Comparison of the effectiveness of erlotinib, gefitinib, and afatinib for treatment of non-small cell lung cancer in patients with common and rare EGFR gene mutations

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are routinely used to treat non-small cell lung cancer (NSCLC) in patients with common activating mutations of the EGFR gene. The aim of the study was to compare the efficacies of EGFR-TKIs in patients with common (exon 19 deletions and exon 21 p.Leu858Arg) and rare EGFR mutations. A retrospective analysis of 180 NSCLC patients with common (n=167) and rare (n=13) EGFR mutations treated with erlotinib (n=98), gefitinib (n=66) and afatinib (n=16) was performed. EGFR mutations were determined using RT-PCR and the EntroGen EGFR Mutations Analysis kit. Partial and complete response (PR and CR), progression-free survival (PFS), and overall survival (OS) were analyzed. Demographic and clinical factors had no impact on PFS or OS in patients treated with EGFR-TKIs. Erlotinib, gefitinib, and afatinib showed similar efficacies based on treatment response, median PFS, and OS. The type of EGFR mutation had no impact on median OS; however, median PFS was significantly longer in patients with the exon 19 deletion compared to patients with the exon 21 p.Leu858Arg substitution and rare EGFR gene mutations (P=0.013). Patients with common EGFR mutations showed significantly longer median PFS than those with rare EGFR mutations (10 vs. 5 months; P=0.009). Erlotinib, gefitinib, and afatinib show similar efficacies in NSCLC patients with both common and rare EGFR mutations. When undergoing EGFR-TKI treatment, patients with rare EGFR mutations showed similar OS but poorer PFS. Further investigation into the associations between particular rare EGFR mutations and EGFR-TKIs treatment outcomes is required.

Beyond PD-L1 Markers for Lung Cancer Immunotherapy

Immunotherapy using immune checkpoints inhibitors has become the standard treatment for first and second line therapy in patients with non-small cell lung cancer (NSCLC). However, proper predictive factors allowing precise qualification of NSCLC patients for immunotherapy have not been developed so far. Expression of PD-L1 on tumor cells and tumor mutation burden are used in qualification of patients to first line therapy with pembrolizumab and atezolizumab in combination with ipilimumab in prospective clinical trials. Nevertheless, not all patients with these predictive factors benefit from immunotherapy. Major methodological difficulties in testing of these factors and in the interpretation of test results still exist. Therefore, other predictive factors are sought. Intensive research on the recognition of tumor immunophenotype and gut microbiome in NSCLC patients are underway. The first correlations between the effectiveness of immunotherapy and the intensity of inflammatory response in the tumor, microbiome diversity, and the occurrence of certain bacterial species in gut have been described. The purpose of our manuscript is to draw attention to factors affecting the efficacy of immunotherapy with anti-PD-L1 antibodies in NSCLC patients. Additional markers, for example TMB (tumor mutations burden) or microbiome profile, are needed to more accurately determine which patients will benefit from immunotherapy treatment.

Failure of Immunotherapy-The Molecular and Immunological Origin of Immunotherapy Resistance in Lung Cancer

Immune checkpoint inhibitors (ICIs) have a huge impact on clinical treatment results in non-small cell lung cancer (NSCLC). Blocking antibodies targeting programmed cell death protein 1 (PD-1), programmed cell death protein ligand 1 (PD-L1) or CTLA-4 (cytotoxic T cell antigen 4) have been developed and approved for the treatment of NSCLC patients. However, a large number of patients develop resistance to this type of treatment. Primary and secondary immunotherapy resistance are distinguished. No solid biomarkers are available that are appropriate to predict the unique sensitivity to immunotherapy. Knowledge of predictive markers involved in treatment resistance is fundamental for planning of new treatment combinations. Scientists focused research on the use of immunotherapy as an essential treatment in combination with other therapy strategies, which could increase cancer immunogenicity by generating tumor cells death and new antigen release as well as by targeting other immune checkpoints and tumor microenvironment. In the present review, we summarize the current knowledge of molecular bases underlying immunotherapy resistance and discuss the capabilities and the reason of different therapeutic combinations.

