Advances in pharmacotherapy of small cell lung cancer

AKT phosphorylation as a predictive biomarker for PI3K/mTOR dual inhibition-induced proteolytic cleavage of mTOR companion proteins in small cell lung cancer

Background

Constitutive activation of PI3K signaling has been well recognized in a subset of small cell lung cancer (SCLC), the cancer type which has the most aggressive clinical course amongst pulmonary tumors. Whereas cancers that acquire a mutation/copy gain in PIK3CA or loss of PTEN have been implicated in enhanced sensitivity to inhibitors targeting the PI3K/AKT/mTOR pathway, the complexities of the pathway and corresponding feedback loops hamper clear predictions as to the response of tumors presenting these genomic features.

Methods

The correlation between the expression profile of proteins involved in the PI3K/AKT/mTOR signaling and cell viability in response to treatment with small molecule inhibitors targeting isoform-specific PI3Ks, AKT, and mTOR was assessed in 13 SCLC cancer cell lines. Athymic nude mice were used to determine the effect of PI3K/mTOR dual inhibition on the growth of xenograft SCLC tumors in vivo. The activation of caspase signaling and proteolytic cleavages of mTOR companion proteins were assessed using recombinant caspases assays and Western blot analyses.

Results

Our results indicate that the sensitivity of these SCLC cell lines to GSK2126458, a dual PI3K/mTOR inhibitor, is positively correlated with the expression levels of phosphorylated AKT (p-AKT) at Thr308 and Ser473. Inhibition of pan-class I PI3Ks or PI3K/mTOR dual inhibition was shown to induce proteolytic cleavage of RICTOR and RPTOR, which were respectively dependent on Caspase-6 and Caspase-3. A combination of a clinically approved PI3Kα-selective inhibitor and an mTORC1 inhibitor was shown to have synergistic effects in inducing the death of SCLC cells with high p-AKT. We observed no clear correlation between PTEN levels and the survival of SCLCs in response to PI3K/mTOR dual inhibition; however, PTEN depletion was shown to increase the susceptibility of low p-AKT SCLC cells to dual PI3K/mTOR inhibitor-induced cell death as well as the proteolytic cleavage of RICTOR.

Conclusions

These results suggest the level of p-AKT can be a companion diagnostic biomarker for the treatment of SCLC involving the combinational use of clinically approved isoform-specific PI3K and mTOR inhibitors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00862-y.

Validation of Pretreatment Prognostic Factors and Prognostic Staging Systems for Small Cell Lung Cancer in a Real-World Data Set

Simple Summary

We present an analysis of a real-world cohort of patients with small cell lung cancer (SCLC) and examine the value of prognostic factors and scores that have been published in recent decades. In our analysis, only a few clinical (age, tumor stage) and a single laboratory parameter (alkaline phosphatase) are associated with the prognosis of patients with SCLC. We could not confirm the prognostic role of most of the published complex prognostic scores.

Abstract

Treatment decisions in patients with small cell lung cancer (SCLC) are made based on the extent of the disease. However, the outcome varies among patients at the same stage. A simple tool to predict outcomes in SCLC patients would be helpful for clinical decision-making. In recent years, several prognostic scores have been proposed. In this study, we evaluated the different prognostic factors in an unselected real-world cohort of patients. We retrospectively collected clinical, radiological and laboratory data from 92 patients diagnosed with SCLC. Univariate and multivariate cox regression analyses of survival were performed to assess the prognostic value of relevant clinical and laboratory factors for SCLC. Furthermore, we examined the association between eight published prognostic scores for SCLC and overall survival (OS). In the overall cohort, the median OS was 10.3 months (20.9 months and 9.2 months for limited disease (LD) SCLC and extensive disease (ED) SCLC, respectively). In univariate analysis, initial staging, number of metastatic sites and presence of liver, bone and adrenal gland metastases were significantly associated with worse OS. Of the established laboratory markers, albumin, alkaline phosphatase and hyponatremia but not lactate dehydrogenase (LDH) significantly predicted OS. All published prognostic scores, with the exception of the Glasgow Prognostic Score, did not significantly predict OS. In multivariate analysis, age, staging and alkaline phosphatase serum levels showed significant association with OS. We could not confirm the prognostic significance of most of the published complex prognostic scores. We therefore recommend using simple clinical and laboratory factors instead of complex scores to estimate the prognosis of SCLC patients in clinical practice.

Advances in Small-Cell Lung Cancer (SCLC) Translational Research

Over the past several years, we have witnessed a resurgence of interest in the biology and therapeutic vulnerabilities of small-cell lung cancer (SCLC). This has been driven in part through the development of a more extensive array of representative models of disease, including a diverse variety of genetically engineered mouse models and human tumor xenografts. Herein, we review recent progress in SCLC model development, and consider some of the particularly active avenues of translational research in SCLC, including interrogation of intratumoral heterogeneity, insights into the cell of origin and oncogenic drivers, mechanisms of chemoresistance, and new therapeutic opportunities including biomarker-directed targeted therapies and immunotherapies. Whereas SCLC remains a highly lethal disease, these new avenues of translational research, bringing together mechanism-based preclinical and clinical research, offer new hope for patients with SCLC.

Real World Analysis of Small Cell Lung Cancer Patients: Prognostic Factors and Treatment Outcomes

In this observational study, we assessed treatment patterns and prognostic factors in patients with small cell lung cancer (SCLC) in a large state-mandated healthcare organization in Israel. Methods: All incident cases with histologically confirmed SCLC who initiated systemic anti-cancer treatment between 2011 and 2017 were identified. Treatment patterns and overall survival (OS) were evaluated for each line of therapy. Results: A total of 235 patients were identified (61% male, median age 64 years, 95% ever smokers, 64% had extensive stage). The first-line treatment was platinum-etoposide regimen for 98.7% of the cohort. The second and third-line regimen were given to 43% and 12% of patients, respectively. Mean OS for extensive and limited stage patients was 9.1 and 23.5 months respectively. In a multivariable model, increased risk for mortality was observed among patients with an ECOG performance status (PS) of 2 compared to a PS of 0-1 for the extensive stage patients (Hazard ratio (HR) = 1.63, 95% confidence ratios (CI): 1.00-2.65); and for males compared to females for the limited stage patients (HR = 2.17; 95% CI: 1.12-4.20). Regarding all 2nd line patients in a multivariable model incorporating relevant confounding factors, demonstrated a significantly better outcome with platinum-based regimens compared to topotecan. Median survival after initiation of 2nd line in platinum-sensitive patients was longer (p = 0.056) for those re-challenged with platinum-based regimen (n = 7): 6.8mo (6.1-not reported (NR)), compared with those switched to a different treatment (n = 27): 4.5 mo (2.6-6.6) for extensive stage patients, and a non-significant difference was also observed for limited stage patients. Conclusion: To our knowledge, this is one of the largest real-world studies of SCLC patients. OS for SCLC patients was similar to that reported in clinical trials. PS for extensive stage patients and sex for limited stage patients were significant correlates of prognosis. Re-challenge of the platinum-based doublet was associated with longer OS compared to switching treatment in extensive stage patients.

