Association of EGFR L858R Mutation in Circulating Free DNA With Survival in the EURTAC Trial.

IMPORTANCE: The EURTAC trial demonstrated the greater efficacy of erlotinib compared with chemotherapy for the first-line treatment of European patients with advanced non-small-cell lung cancer (NSCLC) harboring oncogenic epidermal growth factor receptor (EGFR) mutations (exon 19 deletion or L858R mutation in exon 21) in tumor tissue. OBJECTIVE: To assess the feasibility of using circulating free DNA (cfDNA) from blood samples as a surrogate for tumor biopsy for determining EGFR mutation status and to correlate EGFR mutations in cfDNA with outcome. DESIGN, SETTING, AND PARTICIPANTS: This prespecified analysis was a secondary objective of the EURTAC trial using patients included in the EURTAC trial from 2007 to 2011 with available baseline serum or plasma samples. Patients had advanced NSCLC, oncogenic EGFR mutations in the tumor, and no prior chemotherapy for metastatic disease and were treated with erlotinib or chemotherapy. EGFR mutations were examined in cfDNA isolated from 97 baseline blood samples by our novel peptide nucleic acid-mediated 5´ nuclease real-time polymerase chain reaction (TaqMan) assay. MAIN OUTCOMES AND MEASURES: Overall survival (OS), progression-free survival (PFS), and response to therapy were correlated with type of EGFR mutations in cfDNA. RESULTS: In samples from 76 of 97 (78%) patients with usable blood samples, EGFR mutations in cfDNA were detected. Median OS was shorter in patients with the L858R mutation in cfDNA than in those with the exon 19 deletion (13.7 [95% CI, 7.1-17.7] vs 30.0 [95% CI, 19.3-37.7] months; P < .001). Univariate analyses of patients with EGFR mutations in cfDNA identified the L858R mutation in tumor tissue or in cfDNA as a marker of shorter OS (hazard ratio [HR], 2.70 [95% CI, 1.60-4.56]; P < .001) and PFS (HR, 2.04 [95% CI, 1.20-3.48]; P = .008). For patients with the L858R mutation in tissue, median OS was 13.7 (95% CI, 7.1-17.7) months for patients with the L858R mutation in cfDNA and 27.7 (95% CI, 16.1-46.2) months for those in whom the mutation was not detected in cfDNA (HR, 2.22 [95% CI, 1.09-4.52]; P = .03). In the multivariate analysis of the 76 patients with EGFR mutations in cfDNA, only erlotinib treatment remained an independent predictor of longer PFS (HR, 0.41 [95% CI, 0.23-0.74]; P = .003). CONCLUSIONS AND RELEVANCE: The peptide nucleic acid-mediated 5´ nuclease real-time polymerase chain reaction (TaqMan) assay used in this study can be used to efficiently assess EGFR mutations in cfDNA. The L858R mutation in cfDNA may be a novel surrogate prognostic marker. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00446225.

Phase I study of concurrent chemoradiation with pemetrexed and cisplatin followed by consolidation pemetrexed for patients with unresectable stage III non-small cell lung cancer.

PURPOSE: Although concurrent chemotherapy and radiation is the standard approach for good risk unresectable stage III non-small cell lung cancer (NSCLC) patients, there is no optimal concurrent chemotherapy regimen. Administration of chemotherapy at full dose with maximal activity against local and micrometastatic disease is highly desirable. This study tested the feasibility of 3 cycles of full dose cisplatin and pemetrexed concurrent with definitive thoracic radiotherapy followed by consolidation pemetrexed, without the dose-limiting toxicity (DLT) exceeding 33% of the patients. METHODS: Patients with unresectable stage III NSCLC, good performance status and no serious comorbidity were eligible. Patients received thoracic radiation to a dose of 66 Gy concurrently with three 21-day cycles of pemetrexed 500 mg/m(2), and cisplatin at escalating doses from 60 to 75 mg/m(2). Consolidation chemotherapy of pemetrexed 500 mg/m(2) was provided for 3 more 21-day cycles. Cisplatin doses were escalated as far as no more than 1/3 of the patients in a level developing dose limiting toxicities (DLT). RESULTS: Fifteen eligible patients were enrolled: nine in the first dose level and 3 in the second and third dose levels respectively. Two out of 9 patients in the first dose level experienced DLT (grade 3 esophagitis resulting in delay in treatment administration). The major serious acute toxicities were esophagitis (40%) and febrile neutropenia (20%). With a median follow up time of 22 months, median time to progression and overall survival has not been reached. The rate of survival at 24 months was 57.5% (95% CI: 27.5-87.4%) of the patients. CONCLUSIONS: Three systemic dose levels of pemetrexed and cisplatin could be administered concurrently with radiotherapy. The rate of survival at 24 months was encouraging.

