Optimal Definition of Oligometastasis Showing Survival Benefits of Local Therapies during Tyrosine Kinase Inhibitor Treatment / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#We aimed to investigate the feasibility of four criteria on oligometastasis (OM) concerning clear survival benefits of local therapy (LT) during tyrosine kinase inhibitor (TKI) treatment in non–small cell lung cancer (NSCLC). @*Materials and Methods@#This single-center, retrospective study included patients with advanced NSCLC who received LT because of OM during TKI treatment at Asan Medical Center from January 2011 to December 2020. At the application of LT OM was classified according to four criteria: TNM, European Organization for Research and Treatment of Cancer Lung Cancer Group (EORTC-LCG), National Comprehensive Network (NCCN), and ORGAN. We compared survival outcomes between patients with and without OM. @*Results@#The median overall survival of the 117 patients included in the analysis was 70.8 months (95% confidence interval [CI], 56.6 to 85.1). The patients with OM meeting all four criteria (hazard ratio [HR] with 95% CI of TNM criteria 0.24 with 0.10-0.57; p=0.001, EORTC-LCG criteria 0.34 with 0.17-0.67; p=0.002, NCCN criteria 0.41 with 0.20-0.86; p=0.018 and ORGAN criteria 0.33 with 0.18-0.60; p < 0.001) had significantly longer survival compared with patients who did not after adjusting for confounding factors. Furthermore, increasing the number of extra-thoracic metastatic organs to two or more were independent predictive factors for worse survival outcomes (2 organs: HR, 3.51; 95% CI, 1.01 to 12.14; p=0.048; 3 organs: HR, 4.31; 95% CI, 0.94 to 19.73; p=0.060; 4 organs: HR, 24.47; 95% CI, 5.08 to 117.80; p < 0.001). @*Conclusion@#Patients with OM defined by all four criteria showed prognostic benefits from LT during TKI therapy.

Real-World Study of Osimertinib in Korean Patients with Epidermal Growth Factor Receptor T790M Mutation–Positive Non–Small Cell Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Although osimertinib is the standard-of-care treatment of epidermal growth factor receptor (EGFR) T790M mutation–positive non–small cell lung cancer, real-world evidence on the efficacy of osimertinib is not enough to reflect the complexity of the entire course of treatment. Herein, we report on the use of osimertinib in patients with EGFR T790M mutation–positive non–small cell lung cancer who had previously received EGFR tyrosine kinase inhibitor (TKI) treatment in Korea. @*Materials and Methods@#Patients with confirmed EGFR T790M after disease progression of prior EGFR-TKI were enrolled and administered osimertinib 80 mg daily. The primary effectiveness outcome was progression-free survival, with time-to-treatment discontinuation, treatment and adverse effects leading to treatment discontinuation, and overall survival being the secondary endpoints. @*Results@#A total of 558 individuals were enrolled, and 55.2% had investigator-assessed responses. The median progression-free survival was 14.2 months (95% confidence interval [CI], 13.0 to 16.4), and the median time-to-treatment discontinuation was 15.0 months (95% CI, 14.1 to 15.9). The median overall survival was 36.7 months (95% CI, 30.9 to not reached). The benefit with osimertinib was consistent regardless of the age, sex, smoking history, and primary EGFR mutation subtype. However, hepatic metastases at the time of diagnosis, the presence of plasma EGFR T790M, and the shorter duration of prior EGFR-TKI treatment were poor predictors of osimertinib treatment. Ten patients (1.8%), including three with pneumonitis, had to discontinue osimertinib due to severe adverse effects. @*Conclusion@#Osimertinib demonstrated its clinical effectiveness and survival benefit for EGFR T790M mutation–positive in Korean patients with no new safety signals.