Tumor Microenvironment—A Short Review of Cellular and Interaction Diversity

The tumor microenvironment is a complex network of various interactions between immune cells and non-cellular components such as the extracellular matrix, exosomes and interleukins. Moreover, tumor heterogeneity and its constant modification may alter the immunophenotype and become responsible for its resistance regarding the therapies applied However, it should be remembered that in a strongly immunosuppressive neoplastic microenvironment, the immune system cells undergo reprogramming and most often cease to fulfill their original function. Therefore, understanding what happens within the tumor microenvironment, and which mechanisms are responsible for tumor development and progression should let us know how cancer could protect itself against the immune system. The presented review summarizes the latest information on the interactions between the tumor microenvironment and the cellular and non-cellular components, as well as their impact on cancer development, progression and immune system exhaustion.

The incidence of EGFR-activating mutations in bone metastases of lung adenocarcinoma

Poor prognosis of lung adenocarcinoma is associated with early occurrence of distant metastases. This type of non-small-cell lung carcinoma more frequently involves EGFR gene abnormalities, which determine the efficacy of EGFR tyrosine kinase inhibitor therapies (EGFR TKIs). It is probable that genetic abnormalities present in primary tumor will also be present in metastases. Unfortunately little is known about the incidence of these mutations in the metastases and about the effectiveness of molecularly targeted therapy in such patients. Formalin-fixed, paraffin-embedded tumor tissue was prepared from 431 samples of primary adenocarcinoma, 61 of adenocarcinoma central nervous system (CNS) metastases and 8 of adenocarcinoma bone metastases. The presence of exon 19 deletions was examined using the PCR technique and amplified PCR product fragment length analysis. The ASP-PCR technique was used to evaluate the L858R substitutions in exon 21, and the results were analyzed using ALF Express II sequencer. In the adenocarcinoma metastases to bone obtained from 8 patients, deletions in exon 19 of the EGFR gene were revealed in 3 smoking men and one non-smoking woman, while L858R substitution in exon 21 was found in one smoking woman and one man of unknown smoking status. The incidence of EGFR gene mutations in the bone metastases was 75%, in the primary adenocarcinoma--12.8%, and in the adenocarcinoma metastases to CNS--14.75%. Five patients with EGFR gene mutation revealed in bone metastases were treated with EGFR TKIs; the majority of them had a satisfactory response to therapy.

The efficacy of EGFR gene mutation testing in various samples from non-small cell lung cancer patients: a multicenter retrospective study

Introduction

Testing for the epidermal growth factor receptor (EGFR) gene mutations requires considerable multidisciplinary experience of clinicians (for appropriate patient selection), pathologists (for selection of appropriate cytological or histological material) and geneticists (for performing and reporting reliable molecular tests). We present our experience on the efficacy of routine EGFR testing in various types of tumor samples and the frequency of EGFR mutations in a large series of Polish non-small cell lung cancer (NSCLC) patients.

Methods

Deletions in exon 19 and substitution L858R in exon 21 of EGFR gene were assessed using real-time PCR techniques in 1,138 small biopsies or cytological specimens and in 1,312 surgical samples.

Results

Out of 2,450 diagnostic samples (containing >10 % of tumor cells), the occurrence of EGFR gene mutations was 9 %; more frequently in women (13.9 %) and adenocarcinoma patients (10 %), particularly with accompanying expression of TTF1 (13.0 %). The frequency of EGFR gene mutations was similar in cytological and histological specimens, and in primary and metastatic lesions, and did not depend on the percentage of tumor cells and quality of isolated DNA. Cytological or small biopsy, compared to surgical specimens showed lower percentage of tumor cells, with no impact on the quality of real-time PCR assay.

Conclusion

Cytological and small biopsy samples with low (10–20 %) content of tumor cells and specimens from metastatic lesions are a sufficient source for EGFR mutation testing in NSCLC patients. The incidence of EGFR gene mutations in examined population was similar to those reported in other Caucasian populations.

Polymorphisms in TS, MTHFR and ERCC1 genes as predictive markers in first-line platinum and pemetrexed therapy in NSCLC patients

Purpose

We presented retrospective analysis of up to five polymorphisms in TS, MTHFR and ERCC1 genes as molecular predictive markers for homogeneous Caucasian, non-squamous NSCLC patients treated with pemetrexed and platinum front-line chemotherapy.

