The Efficacy of Risk-score Based Approach for Screening for Hepatocellular Carcinoma with Ultrasound
Date Issued
2011
Date
2011
Author(s)
Chen, Hung-Pin
Abstract
Background: Community-based ultrasound screening for HCC is one of approaches to the prevention of hepatocellular carcinoma (HCC) for adults aged 30 years or older who had not the chance of receiving vaccination against hepatitis B virus infection. Weaimed to evaluate the mass screening for HCC with ultrasound in Changhua, Taiwan, one of areas with higher incidence of HCC.
Method: A total of 41412 residents aged 45-69 years attending the ChangHua Community-based Integrated Screening (CHCIS) constituted our study population. All participants were invited to screen in the light of four risk groups: extremely high (EH), high (H), intermediate (IM), and low (L). EH and H were classified by the median of risk score among those with positive HbsAg or anti-HCV or elevated alpha-fetoprotein level. IM and L were classified by the third quartile of the risk score among those with neither positive of the three markers. Participants were invited to an out-reaching screening program for HCC with ultrasound.
We compared survival curves for those detected by ultrasound screening (ultrasound-detected), detected by two-stage method (two-stage screen-detected), and those diagnosed due to the appearance of clinical symptoms (clinically-detected). Proportional hazards regression model was used to assess the hazard ratios of risk for death from HCC by detection modes. We also calculated the adjusted hazard ratio considering lead-time bias. Prevalence pool was used to estimate the mean sojourn time (MST) in the four risk groups. Efficacy in terms of number-needed-to-screening (NNS) to avoid one interval cancer and NNS to avoid one HCC death was reported.
Results: A total of 19 HCC were confirmed after ultrasound screening. Among them, 42.11% (n=8) had tumor size less than 3 cm, 47.3% (n=9) in 3-5 cm, and 10.53% (n=2) cases had tumor larger than 5 cm.
Among the 19 ultrasound-detected cases (median follow-up time: 21.6 months), 2 (10.53%) died from HCC at 24 and 25 months. There were 24 two-stage screen-detected cases (median follow-up time: 37.3 months), of which 9 (37.5%%) died from HCC. Another 1165 clinically-detected were also identified, of which 798 (68.5%) died from HCC in a median follow-up time of 15.3 months. Compared with clinically-detected cases, the hazard ratios of HCC death were 0.15 (95% CI: 0.04-0.59) and 0.41 (95% CI: 0.21-0.78) for ultrasound-detected and two-stage screen-detected,respectively. The corresponding figures for lead-time bias adjusted hazard ratio was 0.31 (95% CI:0.12-0.84) and 0.63(95% CI 0.37-1.08), respectively. The mean sojourn time (MST) for EH, H, and IM were estimated as 1.10, 1.7, and 3.55 years, respectively.
Three-monthly ultrasound screening could reduce 61% mortality from HCC for the EH group. The efficacy was reduced to 54% for 6-monthly screening, and 51% for 1-yearly screening. It was further reduced when the interscreening interval was further lengthened. Applying the current policy from the government, half-yearly ultrasound check-up for hepatitis B or C virus infection, it requires 4,383 and 37,547 ultrasounds to avoid one HCC death for EH and H groups.
Conclusion: Ultrasound screening can detect small hepatocellular carcinoma with favor survival even after adjustment for lead-time bias. The out-reaching can also enhance yield of screening, even for those without positive for HBsAg or anti-HCV. The results of this program facilitate the policy for risk-stratification tailored screening in the future.
Subjects
Hepatocellular carcinoma
Abdominal ultrasound screening
Risk-score stratification
Community-based Integrated Screening
Changhua
SDGs
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-100-P98842004-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):3e510d81920bad3e45c3a10bee817b6b