From the bench to bedside: biological and methodology considerations for the future of companion diagnostics in nonsmall cell lung cancer

Comprehensive Molecular Analysis of NSCLC; Clinicopathological Associations

BACKGROUND

Selection of NSCLC patients for targeted therapy is currently based upon the presence of sensitizing mutations in EGFR and EML4/ALK translocations. The heterogeneity of molecular alterations in lung cancer has led to the ongoing discovery of potential biomarkers and targets in order to improve survival.

AIM

This study aimed to detect alterations in EGFR, KRAS, BRAF, PIK3CA, MET-gene copy number and ALK rearrangements in a large cohort of 956 NSCLC patients of Hellenic origin using highly sensitive techniques and correlations with clinicopathological characteristics.

RESULTS

Mutations were detected in EGFR 10.6% (101 out of 956 samples), KRAS 26.5% (191 out of 720 samples), BRAF 2.5% (12 out of 471 samples), PIK3CA 3.8% (7 out of 184 samples), MET gene amplification was detected in 18% (31 out of 170) and ALK rearrangements in 3.7% (4 out of 107 samples). EGFR mutations were detected in exon 19 (61.4% of mutant cases), exon 21 p.Leu858Arg (19.8%), exon 20 (15.8%), exon 18 (2.9%) and were correlated with gender histology, smoking status and TTF1 staining. p.Thr790Met mutant cases (3.9%) displayed concurrent mutations in exons 19 or 21. Negative TTF-1 staining showed strong negative predictive value for the presence of EGFR mutations. KRAS mutations were associated with histology, the most common mutation being p.Gly12Cys (38%).

DISCUSSION

In conclusion, only 89 patients were eligible for EGFR -TKIs and ALK inhibitors therapy, whereas 257 patients showed other alterations, highlighting the necessity for a detailed molecular profiling potentially leading to more efficient individualized therapies for NSCLC patients.

Rapid and label-free amplification and detection assay for genotyping of cancer biomarker

As understanding of the molecular pathways that drive malignancy in human cancer improves, personalized genotype-based therapy in combination with the predictive biomarker for the efficacy of targeted therapy is becoming more popular in cancer management. Sanger sequencing, that has been the gold standard for mutation analysis in cancer since the 1970s, suffers from low sensitivity, complexity, and time-consuming and labor-intensive procedure. Although several PCR based molecular testing methods are being emerged, there is no universal assay available for genotyping of cancer biomarkers. Here we present a rapid, simple and sensitive assay for the detection of epidermal growth factor receptor (EGFR) mutation in non-small cell lung cancers (NSCLCs). The assay employs a novel double mis-matched primer (DMP) set to improve the detection ability of isothermal solid-phase amplification/detection (ISAD) based on silicon microring biosensor. We show that the EGFR-DMP can detect EGFR gene mutations within 20 min in a label-free and real-time manner. The EGFR-DMP was able to detect a mutation in a sample containing only 1% of the mutant cells in a mixture of wild-type cells. Furthermore, to validate the proposed assay for potential applications in clinical diagnostics, we examined paraffin-embedded tissue samples from 10 NSCLC patients for the presence of EGFR mutations by performing EGFR-DMP and direct sequencing. The EGFR-DMP assay was able to rapidly detect the mutation, with high sensitivity and specificity. The EGFR-DMP assay offers a robust and sensitive approach for the rapid identification of the EGFR mutation. The high sensitivity and specificity and rapidity of this approach may make it useful for predicting the clinical response to targeted EGFR TKIs as a companion diagnostic.

Analysis of clinicopathological features of the echinoderm microtubule-associated protein-like-4-anaplastic lymphoma kinase fusion gene in Chinese patients with advanced non-small-cell lung cancer

BACKGROUND

The echinoderm microtubule-associated protein-like-4-anaplastic lymphoma kinase (EML4-ALK) fusion gene defines a novel molecular subset of non-small-cell lung cancer (NSCLC). However, the clinicopathological features of patients with the EML4-ALK fusion gene have not been defined completely.

METHODS

Clinicopathological data of 200 Chinese patients with advanced NSCLC were analyzed retrospectively to explore their possible correlations with EML4-ALK fusions.

RESULTS

The EML4-ALK fusion gene was detected in 56 (28.0%) of the 200 NSCLC patients, and undetected in 22 (11.0%) patients because of an insufficient amount of pathological tissue. The median age of the patients with positive and negative EML4-ALK was 48 and 55 years, respectively. Patients with the EML4-ALK fusion gene were significantly younger (P< 0.001). The detection rate of the EML4-ALK fusion gene in patients who received primary tumor or metastatic lymph node resection was significantly higher than in patients who received fine-needle biopsy (P= 0.003). The detection rate of the EML4-ALK fusion gene in patients with a time lag from obtainment of the pathological tissue to EML4-ALK fusion gene detection ≤48 months was significantly higher than in patients >48 months (P= 0.020). The occurrence of the EML4-ALK fusion gene in patients with wild-type epidermal growth factor receptor (EGFR) was significantly higher than in patients with mutant-type EGFR (42.5% [37/87] vs. 6.3% [1/16], P= 0.005).

CONCLUSIONS

Younger age and wild-type EGFR were identified as clinicopathological characteristics of patients with advanced NSCLC who harbored the EML4-ALK fusion gene. The optimal time lag from the obtainment of the pathological tissue to the time of EML4-ALK fusion gene detection is ≤48 months.

[Clinical research of crizotinib in advanced non-small cell lung cancer]

目前在非小细胞肺癌（non-small cell lung cancer, NSCLC）的治疗中，靶向药物治疗占有举足轻重的地位。继表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor tyrosine kinase inhibitor, EGFR-TKI）之后，针对棘皮动物微管相关蛋白4-间变性淋巴瘤激酶（echinoderm microtubule associated protein like 4-anaplastic lymphoma kinase, EML4-ALK）融合基因突变为靶点的克里唑替尼（crizotinib）成为了NSCLC靶向治疗领域的焦点。Ⅰ期、Ⅱ期临床试验均已证实：crizotinib治疗EML4-ALK阳性晚期NSCLC患者有效，并能改善患者症状，毒副作用小，患者耐受性较好。近期发现crizotinib对ROS1受体酪氨酸激酶也具有抑制作用。Crizotinib在ROS1基因重排NSCLC中显示出了非常明显的抗肿瘤活性。与其它TKIs一样，crizotinib也存在耐药现象，其耐药机制待进一步研究。现就crizotinib作用机制、药代动力学及治疗晚期NSCLC的临床研究进展做一综述。

How novel molecular diagnostic technologies and biomarkers are revolutionizing genetic testing and patient care

Technological applications and novel biomarkers in the field of molecular diagnostics have never been evolving at a more rapid pace. These novel applications have the promise to change the face of clinical care as we move into the era of personalized medicine. While some of these technologies and biomarkers have been adopted by some clinical laboratories, most laboratories face a steep learning curve in bringing these dramatically new and different molecular diagnostic applications on board. Furthermore, interpreting the vast amounts and new types of data produced by these novel applications brings forth challenges for laboratorians and clinicians alike. In this article, we discuss how some of these emerging novel molecular diagnostic technologies and analytes, such as next-generation sequencing, chromosomal microarray, microRNAs and circulating fetal nucleic acids are revolutionizing patient care and personalized medicine.

New regulatory framework for cancer drug development

Recent changes to non-clinical cancer guidelines offer a golden opportunity to expedite the translation of new anticancer drugs into the clinic. In this review we look at how these guidelines can be implemented and how they can be integrated with non-clinical and clinical study design to produce robust and safe clinical trials.