Methods

The following polymorphisms in DNA isolated from 115 patients were analyzed: various number of 28-bp tandem repeats in 5′-UTR region of TS gene, single nucleotide polymorphism (SNP) within the second tandem repeat of TS gene (G>C); 6-bp deletion in 3′-UTR region of the TS (1494del6); 677C>T SNP in MTHFR; 19007C>T SNP in ERCC1. Molecular examinations’ results were correlated with disease control rate, progression-free survival (PFS) and overall survival.

Results

Polymorphic tandem repeat sequence (2R, 3R) in the enhancer region of TS gene and G>C SNP within the second repeat of 3R allele seem to be important for the effectiveness of platinum and pemetrexed in first-line chemotherapy. The insignificant shortening of PFS in 3R/3R homozygotes as compared to 2R/2R and 2R/3R genotypes were observed, while it was significantly shorter in patients carrying synchronous 3R allele and G nucleotide. The combined analysis of TS VNTR and MTHFR 677C>T SNP revealed shortening of PFS in synchronous carriers of 3R allele in TS and two C alleles in MTHFR. The strongest factors increased the risk of progression were poor PS, weight loss, anemia and synchronous presence of 3R allele and G nucleotide in the second repeat of 3R allele in TS. Moreover, lack of application of second-line chemotherapy, weight loss and poor performance status and above-mentioned genotype of TS gene increased risk of early mortality.

Conclusion

The examined polymorphisms should be accounted as molecular predictor factors for pemetrexed- and platinum-based front-line chemotherapy in non-squamous NSCLC patients.

In Vitro Antiproliferative Activity of Extracts of Carlina acaulis subsp. caulescens and Carlina acanthifolia subsp. utzka

Various species of the Carlina genus have been used in traditional medicine in many countries to treat numerous skin disorders, including cancer. The objective of this work was to assess the anticancer properties of root and leaf extracts from Carlina acaulis subsp. caulescens and C. acanthifolia subsp. utzka. Anti-tumor properties of the extracts were explored using a tetrazolium-based cell viability assay and flow cytometric apoptosis analysis, followed by immunodetection of phosphoactive ERK1/2 in UACC-903, C32, and UACC-647 human melanoma cell lines. Normal human fibroblasts were used as a control. Leaf extracts inhibited the viability of all tested melanoma cell lines in a dose-dependent fashion while the fibroblasts were less sensitive to such extract. The root extracts inhibited the proliferation of UACC-903 and UACC-647 cells only at the highest doses (300 μg/mL). However, the C32 and fibroblast cells exhibited an increase in the cellular proliferation rate and no caspase activity was observed in response to the root extracts (100 μg/mL). An increase in caspase activity was observed in melanoma cells treated with the leaf extracts of both Carlina species. Leaf extracts from C. acaulis subsp. caulescens (100 μg/mL) inhibited proliferatory ERK1/2 in UACC-903 and C32 cells, as demonstrated by the decrease in ERK1/2 phosphorylation. No reduction in phospho-ERK1/2 was observed in the tested cell lines treated with the root extracts, apart from UACC-647 after incubation with the C. acanthifolia subsp. utzka root extract (100 μg/mL). There was no change in ERK1/2 phosphorylation in the fibroblasts. The extracts from the leaves and roots were analyzed by HPLC and the analysis showed the presence of triterpenes and phenolic acids as the main extract components. The research demonstrated that the extracts from the leaves of the plants were cytotoxic against the human melanoma line and induced apoptosis of the cells. The triterpene fraction present in the tested extracts may be responsible for this activity.

Tissue MicroRNA Expression as a Predictor of Response to Immunotherapy in NSCLC Patients

Introduction

Expression of PD-L1 protein on tumor cells, which is so far the only validated predictive factor for immunotherapy, is regulated by epigenetic and genetic factors. Among the most important ones that regulate gene expression are microRNAs.

Materials and Methods

The study included 60 patients with NSCLC who underwent first or second line immunotherapy with pembrolizumab or nivolumab. FFPE materials were collected before the start of immunotherapy. We examined relative expression of microRNAs (miR-141, miR-200a, miR-200b, miR-200c, miR-429, miR-508-3p, miR-1184, miR-1255a) and PD-L1 mRNA expression. Copy number variation (CNV) of PD-L1 gene by qPCR and FISH methods were assessed. Two single nucleotide polymorphisms (SNPs) in promoter region of PD-L1 gene (rs822335 and rs822336) were examined. Expression of PD-L1 protein on tumor cells was assessed by immunohistochemistry (IHC). The response rate to immunotherapy and progression free survival (PFS) measured in weeks and overall survival (OS) measured in months from the start of immunotherapy were evaluated.

