Jianming Ying

Detection of ROS1 gene rearrangement in lung adenocarcinoma: comparison of IHC, FISH and real-time RT-PCR.

Aims To compare fluorescence in situ hybridization (FISH), immunohistochemistry (IHC) and quantitative real-time reverse transcription-PCR (qRT-PCR) assays for detection of ROS1 fusion in a large number of ROS1-positive lung adenocatcinoma (ADC) patients. Methods Using IHC analysis, sixty lung ADCs including 16 cases with ROS1 protein expression and 44 cases without ROS1 expression were selected for this study. The ROS1 fusion status was examined by FISH and qRT-PCR assay. Results Among 60 cases, 16 (26.7%), 13 (21.7%) and 20 (33.3%) cases were ROS1 positive revealed by IHC, FISH and qRT-PCR, respectively. Using FISH as a standard method for ROS1 fusion detection, the sensitivity and specificity of IHC were 100% and 93.6%, respectively. Three IHC-positive cases, which showed FISH negative, were demonstrated with ROS1 fusion by qRT-PCR analysis. The sensitivity and specificity of qRT-PCR for detection for ROS1 fusion were 100% and 85.1%, respectively. The total concordance rate between IHC and qRT-PCR were 93.3%. Conclusion IHC is a reliable and rapid screening tool in routine pathologic laboratories for the identification of suitable candidates for ROS1-targeted therapy. Some ROS1 IHC-positive but FISH-negative cases did harbor the translocation events and may benefit from crizotinib.

BIRC6-ALK, a Novel Fusion Gene in ALK Break-Apart FISH-Negative Lung Adenocarcinoma, Responds to Crizotinib

e37 Journal of Thoracic Oncology ® • Volume 10, Number 6, June 2015 Crizotinib was approved for the treatment of advanced non–small-cell lung cancer patients with ALK fusion as detected by the ALK fluorescence in situ hybridization (FISH) test. The assay clearly defined that isolated 5′ ALK signals are considered ALK negative because the 5′ probe is not located in the kinase region. However, here, we describe a case with a negative FISH result that was later identified as ALK+ by VENTANA ALK (D5F3) immunohistochemisty (IHC) and responded well to crizotinib. Targeted next generation sequencing revealed a new ALK partner gene, baculoviral inhibition of apoptosis protein repeat containing six (BIRC6), and the paracentric inversion for generating this fusion gene.

Concurrence of EGFR amplification and sensitizing mutations indicate a better survival benefit from EGFR-TKI therapy in lung adenocarcinoma patients

OBJECTIVES Tumor heterogeneity, which causes different EGFR mutation abundance, is believed to be responsible for varied progression-free survival (PFS) in lung adenocarcinoma (ADC) patients receiving EGFR-TKI treatment. Frequent EGFR amplification and its common affection in EGFR mutant allele promote the hypothesis that EGFR mutant abundance might be determined by EGFR copy number variation and therefore examination of EGFR amplification status in EGFR mutant patients could predict the efficacy of EGFR-TKI treatment. MATERIALS AND METHODS In this study, 86 lung ADC patients, who harbored EGFR activating mutations and received EGFR-TKI treatment, were examined for EGFR amplification and expression by Dual-color Silver in situ Hybridization (DISH) and immunohistochemistry analysis, respectively. RESULTS AND CONCLUSION Forty-one of 86 (47.7%) samples with EGFR activating mutations were identified with EGFR amplification. Patients with EGFR gene amplification had a significantly longer PFS than those without (16.3 vs. 9.1 months, p=0.004). The EGFR expression was then examined by immunohistochemistry analysis. Thirty-nine of 86 (45%) tumors had EGFR overexpression, which was significantly correlated with EGFR amplification (p=0.000). However, patients with EGFR overexpression exhibited no difference in PFS (14.1 vs. 13.3 months, p=0.797). In conclusion, EGFR amplification occurs frequently in lung ADC patients harboring EGFR activating mutations, and could serve as an indicator for better response from EGFR-TKI treatment.

