Na Zhou

Discovery of targetable genetic alterations in advanced non-small cell lung cancer using a next-generation sequencing-based circulating tumor DNA assay

Next-generation sequencing (NGS)-based circulating tumor DNA (ctDNA) assays have provided a new method of identifying tumor-driving genes in patients with advanced non-small cell lung carcinoma (NSCLC), especially in those whose cancer tissues are unavailable or in those that have acquired treatment resistance. Here, we describe a total of 119 patients with advanced EGFR-TKI-naive NSCLC and 15 EGFR-TKI-resistant patients to identify somatic SNVs, small indels, CNVs and gene fusions in 508 tumor-related genes. Somatic ctDNA mutations were detected in 82.8% (111/134) of patients in the total cohort. Of the 119 patients with advanced NSCLC, 27.7% (33/119) were suitable for treatment with National Comprehensive Cancer Network (NCCN) guideline-approved targeted drugs. Actionable genetic alterations included 25 EGFR mutations, 5 BRAF mutations, and 1 MET mutation, as well as 1 EML4-ALK gene fusion and 1 KIF5B-RET gene fusion. In 19.3% (23/119) of the patients, we also identified genomic alterations with that could be targeted by agents that are in clinical trials, such as mTOR inhibitors, PARP inhibitors, and CDK4/6 inhibitors. Additionally, the EGFR T790M mutation was found in 46.7% (7/15) of the patients with EGFR-TKI-resistant NSCLC, suggesting that the NGS-based ctDNA assay might be an optional method to monitor EGFR-TKI resistance and to discover mechanisms of drug resistance.

Response to apatinib in chemotherapy-failed advanced spindle cell breast carcinoma

Spindle cell carcinoma of the breast is a rare subtype of metaplastic carcinoma, and no effective chemotherapy special for metaplastic carcinoma exists until now. As spindle cell carcinomas of the breast are typically “Triple Negative”, endocrine therapy and molecular therapy targeted to Her2 might not be favorable, resulting in poor prognosis. Apatinib is currently being tested in patients with breast or lung cancers. Here we report a successful case using Apatinib to treat spindle cell carcinoma of breast. A 52- year- old woman presented with a gradually enlarged lump in left breast, which was revealed to be a triple-negative spindle cell carcinoma, underwent a modified radical mastectomy. After the first line chemotherapy with Cyclophosphamide and Epirubicin, multiple metastases in bilateral lung and left anterior thoracic wall appeared. After disease progressed with therapy of Bevacizumab combined with Albumin-bound Paclitaxel and Cisplatin, we treated the patient with Apatinib according to her VEGFR expression, which showed nearly complete response and controllable and tolerated side effects. Next-generation sequencing analysis of the tumor specimen and real time ctDNA was performed to observe the mutated gene numbers matched with therapeutic effect. The present case can help to provide a new and effective therapy strategy to treat advanced spindle cell carcinoma.

Using molecular ecological network analysis to explore the effects of chemotherapy on intestinal microbial communities of colorectal cancer patients

Intestinal microbiota is now widely known to be key roles in the nutrition uptake, metabolism, and the regulation of human immune responses. However, we do not know how changes the intestinal microbiota in response to the chemotherapy. In this study, we used network-based analytical approaches to explore the effects of five stages of chemotherapy on the intestinal microbiota of colorectal cancer patients. The results showed that chemotherapy greatly reduced the alpha diversity and changed the specie-specie interaction networks of intestinal microbiota, proved by the network size, network connectivity and modularity. The OTU167 and OTU8 from the genus Fusobacterium and Bacteroides were identified as keystone taxa by molecular ecological networks in the first two stages of chemotherapy, and were significantly correlated with tumor makers (P < 0.05). Five stages of chemotherapy did not make the intestinal micro-ecosystem regain a steady state, because of the lower alpha diversity and more complicated ecological networks compared to the healthy individuals. Furthermore, combing the changes of ecological networks with the tumor markers, the intestinal microbiota was closely linked with clinical chemotherapeutic effects. Importance A deeply understanding of the role of intestinal microbiota contributes to help us find path forward for improving the prognosis of colorectal cancer patients. In addition, diet or probiotics interventions will be a possible attempt to improve the clinical chemotherapeutic effects for colorectal cancer patients.

