The Impact of Cigarette Smoking on the Frequency of and Qualitative Differences in KRAS Mutations in Korean Patients with Lung Adenocarcinoma

PURPOSE: This study was designed to determine the relationship of cigarette smoking to the frequency and qualitative differences among KRAS mutations in lung adenocarcinomas from Korean patients. MATERIALS AND METHODS: Detailed smoking histories were obtained from 200 consecutively enrolled patients with lung adenocarcinoma according to a standard protocol. EGFR (exons 18 to 21) and KRAS (codons 12/13) mutations were determined via direct-sequencing. RESULTS: The incidence of KRAS mutations was 8% (16 of 200) in patients with lung adenocarcinoma. KRAS mutations were found in 5.8% (7 of 120) of tumors from never-smokers, 15% (6 of 40) from former-smokers, and 7.5% (3 of 40) from current-smokers. The frequency of KRAS mutations did not differ significantly according to smoking history (p=0.435). Never-smokers were significantly more likely than former or current smokers to have a transition mutation (G-->A or C-->T) rather than a transversion mutation (G-->T or G-->C) that is known to be smoking-related (p=0.011). In a Cox regression model, the adjusted hazard ratios for the risk of progression with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) were 0.24 (95% CI, 0.14-0.42; p<0.001) for the EGFR mutation and 1.27 (95% CI, 0.58-2.79; p=0.537) for the KRAS mutation. CONCLUSION: Cigarette smoking did not influence the frequency of KRAS mutations in lung adenocarcinomas in Korean patients, but influenced qualitative differences in the KRAS mutations.

Treatment Outcome of Patients with Anaplastic Thyroid Cancer: A Single Center Experience

PURPOSE: Anaplastic thyroid cancer is known to have a poor prognosis due to its aggressive and rapid metastasis with median survival of less than 6 months. Multimodal treatment involving surgery and chemoradiotherapy has been used to improve the survival of patients. Here, we retrospectively review of treatment outcome of 13 consecutive patients who were treated at a single center. MATERIALS AND METHODS: We retrospectively reviewed medical records of 13 anaplastic thyroid cancer patients who received multidisciplinary treatment between 2006 and 2010. Kaplan-Meier survival curve was used to analyze progression-free survival and overall survival of patients. RESULTS: The median patient age at diagnosis was 69 years, and six patients had stage IVc diseases. Eight patients received primary surgery followed by radiotherapy or concurrent chemoradiotherapy (CCRT). Five patients received weekly doxorubicin-based definitive CCRT, but only one patient's condition remained stable, while the rest experienced rapid disease progression. The median progression-free survival was 2.8 months (95% CI, 1.2-4.4 months), and the median overall survival was 3.8 months (95% CI, 3.0-4.6 months). CONCLUSION: Patients with anaplastic thyroid cancer showed poor prognosis despite multimodality treatment. Therefore, identification of novel therapeutic targets is warranted to take an effective mode of treatment.