Prognostic Factor and Clinical Outcome in Stage III Non-Small Cell Lung Cancer: A Study Based on Real-World Clinical Data in the Korean Population / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#The optimal treatment for patients with stage III non-small cell lung cancer (NSCLC) remains controversial. This study aimed to investigate prognostic factors and clinical outcome in stage III NSCLC using real-world clinical data in the Korean population. @*Materials and Methods@#Among 8,110 patients with lung cancer selected from 52 hospitals in Korea during 2014-2016, only patients with stage III NSCLC were recruited and analyzed. A standardized protocol was used to collect clinical information and cox proportional hazards models were used to identify risk factors for mortality. @*Results@#A total of 1,383 patients (46.5% had squamous cell carcinoma and 40.9% had adenocarcinoma) with stage III NSCLC were enrolled, and their median age was 70 years. Regarding clinical stage, 548 patients (39.6%) had stage IIIA, 517 (37.4%) had stage IIIB, and 318 (23.0%) had stage IIIC. Pertaining to the initial treatment method, the surgery group (median survival period: 36 months) showed better survival outcomes than the non-surgical treatment group (median survival period: 18 months, p=0.001) in patients with stage IIIA. Moreover, among patients with stage IIIB and stage IIIC, those who received concurrent chemotherapy and radiation therapy (CCRT, median survival period: 24 months) showed better survival outcomes than those who received chemotherapy (median survival period: 11 months), or radiation therapy (median survival period: 10 months, p<0.001). @*Conclusion@#While surgery might be feasible as the initial treatment option in patients with stage IIIA NSCLC, CCRT showed a beneficial role in patients with stage IIIB and IIIC NSCLC.

Active Treatment Improves Overall Survival in Extremely Older Non–Small Cell Lung Cancer Patients: A Multicenter Retrospective Cohort Study / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#As the aging of society progresses, the proportion of extremely older lung cancer patients has also increased; However, studies of these patients with non–small cell lung cancer are limited. Therefore, we investigated the initial treatment modalities and survival outcomes for patients aged 80 years or over. @*Materials and Methods@#We included a multicenter retrospective cohort from the Korean Association for Lung Cancer Registry, which surveys 10% of the newly diagnosed lung cancer patients across 52 hospitals in Korea. We analyzed and compared the 2014–2016 data of the non–small cell lung cancer patients aged ≥ 80 years and those aged < 80 years. @*Results@#Of the 6,576 patients reviewed, 780 patients were aged ≥ 80 years, and 5,796 patients were aged < 80 years. In the patients aged ≥ 80 years, surgery and radiation therapy resulted in longer patient survival among those with a resectable tumor (stage I–II) than the best supportive care (median survival, not reached [surgery] vs. 32.2 months [radiation therapy] vs. 11.43 months [best supportive care]). The duration of survival in patients with advanced-stage (IV) lung cancers was higher after chemotherapy than after the best supportive care (median survival, 8.63 months vs. 2.5 months). Patients with stage IV adenocarcinoma who received targeted therapy had better survival than those who did not (median survival, 9.0 months vs. 4.3 months). @*Conclusion@#Even in extremely older patients, active treatments, such as surgery, radiation therapy, and chemotherapy, can result in better survival outcomes than the best supportive care.

Predictive Factors for Switched EGFR-TKI Retreatment in Patients with EGFR-Mutant Non-Small Cell Lung Cancer / 결핵및호흡기질환

BACKGROUND: Third-generation tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR-TKIs) have proved efficacious in treating non-small cell lung cancer (NSCLC) patients with acquired resistance resulting from the T790M mutation. However, since almost 50% patients with the acquired resistance do not harbor the T790M mutation, retreatment with first- or second-generation EGFR-TKIs may be a more viable therapeutic option. Here, we identified positive response predictors to retreatment, in patients who switched to a different EGFR-TKI, following initial treatment failure. METHODS: This study retrospectively reviewed the medical records of 42 NSCLC patients with EGFR mutations, whose cancers had progressed following initial treatment with gefitinib or erlotinib, and who had switched to a different first-generation EGFR-TKI during subsequent retreatment. To identify high response rate predictors in the changed EGFR-TKI retreatment, we analyzed the relationship between clinical and demographic parameters, and positive clinical outcomes, following retreatment with EGFR-TKI. RESULTS: Overall, 30 (71.4%) patients received gefitinib and 12 (28.6%) patients received erlotinib as their first EGFR-TKI treatment. Following retreatment with a different EGFR-TKI, the overall response and disease control rates were 21.4% and 64.3%, respectively. There was no significant association between their overall responses. The median progression-free survival (PFS) after retreatment was 2.0 months. However, PFS was significantly longer in patients whose time to progression was ≥10 months following initial EGFR-TKI treatment, who had a mutation of exon 19, or whose treatment interval was <90 days. CONCLUSION: In patients with acquired resistance to initial EGFR-TKI therapy, switched EGFR-TKI retreatment may be a salvage therapy for individuals possessing positive retreatment response predictors.