Colorectal carcinomas with KRAS codon 12 mutation are associated with more advanced tumor stages

BackgroundKRAS mutation occurs in 35%-40% of colorectal cancer (CRC). The aim of our study was to evaluate the pathological and molecular features of specific KRAS mutated colorectal carcinomas. KRAS and BRAFV600E mutation tests were performed in 762 primary tumors from a consecutive cohort study of Chinese CRC patients.MethodsDNA mismatch repair (MMR) status was determined by immunohistochemistry (IHC) staining. Assessment of KRAS and BRAF V600E mutational status was performed using a multiplex allele-specific PCR-based assay.ResultsMutations of KRAS (34.8%) and BRAFV600E (3.1%) were nearly mutually exclusive. Both KRAS- and BRAF- mutated tumors were more likely to be located at proximal colon than wild-type (WT) carcinomas. KRAS-mutated carcinomas were more frequently observed in female patients (47.5% vs 37.1%, p = 0.005) and mucinous differentiation (34.7% vs 24.8%, p = 0.004), but have no difference between lymph node (LN) metastases and among pTNM stages. Whereas, BRAF-mutated carcinomas more frequently demonstrated histologic features such as proximal location (60.9% vs 20.9%, p = 0.001), low-grade histology (43.5% vs 18.0%, p = 0.005), mucinous differentiation (69.6% vs 25.9%, p = 0.001) and deficient MMR (dMMR) (21.7% vs 7.6%, p = 0.03). In particular, KRAS codon 12 mutated carcinomas had increased lymph node metastasis (odds ratio [OR] = 1.31; 95% confidence interval [CI] = 1.04 to 1.65; P = 0.02) and were more likely in higher disease stage (III-IV) than that of WT carcinomas (OR = 1.30; 95% CI = 1.03 to 1.64; P = 0.03). However, there were no significant differences in lymph node metastasis and disease stage between KRAS codon 13 mutated carcinoma and WT carcinoma patients.ConclusionsIn summary, KRAS codon 12 mutation, but not codon 13 mutation, is associated with lymph node metastasis and higher tumor stages.

Prevalence and Clinicopathological Characteristics of HER2 and BRAF Mutation in Chinese Patients with Lung Adenocarcinoma

Aims To determine the prevalence and clinicopathological characteristics of BRAF V600E mutation and HER2 exon 20 insertions in Chinese lung adenocarcinoma (ADC) patients. Methods Given the fact that the driver mutations are mutually exclusive in lung ADCs, 204 EGFR/KRAS wild-type cases were enrolled in this study. Direct Sanger sequencing was performed to examine BRAF V600E and HER2 exon 20 mutations. The association of BRAF and HER2 mutations with clinicopathological characteristics was statistically analyzed. Results Among the 204 lung ADCs tested, 11 cases (5.4%) carried HER2 exon 20 insertions and 4 cases (2.0%) had BRAF V600E mutation. HER2 mutation status was identified to be associated with a non-smoking history (p<0.05). HER2 mutation occurs in 9.4% of never smokers (10/106), 8.7% of female (8/92) and 2.7% of male (3/112) in this selected cohort. All four BRAF mutated patients were women and three of them were never-smokers. No HER2 mutant patients harbor BRAF mutation. Conclusions HER2 and BRAF mutations identify a distinct subset of lung ADCs. Given the high prevalence of lung cancer and the availability of targeted therapy, Chinese lung ADC patients without EGFR and KRAS mutations are recommended for HER2 and BRAF mutations detection, especially for those never smokers.