Results

Response to immunotherapy was observed in nine patients (15%, including one complete response), disease stabilization in 22 patients (36.7%), and progression in 29 patients (48.3%). Significantly higher (p=0.015) expression of miR-200b and significantly lower (p=0.043) expression of miR-429 were observed in responders compared to patients who did not respond to immunotherapy. The median PFS in the whole group of patients was 16 weeks, and the median OS was 10.5 month. In univariate analysis, the median PFS was significantly higher in patients with high miR-200b expression (HR=0.4253, 95%CI: 0.1737–1.0417, p=0.05) and high miR-508 expression (HR=0.4401, 95%CI: 0.1903–1.0178, p=0.05) and with low expression of miR-429 (HR=0.1288, 95%CI: 0.01727–0.9606, p=0.0456) compared to patients with low and high expression of these molecules, respectively. The median OS was higher in patients with low expression of miR-429 (HR=0,6288, 95%CI: 0,3053–1,2949, p=0.06) compared with patients with high expression of this microRNA. In multivariate analysis, we found that patients with PD-L1 expression on ≥1% of tumor cells compared to patients without PD-L1 expression on cancer cells had a significantly lower risk of progression (HR=0.3857, 95%CI: 0.1612–0.9226, p=0.0323) and death (HR=0.377, 95%CI: 0.1636–0.8688, p=0.022).

Conclusion

The miR-200b and miR-429 molecules in tumor cells seem to have greatest impact on the effectiveness of immunotherapy in NSCLC patients.

PD-L1 gene copy number and promoter polymorphisms regulate PD-L1 expression in tumor cells of non-small cell lung cancer patients

Most drugs targeting PD-1 or PD-L1 are more effective when cancer cells of non-small cell lung cancer (NSCLC) patients express PD-L1 protein. The polymorphisms of PD-L1 gene and PD-L1 gene copy number could be responsible for PD-L1 mRNA and protein expression. We analyzed PD-L1 protein expression using two IHC assays, mRNA (PD-L1) expression by qRT-PCR, PD-L1 gene promoter region polymorphisms (rs822335 and rs822336) by qPCR and PD-L1 gene copy number by fluorescence in situ hybridization method. Patients with CC genotype in rs822335 had significantly (p = 0.043) higher percentage of tumor cells with PD-L1 expression (test with 22C3 antibody) than patients with CT or TT genotypes. PD-L1 gene copy number significantly positively correlated with percentage of tumor cells with PD-L1 expression detected in tests with 22C3 antibody (p = 0.005, R = +0.442) and with SP142 antibody (p = 0.021, R = +0.369). PD-L1 gene copy number did not correlate with PD-L1 mRNA expression. Patients with PD-L1 expression tested with 22C3 antibody had significantly higher expression of PD-L1 mRNA (p = 0.023), number of chromsosme 9 centromeres (p = 0.023) and PD-L1 gene copy number (p = 0.003) than patients without PD-L1 expression on tumor cells PD-L1 gene polymorphisms and PD-L1 gene copy number may be a predictor for PD-L1 protein expression on tumor cells.

Imperfect Predictors for Lung Cancer Immunotherapy-A Field for Further Research

The armamentarium for lung cancer immunotherapy has been strengthened using two groups of monoclonal antibodies: 1) anti-PD-1 antibodies, including pembrolizumab and nivolumab, which block the programmed death 1 receptor on the lymphocyte surface, resulting in increasing activity of these cells, and 2) anti-PD-L1 antibodies, including atezolizumab, durvalumab, and avelumab, which block the ligand for the PD-1 molecule on tumor cells and on tumor-infiltrating immune cells. The effectiveness of both groups of antibodies has been proven in many clinical trials, which translates into positive immunotherapeutic registrations for cancer patients. Regarding the predictive factor, PD-L1 expression on cancer cells is the only biomarker validated in prospective clinical trials used for qualification to immunotherapy in advanced non-small cell lung cancer (NSCLC) patients. However, it is not an ideal one. Unfortunately, no clinical benefits could be noted in patients with high PD-L1 expression on tumor cells against the effectiveness of immunotherapy that may be observed in patients without PD-L1 expression. Furthermore, the mechanism of antitumor immune response is extremely complex, multistage, and depends on many factors. Cancer cells could be recognized by the immune system, provided tumor-specific antigen presentation, and these arise as a result of somatic mutations in tumor cells. Based on novel immunotherapy registration, high tumor mutation burden (TMB) has become an important predictive factor. The intensity of lymphocyte infiltration in tumor tissue may be another predictive factor. The effectiveness of anti-PD-L1 immunotherapy is observed in patients with high expression of genes associated with the effector function of T lymphocytes (i.e., their ability to produce IFN-gamma). This does not end the list of potential factors that become useful in qualification of cancer patients for immunotherapy. There remains a need to search for new and perfect predictive factors for immunotherapy.