Preparation of FA-targeted magnetic nanocomposites co-loading TFPI-2 plasmid and cis-platinum and its targeted therapy effects on nasopharyngeal carcinoma

The majority of patients diagnosed with nasopharyngeal carcinoma (NPC) present with advanced-stage disease. The main treatment for these patients is concurrent chemoradiotherapy, which has various side effects. To improve the therapeutic effects and reduce the side effects of NPC chemoradiotherapy, we constructed a multifunctional folic acid (FA)-targeted magnetic nanocomposite codelivering tissue factor pathway inhibitor-2 (TFPI-2) and cisplatin (CDDP). This novel nanocomposite (FA-MNP/CDDP/TFPI-2) was obtained by amidation and electrostatic adsorption between FA-methoxypolyethylene glycol-polyethyleneimine (FA-MPEG-PEI) containing the TFPI-2 plasmid and magnetic nanoparticles modified by aldehyde sodium alginate loaded with CDDP. Transmission electron microscopy (TEM) images showed that the size of the individual magnetite particle core was approximately 11.5 nm. The structure and composition of the nanocomposites were identified and examined by ¹H nuclear magnetic resonance (NMR) spectroscopy and ultraviolet (UV) spectrophotometry. The fluorescence analysis, Prussian blue iron staining, magnetic resonance (MR) imaging and whole-body fluorescence imaging results demonstrated that FA-MNP/CDDP/TFPI-2 showed high gene transfection efficiency and could target tumor cells via folate receptor (FR)-mediated delivery. The codelivery analysis showed that the obtained FA-MNP/CDDP/TFPI-2 composite could cause significantly more apoptosis than treatment with CDDP or TFPI-2 alone. The results showed that the FA-MNP/CDDP/TFPI-2 composites were successfully synthesized and indicated to be a specific molecular target for the FR with significant inhibitory effects on the growth of HNE-1 cells.

Individualization of Irinotecan Treatment: A Review of Pharmacokinetics, Pharmacodynamics, and Pharmacogenetics

Since its clinical introduction in 1998, the topoisomerase I inhibitor irinotecan has been widely used in the treatment of solid tumors, including colorectal, pancreatic, and lung cancer. Irinotecan therapy is characterized by several dose-limiting toxicities and large interindividual pharmacokinetic variability. Irinotecan has a highly complex metabolism, including hydrolyzation by carboxylesterases to its active metabolite SN-38, which is 100- to 1000-fold more active compared with irinotecan itself. Several phase I and II enzymes, including cytochrome P450 (CYP) 3A4 and uridine diphosphate glucuronosyltransferase (UGT) 1A, are involved in the formation of inactive metabolites, making its metabolism prone to environmental and genetic influences. Genetic variants in the DNA of these enzymes and transporters could predict a part of the drug-related toxicity and efficacy of treatment, which has been shown in retrospective and prospective trials and meta-analyses. Patient characteristics, lifestyle and comedication also influence irinotecan pharmacokinetics. Other factors, including dietary restriction, are currently being studied. Meanwhile, a more tailored approach to prevent excessive toxicity and optimize efficacy is warranted. This review provides an updated overview on today’s literature on irinotecan pharmacokinetics, pharmacodynamics, and pharmacogenetics.

Radiotherapy may improve survival of ES-SCLC with distant metastasis only for patients with one metastatic site: A population-based study

The aim of the present study was to investigate the prognostic impact of RT on patients with extensive stage small cell lung cancer (ES-SCLC) and distant metastasis. Using the Surveillance Epidemiology and End Results (SEER) database, 8,595 patients with ES-SCLC exhibiting distant metastasis treated between 2010 and 2013 were identified. Patient baseline characteristics were compared using the χ² test. The Kaplan-Meier test was used to analyze subgroup cancer-specific survival (CSS) rate, and differences were compared using a log-rank test. Univariate and multivariate Cox regression models were used to analyze the prognostic variables on CSS. RT was determined to be an independent prognostic factor for patient CSS (P<0.001). In addition, RT could improve the CSS of patients with ES-SCLC with one metastatic lesion (hazard ratio, 0.63; 95% confidence interval, 0.59-0.68; P<0.001), including the bone, brain, liver and lung metastatic sites. However, for patients with two metastatic sites, RT did not improve CSS regardless of metastasis pattern (all P>0.05). To conclude, RT may improve the survival rate of patients with ES-SCLC with distant metastasis, particularly in those with only one metastatic site.

Next-Generation Sequencing May Discriminate Extreme Long-term versus Short-term Survival in Patients with Metastatic Small Cell Lung Cancer (SCLC)

BACKGROUND: Molecular underpinnings that may prognosticate survival could increase understanding of small cell lung cancer (SCLC) tumor behavior. Here, we report the clinicopathological characteristics and biomarker profiles of short-term (ST) versus long-term (LT) survival in patients with metastatic SCLC. METHODS: Of the 876 consecutive metastatic SCLC patients receiving standard of care therapy, 44 met the definition of LT and 91 for ST, respectively. Available FFPE tumor tissue blocks were analyzed by next-generation sequencing (NGS). Analysis included gene mutations, copy number variations, mRNA expression, and protein expression by immunohistochemistry, followed by correlation with clinicopathological characteristics. RESULTS: There were no statistically significant and clinically relevant differences in cases with or without FFPE according to major clinicopathological variables in ST and LT. However, according to NGS, five mutually exclusive gene mutations were identified (E1A binding protein P300 [EP300] p.N217S; p.E152K; human epidermal growth factor receptor 4 [ERBB4] p.E317K; BRCA1, DNA repair associated [BRCA1] p.E1661N, and epidermal growth factor receptor [EGFR] p.V742A). Comparing LT vs. ST survivals, a twofold increase was found in the average predicted number of drugs per patient off compendium. We found high SSTR2 mRNA expressions in all LT patients (vs. two [20%] ST patients), which may reflect more benign neuroendocrine tumor characteristics. CONCLUSIONS: Consolidation radiation therapy and higher predicted drug sensitivity for off compendium were associated with LT compared to ST patients in SCLC. NGS profiling of extreme survivals may improve classification of SCLC and possibly identify clinically relevant new targets.

