significance when analyzing OS. CONCLUSION: Contrary to what happens in a wide range of hematologic and solid tumors, a higher expression of CD47 in patients with LNET is associated with a better progression-free survival, especially in patients with a Ki-67 ≥ 40%. This "paradox" remains to be confirmed and explained by larger studies.

Association of Lung Adenocarcinoma Subtypes According to the IASLC/ATS/ERS Classification and Programmed Cell Death Ligand 1 (PD-L1) Expression in Tumor Cells.

Background: Programmed cell death-ligand 1 (PD-L1) protein expression is one of the most extensively studied biomarkers in patients with non-small cell lung cancer (NSCLC). However, there is scarce information regarding its association with distinct adenocarcinoma subtypes. This study evaluated the frequency of PD-L1 expression according to the IASLC/ATS/ERS classification and other relevant histological and clinical features. Patients and Methods: PD-L1 expression was assessed by immunohistochemistry (IHC). According to its positivity in tumor cells membrane, we stratified patients in three different tumor proportions score (TPS) cut-off points: a) <1% (negative), b) between 1 and 49%, and c) ≥50%; afterward, we analyzed the association among PD-L1 expression and lung adenocarcinoma (LADC) predominant subtypes, as well as other clinical features. As an exploratory outcome we evaluated if a PD-L1 TPS score ≥15% was useful as a biomarker for determining survival. Results: A total of 240 patients were included to our final analysis. Median age at diagnosis was 65 years (range 23-94 years). A PD-L1 TPS ≥1% was observed in 52.5% of the entire cohort; regarding specific predominant histological patterns, a PD-L1 TPS ≥1 was documented in 31.2% of patients with predominant-lepidic pattern, 46.2% of patients with predominant-acinar pattern, 42.8% of patients with a predominant-papillary pattern, and 68.7% of patients with predominant-solid pattern (p = 0.002). On the other hand, proportion of tumors with PD-L1 TPS ≥50% was not significantly different among adenocarcinoma subtypes. At the univariate survival analysis, a PD-L1 TPS cut-off value of ≥15% was associated with a worse PFS and OS. Conclusion: According to IASLC/ATS/ERS lung adenocarcinoma classification, the predominant-solid pattern is associated with a higher proportion of PD-L1 positive samples, no subtype was identified to be associated with a high (≥50%) TPS PD-L1.

Response rate of patients with baseline brain metastases from recently diagnosed non-small cell lung cancer receiving radiotherapy according to EGFR, ALK and KRAS mutation status.

BACKGROUND: Previous studies have identified that patients with EGFR mutations tend to have better responses to targeted therapy, as well as chemotherapy; however, the effect of genetic alterations in terms of radiotherapy (RT)-related outcomes has not been fully assessed. We studied the impact of common non-small cell lung cancer (NSCLC) genetic alterations (EGFR, ALK and KRAS) in relation to objective response rate (ORR) to RT in patients with brain metastases. METHODS: From 2009-2015, 153 patients with an available genotyping status were treated with whole-brain irradiation (WBI) before receiving systemic therapy. Primary outcome was ORR; secondary outcomes included intracranial progression-free survival (IPFS) and overall survival (OS). RESULTS: Overall, ORR was 47.1%. ORR to RT varied significantly according to molecular status: EGFR (64.5%) ALK (54.5%) KRAS (20%) and WT (35.4%) (P = 0.001). EGFR mutation was the only independently associated factor for response to WBI (RR 3.52 [95% CI 1.6-7.7]; P = 0.002). Median IPFS was 10.8 months [95% CI 8.2-13.5] overall; however, IPFS also varied significantly according to molecular status: EGFR (18.2 months), ALK (18.4 months), KRAS (6.0 months) and WT (8.7 months) (P < 0.0001). OS for EGFR, ALK, KRAS and WT patients was 36.6, 32.2, 15.5 and 22.4 months, respectively (P = 0.014). Intracranial-ORR (HR 0.4 [95% CI 0.2-0.6], P < 0.001) and mutation status (HR 0.7 [95% CI 0.6-0.9], P < 0.042) were independently associated with a higher OS. CONCLUSIONS: RT response varies as per tumor molecular status. The presence of EGFR mutations favors the organ-specific response to RT, and is associated with longer OS in patients with NSCLC and BM. KEY POINTS: This study addressed for the first time the difference in radiotherapy-related outcomes in patients with different genotypes of non-small cell lung cancer (NSCLC) before they received systemic therapy. Results show that response to radiotherapy varies as per tumor molecular status, particularly EGFR-mutated tumors, have a favorable response to radiotherapy, contrary to KRAS-mutated tumors.

Association between CD47 expression, clinical characteristics and prognosis in patients with advanced non-small cell lung cancer.