GAB2 Amplification in Squamous Cell Lung Cancer of Non-Smokers

Lung squamous cell cancer (SCC) is typically found in smokers and has a very low incidence in non-smokers, indicating differences in the tumor biology of lung SCC in smokers and non-smokers. However, the specific mutations that drive tumor growth in non-smokers have not been identified. To identify mutations in lung SCC of non-smokers, we performed a genetic analysis using arrays comparative genomic hybridization (ArrayCGH). We analyzed 19 patients with lung SCC who underwent surgical treatment between April 2005 and April 2015. Clinical characteristics were reviewed, and DNA was extracted from fresh frozen lung cancer specimens. All of copy number alterations from ArrayCGH were validated using The Cancer Genome Atlas (TCGA) copy number variation (CNV) data of lung SCC. We examined the frequency of copy number changes according to the smoking status (non-smoker [n = 8] or smoker [n = 11]). We identified 16 significantly altered regions from ArrayCGH data, three gain and four loss regions overlapped with the TCGA lung squamous cell carcinoma (LUSC) patients. Within these overlapped significant regions, we detected 15 genes that have been reported in the Cancer Gene census. We also found that the proto-oncogene GAB2 (11q14.1) was significantly amplified in non-smokers patients and vice versa in both ArrayCGH and TCGA data. Immunohistochemical analyses showed that GAB2 protein was relatively upregulated in non-smoker than smoker tissues (37.5% vs. 9.0%, P = 0.007). GAB2 amplification may have an important role in the development of lung SCC in non-smokers. GAB2 may represent a potential biomarker for lung SCC in non-smokers.

Staging Work-up for Early Lung Cancer: The More the Better? / 결핵및호흡기질환

No abstract available.

Identification of Alternative Splicing and Fusion Transcripts in Non-Small Cell Lung Cancer by RNA Sequencing / 결핵및호흡기질환

BACKGROUND: Lung cancer is the most common cause of cancer related death. Alterations in gene sequence, structure, and expression have an important role in the pathogenesis of lung cancer. Fusion genes and alternative splicing of cancer-related genes have the potential to be oncogenic. In the current study, we performed RNA-sequencing (RNA-seq) to investigate potential fusion genes and alternative splicing in non-small cell lung cancer. METHODS: RNA was isolated from lung tissues obtained from 86 subjects with lung cancer. The RNA samples from lung cancer and normal tissues were processed with RNA-seq using the HiSeq 2000 system. Fusion genes were evaluated using Defuse and ChimeraScan. Candidate fusion transcripts were validated by Sanger sequencing. Alternative splicing was analyzed using multivariate analysis of transcript sequencing and validated using quantitative real time polymerase chain reaction. RESULTS: RNA-seq data identified oncogenic fusion genes EML4-ALK and SLC34A2-ROS1 in three of 86 normal-cancer paired samples. Nine distinct fusion transcripts were selected using DeFuse and ChimeraScan; of which, four fusion transcripts were validated by Sanger sequencing. In 33 squamous cell carcinoma, 29 tumor specific skipped exon events and six mutually exclusive exon events were identified. ITGB4 and PYCR1 were top genes that showed significant tumor specific splice variants. CONCLUSION: In conclusion, RNA-seq data identified novel potential fusion transcripts and splice variants. Further evaluation of their functional significance in the pathogenesis of lung cancer is required.