Profiling of apoptosis- and autophagy-associated molecules in human lung cancer A549 cells in response to cisplatin treatment using stable isotope labeling with amino acids in cell culture

Cis‑diammine‑dichloro‑platinum II‑based adjuvant chemotherapy provides an alternative therapy to improve the survival of patients with lung tumors, especially those with non‑small cell lung cancer (NSCLC). However, drug resistance is a large clinical problem and its underlying mechanism remains unclear. In the present study, NSCLC A549 cells were treated with a low concentration of cisplatin in order to observe and determine the development of chemoresistance, via growth curves, colony forming assays and apoptosis assays. Then the induction of autophagy was examined in the cisplatin‑treated A549 cells with a fluorescence reporter. Profiled proteins in the cisplatin‑treated A549 cells were also assessed using the stable isotope labeling by amino acids in cell culture (SILAC) method, and then the differentially expressed molecules were verified. The results demonstrated that A549 cells became less sensitive to cisplatin [resistant A549 cells (A549R)] following 20 passages in the medium containing a low concentration of cisplatin, with less apoptotic cells post‑cisplatin treatment. A549R cells grew more efficiently in the cisplatin medium, with more colony formation and more cells migrating across the baseline. In addition, NSCLC results demonstrated that more autophagy‑related proteins (ATGs) were expressed in the A549R cells. Furthermore, the western blotting results confirmed this upregulation of ATGs in A549R cells. In addition, two repeated SILAC screening experiments recognized 15 proteins [glucose‑regulated protein, 78 kDa (GRP78), heat shock protein 71, pre‑mRNA processing factor 19, polypyrimidine tract binding protein 1, translationally controlled tumor protein, Cathepsin D, Cytochrome c, thioredoxin domain containing 5, MutS homolog (MSH) 6, Annexin A2 (ANXA2), BRCA2 and Cyclin dependent kinase inhibitor 1A interacting protein, MSH2, protein phosphatase 2A 55 kDa regulatory subunit Bα, Rho glyceraldehyde‑3‑phosphate‑dissociation inhibitor 1 and ANXA4] that were upregulated by >1.5‑fold in heavy (H)‑ and light (L)‑labeled A549R cells. In addition, 16 and 14 proteins were downregulated by >1.5‑fold in the H‑ and L‑labeled A549R cells, respectively. The majority of the downregulated proteins were associated with apoptosis. In conclusion, the present study isolated a cisplatin‑resistant human lung cancer A549 cell clone, with reduced apoptosis and high levels of autophagy, in response to cisplatin treatment. In cisplatin‑resistant A549R cells, SILAC proteomics recognized the high expression of GRP78 and other proteins that are associated with anti‑apoptosis and/or autophagy promotion.

Safety of oral hydration after cisplatin infusion in an outpatient lung cancer unit

PURPOSE

Hydration is needed before and after cisplatin infusion for reducing the risk of nephrotoxicity. Even though there is no standard regimen, patients receive mostly intravenous hydration before and after cisplatin leading hospitalization during at least one night. Since the feasibility has been published, oral hydration after cisplatin was implemented in our practice. The safety of this new way of hydration needs to be assessed in clinical practice.

METHODS

We collected medical records from patients treated by cisplatin for lung cancer in our unit between 2010 and 2016. We retrospectively analyzed the incidence of cisplatin induced nephrotoxicity between after and before the change of hydration regimen.

RESULTS

Our patient cohort included 241 patients hydrated by intravenous regimen (IV/IV group) and 276 patient hydrated by intravenous and oral regimen (IV/PO group). Grade ≥ 1 nephrotoxicity occurred in 39.4 and 25.7% in the IV/IV and IV/PO groups respectively (p = 0.001). Age over 70 at baseline was a predictive factor for nephrotoxicity, but not estimated glomerular filtration rate nor cisplatin-associated drugs. After a multivariate analysis, age remained a predictive factor for nephrotoxicity and IV/PO hydration associated with a decrease in nephrotoxic risk.

CONCLUSION

The implementation of oral hydration in our practice was not associated with an increase in nephrotoxicity. Our observation based on large data from clinical practice shows that oral hydration after cisplatin is safe.

A study on different therapies and prognosis-related factors for 101 patients with SCLC and brain metastases

OBJECTIVE

There is a need to explore multi-discipline general treatment modes to improve the survival period of patients with SCLC and brain metastases undergoing standard radiotherapy treatment.

METHODS

A total of 101 patients with SCLC and brain metastases were included into this study. These patients were classified into 4 groups, based on different treatment modes: chemotherapy group, brain radiotherapy group, brain radiotherapy combined with sequential chemotherapy, and chemotherapy combined with sequential brain radiotherapy. Recent and long-term curative effects were compared among the 4 groups.

RESULTS

A RR of 42.57% was determined for all 4 groups, and median PFS and OS was 11.56 and 17.32 months, respectively. After SCLC with brain metastases manifested in the limited stage, the difference in median survival period was not statistically significant among the 4 treatment groups (P = 0.29). At the extensive stage of SCLC, survival period was superior in the brain radiotherapy combined with sequential chemotherapy group, compared with other groups (P<0.05). Furthermore, median survival period in the brain radiotherapy combined with sequential chemotherapy group was 15.5 ± 1.03 months. This was followed by 12.0 ± 3.06 months in the chemotherapy combined with sequential brain radiotherapy group, 8.0 ± 1.49 months in the chemotherapy group, and 8.0 ± 0.43 months in the brain radiotherapy group.

CONCLUSION

Combining chemotherapy with brain radiotherapy is a better treatment mode compared with single therapy for treating SCLC with brain metastases. Furthermore, it is recommended for patients in the extensive stage to initially receive brain radiotherapy.

Circulating tumor cell interactions with macrophages: implications for biology and treatment

Cancer and metastasis are closely associated with inflammation. Macrophages are important effector cells in enhancing tumor proliferation, invasion and providing protection against the immune system. Despite advanced knowledge of tumor-macrophage interactions, the role of macrophages in emergence and invasion of circulating tumor cells (CTCs) is not known. A series of six CTC cell lines have been derived from blood of patients with extensive disease small cell lung cancer (ED-SCLC) in our lab, most likely representing a homogenous cell population of the actual metastasis-initiating cells (MIC) of CTCs. SCLC has an unfavorable prognosis due to rapid dissemination and early chemoresistant relapses. SCLC CTCs recruit macrophages and elicit secretion of various cytokines and the six CTC lines express chitinase-3-like-1 (CHI3L1), vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP9) in abundance. CHI3L1 is cytokine/growth factor expressed in inflammation and cancer and found to be correlated to metastasis and a dismal prognosis. In conclusion, SCLC CTCs have acquired the essential means for aggressiveness and invasion in a tumor microenvironment specifically shaped by macrophages and inflammation.