OBJECTIVE: CD47 is an antiphagocytic molecule that contributes to tumor cell resistance in host immune surveillance. CD47 overexpression correlated with tumor progression and shorter survival in lung cancer. However, the expression and functional significance of CD47 in Non-Small Cell Lung Cancer (NSCLC) has not been completely understood. MATERIALS AND METHODS: In this retrospective study, CD47 expression was immunohistochemically examined in tumor biopsies from 169 NSCLC patients. The association of CD47 levels (H-score) with clinicopathological characteristics and survival outcomes was evaluated. RESULTS: CD47 protein was detected in 84% of patients with a median expression of 80% (0-100). Tumor CD47 levels above 1% and 50% were found in 84% and 65.7% of patients, respectively. While, median CD47 staining index was 160 (0-300). Patients were divided into two groups according to CD47 expression (high or low), using a cutoff value of 150. High CD47 expression was associated with wood smoke exposure (71.1% vs 28.9%, P = .013) and presence of EGFR (+) mutations (66.7% vs 33.3%, P = .04). Survival analysis carried out in the whole population did not show any association of CD47 expression and survival outcome. However, in patients with EGFR (+) mutations, CD47 expression was associated with higher progression-free survival (PFS) (12.2 vs. 4.4 months, P = .032). When the survival analysis was performed according to CD47 levels (cut off value: 150), both, PFS and overall survival (OS) were shortened in patients with a high expression of CD47 (10.7 vs. NR, P = .156) and (29.2 vs. NR months P = .023), respectively. CONCLUSIONS: CD47 overexpression is not a prognostic factor for PFS and OS in NSCLC patients. However, the presence of EGFR mutations and high expression of CD47 were associated with shortened PFS and OS. Coexpression of these markers represents a potential biomarker and characterizes a therapeutic niche for lung cancer.

Effect of Metformin Plus Tyrosine Kinase Inhibitors Compared With Tyrosine Kinase Inhibitors Alone in Patients With Epidermal Growth Factor Receptor-Mutated Lung Adenocarcinoma: A Phase 2 Randomized Clinical Trial.

IMPORTANCE: Metformin hydrochloride is emerging as a repurposed anticancer drug. Preclinical and retrospective studies have shown that it improves outcomes across a wide variety of neoplasms, including lung cancer. Particularly, evidence is accumulating regarding the synergistic association between metformin and epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs). OBJECTIVE: To assess the progression-free survival (PFS) in patients with advanced lung adenocarcinoma who received treatment with EGFR-TKIs plus metformin compared with those who received EGFR-TKIs alone. DESIGN, SETTING, AND PARTICIPANTS: Open-label, randomized, phase 2 trial conducted at the Instituto Nacional de Cancerología (INCan), Mexico City, Mexico. Eligible patients were 18 years or older, had histologically confirmed stage IIIB-IV lung adenocarcinoma with an activating EGFR mutation. INTERVENTIONS: Patients were randomly allocated to receive EGFR-TKIs (erlotinib hydrochloride, afatinib dimaleate, or gefitinib at standard dosage) plus metformin hydrochloride (500 mg twice a day) or EGFR-TKIs alone. Treatment was continued until occurrence of intolerable toxic effects or withdrawal of consent. MAIN OUTCOMES AND MEASURES: The primary outcome was PFS in the intent-to-treat population. Secondary outcomes included objective response rate, disease control rate, overall survival (OS), and safety. RESULTS: Between March 31, 2016, and December 31, 2017, a total of 139 patients (mean [SD] age, 59.4 [12.0] years; 65.5% female) were randomly assigned to receive EGFR-TKIs (n = 70) or EGFR-TKIs plus metformin (n = 69). The median PFS was significantly longer in the EGFR-TKIs plus metformin group (13.1; 95% CI, 9.8-16.3 months) compared with the EGFR-TKIs group (9.9; 95% CI, 7.5-12.2 months) (hazard ratio, 0.60; 95% CI, 0.40-0.94; P = .03). The median OS was also significantly longer for patients receiving the combination therapy (31.7; 95% CI, 20.5-42.8 vs 17.5; 95% CI, 11.4-23.7 months; P = .02). CONCLUSIONS AND RELEVANCE: To our knowledge, this is the first study to prospectively show that the addition of metformin to standard EGFR-TKIs therapy in patients with advanced lung adenocarcinoma significantly improves PFS. These results justify the design of a phase 3, placebo-controlled study. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03071705.

Response Assessment of 68Ga-DOTA-E-[c(RGDfK)]2 PET/CT in Lung Adenocarcinoma Patients Treated with Nintedanib Plus Docetaxel.

