Six months as a cutoff time point to define early recurrence after liver resection of hepatocellular carcinoma based on post-recurrence survival
UPDATES IN SURGERY
Authors: Liu, Yueh-Wei; Yong, Chee-Chien; Lin, Chih-Che; Wang, Chih-Chi; Chen, Chao-Long; Cheng, Yu-Fan; Wang, Jing-Houng; Yen, Yi-Hao
Abstract
To determine the optimal cutoff time point of early versus late recurrence relative to post-recurrence survival (PRS) among patients who underwent liver resection (LR) for hepatocellular carcinoma (HCC) in a high-volume liver surgery center in East Asia. This was a retrospective study. Patients who underwent LR for HCC between 2011 and 2018 at Kaohsiung Chang Gung Memorial Hospital were enrolled. The optimal cutoff time point to differentiate early versus late recurrence was evaluated relative to PRS. Among 826 patients, 282 (34.1%) of the patients experienced recurrence, with a median time to recurrence of 12.2 months. 6 months was defined as the optimal cutoff time point based on sensitivity analyses relative to PRS. Ninety (31.9%) of the patients developed early recurrence within 6 months, and 192 patients (68.1%) developed late recurrence beyond 6 months. Early recurrence was associated with worse PRS (median PRS, 13.2 versus 48.9 months, p < 0.001), as well as overall survival (OS) (median OS, 16.2 versus 65.4 months, p < 0.001), than late recurrence. Six months was identified as the cutoff time point to differentiate early versus late recurrence among patients undergoing LR for HCC.
Simple and local independent set approximation
THEORETICAL COMPUTER SCIENCE
Authors: Boppana, Ravi B.; Halldorsson, Magnus M.; Rawitz, Dror
Abstract
We study the worst-case behavior of Turan-like bounds for unweighted and weighted independent sets in bounded-degree graphs. In particular, we revisit a randomized approach of Boppana that forms a simple 1-round distributed algorithm, as well as a streaming algorithm and a preemptive online algorithm. We show that it gives a tight (Delta + 1)/2-approximation in unweighted graphs of maximum degree Delta, which is best possible for 1-round distributed algorithms. For weighted graphs, it gives only a (Delta + 1)-approximation, but a simple modification results in an asymptotic expected 0.529(Delta + 1)-approximation. (C) 2020 Elsevier B.V. All rights reserved.