Time-dependent Receiver Operating Characteristic Curve Analysis Research Articles

Volume-Based Parameters of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Improve Outcome Prediction in Early-Stage Non–Small Cell Lung Cancer After Surgical Resection

To evaluate the prognostic significance and predictive performance of volume-based parameters of F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) in early-stage non-small cell lung cancer (NSCLC). Although surgical resection remains the optimal treatment for early-stage NSCLC, approximately 40% of patients with stage I and 60% of patients with stage II NSCLC relapse and die within 5 years after curative resection. Therefore, identification of additional prognostic biomarkers is needed to develop risk-adapted treatment strategies. We retrospectively reviewed 529 consecutive patients with pathologically proven early-stage NSCLC who underwent preoperative F-FDG PET/CT. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for the primary tumors were measured. Overall survival (OS) and disease-free survival (DFS) were assessed by the Kaplan-Meier method. The prognostic significance of PET parameters and other clinicopathological variables was assessed by Cox proportional hazards regression analysis. To evaluate and compare the predictive performance of PET parameters, time-dependent receiver operating characteristic (ROC) curve analysis was used. In the multivariate analyses, volume-based parameters of PET (MTV and TLG) that were analyzed as continuous variables were significantly associated with an increased risk of recurrence (P = 0.001 for MTV, P < 0.001 for TLG) and death (P = 0.009 for MTV, P = 0.007 for TLG), after adjusting for age, sex, histology, tumor stage, and type of surgery. SUVmax analyzed as a continuous variable was not a significant prognostic factor for both DFS (P = 0.056) and OS (P = 0.525). In the time-dependent ROC curve analysis, the volume-based parameter of PET showed better predictive performance than SUVmax (P < 0.001). The volume-based parameter of PET is an independent prognostic factor for survival in addition to pathological tumor-node-metastasis stage and a promising tool for better prediction of outcome in patients with early-stage NSCLC.

Measurement of tumor volume by PET to evaluate prognosis in patients with advanced non-small cell lung cancer treated by non-surgical therapy

Patients with advanced non-small cell lung cancer (NSCLC) seem to have disparity in prognosis. Accurate prediction of prognosis could be useful in the future to predict individual risk and to develop more aggressive or alternative treatment strategies. To evaluate the prognostic value of metabolic tumor volume (MTV) measured by 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in patients with NSCLC. We retrospectively reviewed 120 patients with pathologically proven NSCLC (61 squamous cell carcinomas and 59 adenocarcinomas) who underwent pretreatment 18F-FDG PET. MTV and maximum standardized uptake value (SUVmax) for the primary tumors were measured by 18F-FDG PET. Pretreatment variables (age, sex, American Joint Committee on Cancer [AJCC] stage, histological type, SUVmax, and MTV) were analyzed to identify their correlation with two-year survival. To further evaluate and compare the predictive value of PET parameters, MTV, and SUVmax, time-dependent receiver-operating characteristic curve (ROC) analysis was used. In the univariate analysis, AJCC stage, histological type, MTV, and SUVmax of primary tumor were significant predictors of survival. On multivariate analysis, independent prognostic factors associated with decreased two-year survival were AJCC stage (hazard ratio [HR] 2.236, P = 0.003), histological type (HR 2.038, P = 0. 004), and MTV (HR 1.016, P = 0.001). SUVmax was not a significant factor (HR 0.96, P = 0.490). On time-dependent ROC analysis, MTV showed good predictive performance for two-year survival consistently better than SUVmax. MTV, a volumetric parameter of 18F-FDG PET, is an important independent prognostic factor for survival and a better predictor of survival than SUVmax for the primary tumor in patients with advanced NSCLC.

Fluctuations of Epstein-Barr Virus Serological Antibodies and Risk for Nasopharyngeal Carcinoma: A Prospective Screening Study with a 20-Year Follow-Up

BackgroundThe impact of variation of Epstein-Barr virus (EBV) antibody titers before the development of nasopharyngeal carcinoma (NPC) is still unclear. We analyzed the fluctuations of antibodies against EBV before histopathological diagnosis to assess the risk of NPC and aimed to provide a reliable basis for screening in high risk populations.MethodsThis study was based on a population-based screening program in Sihui County in Guangdong Province of China. A total of 18,986 subjects were recruited in 1987 and 1992, respectively. Baseline and repeated serological tests were performed for IgA antibodies against EBV capsid antigen (VCA/IgA) and early antigen (EA/IgA). Follow-up until the end of 2007 was accomplished through linkage with population and health registers. Cox proportional hazards regression model was used to estimate the relative risk of NPC in association with EBV antibodies. Time-dependent receiver operating characteristic curve (ROC) analysis was used to further evaluate the predictive ability.ResultsA total of 125 NPCs occurred during an average of 16.9 years of follow-up. Using baseline information alone or together with repeated measurements, serological levels of VCA/IgA and EA/IgA were significantly associated with increased risks for NPC, with a striking dose-response relationship and most prominent during the first 5 years of follow-up. Considering the fluctuant types of serological titers observed during the first three tests, relative risk was highest among participants with ascending titers of EBV VCA/IgA antibodies with an adjusted hazard ratio (HR) of 21.3 (95% confidence interval [CI] 7.1 to 64.1), and lowest for those with decreasing titers (HR = 1.5, 95% CI 0.2 to 11.4), during the first 5 years of follow-up. Time-dependent ROC analysis showed that VCA/IgA had better predictive performance for NPC incidence than EA/IgA.ConclusionOur study documents that elevated EBV antibodies, particularly with ascending titers, are strongly associated with an increased risk for NPC.

Prognostic Value of Metabolic Tumor Volume Measured by 18F-Fluorodeoxyglucose Positron Emission Tomography in Patients with Esophageal Carcinoma

The aim of this study was to evaluate the prognostic value of metabolic tumor volume (MTV) measured by (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) in patients with esophageal carcinoma. We retrospectively reviewed 151 patients with pathologically proven esophageal carcinoma (146 squamous cell carcinomas and 5 adenocarcinomas) who underwent pretreatment (18)F-FDG PET. MTV and maximum standardized uptake value (SUVmax) for the primary tumors were measured by (18)F-FDG PET. The prognostic significance of MTV, SUVmax, and other clinicopathological variables was assessed by Cox proportional hazards regression analysis. To further evaluate and compare the predictive performance of PET parameters, MTV and SUVmax, time-dependent receiver operating characteristic curve (ROC) analysis was used. In the univariate analysis, age, American Joint Committee on Cancer (AJCC) stage, tumor-node-metastasis (TNM) factors, MTV, and SUVmax of primary tumor were significant predictors of survival. On multivariate analysis adjusted for age, sex, and treatment modality, independent predictive factors associated with decreased overall survival were T stage [hazard ratio (HR) 4.325, P = 0.006], M stage (HR 2.009, P = 0.007), and MTV (HR 1.013, P = 0.021). SUVmax was not a significant factor (HR 0.97, P = 0.061). On time-dependent ROC analysis, MTV showed good predictive performance for overall survival consistently better than SUVmax. MTV, a volumetric parameter of (18)F-FDG PET, is an important independent prognostic factor for survival and a better predictor of survival than SUVmax for the primary tumor in patients with esophageal carcinoma.

New time-dependent approach to analyse the prognostic significance of immunohistochemical biomarkers in colon cancer and diffuse large B-cell lymphoma

Aims: Receiver operating characteristic (ROC) curve analysis is a well-established method to study the accuracies of biological markers. It may, however, be suboptimal for analysing outcomes over time, such as...