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In non-small-cell lung cancer (NSCLC), epidermal growth factor receptor (EGFR) and K-RAS mutations of the primary tumour are associated with responsiveness and resistance to tyrosine kinase inhibitors (TKIs), respectively. However, the EGFR and K-RAS mutation status in metastases is not well studied. We compared the mutation status of these genes between the primary tumours and the corresponding metastases of 25 patients. Epidermal growth factor receptor and K-RAS mutation status was different between primary tumours and corresponding metastases in 7 (28%) and 6 (24%) of the 25 patients, respectively. Among the 25 primary tumours, three 'hotspot' and two non-classical EGFR mutations were found; none of the corresponding metastases had the same mutation pattern. Among the five (20%) K-RAS mutations detected in the primary tumours, two were maintained in the corresponding metastasis. Epidermal growth factor receptor and K-RAS mutations were detected in the metastatic tumours of three (12%) and five (20%) patients, respectively. The expressions of EGFR and phosphorylated EGFR showed 10 and 50% discordance, in that order. We conclude that there is substantial discordance in EGFR and K-RAS mutational status between the primary tumours and corresponding metastases in patients with NSCLC and this might have therapeutic implications when treatment with TKIs is considered.

Liquid biopsy provides real-time monitoring of tumor evolution and response to therapy through analysis of circulating tumor cells (CTCs) and plasma-circulating tumor DNA (ctDNA). epigenetic silencing potentially affects response to endocrine treatment. We evaluated methylation in CTCs and paired plasma ctDNA. We evaluated methylation in CTCs and paired plasma ctDNA as a potential biomarker for response to everolimus/exemestane treatment. A highly sensitive and specific real-time MSP assay for methylation was developed and validated in (i) 65 primary breast tumors formalin-fixed paraffin-embedded (FFPE), (ii) EpCAM CTC fractions (122 patients and 30 healthy donors; HD), (iii) plasma ctDNA (108 patients and 30HD), and (iv) in CTCs (CellSearch) and in paired plasma ctDNA for 58 patients with breast cancer. methylation status was investigated in CTCs isolated from serial peripheral blood samples of 19 patients with ER/HER2 advanced breast cancer receiving everolimus/exemestane. methylation was detected in: (i) 25/65 (38.5%) FFPEs, (ii) : 26/112 (23.3%) patients and 1/30 (3.3%) HD, and (iii) 8/108 (7.4%) patients and 1/30 (3.3%) HD. methylation was highly concordant in 58 paired DNA samples, isolated from CTCs (CellSearch) and corresponding plasma. In serial peripheral blood samples of patients treated with everolimus/exemestane, methylation was observed in 10/36 (27.8%) CTC-positive samples, and was associated with lack of response to treatment ( = 0.023, Fisher exact test). We report for the first time the detection of methylation in CTCs and a high concordance with paired plasma ctDNA. methylation in CTCs was associated with lack of response to everolimus/exemestane regimen. methylation should be further evaluated as a potential liquid biopsy-based biomarker..

BACKGROUND: In this superiority study, pemetrexed was compared with erlotinib in pre-treated patients with metastatic non-small cell lung cancer (NSCLC). METHODS: Patients with stage IIIB/IV NSCLC who progressed after first-line or second-line treatment were randomized to receive either pemetrexed or erlotinib. In total, 21.7% of patients in the pemetrexed arm and 23.5% of patients in the erlotinib arm had squamous cell histology, and treatment was third line in 39.2% and 46.4% of patients, respectively. The primary study endpoint was time to tumor progression (TTP). Epidermal growth factor receptor/v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (EGFR/KRAS) mutation status also was investigated. RESULTS: There was no difference in terms of the TTP (P 5.195), the objective response rate (P 5.469), or overall survival (P 5.986) between the 2 treatment arms. In patients who had squamous cell histology, erlotinib resulted in a superior TTP compared with pemetrexed (4.1 months vs 2.5 months, respectively; P 5.006). The incidence of grade 3 and 4 neutropenia, thrombocytopenia, and asthenia was significantly higher in the pemetrexed arm, whereas the incidence of grade 3 and 4 skin rash was higher in the erlotinib arm. CONCLUSIONS: Both pemetrexed and erlotinib had comparable efficacy in pre-treated patients with metastatic NSCLC, and the current results indicated that genotyping of tumor cells may have an important effect on treatment efficacy. Cancer 2013;119:2754-64.

