Near-surface termination of upward-propagating strike-slip ruptures on the Yangsan Fault, Korea.

We present a new example of the termination of strike-slip paleoearthquake ruptures in near-surface regions on the Yangsan Fault, Korea, based on multi-scale structural observations. Paleoearthquake ruptures occur mostly along the boundary between the inherited fault core and damage zone (N10-20°E/> 75°SE). The ruptures propagated upward to the shallow subsurface along a < 3-cm-wide specific slip zone with dextral-slip sense, along which the deformation mechanism is characterized mainly by granular flow in near-surface region. The ruptures either reach the surface or are terminated in unconsolidated sediment below the surface. In the latter case, the rupture splays show westward bifurcation, and their geometry and kinematics show a change to NNW-strike with low-angle dip and dextral-reverse oblique-slip sense in the strata. We suggest that the upward termination of the contractional strike-slip ruptures is controlled by the inherited fault geometry that is unfavorable with respect to the stress field (ENE-WSW σHmax) at basement depths in terms of movement on the fault, and the lack of extension of the fault into shallow subsurface; a depth-dependent change in stress from σHmax > σv > σHmin to σHmax > σHmin > σv at depth of a ~ 200 m; and the physical properties of unconsolidated sediment, which have low inter-granular cohesion, resulting in distributed deformation.

Fully Customized Photoacoustic System Using Doubly Q-Switched Nd:YAG Laser and Multiple Axes Stages for Laboratory Applications.

We developed a customized doubly Q-switched laser that can control the pulse width to easily find weak acoustic signals for photoacoustic (PA) systems. As the laser was constructed using an acousto-optic Q-switcher, in contrast to the existing commercial laser system, it is easier to control the pulse repetition rate and pulse width. The laser has the following control ranges: 10 Hz-10 kHz for the pulse repetition rate, 40-150 ns for the pulse width, and 50-500 µJ for the pulse energy. Additionally, a custom-made modularized sample stage was used to develop a fully customized PA system. The modularized sample stage has a nine-axis control unit design for the PA system, allowing the sample target and transducer to be freely adjusted. This makes the system suitable for capturing weak PA signals. Images were acquired and processed for widely used sample targets (hair and insulating tape) with the developed fully customized PA system. The customized doubly Q-switched laser-based PA imaging system presented in this paper can be modified for diverse conditions, including the wavelength, frequency, pulse width, and sample target; therefore, we expect that the proposed technique will be helpful in conducting fundamental and applied research for PA imaging system applications.

The Highest Metabolic Activity on FDG PET Is Associated With Overall Survival in Limited-Stage Small-Cell Lung Cancer.

We evaluated the prognostic value of F-fluorodeoxyglucose positron emission tomography (FDG PET) parameters for limited-stage small-cell lung cancer (LS-SCLC).We retrospectively enrolled 59 LS-SCLC patients who underwent pretreatment FDG PET/CT. Various PET parameters were measured in all malignant lesions, and we recorded the highest maximum standardized uptake value (SUVmax), and sum of metabolic tumor volume (MTVsum) and total lesion glycolysis (TLGsum). The relationship between the highest SUVmax and volumetric PET parameters was evaluated. The prognostic significances of PET parameters and clinical variables were assessed using Cox's proportional hazard regression analysis. Overall survival (OS) and progression-free survival (PFS) were assessed by the Kaplan-Meier method.The SUVmax of the highest metabolic lesion had a significant positive correlation with MTVsum and TLGsum (P < 0.001). Upon multivariate analysis, the highest SUVmax was an independent predictor of OS (1 unit increase, hazard ratio [HR]: 1.133, P = 0.003) and MTVsum was a significant prognostic factor of PFS (10-cm increase, HR: 1.027, P = 0.034) after adjusting for age, sex, performance status, tumor stage, and treatment modality. The highest SUVmax was a prognostic factor for PFS with marginal significance (1 unit increase, HR: 1.078, P = 0.053). Patients with higher SUVmax (≥11) were also characterized by a significantly shorter median OS (P < 0.001) and PFS (P = 0.002) compared with patients with lower SUVmax.The highest SUVmax is an independent prognostic factor for survival in LS-SCLC patients. Therefore, the highest SUVmax might be a possible imaging biomarker for risk stratification in LS-SCLC. A further study in a large cohort is needed to validate the prognostic significance of the parameter.

Multinational Randomized Phase III Trial With or Without Consolidation Chemotherapy Using Docetaxel and Cisplatin After Concurrent Chemoradiation in Inoperable Stage III Non-Small-Cell Lung Cancer: KCSG-LU05-04.