Mechanisms of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Resistance and Strategies to Overcome Resistance in Lung Adenocarcinoma / 결핵및호흡기질환

Somatic mutations that lead to hyperactivation of epidermal growth factor receptor (EGFR) signaling are detected in approximately 50% of lung adenocarcinoma in people from the Far East population and tyrosine kinase inhibitors are now the standard first line treatment for advanced disease. They have led to a doubling of progression-free survival and an increase in overall survival by more than 2 years. However, emergence of resistant clones has become the primary cause for treatment failure, and has created a new challenge in the daily management of patients with EGFR mutations. Identification of mechanisms leading to inhibitor resistance has led to new therapeutic modalities, some of which have now been adapted for patients with unsuccessful tyrosine kinase inhibitor treatment. In this review, we describe mechanisms of tyrosine kinase inhibitor resistance and the available strategies to overcoming resistance.

Combined treatment with silibinin and either sorafenib or gefitinib enhances their growth-inhibiting effects in hepatocellular carcinoma cells

BACKGROUND/AIMS: Silibinin, the main component of silymarin, is used as a hepatoprotectant and exhibits anticancer effects against various cancer cells. This study evaluated the effects of a combination of silibinin with either gefitinib or sorafenib on hepatocellular carcinoma (HCC) cells. METHODS: Several different human HCC cell lines were used to test the growth-inhibiting effects and cell toxicity of silibinin both alone and in combination with either gefitinib or sorafenib. The cell viability and growth inhibition were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, trypan blue staining, and a colony-forming assay. Furthermore, changes in epidermal growth factor receptor (EGFR)-related signals were evaluated by Western blot analysis. RESULTS: Gefitinib, sorafenib, and silibinin individually exhibited dose-dependent antiproliferative effects on HCC cells. Combined treatment with silibinin enhanced the gefitinib-induced growth-inhibiting effects in some HCC cell lines. The combination effect of gefitinib and silibinin was synergistic in the SNU761 cell line, but was only additive in the Huh-BAT cell line. The combination effect may be attributable to inhibition of EGFR-dependent Akt signaling. Enhanced growth-inhibiting effects were also observed in HCC cells treated with a combination of sorafenib and silibinin. CONCLUSIONS: Combined treatment with silibinin enhanced the growth-inhibiting effects of both gefitinib and sorafenib. Therefore, the combination of silibinin with either sorafenib or gefitinib could be a useful treatment approach for HCC in the future.

An important role for peroxiredoxin II in survival of A549 lung cancer cells resistant to gefitinib

Redox adaptation is an important concept that explains the mechanisms by which cancer cells survive under persistent endogenous oxidative stress and become resistant to certain anticancer agents. To investigate this concept, we determined the expression levels of peroxiredoxins (Prxs), antioxidant enzymes in drug-resistant non-small cell lung carcinoma cells. Prx II was remarkably increased only in A549/GR (gefitinib-resistant) cells compared with A549 cells, consistent with methylation/demethylation. Prx II was highly methylated in the A549 cells but was demethylated in the A549/GR cells. The elevated expression of Prx II resulted in the downregulation of reactive oxygen species (ROS) and cell death and upregulation of cell cycle progression in the A549/GR cells. When Prx II mRNA in the A549/GR cells was knocked down, the levels of ROS and apoptosis were significantly recovered to the levels of the controls. In addition, signaling molecules involved in apoptosis were increased in the A549/GR-shPrx II cells. There was no difference in the expression of MAPK/ERK between the A549/GR cells and A549/GR-shPrx II cells, but the phosphorylation of JNK was increased in the A549/GR cells and was markedly decreased in the A549/GR-shPrx II cells. Colony number and tumor growth were significantly decreased in the A549/GR-shPrx II cells compared with the A549/GR cells. Our findings suggest that Prx II has an important role in cancer cell survival via the modulation of signaling molecules involved in apoptosis and the phosphorylation of JNK by the downregulation of ROS levels in A549/GR cells.