Nintedanib is an oral angiokinase inhibitor used as second-line treatment for non-small cell lung cancer. New radiotracers, such as 68Ga-DOTA-E-[c(RGDfK)]2, that target αvß3 integrin might have an impact as a noninvasive method for assessing angiogenesis inhibitors. Methods: From July 2011 through October 2015, 38 patients received second-line nintedanib plus docetaxel. All patients underwent PET/CT with 68Ga-DOTA-E-[c(RGDfK)]2 radiotracer and blood-sample tests to quantify angiogenesis factors (fibroblast growth factor, vascular endothelial growth factor, and platelet-derived growth factor AB) before and after completing 2 therapy cycles. Results: Of the 38 patients, 31 had available baseline and follow-up PET/CT. Baseline lung tumor volume addressed with 68Ga-DOTA-E-[c(RGDfK)]2 PET/CT correlated with serum vascular endothelial growth factor levels, whereas baseline lung/liver SUVmax index correlated with platelet-derived growth factor AB. After treatment, the overall response rate and disease control rate were 7.9% and 47.3%, respectively. A greater decrease in lung tumor volume (-37.2% vs. -27.6%) was associated with a better disease control rate in patients (P = 0.005). Median progression-free survival was 3.7 mo. Nonsmokers and patients with a higher baseline lung tumor volume were more likely to have a higher progression-free survival (6.4 vs. 3.74 [P = 0.023] and 6.4 vs. 2.1 [P = 0.003], respectively). Overall survival was not reached. Patients with a greater decrease in lung SUVmax (not reached vs. 7.1 mo; P = 0.016) and a greater decrease in the lung/spleen SUVmax index (not reached vs. 7.1; P = 0.043) were more likely to have a longer overall survival. Conclusion:68Ga-DOTA-E-[c(RGDfK)]2 PET/CT is a potentially useful tool for assessing responses to angiogenesis inhibitors. Further analysis and novel studies are warranted to identify patients who might benefit from this therapy.

Diagnosis of EML4-ALK Translocation With FISH, Immunohistochemistry, and Real-time Polymerase Chain Reaction in Patients With Non-Small Cell Lung Cancer.

OBJECTIVE: To assess anaplastic lymphoma kinase (ALK) rearrangement detection with immunohistochemistry (IHC) and real-time polymerase chain reaction (RT-qPCR) in comparison with fluorescence in situ hybridization (FISH). METHODS: Tumor tissue samples from 230 patients with advanced non-small cell lung cancer (NSCLC) were analyzed by FISH to detect ALK rearrangements. Additional IHC tests using 5A4 clone and RT-qPCR (variants 1 to 5) were performed in 63 and 48 patients, respectively. RESULTS: Thirteen percent of FISH tests were not evaluable. From the remaining tests (n=200), 18 (9.0%) were ALK positive (ALK). ALK patients were significantly younger at the time of diagnosis (below 55 y, 14.3% vs. 5.5%, P=0.035), were light smokers (tobacco index <10, 12.6% vs. 4.1%, P=0.049), and presented adenocarcinoma with a mucinous component (30.8 vs. 8.0%, P=0.007). When comparing FISH with IHC using a cutoff of 1+ or 2+, and only 2+ staining intensity, the sensitivity, specificity, negative predictive value, and positive predictive value were as follows: 83.3%, 100.0%, 93.75%, and 100.0%; and 55.6%, 100.0%, 84.9%, and 100.0%, respectively. For RT-qPCR, these results were 55.6, 100, 90.7, and 100.0%, respectively. CONCLUSIONS: Our results suggest that RT-qPCR is an inadequate initial test for detecting ALK-positive lung cancer. IHC is highly useful as an initial screening test for ALK rearrangement detection in NSCLC. These results contribute to the medical literature on the establishment of IHC as a standard diagnostic test for ALK rearrangements in NSCLC.

Reduction in Hepatocyte Growth Factor Serum Levels is Associated with Improved Prognosis in Advanced Lung Adenocarcinoma Patients Treated with Afatinib: a Phase II Trial.

