Changes in Presentation, Treatment, and Survival of Patients with Hepatocellular Carcinoma in Damietta, Egypt, 2007-2019: A Retrospective Monocentric Cohort Study.

Introduction: We aimed to assess temporal changes in the presentation and survival of patients with hepatocellular carcinoma (HCC) in the northern Egypt region, one of the regions reporting the highest incidence of the disease globally. Methods: We conducted a monocentric retrospective study. Patients presenting at the Damietta Oncology referral center between 2007 and 2019 with a diagnosed HCC were eligible. Individual, clinical and tumor characteristics at HCC diagnosis, including the Barcelona Clinic Liver Cancer (BCLC) staging, were retrieved from medical files and patients' final vital status was ascertained by combining various data sources. Patients were divided into 2 groups based on diagnosis period: pre- and post-2014. Survival was analysed based on Kaplan-Meier curves and differences in restricted mean survival time (RMST). Results: Data from 5097 patients (among 5210 eligible, 97.8%) were analyzed. We observed a significant trend toward HCC diagnosed at earlier stage in the post- vs pre-2014 period (BCLC stage 0/A or B: 37.2% vs 27.1%, p<10-3). Overall patient's survival after the HCC diagnosis was poor, with a median of 8.1 months. The BCLC staging system performed well in predicting survival. Despite a trend toward HCC diagnosed at earlier stages, we did not observe a significant improvement in survival over time. Overall, treatments offered in this medical center were in line with international guidelines, and 16.1% of the patients who received a curative treatment had an improved survival (30.7 months in median). However, HCC recurrence was frequent among patients cured for HCC, with a median time to recurrence of 22 months. Discussion: Overall survival after HCC diagnosis in Egypt remains poor but is significantly improved by curative therapy. Despite a trend toward earlier diagnosis of HCC, we did not observe a general improvement in survival over time, which remains to be clearly understood.

Sliding mode disturbance observer-based control of a twin rotor MIMO system.

This work proposes a robust tracking controller for a helicopter laboratory setup known as the twin rotor MIMO system (TRMS) using an integral sliding mode controller. To eliminate the discontinuity in the control signal, the controller is augmented by a sliding mode disturbance observer. The actuator dynamics is handled using a backstepping approach which is applicable due to the continuous chattering-free nature of the command signals generated using the disturbance observer based controller. To avoid the complexity of analytically differentiating the command signals, a first order sliding mode differentiator is used. Stability analysis of the closed loop system and the ultimate boundedness of the tracking error is proved using Lyapunov stability arguments. The proposed controller is validated by several simulation studies and is compared to other schemes in the literature. Experimental results using a hardware-in-the-loop system validate the robustness and effectiveness of the proposed controller.