An important role for peroxiredoxin II in survival of A549 lung cancer cells resistant to gefitinib

Redox adaptation is an important concept that explains the mechanisms by which cancer cells survive under persistent endogenous oxidative stress and become resistant to certain anticancer agents. To investigate this concept, we determined the expression levels of peroxiredoxins (Prxs), antioxidant enzymes in drug-resistant non-small cell lung carcinoma cells. Prx II was remarkably increased only in A549/GR (gefitinib-resistant) cells compared with A549 cells, consistent with methylation/demethylation. Prx II was highly methylated in the A549 cells but was demethylated in the A549/GR cells. The elevated expression of Prx II resulted in the downregulation of reactive oxygen species (ROS) and cell death and upregulation of cell cycle progression in the A549/GR cells. When Prx II mRNA in the A549/GR cells was knocked down, the levels of ROS and apoptosis were significantly recovered to the levels of the controls. In addition, signaling molecules involved in apoptosis were increased in the A549/GR-shPrx II cells. There was no difference in the expression of MAPK/ERK between the A549/GR cells and A549/GR-shPrx II cells, but the phosphorylation of JNK was increased in the A549/GR cells and was markedly decreased in the A549/GR-shPrx II cells. Colony number and tumor growth were significantly decreased in the A549/GR-shPrx II cells compared with the A549/GR cells. Our findings suggest that Prx II has an important role in cancer cell survival via the modulation of signaling molecules involved in apoptosis and the phosphorylation of JNK by the downregulation of ROS levels in A549/GR cells.

Treatment of Non-small Cell Lung Carcinoma after Failure of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor / Journal of the Korean Cancer Association, 대한암학회지

Since the first description of non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutation as a distinct clinical entity, studies have proved EGFR tyrosine kinase inhibitors (TKIs) as a first choice of treatment. The median response duration of TKIs as a first-line treatment for EGFR mutant tumors ranges from 11 to 14 months. However, acquired resistance to EGFR-TKIs is inevitable due to various mechanisms, such as T790M, c-Met amplification, activation of alternative pathways (IGF-1, HGF, PI3CA, AXL), transformation to mesenchymal cell or small cell features, and tumor heterogeneity. Until development of a successful treatment strategy to overcome such acquired resistance, few options are currently available. Here we provide a summary of the therapeutic options after failure of first line EGFR-TKI treatment for NSCLC.

Effect of Menu Calorie Labels on Menu Sales and Consumer's Recognition at a Korean Restaurant in a Hotel / 대한지역사회영양학회지

Effect of Menu Calorie Labels on Menu Sales and Consumer's Recognition at a Korean Restaurant in a Hotel The role of calorie information is to help consumers make healthier food choices. However, calorie information is generally unavailable in restaurants. Even in high-end hotel restaurants, which try to provide high quality foods and service, calorie labeling is not mandatory. Therefore, the purpose of this study was to evaluate the effect of calorie labeling on menu sales and consumer's recognition at a Korean restaurant in Kangwonland hotel. The calorie contents of 10 dishes sold in the restaurant were calculated using the food composition table. After making a new menu plate displaying calorie information, the new menu plate and old menu plate were provided every other week for 4 weeks. When we compared the sales between the periods of calorie labeled and calorie unlabeled, sales of 4 items among the 5 food items providing less than 1000 kcal, increased, however the 3 items among the menu providing more than 1000 kcal decreased. As the survey results of total 405 consumers (male n = 232, female n = 173) showed the new menu plate, 68.2% of subjects recognized calorie labeling on the menu plate. Among the subjects who recognized calorie labeling, 58.3% answered that calorie information affected their food choices. And most of them answered that they chose lower calorie foods based on the information provided. The results suggest that displaying calorie information on the menu plate at a Korean restaurant was effective in changing consumer's food choices.