Synchronous Adie's syndrome and type 1 antineuronal nuclear antibody (anti-Hu)-related paraneoplastic neurological syndromes as predictors of complete response in limited-stage small-cell lung cancer: A case report

Adie's syndrome (AS) and paraneoplastic sensorimotor neuropathy with cerebellar ataxia (PSN CA) are extremely rare, rapidly progressive, autoimmune diseases associated with the development of antibodies against neuronal-specific Hu proteins that are abnormally expressed in small-cell lung cancer (SCLC). We herein present the unique case of a 55-year-old obese woman, previous heavy smoker, who, during treatment with standard cisplatin-etoposide chemotherapy for limited-stage SCLC, developed simultaneous AS and worsening symptoms consistent with PSN CA that led to significant neurological disability and severe axonal electrophysiological pattern on nerve conduction studies. Serology confirmed the presence of low-titre type 1 antineuronal nuclear antibodies (ANNA-1), previously referred to as anti-Hu antibodies. Following plasmapheresis, immunosuppressive therapy and physical rehabilitation, the neurological symptoms progressively improved. The tumour completely regressed, with no recurrence detected on subsequent radiological examinations. The aim of this case was to highlight the importance of a multidisciplinary team approach for early recognition and rapid treatment of paraneoplastic neurological syndromes (PNS) as key to achieving significant recovery and marked improvement of the neurological deficit. This report extends the literature by confirming earlier studies showing that the presence of serum ANNA-1 in SCLC, an aggressive type of pulmonary carcinoma that is challenging to treat, may portend a more favourable prognosis and response to chemotherapy. Thus, patients with SCLC and new-onset neurological symptoms should be tested for ANNA-1. The role of a multimodality approach to treating PNS is also emphasized.

Survival changes in patients with small cell lung cancer and disparities between different sexes, socioeconomic statuses and ages

Small cell lung cancer (SCLC), as a proportion, makes up only 15–17% of lung cancer cases. The development of treatments for SCLC has remained stagnant for decades, and SCLC is expected to persist as a threat to human health. To date, no publications based on large populations have been reported. We calculated survival changes in patients with SCLC during each decade between 1983 and 2012 to determine the roles of race, sex, age, and socioeconomic status (SES) on survival rates based on the Surveillance, Epidemiology, and End Results (SEER) registries. In total, 106,296 patients with SCLC were identified, with the overall incidence per 100,000 decreasing each decade from 9.6 to 7.8 to 5.8. The median survival for SCLC remained 7 months, and the 12-month relative survival rates (RSRs) remained relatively stable at 32.9%, 33.2% and 33.2% during each decade. The 5-year RSRs significantly improved from 4.9% to 5.9% to 6.4% during each decade, but remained extremely low. In addition, a narrowing of the survival gaps among SES groups and stable survival gaps between sexes were observed. Although the incidence of SCLC decreased during each decade, the overall survival remained relatively stable, highlighting the urgency of developing novel treatments and the importance of prevention and early detection.

Effects of the regulation of polysialyltransferase ST8SiaII on the invasiveness and metastasis of small cell lung cancer cells

Invasiveness and metastasis may seriously affect the prognosis of small cell lung cancer (SCLC). In the present study, we analyzed the effects and inherent mechanisms of action of polysialic acid-modified neural cell adhesion molecule (NCAM) on the invasive and metastatic potential of SCLC. Gene transfection and short hairpin RNA (shRNA) interference were used to enhance or inhibit, respectively, the expression of polysialyltransferase ST8SiaII in the SCLC cell line H446. We studied in vitro positive or negative changes in the invasive and metastatic potential of the SCLC cells as well as the changes in expression of genes related to signaling molecules and metastasis. When ST8SiaII expression was enhanced, the in vitro transmembrane invasion (P<0.01) and migration (P<0.01) abilities of the SCLC cells markedly increased. Phosphorylation levels of fibroblast growth factor receptor 1 (FGFR1), extracellular signal-related kinase 1/2 (ERK1/2), and matrix metalloproteinase-9 (MMP-9) in the SCLC cells were also significantly increased. In contrast, when ST8SiaII expression was inhibited, the transmembrane invasion (P<0.01) and migration (P<0.01) of the SCLC cells as well as expression of the above signaling molecules were suppressed. Polysialic acid-modified NCAM on the surface of SCLC cells is closely related to the metastatic potential of these cells; regulation of ST8SiaII may thus affect the invasiveness and metastasis of SCLC, and these processes may be associated with phosphorylation of FGFR1, ERK1/2 or MMP-9.

Patterns of care and survival among small cell lung cancer patients: Experience from a tertiary center in India

BACKGROUND/PURPOSE

Lung cancer is the commonest malignancy and the most common cause of cancer related mortality in males worldwide. Non-small cell lung cancer (NSCLC) is the commonest histology while small cell lung cancer (SCLC) contributes to only 15% of all cases of lung cancer. This report intended to present the patterns of care, survival outcomes and prognostic factors of SCLC treated in a tertiary care institute.

RESULTS

A total of 85 patients of SCLC were registered in radiotherapy unit I during the period January, 2005 to December, 2012. The median age of the cohort was 56.5years (95% CI 34-72). The majority of the patients were male with a male:female ratio of 6.7:1. Sixty eight percent of the patients were smokers. Sixty percent patients presented with extensive stage disease. Radiotherapy (RT) was used in 76% of the patients while chemotherapy was used in 75% of the patients. Platinum Etoposide was the most common regimen which was used in 70% of the patients who received chemotherapy. The median progression free survival (PFS) of the entire cohort was 11.4months (95% CI 9.11-13.58months). Stage, performance status, and use of chemotherapy were found to be significant factors affecting survival outcome in patients with SCLC.

CONCLUSION

The pattern of care and survival outcomes in the present study parallels that of the various published retrospective reviews. Basic research and development of targeted agents may be the way forward in improving the outcome of patients with SCLC.

Molecular Role of EGFR-MAPK Pathway in Patchouli Alcohol-Induced Apoptosis and Cell Cycle Arrest on A549 Cells In Vitro and In Vivo

Nowadays, chemotherapy is still the main effective treatment for cancer. Herb prescriptions containing Pogostemon cablin Benth (also known as "Guang-Huo-Xiang") have been widely used in Chinese medicine today. In our research, we found that patchouli alcohol, a compound isolated from the oil of Pogostemon cablin Benth, exerted antitumor ability against human lung cancer A549 cells ability both in vitro and in vivo. MTT assay was used to assess cell viability. Hoechst 33342 staining and TUNEL cover glass staining provided the visual evidence of apoptosis. Caspase activity measurement showed that patchouli alcohol activated caspase 9 and caspase 3 of mitochondria-mediated apoptosis. Consistently, patchouli alcohol inhibited the xenograft tumor in vivo. Further investigation of the underlying molecular mechanism showed that MAPK and EGFR pathway might contribute to the antitumor effect of patchouli alcohol. Our study proved that patchouli alcohol might be able to serve as a novel antitumor compound in the clinical treatment of lung cancer.