'Classical' mutations in the EGFR tyrosine kinase domain (exons 18, 19 and 21) have been associated with sensitivity to tyrosine kinase inhibitors (TKIs) in patients with NSCLC. The aim of the current study was to evaluate whether other than the classical G719X, DEL19 and L858R mutations of EGFR confer sensitivity to TKIs. Genomic DNA was extracted from microdissected formalinfixed paraffin-embedded tumour tissue from 86 patients treated with gefitinib. Exons 18, 19 and 21 were amplified and subjected to direct sequencing. Eleven (13%) patients harboured the classical exon's 18, 19 and 21 mutations, while 14 (16%) had 'other' variants. There was a significantly higher percentage of 'never-smoker' patients with 'classical' EGFR mutations (P ¼ 0.002). Among patients with 'classical' mutations 3 patients achieved PR and 7 SD, while in the 'other' mutations group 10 patients had SD as best response. In the wild-type group, there were 3 patients with PR and 25 with SD. Median TTP was 16, 64 (P ¼ 0.002) and 21 weeks and median survival was 36, 78 and 67 weeks for patients with wild-type, 'classical' and 'other' EGFR mutations, respectively. The clinical relevance of 'other' EGFR mutation variants remains uncertain and requires further assessment in a prospective study.

Metastasis is the main cause of mortality in patients with colorectal cancer. However, most of the targeted therapies and predictive molecular biomarkers were developed based mainly on primary tumors. The current study was conducted to determine the degree of discordance between potential predictive and/or prognostic molecular markers in primary colorectal tumors and corresponding metastases, as this could have an impact on the efficacy of targeted therapies in the advanced colorectal cancer. KRAS, PIK3CA and BRAF mutations were determined by Sanger sequencing and mutant-enriched polymerase chain reaction (PCR) assays in 83 paired samples, MET gene copy number by quantitative PCR in 59, MET expression by immunohistochemistry in 73 and nuclear and cytoplasmic expression of PTEN by immunohistochemistry in 78 and 71 pairs, respectively. A certain degree of discordance between primary tumors and corresponding metastases was demonstrated for all examined biomarkers except BRAF mutations. PIK3CA exon 9 mutations in primary tumors and loss of PTEN nuclear expression in metastases correlated with KRAS mutations. KRAS wild-type status in primary tumors was associated with loss of PTEN cytoplasmic expression and high gene copy number of MET. Survival and clinical data were available for 68 patients. The multiple regression analysis revealed that the right-sided tumor localization and overexpression of MET were associated with shorter overall survival.

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BackgroundTo prospectively evaluate the usefulness of the BRAFV600E mutation detection in daily clinical practice in patients with metastatic Colorectal Cancer (mCRC). Patients and Methods504 mCRC patients treated with systemic chemotherapy ± biologics were analyzed. ResultsA statistically significant higher incidence of the BRAF mutation was observed in patients with ECOG-PS 2 (p=0.001), multiple metastatic sites (p=0.002),> 65 years old (p=0.004), primary tumors located in the colon (p<0.001), high-grade tumors (p=0.001) and in those with mucinous features (p=0.037). Patients with BRAFV600E mutated tumors had a statistically significantly reduced progression-free survival (PFS) compared to wild-type (wt) ones (4.1 and 11.6 months, respectively; p<0.001) and overall survival (OS) (14.0 vs. 34.6 months, respectively; p<0.001). In the multivariate analysis the BRAFV600E mutation emerged as an independent factor associated with reduced PFS (HR: 4.1, 95% CI 2.7–6.2; p<0.001) and OS (HR: 5.9, 95% CI 3.7–9.5; p<0.001). Among the 273 patients treated with salvage cetuximab or panitumumab, the BRAFV600E mutation was correlated with reduced PFS (2.2 vs. 6.0 months; p<0.0001) and OS (4.3 vs. 17.4 months; p<0.0001). ConclusionsThe presence of BRAFV600E-mutation in mCRC characterizes a subgroup of patients with distinct biologic, clinical and pathological features and is associated with very poor patients’ prognosis.