Neuroendocrine Differentiation in Acquired Resistance to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor / 결핵및호흡기질환

BACKGROUND: Small cell lung cancer (SCLC) transformation during epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in lung cancer has been suggested as one of possible resistance mechanisms. METHODS: We evaluated whether SCLC transformation or neuroendocrine (NE) differentiation can be found in the cell line model. In addition, we also investigated its effect on responses to conventional chemotherapeutic drugs of the SCLC treatment. RESULTS: Resistant cell lines to various kinds of EGFR-TKIs such as gefitinib, erlotinib, CL-387,785 and ZD6474 with A549, PC-9 and HCC827 lung adenocarcinoma cell lines were established. Among them, two resistant cell lines, A549/GR (resistant to gefitinib) and PC-9/ZDR (resistant to ZD6474) showed increased expressions of CD56 while increased synaptophysin, Rb, p16 and poly(ADP-ribose) polymerase were found only in A549/GR in western blotting, suggesting that NE differentiation occurred in A549/GR. A549/GR cells were more sensitive to etoposide and cisplatin, chemotherapeutic drugs for SCLC, compared to parental cells. Treatment with cAMP and IBMX induced synaptophysin and chromogranin A expression in A549 cells, which also made them more sensitive to etoposide and cisplatin than parental cells. Furthermore, we found a tissue sample from a patient which showed increased expressions of CD56 and synaptophysin after development of resistance to erlotinib. CONCLUSION: NE differentiation can occur during acquisition of resistance to EGFR-TKI, leading to increased chemosensitivity.

Bronchial Anthracofibrosis and Macroscopic Tissue Pigmentation on EBUS-TBNA Predict a Low Probability of Metastatic Lymphadenopathy in Korean Lung Cancer Patients

The identification of mediastinal lymph nodes (LNs) in lung cancer is an important step of treatment decision and prognosis prediction. The endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is widely used to assess the mediastinal LNs and tissue confirmation in lung cancer. As use of bronchoscopy or EBUS-TBNA has been increased, bronchial anthracofibrosis (BAF) has been detected frequently. Moreover, BAF is often accompanied by mediastinal lymphadenopathy and showed false-positive positron emission tomography uptake, which mimics metastatic lymphadenopathy in lung cancer patients. However, clinical implication of BAF during bronchoscopy is not well understood in lung cancer. We retrospectively reviewed 536 lung cancer patients who performed EBUS-TBNA and observed BAF in 55 patients. A total of 790 LNs were analyzed and macroscopic tissue pigmentation was observed in 228 patients. The adjusted odds ratio for predicting malignant LN was 0.46 for BAF, and 0.22 for macroscopic tissue pigmentation. The specificity of BAF and macroscopic tissue pigmentation for predicting a malignant LN was 75.7% and 42.2%, respectively, which was higher than the specificity of using LN size or standard uptake value on PET. In conclusion, BAF and macroscopic tissue pigmentation during EBUS-TBNA are less commonly found in malignant LNs than reactive LNs in Korean lung cancer patients.

Gefitinib in Selected Patients with Pre-Treated Non-Small-Cell Lung Cancer: Results from a Phase IV, Multicenter, Non-Randomized Study (SELINE) / 결핵및호흡기질환

BACKGROUND: This study was designed to analyze the efficacy of gefitinib as a second-line therapy, according to the clinical characteristics in Korean patients with non-small-cell lung cancer (NSCLC). METHODS: In this Phase IV observational study, we recruited patients, previously failed first-line chemotherapy, who had locally advanced or metastatic NSCLC, and who were found to be either epidermal growth factor receptor (EGFR) mutation-positive or satisfied 2 or more of the 3 characteristics: adenocarcinoma, female, and non-smoker. These patients were administered with gefitinib 250 mg/day, orally. The primary endpoints were to evaluate the objective response rate (ORR) and to determine the relationship of ORRs, depending on each patient's characteristics of modified intent-to-treat population. RESULTS: A total of 138 patients participated in this study. One subject achieved complete response, and 42 subjects achieved partial response (ORR, 31.2%). The subgroup analysis demonstrated that the ORR was significantly higher in patients with EGFR mutation-positive, compared to that of EGFR mutation-negative (45.8% vs. 14.0%, p=0.0004). In a secondary efficacy variable, the median progression-free survival (PFS) was 5.7 months (95% confidence interval, 3.9~8.4 months) and the 6-month PFS and overall survival were 49.6% and 87.9%, respectively. The most common reported adverse events were rash (34.4%), diarrhea (26.6%), pruritus (17.5%), and cough (15.6%). CONCLUSION: Gefitinib was observed in anti-tumor activity with favorable tolerability profile as a second-line therapy in these selected patients. When looking at EGFR mutation status, EGFR mutation-positive showed strong association with gefitinib by greater response and prolonged PFS, compared with that of EGFR mutation-negative.