HER2 gene assessment in liquid biopsy of gastric and esophagogastric junction cancer patients qualified for surgery

BACKGROUND

Amplification of HER2 gene (ERBB2) and overexpression of HER2 protein on cancer cells are found in 10-26% of gastric cancer (GC) and esophagogastric junction cancer (EGJC). Gene copy number variation (CNV) could be detected in these patients in liquid biopsy and in cancer cells.

METHODS

We analysed HER2 gene CNV used qPCR method in 87 sera collected from GC and EGJC patients before surgical treatment and in 40 sera obtained from healthy donors. HER2 gene CNV was also assessed in formalin-fixed paraffin-embedded (FFPE) tumor tissue. Furthermore, we assessed the number of HER2 gene copies and HER2 expression in cancer cells using the fluorescent in situ hybridization method (FISH) and immunohistochemistry (IHC).

RESULTS

We found that the HER2 gene copy number in liquid biopsy was higher in GC and EGJC patients compared to healthy people (p = 0.01). Moreover, EGJC patients had higher number of HER2 gene copies than healthy donors (p = 0.0016). HER2 CNV examination could distinguish healthy individuals and patients with gastric or esophagogastric junction cancers with sensitivity and specificity of 58% and 98% (AUC = 0.707, 95% CI 0.593-0.821, p = 0.004). We found that patients with a high copy number of the HER2 gene in the tumor tissue assessed by qPCR (but not by FISH) have significantly more often a high number of HER2 gene copies in liquid biopsy (p = 0.04).

CONCLUSIONS

We suggested that HER2 testing in liquid biopsy could be used as an auxiliary method to analysis of HER2 status in tumor tissue in gastric or esophagogastric junction cancers.

Endocrine Adverse Events of Nivolumab in Non-Small Cell Lung Cancer Patients-Literature Review

In recent years, we have observed significant progress in cancer treatment associated with the development of immunotherapy. A programmed cell death 1 molecule (PD-1) on the surface of T lymphocytes may be stimulated via a specific PD-ligand 1 (PD-L1), which inhibits lymphocyte activation and leads to apoptosis. Some malignant cells are characterized by high PD-L1 expression. Nivolumab, an anti-PD-1 antibody, blocks the interaction between PD-1 and its ligands and inhibits the signaling pathway by preventing the tumor-derived PD-L1 from blocking T lymphocytes. In patients with non-small cell lung cancer (NSCLC), it is used either in monotherapy or in combination with other drugs. Immunotherapy is associated with the possibility of immune-related adverse effects (irAE) including endocrinopathies (3–23%). Thyroid disorders are the most common, with severity rarely exceeding grade 2. Hypophysitis, adrenal insufficiency and diabetes are possible complications which require immediate treatment. Individuals with autoimmune diseases diagnosed prior to immunotherapy are at risk of its exacerbation. In the management of patients receiving immunotherapy, evaluation of history of autoimmune diseases, awareness and early diagnosis of irAE are crucial and may affect treatment outcomes.

Aptamers in Non-Small Cell Lung Cancer Treatment

Aptamers are short, single-stranded oligonucleotides which are capable of specifically binding to single molecules and cellular structures. Aptamers are also known as “chemical antibodies”. Compared to monoclonal antibodies, they are characterized by higher reaction specificity, lower molecular weight, lower production costs, and lower variability in the production stage. Aptamer research has been extended during the past twenty years, but only Macugen^® has been accepted by the Food and Drug Administration (FDA) to date, and few aptamers have been examined in clinical trials. In vitro studies with aptamers have shown that they may take part in the regulation of cancer progression, angiogenesis, and metastasis processes. In this article, we focus on the potential use of aptamers in non-small cell lung cancer treatment.

