ABSTRACT
After the development of EGFR tyrosine kinase inhibitors (TKIs), genetic testing of EGFR became required for effective treatment of lung cancer. Initially, the testing was conducted separately for each mutated region. However, many EGFR mutations have since been identified that determine the efficacy of EGFR-TKIs. Therefore, genetic testing of EGFR by next generation sequencing (NGS) may be a suitable strategy for lung cancer. Here we examined the applicability of the NGS method in regard to sensitivity, time and cost. A total of 939 specimens were obtained from 686 lung cancer patients at our hospital. DNA and RNA were simultaneously extracted from specimens derived from surgery, bronchoscopy, and fluid aspiration. Specimens included cerebrospinal fluid, pleural effusion, abdominal fluid, and pericardial effusion. From RNA, target regions (EGFR, KRAS, ALK fusion and RET fusion) were enriched by RT-PCR and sequenced with MiSeq. From DNA, PCR or PCR-RFLP conventional methods were performed. NGS and conventional methods were carried out routinely per week. Among the total 939 specimens, 38 specimens could not be examined with NGS. Among these, 34 specimens were analyzed by conventional testing with simultaneously extracted DNA. The remaining four specimens could not be tested with either method. Compared with the conventional method, the concordance rate of mutations was 99% (892/901), excluding specimens with NGS failure. The time period required from processing of specimens to results was 4 days, and the cost per sample was sufficiently low. In conclusion, the genetic testing with NGS method was useful for lung cancer treatment. The cost, sensitivity and time were able to tolerate routine examinations.
Subject(s)
Genetic Testing , High-Throughput Nucleotide Sequencing , Lung Neoplasms/diagnosis , Lung Neoplasms/genetics , Oncogene Proteins, Fusion/genetics , Adult , Aged , Aged, 80 and over , Anaplastic Lymphoma Kinase , Bronchoscopy , ErbB Receptors/genetics , Female , Humans , Lung Neoplasms/pathology , Lung Neoplasms/surgery , Male , Middle Aged , Mutation , Oncogene Proteins, Fusion/isolation & purification , Proto-Oncogene Proteins c-ret/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Receptor Protein-Tyrosine Kinases/geneticsABSTRACT
Of the 1548 patients with primary lung cancer who were admitted to our hospital from January 2001 through March 2005, 37 in whom meningeal carciomatosis was diagnosed on cytologic examination of cerebrospinal fluid or magnetic resonance imaging of the brain and spinal cord were studied retrospectively. The most common histologic type was adenocarcinoma, diagnosed in 70% of those patients. The results of cytologic examination of cerebrospinal fluid were positive in 71%. The time from the date of diagnosis of lung cancer to the date of diagnosis of meningeal carcinomatosis ranged from -2 days to 8 years (median, 407 days). Survival from the date of diagnosis of meningeal carcinomatosis ranged from 10 to 392 days (median, 106 days). Treatment for meningeal carcinomatosis was decided on the basis of the patient's general condition and the contorol status of the primary lesion. Radiotherapy, systemic chemotherapy, and palliative therapy were combined. Gefitinib was most often used for chemotherapy after the onset of meningeal carcinomatosis, and 60% of the patients given gefitinib had stable disease. One of these patients (adenocarcinoma) survived for longer than 1 year. Further investigatons are needed to establish standard treatments, including the use of gefitinib, that can improve the quality of life and prolong the survival of patients with meningeal carcinomatosis.