Anti-proliferation effects, efficacy of cyasterone in vitro and in vivo and its mechanism

Cyasterone was demonstrated potential inhibition effect in mouse skin carcinoma cells in published report. However, the molecular mechanisms of the cyasterone on cells remain unknown. Herein, we investigated the effects of cyasterone-induced apoptosis in A549 and MGC823 cells in vitro. MTT assay showed that cyasterone caused a significantly decreasing of the proliferation of A549 and MGC823 cells in a time-and dose-dependent manner with IC₅₀ values of 38.50±3.73μg/mL on A549 cells and 32.96±1.24μg/mL on MGC823 cells at 48h, respectively. Hoechst staining and TUNEL staining results indicated the quintessential apoptosis features in immunofluorescence image. Apoptosis and cell cycle were determined by flow cytometry. Cyasterone treatment triggered inhibition of epidermal growth factor receptor- phosphatidylinositol 3 kinase/protein kinase B (EGFR-AKT) signaling pathways and activation of P38 pathways. Furthermore, cyasterone inhibited MGC823 cells xenografted tumor growth in vivo with few changes in body weights. In conclusion, our findings provide the evidence that cyasterone inhibits growth of A549 and MGC823 cells, via regulating EGFR signaling pathway. Our results indicated that cyasterone, a natural EGFR inhibitor, maybe a promising anti-cancer agent.

Wide application of a novel topoisomerase I inhibitor-based drug conjugation technology

To establish a novel and widely applicable payload-linker technology for antibody-drug conjugates (ADCs), we have focused our research on applying exatecan mesylate (DX-8951f), a potent topoisomerase I inhibitor, which exhibits extensive antitumor activity as well as significant myelotoxicity, as the payload part. Through this study, we discovered a promising exatecan derivative (DX-8951 derivative, DXd), that has the characteristics of low membrane permeability and shows considerably less myelotoxicity than that shown by exatecan mesylate in an in vitro human colony forming unit-granulocyte macrophage assay. DXd was further used for drug conjugation by using commercially or clinically useful monoclonal antibodies to evaluate the potency of the ADC. The result revealed that the DXd-ADCs targeting CD30, CD33, and CD70 were effective against each of their respective target-expressing tumor cell lines. Moreover, a novel DXd-ADC targeting B7-H3, which is a new target for ADCs, also showed potent antitumor efficacy both in vitro and in vivo. In conclusion, this study showed that this novel topoisomerase I inhibitor-based ADC technology is widely applicable to a diverse number of antibodies and is expected to mitigate myelotoxicity, thereby possibly resulting in better safety profiles than that of existing ADC technologies.

Migration Suppression of Small Cell Lung Cancer by Polysaccharides from Nostoc commune Vaucher

Nostoc commune Vauch., classified into cyanobacteria, has been always well appreciated as a healthy food and medicine worldwide owing to its rich nutrition and potent bioactivities. Nevertheless, the inhibitory effect of polysaccharides from N. commune Vauch. (NVPS) against cancer cell progression and metastasis is still being unraveled. The results in this study showed that NVPS remarkably suppressed cell migration through blocking the epithelial-mesenchymal transition program in NCI-H446 and NCI-H1688 human small cell lung cancer cells. The inhibitory effects were attributed to the suppression of integrin β1/FAK signaling through regulating cell-matrix adhesion. Furthermore, NVPS treatment could increase E-cadherin expression, but down-regulate N-cadherin, Vimentin, and MMP-9 expression, which resulted in the blockage of STAT3 nuclear translocation and JAK1 signaling. These findings suggest that NVPS may be a good candidate for development as a possible antitumor agent against small cell lung cancer.

The action and mechanism of myrislignan on A549 cells in vitro and in vivo

Myrislignan is a natural compound with little pharmacological study. In our investigation, we investigated the effect of myrislignan in the induction of apoptosis in A549 cells in vitro and in vivo. Myrislignan inhibited the proliferation of A549 cells in a dose- and time-dependent manner assayed by MTT. In addition, Hoechst flow cytometry showed that myrislignan significantly induced apoptosis and cell cycle arrest in A549 cells. The apoptosis and anti-cell proliferation was mediated by the activation of mitogen-activated protein kinase and the inhibition of epidermal growth factor receptor signal pathway, change of mitochondrial membrane potential, the releasing of c-Myc, the downregulation of the level of the anti-apoptotic protein Bcl-2, and the upregulation of the level of the pro-apoptotic protein Bax. In conclusion, those results reveal a potential mechanism for the anti-cancer effect of myrislignan on human lung cancer, while suggesting that myrislignan may be a promising compound for the treatment of lung cancer.

Intrathoracic extensive-stage small cell lung cancer: assessment of the benefit of thoracic and brain radiotherapy using the SEER database

BACKGROUND

Extensive-stage small cell lung cancer (ESCLC) includes metastatic disease and locally advanced disease confined to the thorax that cannot be encompassed in a typical radiation portal. We assessed and then compared the benefits of thoracic radiotherapy (TRT) and/or brain radiotherapy (BRT) on overall survival (OS) between the intrathoracic (T-ESCLC) and metastatic (M-ESCLC) groups using the Surveillance Epidemiology and End Results database.

METHODS

TRT and BRT data were available for 10150 patients treated from 1988-1997. The T-ESCLC group included 1774 patients. The Kaplan-Meier method was used to estimate OS and the proportional hazards model was used to estimate OS hazard ratios for prognostic factors including age, gender, race, tumor size, T/N stage, TRT, and BRT.

RESULTS

The 2-year OS for T-ESCLC was 7.8 % compared to 3 % in the M-ESCLC group (p < 0.001). In the T-ESCLC group, TRT and BRT were delivered to 750 and 102 patients, respectively. The 2-year OS was 13 % in the TRT group compared to 4.1 % in the no-TRT group (p ≤ 0.001) and 22.5 % in the BRT group compared to 7 % in the no-BRT group (p < 0.001). In the M-ESCLC group, TRT and BRT were delivered to 3093 and 1887 patients, respectively. The 2-year OS was 4.4 % in the TRT group compared to 2.8 % in the no-TRT group (p < 0.001) and 4.3 % in the BRT compared to 2.6 % in the no-BRT group (p < 0.001). Age, gender, TRT and BRT were significant OS prognostic factors in both groups.