Immunohistochemical assays incorporating SP142 and 22C3 monoclonal antibodies for detection of PD-L1 expression in NSCLC patients with known status of EGFR and ALK genes

Different immunohistochemical (IHC) assays were approved for PD-L1 expression examination on tumor cells in qualification to immune-checkpoint inhibitors therapy in NSCLC patients. These assays have some similarities, but also very serious differences. We assessed 2 IHC tests for PD-L1 expression evaluation in NSCLC tumors with different pathological diagnoses and genetic abnormalities.

We enrolled 48 NSCLC patients (median age: 65 years) with known status of EGFR and ALK genes. We compared the effectiveness of PD-L1 expression examination of two IHC assays with 22C3 (Dako) and SP142 antibodies (Ventana). IHC tests were performed in resected tissue samples and in cellblocks from bronchoscopy biopsies (formalin-fixed paraffin-embedded). IHC staining was carried out on Dako Autostainer Link 48 and Ventana Benchmark GX.

The percentage of tumors with PD-L1 expression of ≥5% and ≥50% on tumor cells was significantly (p<0.05) higher in assay with 22C3 (66.7% and 45.8%) than with SP142 antibody (39.6% and 22.9%). The median percentage of tumor cells with PD-L1 expression was significantly (p<0.0001) higher in test with 22C3 than with SP142 antibody. Percentage of squamous cell carcinoma (SCC) patients with PD-L1 expression was significantly higher than of non-SCC patients. Large group of patients without PD-L1 expression on tumor cells was identified among patients with common EGFR mutations and ALK rearrangement.

Our results support that the highest PD-L1 expression on tumor cells occurs in SCC patients and in adenocarcinoma patients without common, druggable genetic abnormalities. The above mentioned results were clearly visible in IHC assay with 22C3 (strong cell staining).

Analysis of KRAS, NRAS, BRAF, and PIK3CA mutations could predict metastases in colorectal cancer: A preliminary study

BACKGROUND

Colorectal cancer (CRC) is usually diagnosed in the metastatic stage, when chemotherapy and molecularly-targeted therapies, instead of surgery, play the most important therapeutic role. Application of anti-epidermal growth factor receptor (EGFR) therapy requires the analysis of RAS mutation status and only RAS wild-type (wt) patients are qualified for the therapy.

OBJECTIVES

The objective of this study was to analyze driver mutations in KRAS, NRAS, BRAF, and PIK3CA genes in CRC patients.

MATERIAL AND METHODS

We assessed the KRAS, NRAS, BRAF, and PIK3CA genes in 102 inoperable, locally advanced and advanced CRC patients. Real-time polymerase chain reaction (RT-PCR) and high resolution melt PCR (HRM-PCR) techniques with DNA intercalating dye were applied in the study.

RESULTS

Forty-six patients demonstrated the presence of examined mutations (45.1%). No significant differences in driver mutation occurrence between men and women, as well as between younger (<65 years) and older (≥65 years) patients were found. The mutations were present significantly more frequently in metastatic than in primary tumors (p = 0.039) due to the high incidence of KRAS gene mutations in metastatic tissue. BRAF and PIK3CA mutations were found only in primary tumors. The incidence of PIK3CA mutations was significantly higher (11.77%) in early than in advanced stages of the disease (1.96%; p = 0.05); NRAS mutations were found only in metastatic cancer (7.85%; p = 0.041). Only a single mutation of the PIK3CA and no mutations of NRAS were found in rectal cancer.

CONCLUSIONS

Our results have shown low occurrence of driver mutations in Polish CRC patients, involving also mutations in rarely tested genes. The extent of the research panel of additional mutations could contribute to creating a better method of qualifying patients for molecularly targeted therapies and obtaining a better outcome for these therapeutic strategies.

The applicability of a predictive index for second- and third-line treatment of unselected non-small-cell lung cancer patients

BACKGROUND

Tyrosine kinase inhibitors of EGFR (TKI-EGFR) induced response in only 10% of Caucasian non-small-cell lung cancer patients in second- or third-line treatment. Independent predictive factors for qualification to TKI-EGFR treatment have not been assessed. In 2008, a prognostic index was reported for patients treated with erlotinib in the BR.21 trial, but its application for real, unselected patients is limited.