A CLDN1-Negative Phenotype Predicts Poor Prognosis in Triple-Negative Breast Cancer

Introduction Triple-negative breast cancer (TNBC) is a heterogeneous disease with no definitive prognostic markers. As a major component of tight junctions, claudins (CLDNs) presumably play an important role in carcinogenesis and progression of breast cancer. This study was aimed at determining the relationship between the expression of CLDNs and the clinical outcomes of TNBCs. Materials and Methods The surgical specimens of primary breast tumors from a consecutive cohort of 173 TNBC patients were retrospectively collected. The membranous expression of CLDN1, CLDN2, CLDN4, and CLDN7 was measured by immunohistochemistry. Then, the associations between CLDN expression, clinicopathological features, and clinical outcomes were assessed. Results Positive CLDN1, CLDN2, CLDN4, and CLDN7 membrane expression was detected in 44.5%, 54.9%, 76.9%, and 73.4% of the cohort specimens, respectively. A lack of CLDN1 expression was related to only lymph node metastasis (P = 0.014). The rate of CLDN4-positive tumors was significantly increased in tumors of a higher grade (P = 0.003). Importantly, negative CLDN1 expression was associated with worse relapse-free survival (RFS) in both lymph node positive (LN+) and negative (LN−) cases (both P<0.001). Similarly it was also associated with shorter overall survival (OS)(P = 0.003 in LN+ cases; P = 0.018 in LN− cases). In the LN+ subgroup, CLDN2-negative cases had a significantly higher risk of recurrence (P = 0.008). Multivariate analysis revealed that negative CLDN1 expression was an independent prognostic factor for high risk of both recurrence and death (HR 5.529, 95% CI 2.664–11.475, P<0.001; HR 3.459, 95% CI 1.555–7.696, P = 0.002). However, neither CLDN4 nor CLDN7 expression was associated with survival. Conclusion In TNBC, the CLDN1-negative phenotype predicts a high risk of recurrence and death. The absence of CLDN1 expression is strongly suggested to be an independent adverse prognostic factor in this heterogeneous subtype of breast cancer.

PIK3CA Gene Mutations and Overexpression: Implications for Prognostic Biomarker and Therapeutic Target in Chinese Esophageal Squamous Cell Carcinoma

Aims To evaluate PIK3CA gene mutations and PIK3CA expression status in Chinese esophageal squamous cell carcinoma (ESCC) patients, and their correlation with clinicopathological characteristics and clinical outcomes. Methods Direct sequencing was applied to investigate mutations in exons 9 and 20 of PIK3CA in 406 Chinese ESCC patients. PIK3CA expression was evaluated using immunohistochemistry analysis. The associations of PIK3CA gene mutations and PIK3CA expression with clinicopathological characteristics and clinical outcome were examined. Results Thirty somatic point mutations (30/406, 7.4%) were identified in exon 9 whereas no mutations were detected in exon 20. PIK3CA mutations were not correlated with clinicopathological characteristics or clinical outcomes. However in the ESCC patients with family cancer history, PIK3CA mutations were independently correlated with worse overall survival (multivariate hazard ratio (HR) = 10.493, 95% CI: 2.432–45.267, P = 0.002). Compared to normal esophageal tissue, PIK3CA was significantly overexpressed in cancer tissue (P<0.001). PIK3CA overexpression was independently associated with higher risk of local recurrence (multivariate HR  = 1.435, 95% CI: 1.040–1.979, P = 0.028). In female ESCC patients, PIK3CA overexpression was independently correlated with worse overall survival (multivariate HR  = 2.341, 95% CI: 1.073–5.108, P = 0.033). Conclusions Our results suggest PIK3CA gene mutation and overexpression could act as biomarkers for individualized molecular targeted therapy for Chinese ESCC patients.

Icotinib in Patients with Pretreated Advanced Esophageal Squamous Cell Carcinoma with EGFR Overexpression or EGFR Gene Amplification: A Single-Arm, Multicenter Phase 2 Study.