CONCLUSIONS

Our study suggests that T-ESCLC is a disease entity distinct from M-ESCLC. Prospective studies to determine whether TRT should be recommended for the thoracic-only subgroup are warranted.

A review of the role of surgery for small cell lung cancer and the potential prognostic value of enumeration of circulating tumor cells

Small cell lung cancer (SCLC) is disseminated in the majority of patients at first presentation and, thus, treated with chemoradiotherapy. Despite initial high response rates, chemoresistance appears rapidly and results in a dismal prognosis. However, patients with limited cancer may exhibit better disease control upon surgical treatment. Correct staging is highly critical in the selection of those patients which are likely to benefit from surgery. Studies of the inclusion of surgery in the multimodal treatment of SCLC vary widely in number of patients, selection, treatment and follow-up. Nevertheless surgical therapy for confined SCLCs achieves favorable long-term survival compared to chemoradiotherapy, depending on a precise assessment of the degree of tumor dissemination. Recently, extremely high counts of circulating tumor cells (CTCs) were reported in patients with SCLC compared to other malignancies. In several studies the number of CTCs was found to constitute a prognostic parameter and a marker of response to therapy. Therefore, the assessment of CTCs as so-called "Liquid Biopsy" seems to constitute a more precise method to detect tumor dissemination earlier when compared to clinical staging. In conclusion, in the era of precision oncology enumeration and identification of CTCs of SCLC patients have the potential to help in the selection of patients most suitable for tumor surgery.

Treatment for small cell lung cancer, where are we now?-a review

Small cell lung cancer (SCLC) represents between 13% and 15% of all diagnosed lung cancers worldwide. It is an aggressive neoplasia, with a 5-year mortality of 90% or more. It has historically been classified as limited disease (LD) and extensive disease (ED) in most study protocols. The cornerstone of treatment for any stage of SCLC is etoposide-platinum based chemotherapy; in limited stage (LS), concomitant radiotherapy to thorax and mediastinum. Prophylactic radiotherapy to the central nervous system (CNS) [prophylactic cerebral irradiation (PCI)] has diminished the incidence of brain metastasis as the site for relapse in LD and ED patients, therefore it should be offered to patients with complete response to induction first-line treatment. Regarding second-line treatment, results are more modest and topotecan is accepted as treatment for this scenario offering a modest benefit.

Small cell lung cancer: Circulating tumor cells of extended stage patients express a mesenchymal-epithelial transition phenotype

Small cell lung cancer (SCLC) is distinguished by aggressive growth, early dissemination and a poor prognosis at advanced stage. The remarkably high count of circulating tumor cells (CTCs) of SCLC allowed for the establishment of permanent CTC cultures at our institution for the first time. CTCs are assumed to have characteristics of cancer stem cells (CSCs) and an epithelial-mesenchymal transition (EMT) phenotype, but extravasation of tumors at distal sites is marked by epithelial features. Two SCLC CTC cell lines, namely BHGc7 and BHGc10, as well as SCLC cell lines derived from primary tumors and metastases were analyzed for the expression of pluripotent stem cell markers and growth factors. Expression of E-cadherin and β-Catenin were determined by flow cytometry. Stem cell-associated markers SOX17, α-fetoprotein, OCT-3/4, KDR, Otx2, GATA-4, Nanog, HCG, TP63 and Goosecoid were not expressed in the 2 CTC lines. In contrast, high expression was found for HNF-3β/FOXA2, SOX2, PDX-1/IPF1 and E-cadherin. E-cadherin expression was restricted to the 2 CTCs and 2 cell lines derived from pleural effusion (SCLC26A) and bone metastases (NCI-H526), respectively. Thus, these SCLC CTCs established from extended disease SCLC patients lack expression of stem cell markers which suppress the epithelial phenotype. Instead they express high levels of E-cadherin consistent with a mesenchymal-epithelial transition (MET or EMrT) and form large tumorospheres possibly in response to the selection pressure of first-line chemotherapy. HNF-3β/FOXA2 and PDX-1/IPF1 expression seem to be related to growth factor dependence on insulin/IGF-1 receptors and IGF-binding proteins.

Second-line therapy for small cell lung cancer: exploring the potential role of circulating tumor cells

BACKGROUND

Small cell lung cancer (SCLC) is an aggressive and invasive variant of lung tumors. SCLC, especially in advanced stages, is distinguished by extremely high numbers of circulating tumor cells (CTCs) in comparison to other malignancies. CTCs are operative in tumor spread and are currently enumerated to assess prognosis and response to cytotoxic therapy. Chemosensitivity of SCLC CTCs compared to primary tumors and metastases is not known.

METHODS

Establishment of two SCLC CTC cell lines, namely BHGc7 and BHGc10, allowed the in vitro characterization of their chemosensitivity to the second-line chemotherapeutics topotecan and epirubicin in comparison to a range of SCLC cell lines.

RESULTS

The SCLC CTC cell lines exhibited an approximately 7- and 12-fold increased chemosensitivity to epirubicin compared to topotecan, respectively, in in vitro cytotoxicity assays. In comparison to a panel of six SCLC cell lines, the two CTC lines showed a significantly higher chemosensitivity to epirubicin (range, 3- to 16-fold) and topotecan (range, 2.2- to 14.4-fold), respectively.

CONCLUSIONS

CTC cell lines derived from SCLC patients with recurrent disease exhibit high chemosensitivity to epirubicin vs. topotecan and show considerable more cytotoxicity in response to both compounds in comparison to a panel of SCLC cell lines. Thus, a decrease in the number of CTCs in response to second-line chemotherapy in SCLC patients may overestimate the effect on resident SCLC lesions and metastases.

Small cell lung cancer (SCLC): no treatment advances in recent years

Small cell lung cancer (SCLC) is an aggressive malignancy with a distinct natural history and dismal prognosis. Given its predisposition for early dissemination, patients are commonly diagnosed with metastatic disease and chemotherapy is regarded as the cornerstone of approved treatment strategies. However, over the last 30 years there has been a distinct paucity of significant breakthroughs in SCLC therapy. Thus, SCLC is characterized as a recalcitrant neoplasm with limited therapeutic options. By employing well-established research approaches, proven to be efficacious in non-small cell lung cancer (NSCLC), a growing amount of data has shed light on the molecular biology of SCLC and enhanced our knowledge of the "drivers" of tumor cell survival and proliferation. New therapeutic targets have emerged, but no significant improvement in patients' survival has been demonstrated thus far. In a sense, the more we know, the more we fail. Nowadays this is starting to change and methodical research efforts are underway. It is anticipated that the next decade will see a revolution in the treatment of SCLC patients with the application of effective precision medicine and immunotherapy strategies.