OBJECTIVES

Based on clinical and molecular factors of patients treated with erlotinib, we tried to create a predictive index which could be applied in real treatment practice.

METHODS

In a Cox regression model, we established 6 factors which affected overall survival for erlotinib treatment: performance status, erlotinib-induced rash, time from diagnosis to treatment, gender, weight loss and LDH level. We analyzed the risk factors of early progression and survival shorter than 6 months. In addition we included: time from first-line chemotherapy to erlotinib treatment, smoking status, mutation status in EGFR and anemia.

RESULTS

Our model consisted of 10 factors that were assigned points according to HR or χ2 and p value. The score was used to separate patients into 4 risk categories of unfavorable disease course based on 10th, 50th and 90th percentiles: low risk (I), intermediate low risk (II), intermediate high risk (III) and high risk (IV). Survival probability was significantly higher for group I, intermediate for groups II and III, and significantly lower for group IV (χ2 = 49.5, p < 0.0001). Based on the previously reported index we could not qualify our patients for the low risk group.

CONCLUSIONS

Our model could be useful for qualification for erlotinib treatment of patients with numerous adverse factors and limited access to genetic examination.

Polymorphisms of Genes Encoding Multidrug Resistance Proteins as a Predictive Factor for Second-Line Docetaxel Therapy in Advanced Non-small Cell Lung Cancer

Multidrug resistance (MDR) remains a substantial problem in chemotherapy. The purpose of the study was to investigate potential factors, including MDR genes polymorphisms, that could be used in qualification for second-line docetaxel therapy in non-small cell lung cancer (NSCLC) patients after failure of platinum based chemotherapy. Study group comprised of 58 Caucasian subjects. Evaluation of Single Nucleotide Polymorphisms (SNPs) of ABCC2/MRP2 and ABCB1/MDR1 genes was performed using the High Resolution Melting (HRM) technique. TUBB3 gene expression was evaluated on RNA isolated from tumor tissue. Results with p value of <0.05 were considered significant. Factors associated with reduced risk of disease progression included good performance status (PS), long period between diagnosis and docetaxel treatment, and smoking for <10 pack-years. Disease control occurred more often in patients with G/G genotype of the ABCC2/MRP2 gene. Median overall survival was 4.25 months. Factors such as: good PS, disease control after docetaxel, long period from diagnosis to docetaxel, lack of significant weight loss, and third-line treatment were associated with prolongation of patients survival. Overall survival probability was significantly lower in patients with significant weight loss, poor PS, lack of disease control after docetaxel, and without third-line treatment. Factors that characterized the highest risk of survival shortening were: inability to apply third-line treatment, lack of best response to first-line therapy, poor PS, and C/G or G/G genotypes of ABCC2/MRP2 gene. We concluded that assessed factors had mainly prognostic and not predictive value. Finding reliable molecular predictors for second line docetaxel therapy requires further clinical trials.

Clinical Application Perspectives of Lung Cancers 3D Tumor Microenvironment Models for In Vitro Cultures

Despite the enormous progress and development of modern therapies, lung cancer remains one of the most common causes of death among men and women. The key element in the development of new anti-cancer drugs is proper planning of the preclinical research phase. The most adequate basic research exemplary for cancer study are 3D tumor microenvironment in vitro models, which allow us to avoid the use of animal models and ensure replicable culture condition. However, the question tormenting the scientist is how to choose the best tool for tumor microenvironment research, especially for extremely heterogenous lung cancer cases. In the presented review we are focused to explain the key factors of lung cancer biology, its microenvironment, and clinical gaps related to different therapies. The review summarized the most important strategies for in vitro culture models mimicking the tumor–tumor microenvironmental interaction, as well as all advantages and disadvantages were depicted. This knowledge could facilitate the right decision to designate proper pre-clinical in vitro study, based on available analytical tools and technical capabilities, to obtain more reliable and personalized results for faster introduction them into the future clinical trials.

Discrepancies between ALK protein disruption and occurrence of ALK gene rearrangement in Polish NSCLC patients

BACKGROUND

Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) rearrangement are predisposed to molecularly targeted therapies. Proper diagnostic is crucial for quick and correct patients qualification to optimal treatment method. Genetic tests to detect predictive factors could be performed sequentially. After excluding EGFR mutations, abnormal ALK protein expression should be tested using immunohistochemistry (IHC) method. In patients with disrupted ALK expression, the rearrangement of the ALK gene should be confirmed by FISH method. Despite few years of experience in analysis of these predictive factors, there are still problems in interpretation of diagnostic tests results. Especially, some recommendations for ALK IHC diagnosis are not precise.