Introduction: Epidermal growth factor receptor (EGFR) has been reported to be overexpressed and amplified in a high percentage of patients with esophageal squamous cell carcinoma (ESCC). The activity of icotinib, an EGFR tyrosine kinase inhibitor, was assessed in previously treated ESCC with EGFR overexpression or amplification. Methods: For this phase 2, single‐arm, multicenter trial undertaken at six hospitals in China, we included Chinese patients with previously treated, histologically confirmed advanced ESCC and EGFR overexpression (immunohistochemical staining sore of 3+) or amplification (positive fluorescence in situ hybridization result). These patients received oral icotinib (250 mg, three times daily).The primary end point was the proportion of patients with objective responses as assessed by an independent radiology review committee. Results: Between December 5, 2013, and May 28, 2015, a total of 281 patients were screened. Fifty‐four eligible patients were enrolled. Nine responses were observed, including one complete response and eight partial responses, and 16 patients had stable disease, resulting in a 16.7% objective response rate (95% confidence interval [CI]: 6.7–26.6) and 46.3% disease control rate (95% CI: 33.0–59.6). The median progression‐free survival and overall survival times were 52 (95% CI: 40–95) days and 153 (95% CI: 139–218) days, respectively. A total of 43 patients experienced at least one adverse event, but most were only grade 1 to 2 in severity. The most frequent was rash (48.1%), followed by diarrhea (22.2%). Conclusions: Icotinib showed favorable activity in patients with advanced, previously treated ESCC with EGFR overexpression or amplification. These findings suggest further research into EGFR overexpression or amplification for selecting responsive patients.

Assessment of cytology based molecular analysis to guide targeted therapy in advanced non-small-cell lung cancer

To investigate the use of molecular testing on cytological specimens in selecting advanced non-small cell lung cancer (NSCLC) patients who are adequate for targeted treatment, a total of 137 NSCLC cases were analyzed by fluorescence in situ hybridization (FISH) for anaplastic lymphoma kinase (ALK) rearrangements, and Epidermal growth factor receptor (EGFR), kirsten rat sarcoma viral oncogene homolog (KRAS) mutations were evaluated by quantitative real-time PCR (qRT-PCR) platform combining amplification refractory mutation system (ARMS) primers and TaqMan probes. Cytological specimens included 91 fine-needle aspirates, 5 fibreoptic bronchoscopic derived samples and 41 pleural effusions. Among 137 NSCLCs analyzed for ALK FISH, 16 (11.7%, of 137) were detected to harbor ALK rearrangement. FISH positive cases were all defined as adenocarcinoma (ADC) histologic subtype and the FNA samples showed the highest ALK positive rate (13.2%, 12/91). Of the 9 ALK FISH positive patients who received crizotinib treatment, 8 (88.9%) patients exhibited tumor regression. In addition, 60 (44.8%, of 134) cases were found to harbor EGFR mutations and 22 patients with EGFR sensitive mutations who received gefitinib or erlotinib treatment showed a median PFS of 16.0 months. Mutations of KRAS occurred in 8 (6.0%, of 134) cases and this was mutually exclusive from EGFR mutation. Our results demonstrated that ALK FISH and EGFR, KRAS mutational analysis on cytological specimens are sensitive methods for screening advanced stage NSCLC patients who are adequate for targeted treatment.

Predictive value of EGFR overexpression and gene amplification on icotinib efficacy in patients with advanced esophageal squamous cell carcinoma.

This study aimed to search for a molecular marker for targeted epithelial growth factor receptor (EGFR) inhibitor Icotinib by analyzing protein expression and amplification of EGFR proto-oncogene in esophageal squamous cell carcinoma (ESCC) patients. Immunohistochemistry and fluorescence in situ hybridization (FISH) was used to assess EGFR expression and gene amplification status in 193 patients with ESCC. We also examined the association between EGFR overexpression and the efficacy of a novel EGFR TKI, icotinib, in 62 ESCC patients. Of the 193 patients, 95 (49.2%) patients showed EGFR overexpression (3+), and 47(24.4%) patients harbored EGFR FISH positivity. EGFR overexpression was significantly correlated with clinical stage and lymph node metastasis (p<0.05). In addition, EGFR overexpression was significantly correlated with EGFR FISH positivity (p<0.001). Among the 62 patients who received icotinib, the response rate was 17.6% for patients with high EGFR-expressing tumors, which was markedly higher than the rate (0%) for patients with low to moderate EGFR-expressing tumors (p=0.341). Furthermore, all cases responded to icotinib showed EGFR overexpression. In conclusion, our study suggests that EGFR overexpression might potentially be used in predicting the efficacy in patients treated with Icotinib. These data have implications for both clinical trial design and therapeutic strategies.