From Bench to Bedside: Attempt to Evaluate Repositioning of Drugs in the Treatment of Metastatic Small Cell Lung Cancer (SCLC)

Backgrounds

Based on in vitro data and results of a recent drug repositioning study, some medications approved by the FDA for the treatment of various non-malignant disorders were demonstrated to have anti-SCLC activity in preclinical models. The aim of our study is to confirm whether use of these medications is associated with survival benefit.

Methods

Consecutive patients with pathologically confirmed, stage 4 SCLC were analyzed in this retrospective study. Patients that were prescribed statins, aspirin, clomipramine (tricyclic antidepressant; TCA), selective serotonin reuptake inhibitors (SSRIs), doxazosin or prazosin (α1-adrenergic receptor antagonists; ADRA1) were identified.

Results

There were a total of 876 patients. Aspirin, statins, SSRIs, ADRA1, and TCA were administered in 138, 72, 20, 28, and 5 cases, respectively. A statistically significant increase in median OS was observed only in statin-treated patients when compared to those not receiving any of the aforementioned medications (OS, 8.4 vs. 6.1 months, respectively; p = 0.002). The administration of SSRIs, aspirin, and ADRA1 did not result in a statistically significant OS benefit (median OS, 8.5, 6.8, and 6.0 months, respectively). The multivariate Cox model showed that, besides age and ECOG PS, radiotherapy was an independent survival predictor (Hazard Ratio, 2.151; 95% confidence interval, 1.828–2.525; p <0.001).

Conclusions

Results of drug repositioning studies using only preclinical data or small numbers of patients should be treated with caution before application in the clinic. Our data demonstrated that radiotherapy appears to be an independent survival predictor in stage 4 SCLC, therefore confirming the results of other prospective and retrospective studies.

Small cell lung cancer: Recruitment of macrophages by circulating tumor cells

Tumor-associated macrophages (TAMs) play an important role in tumor progression, suppression of antitumor immunity and dissemination. Blood monocytes infiltrate the tumor region and are primed by local microenvironmental conditions to promote tumor growth and invasion. Although many of the interacting cytokines and factors are known for the tumor-macrophage interactions, the putative contribution of circulating tumor cells (CTCs) is not known so far. These specialized cells are characterized by increased mobility, ability to degrade the extracellular matrix (ECM) and to enter the blood stream and generate secondary lesions which is a leading cause of death for the majority of tumor patients. The first establishment of two permanent CTC lines, namely BHGc7 and 10, from blood samples of advanced stage small cell lung cancer (SCLC) patients allowed us to investigate the CTC-immune cell interaction. Cocultures of peripheral blood mononuclear cells (PBMNCs) with CTCs or addition of CTC-conditioned medium (CTC-CM) in vitro resulted in monocyte-macrophage differentiation and appearance of CD14⁺, CD163^weak and CD68⁺ macrophages expressing markers of TAMs. Furthermore, we screened the supernatants of CTC-primed macrophages for presence of approximately 100 cytokines and compared the expression with those induced by the local metastatic SCLC26A cell line. Macrophages recruited by SCLC26A-CM showed expression of osteopontin (OPN), monocyte chemoattractant protein-1 (MCP-1), IL-8, chitinase3-like 1 (CHI3L1), platelet factor (Pf4), IL-1ra and matrix metalloproteinase-9 (MMP-9) among other minor cytokines/chemokines. In contrast, BHGc7-CM induced marked overexpression of complement factor D (CFD)/adipsin and vitamin D-BP (VDBP), as well as increased secretion of OPN, lipocalin-2 (LCN2), CHI3L1, uPAR, MIP-1 and GDF-15/MIC-1. BHGc10, derived independently from relapsed SCLC, revealed an almost identical pattern with added expression of ENA-78/CXCL5. CMs of the non-tumor HEK293 cell line revealed no induction of macrophages, whereas incubation of PBMNCs with recombinant CHI3L1 gave positive results. Thus, the specific contributions of CTCs in SCLC affect CFD/adipsin, possibly involved in immunity/cachexia, VDBP which gives rise to group-specific component protein-derived macrophage-activating factor (GcMAF), GDF-15/MIC-1 which enhances the malignant phenotype of tumor cells and ENA-78/CXCL5 which attracts angiogenic neutrophils. In conclusion, CTCs are competent to specifically manipulate TAMs to increase invasiveness, angiogenesis, immunosuppression and possibly lipid catabolism.

Phosphorylated 4E-binding protein 1 expression is associated with poor prognosis in small-cell lung cancer

Phosphorylation of eukaryotic translation initiation factor 4E (eIF4E) binding protein (4E-BP1) results in release of eIF4E, which sequentially relieves translational repression and enhances oncogenic protein synthesis. We assessed the expression of phosphorylated 4E-BP1 (p-4E-BP1) in small-cell lung cancer (SCLC) and its correlation with clinicopathological factors and patient survival. This study included 117 SCLCs, which comprised 108 primary and 9 metastatic tumor tissues. We performed immunohistochemical staining for p-4E-BP1 in 117 tumors and found that 77 (66 %) were positive for p-4E-BP1 with cytoplasmic and/or nuclear immunostaining. The positive rate of p-4E-BP1 staining was significantly higher in never smokers (p = 0.034) and metastatic tumor tissues (p = 0.027). Patients with p-4E-BP1-positive SCLC tended to have poor performance status, although the difference was not statistically significant (p = 0.087). High p-4E-BP1 expression was significantly correlated with worse overall survival (OS) in all cohorts (p = 0.016). After stratification by clinical stage, p-4E-BP1 expression showed a stronger relationship with OS in patients with limited disease (p = 0.008). In addition, when stratified by treatment status, p-4E-BP1 expression was still significantly associated with worse OS in a subgroup of patients who completed treatment (p = 0.021). Our results indicate that p-4E-BP1 expression could represent oncogenic potential and contribute to the progression and aggressiveness of SCLC, suggesting it could be a candidate prognostic biomarker of SCLC, especially in limited disease.

Retrospective study of irinotecan/cisplatin followed by etoposide/cisplatin or the reverse sequence in extensive-stage small cell lung cancer

Background

Much research has confirmed the favorable effect of irinotecan/cisplatin (IP) and etoposide/cisplatin (EP) on extensive-stage small cell lung cancer (E-SCLC). This study investigated two sequential orders of IP and EP in the treatment of E-SCLC. We also compared the efficacy and safety of IP and EP in first-line chemotherapy in E-SCLC.

