Purpose: Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) confer a strong sensitivity to gefitinib, a selective tyrosine kinase inhibitor of EGFR. Experimental Design: We examined EGFR mutations at exons 18, 19, and 21 in tumor tissue from 68 gefitinib-treated, chemorefractory, advanced non–small cell lung cancer patients from the United States, Europe, and Asia and in a highly gefitinib-sensitive non–small cell lung cancer cell line and correlated their presence with response and survival. In addition, in a subgroup of 28 patients for whom the remaining tumor tissue was available, we examined the relationship among EGFR mutations, CA repeats in intron 1 of EGFR, EGFR and caveolin-1 mRNA levels, and increased EGFR gene copy numbers. Results: Seventeen patients had EGFR mutations, all of which were in lung adenocarcinomas. Radiographic response was observed in 16 of 17 (94.1%) patients harboring EGFR mutations, in contrast with 6 of 51 (12.6%) with wild-type EGFR (P < 0.0001). Probability of response increased significantly in never smokers, patients receiving a greater number of prior chemotherapy regimens, Asians, and younger patients. Median survival was not reached for patients with EGFR mutations and was 9.9 months for those with wild-type EGFR (P = 0.001). EGFR mutations tended to be associated with increased numbers of CA repeats and increased EGFR gene copy numbers but not with EGFR and caveolin-1 mRNA overexpression (P = not significant). Conclusions: The presence of EGFR mutations is a major determinant of gefitinib response, and targeting EGFR should be considered in preference to chemotherapy as first-line treatment in lung adenocarcinomas that have demonstrable EGFR mutations.

Bone marrow fibrosis in myelodysplastic syndromes: a prospective evaluation including mutational analysis

Assessment of telomere length (TL) in peripheral blood leukocytes is part of the diagnostic algorithm applied to patients with acquired bone marrow failure syndromes (BMFSs) and dyskeratosis congenita (DKC). Monochrome multiplex–quantitative polymerase chain reaction (MM–qPCR) and fluorescence in situ hybridization (flow‐FISH) are methodologies available for TL screening. Dependent on TL expressed in relation to percentiles of healthy controls, further genetic testing for inherited mutations in telomere maintenance genes is recommended. However, the correct threshold to trigger this genetic workup is still under debate. Here, we prospectively compared MM–qPCR and flow‐FISH regarding their capacity for accurate identification of DKC patients. All patients (n = 105) underwent genetic testing by next‐generation sequencing and in 16 patients, mutations in DKC‐relevant genes were identified. Whole leukocyte TL of patients measured by MM–qPCR was found to be moderately correlated with lymphocyte TL measured by flow‐FISH (r² = 0.34; P < 0.0001). The sensitivity of both methods was high, but the specificity of MM–qPCR (29%) was significantly lower compared with flow‐FISH (58%). These results suggest that MM–qPCR of peripheral blood cells is inferior to flow‐FISH for clinical routine screening for suspected DKC in adult patients with BMFS due to lower specificity and a higher rate of false‐positive results.

Summary: The landscape of medical sequencing has rapidly changed with the evolution of next generation sequencing (NGS). These technologies have contributed to the molecular characterization of the myelodysplastic syndromes (MDS) and chronic myelomonocytic leukaemia (CMML), through the identification of recurrent gene mutations, which are present in >80% of patients. These mutations contribute to a better classification and risk stratification of the patients. Currently, clinical laboratories include NGS genomic analyses in their routine clinical practice, in an effort to personalize the diagnosis, prognosis and treatment of MDS and CMML. NGS technologies have reduced the cost of large‐scale sequencing, but there are additional challenges involving the clinical validation of these technologies, as continuous advances are constantly being made. In this context, it is of major importance to standardize the generation, analysis, clinical interpretation and reporting of NGS data. To that end, the Spanish MDS Group (GESMD) has expanded the present set of guidelines, aiming to establish common quality standards for the adequate implementation of NGS and clinical interpretation of the results, hoping that this effort will ultimately contribute to the benefit of patients with myeloid malignancies.