Assessment of DDR2, BRAF, EGFR and KRAS mutations as therapeutic targets in non-adenocarcinoma lung cancer patients

Identification of Biomarkers for Lung Adenocarcinoma With Qi Deficiency and Phlegm Dampness

BACKGROUND

Qi deficiency and phlegm dampness (QPD) is one of the most common traditional Chinese medicine (TCM) syndromes in lung adenocarcinoma (LUAD). This study aimed to identify syndrome-specific biomarkers for LUAD with QPD syndrome.

METHODS

Peripheral blood mononuclear cells (PBMCs) from LUAD patients with QPD, LUAD patients with non-QPD (N-QPD), and healthy control (H) were collected and analyzed with RNA-seq to identify differentially expressed genes (DEGs). The area under the receiver operator characteristic curve (AUC) of each DEG was calculated, and the top 10 highest AUC DEGs were validated by qRT-PCR. Logistic regression analysis was used to develop a diagnostic model evaluated with AUC.

RESULTS

A total of 135 individuals were enrolled in this study (training set: 15 QPD, 15 N-QPD, 15 H; validation set: 30 QPD, 30 N-QPD, 30 H). A total of 1480 DEGs were identified between QPD and N-QPD. The qRT-PCR results showed that the expression of DDR2 was downregulated, and PPARG was upregulated, which was in line with the finding of the training set. We developed a diagnostic model with these two genes. The AUC of the diagnostic model in the training cohort and validation cohort was 0.891 and 0.777, respectively.

CONCLUSIONS

We identified the two genes (DDR2 and PPARG) as syndrome-specific biomarkers for LUAD with QPD syndrome and developed a novel diagnostic model, which may help to improve the accuracy and sensibility of clinical diagnosis and provide a new target for natural drug treatment of LUAD.

Comparison of survival results of patients with T0 and T1-2-3 in pathological T staging in patients with non-small cell lung cancer who underwent surgery after neoadjuvant treatment

Aim

In this study, we aimed to compare the survival results of patients who underwent neoadjuvant treatment with NSCLC between March 1997 and August 2014 and were found to have T0N0 and T1-2-3/N0.

Material and methods

A hundred ninety-five patients who had complete neoadjuvant therapy, complete lung resection and lymph node dissection, and pathologically diagnosed as T0 or T1-2-3/N0, M0 were included in the study.

Results

Of the 195 patients included in the study, 181 were male, 14 were female and the mean age of the patients was 57.9. The mean age of the groups was as follows: group 1: 58.1, group 2: 57.7, group 3: 59.7 and group 4: 56.8. In our series the most common complication was atelectasis (n = 19). Others were prolonged air leak (n = 16), pneumonia (n = 12), apical pleural space (n = 6), wound infection (n = 3), cardiac problems (n = 3), hematoma (n = 3), bronchopleural fistula (n = 3), empyema (n = 2), chylothorax (n = 1). The 5-year survival rate for patients in the T0N0 group was 76.3%. This rate was 71.8% in group 2, 63.6% in group 3 and 44.1% in group 4.

Conclusions

Survival was found to be better in patients who underwent surgery after neoadjuvant therapy and had a complete pathological response. We believe that we can provide better results with the increase in the number of cases detected as TxN0 after the neoadjuvant treatment and prolongation of the follow-up period.

Distribution of KRAS, DDR2, and TP53 gene mutations in lung cancer: An analysis of Iranian patients

Purpose

Lung cancer is the deadliest known cancer in the world, with the highest number of mutations in proto-oncogenes and tumor suppressor genes. Therefore, this study was conducted to determine the status of hotspot regions in DDR2 and KRAS genes for the first time, as well as in TP53 gene, in lung cancer patients within the Iranian population.

Experimental design

The mutations in exon 2 of KRAS, exon 18 of DDR2, and exons 5–6 of TP53 genes were screened in lung cancer samples, including non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) using PCR and sequencing techniques.

Results

Analysis of the KRAS gene showed only a G12C variation in one large cell carcinoma (LCC) patient, whereas variants were not found in adenocarcinoma (ADC) and squamous cell carcinoma (SCC) cases. The Q808H variation in the DDR2 gene was detected in one SCC sample, while no variant was seen in the ADC and LCC subtypes. Variations in the TP53 gene were seen in all NSCLC subtypes, including six ADC (13.63%), seven SCC (15.9%) and two LCC (4.54%). Forty-eight variants were found in the TP53 gene. Of these, 15 variants were found in coding regions V147A, V157F, Q167Q, D186G, H193R, T211T, F212L and P222P, 33 variants in intronic regions rs1625895 (HGVS: c.672+62A>G), rs766856111 (HGVS: c.672+6G>A) and two new variants (c.560-12A>G and c.672+86T>C).