BACKGROUND: C-met and its ligand, hepatocyte growth factor (HGF) have been associated with the resistance mechanism of EGFR-TKIs. HGF was evaluated as a clinical-marker of response in NSCLC patients treated with afatinib. METHODS: Sixty-six patients with stage IIIB/IV lung adenocarcinoma and progression to any-line chemotherapy received afatinib 40 mg/day. Mutational EGFR and HER2 status were assessed by RT-PCR. HER2 amplification was evaluated by FISH. Serum HGF content was measured by ELISA before and 2 months after the start of treatment. HGF levels were assessed with the objective response rate (ORR), progression-free-survival (PFS), and overall survival (OS). This trial was registered on ClinicalTrials.gov: NCT01542437. RESULTS: Fifty patients (75 %) were EGFR mutation positive. Response was achieved in 59 % of all patients and 78 % of EGFR mutated patients. Median PFS was 10 [95 % CI 6.8-13.1] and 14.5 months [10.9-18.9] for all and EGFR mutated patients, respectively. Median OS was 22.8 [17.5-28.1] and 32.4 months [18.3-46.6] for all and EGFR mutated patients, respectively. Patients with reduced serum HGF levels had improved ORR (75 % vs 44 %; p = 0.011), PFS (15.1 [2.9-27.3] vs 6.5 months [3.9-9.1]; p = 0.005) and OS (NR vs 14.5 months [7.8 - 21.3] p = 0.007). A reduction in serum HGF levels was an independent factor associated with longer PFS (HR 0.40; p = 0.021) and OS (HR 0.31; p = 0.006) in all and EGFR mutated patients. CONCLUSIONS: A reduction in serum HGF levels was associated with improved outcomes in patients treated with afatinib. These results suggest HGF might have a role as a mechanism of resistance to EGFR-TKIs. HGF could represent a potential therapeutic target to prevent or reverse resistance particularly in EGFR mutated patients.

Células madre mesenquimales y su relación con el cáncer de pulmón / Relationship between Mesenchimal Stem Cells and Lung Cancer

Recientemente, para explicar la heterogeneidad del tumor y los procesos de carcinogénesis, se ha propuesto la teoría de la "célula madre del cáncer" (CSC). Según esta teoría, el tumor puede ser originado por un anormal organogénesis ocasionado en la CSC, que deriva de las mutaciones de la célula madre adulta "normal". Las mutaciones en la CSC se transmiten a cada célula hija la cual puede detenerse en cualquiera de los numerosos puntos antes de la maduración completa. Bien, independientemente de su origen, estas células poseen varias propiedades de las células madre normales, incluyendo autorenovación, un potencial de proliferación ilimitada para producir los linajes heterogéneos de células del cáncer que componen el crecimiento del tumor y las metástasis, además de que son altamente resistentes a la quimioterapia convencional. Estas características son las que las hacen como posibles causas de recurrencia de la enfermedad y la metástasis. La existencia de CSC se demostró por primera vez en la leucemia aguda mieloide y más recientemente en otras leucemias, glioblastoma, melanoma y tumores sólidos de origen epitelial. En esta revisión estudiaremos las células madre de pulmón y su posible relación con el cáncer de pulmón.

Recently, the theory of "cancer stem cells" (CSC) was proposed to explain tumor heterogeneity and carcinogenesis processes. According to this theory, tumors may be caused by an abnormal organogenesis caused by CSC, which derives from mutations of "normal" adult stem cells. Mutations into CSC are transmitted to each daughter cell; transmission can stop at any of several points before full maturity. Whatever their origin, these cells possess several properties of normal stem cells, including self-renewal, unlimited proliferation potential to produce heterogeneous lineages of cancer cells including tumor growth and metastasis, and high resistance to conventional chemotherapy. These characteristics make them possible causes of disease relapse and metastasis. The existence of CSC was frst demonstrated in acute myeloid leukemia and more recently in other leukemias, glioblastoma, melanoma and solid tumors of epithelial origin. In this work, our aim is to demonstrate the possible relationship between stem cells and lung cancer.

Molecular Epidemiology of ALK Rearrangements in Advanced Lung Adenocarcinoma in Latin America

OBJECTIVE:Latin American countries are heterogeneous in terms of lung cancer incidence and exposure to potential carcinogens. We evaluated the frequency and clinical characteristics of ALK rearrangements (ALKr) in Latin America.METHODS:A total of 5,130 lung cancer patients from 10 Latin American countries were screened for inclusion. ALKr detection was performed by fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to assess method variability. Demographic and clinicopathologic characteristics were analyzed.RESULTS:Among the 5,130 patients screened, 8.4% (n = 433) had nonevaluable FISH tests. Evaluable FISH analyses revealed positive ALKr in 6.8% (320/4,697) of the study population, which included patients from 9 countries. ALKr distribution for each country was: Mexico 7.6% (79/1,034), Colombia 4.1% (10/242), Argentina 6.0% (153/2,534), Costa Rica 9.5% (13/137), Panama 4.4% (5/114), Uruguay 5.4% (2/37), Chile 8.6% (16/185), Venezuela 8.9% (13/146), and Peru 10.8% (29/268). RT-PCR showed high positive (83.6%) and negative (99.7%) predictive values when compared to the gold standard FISH. In contrast, IHC only showed a high negative predictive value (94.6%).CONCLUSIONS: Although there is a clear country and continental variability in terms of ALKr frequency, this difference is not significant and the overall incidence of ALKr in Latin America does not differ from the rest of the world(AU)