Methods

Ninety-three untreated patients with E-SCLC were randomly allocated to two groups. Group A received IP as first-line therapy until progression and then changed to EP; group B received EP as first-line therapy until tumor progression followed by IP. The primary endpoints were overall survival and time to second tumor progression. The secondary endpoints were first progression-free survival (PFS), ie, time from randomization to first occurrence of tumor progression after first-line treatment with IP or EP, tumor response, and safety of the different sequential treatment orders of IP and EP.

Results

Median overall survival was 15.4 months in group A (IP followed by EP) versus 15.7 months in group B (EP followed by IP; P=0.483). The median time to second tumor progression was 9.5 months in group A versus 9.9 months in group B (P=0.361). As first-line and second-line therapy, IP achieved a 95.9% and 60% disease control rate, respectively, and EP achieved 95.6% and 59% disease control rate. The median first PFS was not significantly different between group A and group B (6.5 months and 6.3 months, respectively; P=0.256). Grade 3/4 diarrhea appeared to be significantly more frequent with IP than with EP. The probability of anemia and thrombocytopenia was not significantly different between the two groups. However, significantly more patients who received the IP regimen as second-line treatment developed grade 3/4 neutropenia than those who received the IP regimen as first-line therapy.

Conclusion

There were no statistically significant differences in between the two sequences of IP and EP in the treatment of E-SCLC. Except EP regimen, IP may be another reserved regimen in the first-line treatment of E-SCLC.

How to target small cell lung cancer

Small cell lung cancer (SCLC) is a highly malignant disease with dismal prognosis. Although great progress has been made in investigating genetic aberrations and putative drivers of this tumor entity, the mechanisms of rapid dissemination and acquisition of drug resistance are not clear. The majority of SCLC cases are characterized by inactivation of the tumor suppressors p53 and retinoblastoma (Rb) and, therefore, interchangeable drivers will be difficult to target successfully. Access to pure cultures of SCLC circulating tumor cells (CTCs) and study of their tumor biology has revealed a number of new potential targets. Most important, expression of chitinase-3-like-1/YKL-40 (CHI3L1) which controls expression of vascular epithelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP9) was newly described in these cells. The process switching CHI3L1-negative SCLC cells to CHI3L1-positive CTCs seems to be associated with cytokines released by inflammatory immune cells. Furthermore, these CTCs were found to promote monocyte-macrophage differentiation, most likely of the M2 tumor-promoting type, recently described to express PD-1 immune checkpoint antigen in SCLC. In conclusion, dissemination of SCLC seems to be linked to conversion of regular tumor cells to highly invasive CHI3L1-positive CTCs, which are protected by immune system suppression. Besides the classical targets VEGF, MMP-9 and PD-1, CHI3L1 constitutes a new possibly drugable molecule to retard down dissemination of SCLC cells, which may be similarly relevant for glioblastoma and other tumor entities.

Smoking, inflammation and small cell lung cancer: recent developments

Small cell lung cancer (SCLC) accounts for 15 % of all lung tumors and represents an invasive neuroendocrine malignancy with poor survival rates. This cancer is highly prevalent in smokers and characterized by inactivation of p53 and retinoblastoma. First in vitro expansion of circulating tumor cells (CTCs) of SCLC patients allowed for investigation of the cell biology of tumor dissemination. In the suggested CTC SCLC model, the primary tumor attracts and educates tumor-promoting and immunosuppressive macrophages which in turn arm CTCs to spread and generate distal lesions. Preexisting inflammatory processes associated with chronic obstructive pulmonary disease (COPD) seem to potentiate the subsequent activity of tumor-associated macrophages (TAM). Activation of signal transducer and activator of transcription 3 (STAT3) and expression of chitinase-3-like 1/YKL-40 in SCLC CTCs seems to be associated with drug resistance. In conclusion, inflammation-associated generation of invasive and chemoresistant CTCs most likely explains the characteristic features of SCLC, namely early dissemination and rapid failure of chemotherapy.

Predictive biomarkers in precision medicine and drug development against lung cancer

The molecular characterization of various cancers has shown that cancers with the same origins, histopathologic diagnoses, and clinical stages can be highly heterogeneous in their genetic and epigenetic alterations that cause tumorigenesis. A number of cancer driver genes with functional abnormalities that trigger malignant transformation and that are required for the survival of cancer cells have been identified. Therapeutic agents targeting some of these cancer drivers have been successfully developed, resulting in substantial improvements in clinical symptom amelioration and outcomes in a subset of cancer patients. However, because such therapeutic drugs often benefit only a limited number of patients, the successes of clinical development and applications rely on the ability to identify those patients who are sensitive to the targeted therapies. Thus, biomarkers that can predict treatment responses are critical for the success of precision therapy for cancer patients and of anticancer drug development. This review discusses the molecular heterogeneity of lung cancer pathogenesis; predictive biomarkers for precision medicine in lung cancer therapy with drugs targeting epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 receptor tyrosine kinase (ROS1), and immune checkpoints; biomarkers associated with resistance to these therapeutics; and approaches to identify predictive biomarkers in anticancer drug development. The identification of predictive biomarkers during anticancer drug development is expected to greatly facilitate such development because it will increase the chance of success or reduce the attrition rate. Additionally, such identification will accelerate the drug approval process by providing effective patient stratification strategies in clinical trials to reduce the sample size required to demonstrate clinical benefits.

Lysosome-associated protein transmembrane-4β-35 is a novel independent prognostic factor in small cell lung cancer

The lysosome-associated protein transmembrane-4β-35 (LAPTM4B-35) protein has been indicated to be involved in solid tumors, while its role in small cell lung cancer (SCLC) remains unknown. The aim of this study is to investigate the LAPTM4B-35 protein expression and its clinical and prognostic role in SCLC patients. A total of 88 SCLC patients who underwent radical surgery between 2002 and 2010 were enrolled in the study. The level of messenger RNA (mRNA) and protein was detected from the fresh paired tumor specimens and adjacent normal tissues. The clinicopathological and survival data were collected. And the relationship between LAPTM4B-35 and clinicopathological features was analyzed. The prognostic value of LAPTM4B-35 for SCLC was investigated by univariate and multivariate analyses. The LAPTM4B-35 was overexpressed significantly in SCLC cancer tissues. The elevated protein expression was correlated strongly with clinical stage (p = 0.012) and tumor recurrence (p = 0.023). The 5-year overall survival and disease-free survival (DFS) were significantly worse in the patients with high LAPTM4B-35 level. Multivariate Cox analysis indicated that high LAPTM4B-35 expression was an independent prognostic factor for overall survival (OS) and DFS (p = 0.017 vs p = 0.011). LAPTM4B-35 overexpression was an independent factor in SCLC prognosis, which may be considered a potential useful marker in defining the SCLC prognosis.