Publisher Correction: Discovery of targetable genetic alterations in advanced non-small cell lung cancer using a next-generation sequencing-based circulating tumor DNA assay

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Comprehensive Molecular Characterization of Young Chinese Patients with Lung Adenocarcinoma Identified a Distinctive Genetic Profile

BACKGROUND Occurrence at a younger age has been demonstrated to be associated with a distinct biology in non-small cell lung cancer. However, genomics and clinical characteristics among younger patients with lung adenocarcinoma remain to be determined. Here we studied the potentially targetable genetic alterations by next-generation sequencing (NGS) assay in young Chinese patients with lung adenocarcinoma. MATERIALS AND METHODS Seventy-one surgically resected lung adenocarcinoma tissue samples from patients aged less than 45 years were collected with informed consent from all patients. Targeted NGS assays were used to identify actionable genetic alterations in the cancer tissues. Additionally, the genomic and clinicopathologic characteristics of 106 patients with lung adenocarcinoma who received NGS testing over the same period were analyzed retrospectively. RESULTS The frequencies of targetable genetic alterations in 177 patients with lung adenocarcinoma were analyzed by defined age categories, which unveiled a distinctive molecular profile in the younger group, aged less than 45 years. Notably, higher frequency of ALK and HER2 genetic alterations were associated with young age. However, a reverse trend was observed for KRAS, STK11 and EGFR exon 20 mutations, which were more frequently identified in the older group, aged more than 46 years. Furthermore, concurrent EGFR/TP53 mutations were much more prevalent in the younger patients (81.6% vs. 46.8%), which might have a poor response to treatment with epidermal growth factor receptor tyrosine kinase inhibitor. CONCLUSION In this study, NGS assay revealed a distinctive genetic profile in younger patients with adenocarcinoma. High frequency of concurrent EGFR/TP53 mutations was found in the younger patients, which especially warranted personalized treatment in this population. IMPLICATIONS FOR PRACTICE Further investigation is needed to understand the genomics and clinical characteristics of young patients with lung adenocarcinoma. In the present study, hybrid capture-based next-generation sequencing assays were used to identify targeted genetic alterations in young lung adenocarcinoma patients. Young patients with lung adenocarcinoma, aged less than 45 years, harbored a higher frequency of ALK and HER2 genetic alterations compared with patients aged more than 46 years. Dramatically, concurrent EGFR/TP53 mutations were much more prevalent in younger patients, which had a poor response to treatment with epidermal growth factor receptor kinase inhibitor. These results reveal a distinctive genetic profile in younger patients with adenocarcinoma, which might improve the treatment of this subpopulation.

Targeted next generation sequencing in Chinese colorectal cancer patients guided anti-EGFR treatment and facilitated precision cancer medicine

Objective Colorectal cancer (CRC) patients with both RAS and BRAF wild-type tumors determined by non-next generation sequencing (NGS) testing may still not respond due to the presence of additional mutated genes such as PIK3CA or PTEN. In this study, a broad, hybrid capture-based NGS assay was used to identify RAS, BRAF and additional targetable genetic alterations from Chinese CRC tissues. Methods Fifty-seven cases of CRC were enrolled, and all the patients signed the informed consent. In total, 7708 exons of 508 tumor-related genes and 78 introns of 19 frequently rearranged genes were assessed for base substitutions, INDELs, copy number alterations, and gene fusions. Results The study found that 50.9% (29/57) of the tumors harbored KRAS mutations, 3.5% (2/57) harbored NRAS mutations and 3.5% (2/57) harbored BRAF mutations. More specifically, 89.7% (26/29) of RAS mutations were located in codon 12. Except for RAS and RAF, anti-EGFR therapy response genetic mutations in PTEN (n=2) and PIK3CA (n=1) were found in 4.7% (3/64) of the samples. Actionable alterations were found in HER2 (n = 7), CCND2 (n = 2), NF1 (n = 1), and BRCA1 (n = 1). Conclusions Our results illustrated that 82.5% (47/57) of the samples harbored at least one actionable genetic alteration identified by NGS. HER2 amplifications or mutations, which were identified in 12.3% of the tissues, defined a unique molecular subtype of CRC. The study suggests that high-throughput NGS testing in CRC tissues is a comprehensive and efficient genomic profiling assay to guide personalized therapy.