Conclusions

In conclusion, KRAS, DDR2, and TP53 variants were detected in 2%, 2.17% and 79.54% of all cases, respectively. The frequency of DDR2 mutation is nearly close to other studies, while KRAS and TP53 mutation frequencies are lower and higher than other populations, respectively. Three new putative pathogenic variants, for the first time, have been detected in Iranian patients with lung cancer, including Q808H in DDR2, F212L, and D186G in coding regions of TP53. In addition, we observed five novel benign variants, including Q167Q, P222P and T211T in coding sequence, and c.560-12A>G and c.672+86T>C, in intronic region of TP53. Mutations of KRAS and DDR2 were found in LCC and SCC subtypes, respectively, whereas mutations of TP53 were seen in SCC and ADC subtypes with higher frequencies and LCC subtype with lower frequency. Therefore, Iranian lung cancer patients can benefit from mutational analysis before starting the conventional treatment. A better understanding of the biology of these genes and their mutations will be critical for developing future targeted therapies.

Prevalence of Mutations in Discoidin Domain-Containing Receptor Tyrosine Kinase 2 (DDR2) in Squamous Cell Lung Cancers in Korean Patients

Purpose

The discoidin domain-containing receptor tyrosine kinase 2 (DDR2) is known to contain mutations in a small subset of patients with squamous cell carcinomas (SCC) of the lung. Studying the DDR2 mutations in patients with SCC of the lung would advance our understanding and guide the development of therapeutic strategies against lung cancer.

Materials and Methods

We selected 100 samples through a preliminary genetic screen, including specimens from biopsies and surgical resection, and confirmed SCC by histologic examination. DDR2 mutations on exons 6, 15, 16, and 18 were analyzed by Sanger sequencing of formalin-fixed, paraffin-embedded tissue samples. The functional effects of novel DDR2 mutants were confirmed by in vitro assays.

Results

We identified novel somatic mutations of DDR2 in two of the 100 SCC samples studied. One mutation was c.1745T>A (p.V582E) and the other was c.1784T>C (p.L595P), and both were on exon 15. Both patients were smokers and EGFR/KRAS/ALK-triple negative. The expression of the mutant DDR2 induced activation of DDR2 by the collagen ligand and caused enhanced cell growth and tumor progression. Moreover, dasatinib, a DDR2 inhibitor, showed potential efficacy against DDR2 L595P mutant–bearing cells.

Conclusion

Our results suggest that a mutation in DDR2 occurs naturally with a frequency of about 2% in Korean lung SCC patients. In addition, we showed that each of the novel DDR2 mutations were located in a kinase domain and induced an increase in cell proliferation rate.

Large Cell Neuroendocrine Carcinoma of the Lung: Clinico-Pathologic Features, Treatment, and Outcomes

BACKGROUND

Large cell neuroendocrine carcinoma (LCNEC) accounts for approximately 3% of lung cancers. Pathologic classification and optimal therapies are debated. We report the clinicopathologic features, treatment and survival of a series of patients with stage IV LCNEC.

MATERIALS AND METHODS

Cases of pathologically-confirmed stage IV LCNEC evaluated at Memorial Sloan Kettering Cancer Center from 2006 to 2013 were identified. We collected demographic, treatment, and survival data. Available radiology was evaluated by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 criteria.

RESULTS

Forty-nine patients with stage IV LCNEC were identified. The median age was 64 years, 63% of patients were male, and 88% were smokers. Twenty-three patients (n = 23/49; 47%) had brain metastases, 17 at diagnosis and 6 during the disease course. Seventeen LCNEC patients (35%) had molecular testing, of which 24% had KRAS mutations (n = 4/17). Treatment data for first-line metastatic disease was available on 37 patients: 70% (n = 26) received platinum/etoposide and 30% (n = 11) received other regimens. RECIST was completed on 23 patients with available imaging; objective response rate was 37% (95% confidence interval, 16%-62%) with platinum/etoposide, while those treated with other first-line regimens did not achieve a response. Median overall survival was 10.2 months (95% confidence interval, 8.6-16.4 months) for the entire cohort.