Pretreatment EGFR T790M mutation and BRCA1 mRNA expression in erlotinib-treated advanced non-small-cell lung cancer patients with EGFR mutations.

PURPOSE: Advanced non-small-cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations (deletion in exon 19 or L858R) show an impressive progression-free survival of 14 months when treated with erlotinib. However, the presence of EGFR mutations can only imperfectly predict outcome. We hypothesized that progression-free survival could be influenced both by the pretreatment EGFR T790M mutation and by components of DNA repair pathways. EXPERIMENTAL DESIGN: We assessed the T790M mutation in pretreatment diagnostic specimens from 129 erlotinib-treated advanced NSCLC patients with EGFR mutations. The expression of eight genes and two proteins involved in DNA repair and four receptor tyrosine kinases was also examined. RESULTS: The EGFR T790M mutation was observed in 45 of 129 patients (35%). Progression-free survival was 12 months in patients with and 18 months in patients without the T790M mutation (P = 0.05). Progression-free survival was 27 months in patients with low BRCA1 mRNA levels, 18 months in those with intermediate levels, and 10 months in those with high levels (P = 0.02). In the multivariate analysis, the presence of the T790M mutation (HR, 4.35; P = 0.001), intermediate BRCA1 levels (HR, 8.19; P < 0.0001), and high BRCA1 levels (HR, 8.46; P < 0.0001) emerged as markers of shorter progression-free survival. CONCLUSIONS: Low BRCA1 levels neutralized the negative effect of the T790M mutation and were associated with longer progression-free survival to erlotinib. We advocate baseline assessment of the T790M mutation and BRCA1 expression to predict outcome and provide alternative individualized treatment to patients based on T790M mutations and BRCA1 expression.

Hepatitis A virus receptor blocks cell differentiation and is overexpressed in clear cell renal cell carcinoma.

BACKGROUND: The molecular mechanisms underlying tumorigenesis and progression of clear cell renal cell carcinoma (ccRCC) are not well understood. We aimed to identify new molecular markers to provide insight into these processes. METHODS: This work reports on the identification of human hepatitis A virus cellular receptor 1 (hHAVcr-1) as a differentially expressed gene in ccRCC using RNA-based arbitrarily primed polymerase chain reaction (RAP-PCR). Results were further confirmed by Northern and Western blot assays. Carcinoma 769-P and normal HK-2 cells derived from proximal tubule epithelial cells, grown under different culture conditions, were used to understand the putative role of hHAVcr-1 in renal malignancy. hHAVcr-1 stable transfected clones and dipeptidyl peptidase IV (DPPIV) assays allowed assessing its involvement in cell differentiation. RESULTS: The hHAVcr-1 is overexpressed in eight out of 13 ccRCC and its expression neglected in benign oncocytomas. In culture, hhavcr-1 is dramatically overexpressed in normal and tumor cell lines that, having acquired the fully differentiated phenotype, are induced to de-differentiate by means of phorbol ester phorbol 12-myristate-13-acetate (PMA) treatment. Similarly, differentiation prevention by addition of PMA to confluent cells also increases hhavcr-1 expression. hHAVcr-1 stable transfected 769-P cells proved that hhavcr-1 itself blocks differentiation. Since hhavcr-1 is expressed at higher levels in tumor cells, we used an African green monkey cell model to show that immunotoxins directed against the monkey homologue of hhavcr-1 could kill kidney cells. CONCLUSION: Our results showed that hHAVcr-1 blocks differentiation of proximal tubule epithelial cells and that it could be used as a target for therapy of kidney carcinomas.