There is no consensus about factors that increase risk of hepatocellular carcinoma (HCC) among patients with chronic hepatitis B who have achieved seroclearance of hepatitis B surface antigen (HBsAg). To assess the available evidence about risk factors for HCC after HBsAg seroclearance, Scopus, EMBASE, PubMed and Cochrane Library databases were systematically searched for relevant studies published through 15 September 2017. A total of 28 studies involving more than 105 411 patients with chronic hepatitis B were included. HBsAg seroclearance occurred spontaneously in 7656, while it occurred after interferon or nucleos(t)ide analogue therapy in 1248. The rate of HBsAg seroclearance was 6.77%. Incidence of HCC was significantly lower among patients who experienced HBsAg seroclearance than among those who remained HBsAg-positive (1.86% vs 6.56%, P < .001). Risk factors of HCC occurrence included cirrhosis (incidence with vs without: 9.51% vs 1.66%), male gender (2.34% vs 0.64%) and age ≥ 50 year at HBsAg seroclearance (2.34% vs 0.63%) (all P < .001). The available evidence suggests that HCC can develop at a low rate after HBsAg seroclearance, so periodic surveillance is recommended, especially for male patients, patients with cirrhosis and patients who experience HBsAg seroclearance when at least 50 years old.

V2284 Cyg is a neglected W UMa-type binary star for photometric investigations. Monitored by the Kepler Space Telescope from 2009 to 2013, its light curves are continuously stable, suggesting that both components are inactive during this time interval. Based on the short-cadence observations, we determined the photometric solutions by using the 2013 version of the Wilson-Devinney code. These parameters reveal that V2284 Cyg is a W-type system with a degree of contact factor of f=39.23% and a mass ratio of q=2.90. Meanwhile, hundreds of times of minimum light were obtained and applied to analyze the orbital period changes. In the O-C diagram, a smallamplitude cyclic oscillation (A 3 =0.00030 days and T 3 =2.06 years) superimposed on a secular decreasing was found. The continuous decreasing may be a result from the mass transfer from the more massive component to the less massive one. With the long-term decreasing of the orbital period, this binary will evolve into a deeper contact system. Because the light curve is stable, the cyclic variation is plausibly explained as the light-travel time effect (LTTE) due to the presence of an additional body. The mass of the companion is. If the orbital plane inclination is a random distribution, it is a brown dwarf with 66.7% probability. Therefore, the companion of V2284 Cyg is possibly the first candidate of the brown dwarf orbiting around contact binary, where both component are sharing a common convective envelope.