METHODS

Mutations in EGFR gene were examined using real-time PCR technique in 1,108 formalin-fixed paraffin-embedded (FFPE) tissues, 398 FFPE cell-blocks and 470 cytological specimens of NSCLC. The disrupted ALK protein expression was analysed in 1,100 samples including 782 histological and 306 cytological (cell-blocks) samples using IHC. Twelve materials (1.1%) were non-diagnostic in IHC. ALK gene rearrangement using FISH method was analysed in IHC positive cases.

RESULTS

The frequency of EGFR mutations was 8.6%. EGFR mutations occurred significantly more often in females (P=0.00001, χ2=62.732) and in adenocarcinoma cases (P=0.0002, χ2=14.222). The exon 19 deletions (49%) and exon 21 Leu858Arg substitution (38%) were the most common, rare EGFR mutations occurred in 13% of patients. Any expression of abnormal ALK protein was detected in 202 cases (18.57%). ALK gene rearrangement was confirmed in 49 cases (4.5%). ALK gene rearrangement is significantly more common in female than in male (P=0.0105, χ2=6.541). In patients with ALK gene rearrangement, the median percentage of nuclei with ALK rearrangement was only 25.5%. The polysomy (≥4 gene copy number per nuclei) of ALK gene was observed in 39 cases (21.4% of patients with diagnostic result of FISH examination). Median number of ALK gene copy per nuclei was 2.9±0.77. Significant positive correlation between percentage of cells with abnormal ALK expression in IHC test and percentage of nuclei with ALK rearrangement in FISH method was detected (R=0.617, P<0.00001). Significant negative correlation between the number of copies of ALK gene and the percentage of cells with expression of abnormal ALK was observed (R=-0.2004, P<0.05). ALK gene rearrangement was significantly more frequently observed in the material with coarse-grained cytoplasmic and membranous IHC staining than in materials with light cytoplasmic stippling. The occurrence of cytoplasmic stippling correlated with the increase of ALK gene copy number.

CONCLUSIONS

We indicated that diagnosis of ALK disruption in NSCLC patients should be notably careful using IHC and FISH methods. Recommendations for ALK diagnosis should include the way of interpretation of cases with low percentage of cells with abnormal ALK protein expression in IHC test, character of IHC reaction, and cases with ALK gene polysomy in FISH method.

Beta-2-adrenoreceptor polymorphism at position 16 determines the clinical severity of chronic obstructive pulmonary disease

The Arg/Arg homozygosity at codon 16 of the beta-2-adrenoreceptor (ADRB2) gene has been thought to predispose asthma patients to a poorer therapeutic response to beta-2-mimetics, or to worse control of the disease. In contrast, the results of the studies analysing the effect of ADRB2 polymorphisms on the response to beta-2-adrenoreceptor agonists in chronic obstructive pulmonary disease (COPD) patients are sparse and inconclusive. The aim of this research was to verify if p.Arg16Gly (c.46A > G) and p.Gly27Glu (c.79G > C) single nucleotide polymorphisms (SNPs) exert a negative effect on the selected clinical indicators of COPD. The SNPs of the ADRB2 were identified by multiplex allele-specific PCR on DNA isolated from the venous blood leukocytes of 92 patients with stable grade COPD. In addition, all of the patients were asked about the course of COPD during the 12 months preceding the study, including the frequency of exacerbations requiring hospitalisation, the number of antibiotic therapy courses given due to the lower respiratory tract infection, and the number of courses of systemic corticosteroid therapy administered due to the exacerbation of COPD. Arg/Arg homozygotes at codon 16 required at least two courses of antibiotic therapy administered as a result of a lower respiratory tract infection significantly more frequently than carriers of other polymorphic variants of the ADRB2. Moreover, they were the only ones who required three or more courses of corticosteroid therapy due to COPD exacerbation. No significant relationships were observed between the polymorphism at codon 27 and the analysed clinical indicators of COPD severity. These data suggested that Arg/Arg homozygosity at codon 16 of the ADRB2 gene predisposes patients to a clinically more severe course of COPD.