PURPOSE: To determine the efficacy of consolidation chemotherapy (CC) with docetaxel and cisplatin (DP) after concurrent chemoradiotherapy (CCRT) with the same agents in locally advanced non-small-cell lung cancer (LA-NSCLC). PATIENT AND METHODS: Patients were randomly assigned to either CCRT alone (observation arm) or CCRT followed by CC (consolidation arm). CCRT with docetaxel (20 mg/m(2)) and cisplatin (20 mg/m(2)) was administered every week for 6 weeks with a total dose of 66 Gy of thoracic radiotherapy in 33 fractions. In the consolidation arm, patients were further treated with three cycles of DP (35 mg/m(2) each on days 1 and 8, every 3 weeks). The primary end point was 40% improvement in progression-free survival (PFS) compared with observation. RESULTS: From October 2005 to April 2011, 437 patients were randomly assigned. Seventeen patients did not start CCRT as a result of consent withdrawal or ineligibility reasons after random assignment, leaving 420 patients for this analysis (n = 211 for observation; n = 209 for consolidation). Patient characteristics were similar in both arms. In the consolidation arm, 143 patients (68%) received CC, of whom 88 (62%) completed three planned cycles. The median PFS was 8.1 months in the observation arm and 9.1 months in the consolidation arm (hazard ratio, 0.91; 95% CI, 0.73 to 1.12; P = .36). Median overall survival times were 20.6 and 21.8 months in the observation and consolidation arms, respectively (HR, 0.91; 95% CI, 0.72 to 1.25; P = .44). CONCLUSION: CC with DP after CCRT with weekly DP in LA-NSCLC failed to further prolong PFS. CCRT alone should remain the standard of care.

Erlotinib monotherapy for stage IIIB/IV non-small cell lung cancer: a multicenter trial by the Korean Cancer Study Group.

BACKGROUND: Erlotinib (Tarceva, OSI Pharmaceuticals, Melville, NY) is an oral, epidermal growth factor receptor tyrosine kinase inhibitor that has antitumor activity and good tolerability in non-small cell lung cancer (NSCLC). In particular, higher response rates have been reported in Asian patients than in Western patients. The aim of this study conducted by the Korean Cancer Study Group was to evaluate the efficacy and tolerability of erlotinib monotherapy as a palliative treatment for advanced NSCLC patients in Korea. PATIENTS AND METHODS: Patients with histologically or cytologically confirmed stage IIIB or IV NSCLC including recurrent or metastatic disease, with performance status from 0 to 3, were eligible either if they had received any anticancer treatment except epidermal growth factor receptor inhibitors or if they were unsuitable for chemotherapy because of poor performance status. Enrolled patients were treated with oral erlotinib at a dose of 150 mg daily until disease progression or development of intolerable toxicity. RESULTS: A total of 120 patients were enrolled between January 2005 and May 2006. Forty-four patients (36.7%) were female and 72 patients were current or former smoker. Fifty percent of patients had received one prior palliative chemotherapy regimens and 34.2% had two or more prior palliative regimens. The overall tumor response rate was 24.2% (95% confidence interval [CI], 16.8-32.8%) with 4 complete responses and 25 partial responses, and the disease control rate was 56.7%. The favorable clinical variables for tumor response were female (P = 0.001), never smokers (P = 0.041), and adenocarcinoma (P = 0.001). The most common adverse event was skin rash (78% of which grade 3 or 4 skin rash occurred in 13.3% of the patients). With a median follow-up of 23.6 months, the median time to progression was 2.7 months (95% CI, 2.2-3.2), and the median overall survival was 12.9 months (95% CI, 6.9-18.8). By multivariate analysis, female and development of skin rash were significantly associated with longer time to progression and overall survival. CONCLUSION: Erlotinib monotherapy showed significant antitumor activity and an acceptable tolerability profile as a palliative treatment in advanced NSCLC patients in Korea, especially in females, never smokers, and patients with adenocarcinoma histology.

Are there any ethnic differences in molecular predictors of erlotinib efficacy in advanced non-small cell lung cancer?

PURPOSE: This study investigated possible molecular predictors of outcome in Korean patients with advanced non-small cell lung cancer treated with erlotinib. EXPERIMENTAL DESIGN: One hundred and twenty patients received erlotinib and were followed prospectively. Ninety-two tissue samples were analyzed for epidermal growth factor receptor (EGFR) gene mutations (exons 18, 19, and 21), 88 for EGFR gene amplification by real-time PCR, and 75 for EGFR protein expression by immunohistochemistry. RESULTS: The overall tumor response rate was 24.2% (complete response, 4; partial response, 25) with 56.7% of disease control rate. With a median follow-up of 23.6 months, the median time to progression (TTP) was 2.7 months and the median overall survival was 12.9 months. EGFR gene mutations were found in 26.1% (24 of 92), EGFR gene amplification in 40.9% (36 of 88), and EGFR protein expression in 72% (54 of 75). There was a strong association between EGFR gene mutations and gene amplification (gamma = 0.241). Patients with EGFR gene mutations or gene amplification showed both better response rate (58.3% versus 16.2%, P < 0.001; 41.7% versus 17.3%, P = 0.012) and TTP (8.6 versus 2.5 months, P = 0.003; 5.8 versus 1.8 months, P < 0.001) and overall survival (not reached versus 10.8 months, P = 0.023; not reached versus 10.1 months, P = 0.033). By multivariate analysis, EGFR gene mutation was the only significant molecular predictor for TTP (hazard ratio, 0.47; 95% confidence interval, 0.25-0.89). CONCLUSIONS: Our findings indicate that EGFR gene mutation is a more predictive marker for improved TTP than EGFR gene amplification in erlotinib-treated Korean non-small cell lung cancer patients. Prospective studies from diverse ethnic backgrounds are required to determine the exact role of these molecular markers.