CONCLUSION

Patients with stage IV LCNEC have a high incidence of brain metastases. KRAS mutations are common. Patients with stage IV LCNEC do not respond as well to platinum/etoposide compared with historic data for extensive stage small-cell lung cancer; however, the prognosis is similar. Prospective studies are needed to define optimum therapy for stage IV LCNEC.

[Detection and Analysis of EGFR and KRAS Mutations in the Patients with Lung Squamous Cell Carcinomas]

背景与目的

表皮生长因子受体(epidermal growth factor receptor, EGFR)突变和KRAS基因突变是非小细胞肺癌(non-small cell lung cancer, NSCLC)靶向治疗的重要分子标志, 但关于肺鳞癌中EGFR和KRAS基因突变情况的报道甚少。本研究旨在分析肺鳞癌EGFR和KRAS基因突变与临床特征的关系。

方法

收集初治肺鳞癌患者139例, 有可供检测的肿瘤组织标本。利用突变富集液相芯片法进行EGFR和KRAS基因突变检测。

结果

139例肺鳞癌中, EGFR基因突变25例(18%), KRAS基因突变7例(5%), EGFR和KRAS基因同时发生突变1例(0.7%)。女性和不吸烟患者EGFR基因突变率高于男性和吸烟患者(33.3% vs 16.5%, 29.6% vs 16.1%), 但差异均无统计学意义(P > 0.05, P > 0.05);不同年龄、分期及病理取材标本之间差异均无统计学意义(P > 0.05)。男性患者KRAS基因突变率高于女性患者(5.5% vs 0%), 但差异无统计学意义(P > 0.05);在不同年龄、分期、病理取材标本及是否吸烟各亚组分析中KRAS基因突变差异无统计学意义(P > 0.05)。

结论

肺鳞癌患者EGFR和KRAS基因突变发生率均较低, 且都与临床特征无明显相关。肺鳞癌患者使用酪氨酸激酶抑制剂(tyrosine kinase inhibitors, TKIs)靶向治疗药物之前, 也应检测EGFR基因和KRAS基因的突变情况。

Targeting of MEK in lung cancer therapeutics

The MAP-kinase pathway, consisting of the kinases RAS, RAF, MEK, and ERK, is crucial for cell proliferation, inhibition of apoptosis, and migration of cells. Direct inhibition of RAS is not yet possible, whereas inhibition of RAF is already established in malignant melanoma and under investigation in non-small-cell lung cancer (NSCLC). Due to their structure and function, the MEK proteins are attractive targets for cancer therapy and are also under investigation in NSCLC. We discuss strategies of targeting the RAS-RAF-MEK-ERK pathway with emphasis on MEK inhibition, either alone or in combination with other targets or conventional chemotherapy.

Large cell carcinoma of the lung: a tumor in search of an author. A clinically oriented critical reappraisal

Large cell carcinoma (LCC) is a merely descriptive term indicating a subtype of lung cancer with no specific features of small-cell lung cancer (SCLC), adenocarcinoma (ADC) or squamous cell carcinoma (SQC). This diagnosis is allowed on surgical specimens only, whereas its counterpart in biopsy/cytology samples is non-small-cell lung carcinoma (NSCLC), not otherwise specified (NOS). Although these two terms do not fulfill the same concept, they can be interchangeable synonyms at the clinical level, reflecting, in different ways, the inability to define a specific subtype. Immunohistochemistry (IHC), next generation sequencing (NGS) analysis and, historically, electron microscopy have been unveiling diverse cell differentiation lineages in LCC, resulting in LCC-favor ADC, LCC-favor SQC and LCC-favor large-cell neuroendocrine carcinoma (LCNEC), the latter hopefully to be included into the neuroendocrine tumor (NET) group in the future. Paradoxically, however, the interpretation issues of LCC/NSCLC-NOS are not diminishing, but even increasing albeight an accurate diagnosis is oncologically required and crucial. Also, rare LCC/NSCLC-NOS cases exhibiting null/unclear phenotype, are difficult to classify, and this terminology could be maintained for the sake of classification (basically these tumors are serendipitous ADC, as also confirmed by the lack of p40). In this review article, seven relevant issues to LCC have been addressed by using a question-answer methodology, with final key points discussing major interpretation issues. In conclusion, most LCC/NSCLC-NOS may be eventually re-classified and addressed by exploiting IHC and/or molecular testing to satisfy the criteria of precision medicine (the right drug, to the right patient, at the right time).