Mechanisms of Acquired Resistance to Epidermal Growth Factor Receptor Inhibitors and Overcoming Strategies in Lung Cancer

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as gefitinib and erlotinib show good response and survival benefit in EGFR-mutant lung cancer, acquired resistance inevitably develops which limits the median response duration to around 1 year. Secondary T790M gatekeeper mutation is the most common mechanism representing approximately 50% of resistance. The suggested strategies for overcoming T790M including irreversible EGFR-TKIs, mutant-selective EGFR-TKIs, EGFR dual targeting and HSP90 inhibitors should be further investigated for clinical application. Bypass signals through MET or AXL also contribute to resistance, which lead to development of MET or AXL inhibitors. Other mechanisms such as small cell transformation, epithelial-to-mesenchymal transition, PI3KCA mutation, ERK/HER2 amplification and miRNAs are other suggested candidates awaiting validation. As many resistant mechanisms have been recognized, it is important to obtain tissue samples after resistance to provide appropriate treatment. In this review, recent advances in the understanding of resistance and novel ways of overcoming it are discussed.

Cutaneous Metastasis from Lung Cancer: A Single-Institution Retrospective Analysis / 결핵및호흡기질환

BACKGROUND: Lung cancer is responsible for substantial proportions of cutaneous metastasis from internal malignancies. The aim of this study was to evaluate the clinical manifestations and outcomes of cutaneous metastasis in Korean lung cancer patients. METHODS: On a retrospective basis, we analyzed medical records of all patients diagnosed with lung cancer from 2000 to 2006. RESULTS: Cutaneous metastases were found in 10 of 4,385 patients. The number of cases was highest for squamous cell carcinoma. However, there was no metastasis from 754 cases of small cell carcinomas. Cutaneous metastasis was detected during staging work-up in 4 patients and it was the presenting sign of recurrence post-operative in 2 patients. Average time from the diagnosis to discovery of cutaneous metastasis was 16.3 months and median survival was 8.5 months (range, 1.8~19.1 months). CONCLUSION: Physicians should be acquainted with clinical manifestations and outcomes of cutaneous metastasis from lung cancer to detect new, recurrent cancer, or disease progression, and to administer appropriate and prompt management.

Solitary Pulmonary Metastasis of a Thyroid Papillary Microcarcinoma, Masquerading as Primary Lung Cancer

Although pulmonary metastasis of thyroid cancer is not uncommon, it mostly occurs as multiple discrete nodules on the lung parenchyma. Because thyroid cancer presenting with an isolated large lung mass is extremely rare and the diagnosis is frequently based on small pieces of tissue obtained by a fine needle, the wrong diagnosis such as lung cancer is prone to be made. A 60-year-old man was admitted for evaluation of a lung mass detected on chest radiography. Cytological examination of the bronchial washing specimens suggested adenocarcinoma. Surgery for early lung cancer was performed considering that no other abnormalities were found during the work-up that included 18-fludeoxyglucose positron emission tomography computer tomography (18FDG-PET/CT). Unexpectedly, the diagnosis of papillary thyroid cancer with lung metastasis was made, which prompted us to evaluate the thyroid gland and then remove the primary cancer by subsequent operation. Although it is uncommon, physician should be aware of this possibility, which could help to avoid the wrong diagnosis. Here we report on a typical case of solitary pulmonary metastasis of thyroid cancer and we summarize the previously reported cases with a review of the relevant literature.