Alpha-fetoprotein and/or liver ultrasonography for liver cancer screening in patients with chronic hepatitis B

  • Review
  • Intervention

Authors


Abstract

Background

Chronic hepatitis B infection may cause liver cancer (hepatocellular carcinoma (HCC)). Alpha-fetoprotein (AFP) and liver ultrasonography (US) are used to screen these patients for HCC. It is uncertain whether screening is worthwhile.

Objectives

To review randomised trials on screening for HCC with alpha-fetoprotein and/or liver ultrasonography among people with hepatitis B surface antigen (HBsAg) whether asymptomatic or with clinical liver disease.

Search methods

Relevant reports were searched from electronic databases until August 2002 (The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Controlled Trials Register, MEDLINE, EMBASE, HealthStar, and the Chinese Medical Literature Electronic Databases, MedCyber) supplemented with manual searches on the bibliographies of papers found and communication to people familiar with chronic hepatitis B.

Selection criteria

Randomised trials on screening for liver cancer were included irrespective of language. Studies were excluded if the hepatitis B status was uncertain, if patients were not adequately followed, if the screening tests were not sensitive, widely-used ones, or if the test was used for diagnosis rather than screening for HCC.

Data collection and analysis

We analysed independently all the studies considered for inclusion. We wrote to the relevant authors for further information. Data were analysed with Peto's odds ratio (OR) with 95% confidence interval (CI).

Main results

Two trials met the selection criteria. One trial (n = 18,816) compared bi-annual AFP plus US screening with no screening for five years. No data on all-cause mortality were available. The two groups did not differ significantly regarding HCC mortality (OR 0.81; 95% CI 0.54 to 1.22). Number of patients with HCC was significantly increased in the screened group (OR 1.37; 95% CI 1.00 to 1.88). Most HCCs in the screened group, but none in the control group, were at an early stage. The survival rate of patients with resected HCC in the screened group reached 52.7% after three and five years, but was 0% for those in the control group. The authors' estimated lead-time for HCC was 5.4 months, suggesting that screening prolonged the survival of HCC. Another trial (n = 1069) compared AFP plus US versus AFP screening, but could not decide which approach was superior due to the small sample size (number of detected HCC: OR 0.74; 95% CI 0.26 to 2.12).

Authors' conclusions

There are not enough quality trials to support or refute screening of HBsAg-positive patients for HCC. It is possible that screening may be effective, but also that harm caused by screening/treatment may outweigh any gain. More and better-designed large randomised trials are required.

摘要

背景

Alphafetoprotein和肝臟超音波檢查用於慢性B型肝炎病人的肝癌篩檢

慢性B型肝炎感染會導致肝癌(hepatocellular carcinoma,HCC)。 Alphafetoprotein (AFP)和肝臟超音波檢查 (US) 都被用於肝癌病人的篩檢。但不確定這篩檢是否值得。

目標

對採用Alphafetoprotein和/或肝臟超音波檢查對有B型肝炎細胞表面抗原(hepatitis B surface antigen,HBsAg)的族群中,不管臨床有無肝病症狀,篩檢肝癌的隨機試驗進行文獻回顧。

搜尋策略

搜索至2002年8月的電子資料庫的相關報告 (The Cochrane HepatoBiliary Group Controlled Trials Register、The Cochrane Controlled Trials Register、MEDLINE、EMBASE、HealthStar和 Chinese Medical Literature Electronic Databases、MedCyber),並且手動搜索文獻的參考目錄加以補充,同時聯絡熟悉慢性B型肝炎的專家。

選擇標準

收納篩檢肝癌隨機試驗,沒有語言限制。有下列情形的試驗則予以排除:不確定是否是B型肝炎、未適當追蹤病人、不是廣為使用敏感的篩檢檢查、或是適於用來診斷而非篩檢HCC者。

資料收集與分析

作者們所有可能納入的試驗。我們向相關作者寫信取得更多資訊。 使用Peto odds ratio(OR)及其95%信賴區間 (CI)分析資料。

主要結論

共有2項試驗符合篩選標準。 一試驗(n = 18,816) 比較一年兩次AFP與US篩檢的方法及5年內沒有篩檢。沒有所有死因致死死亡率的資料。這2組在HCC死亡率上沒有顯著差異(OR 0.81; 95% CI 0.54 1.22)。 篩檢組中有HCC的人數明顯增加(OR 1.37; 95% CI 1.00 – 1.88)。 不像控制組,篩檢組大部分在早期發現HCC。在篩檢組切除HCC病人存活率達到52.7% ,但是控制組則為0%。作者估計HCC的前置時間為5.4個月,這說明篩檢可以延長HCC的存活率。 另外一項實驗比較了AFP結合US篩檢和單獨使用AFP篩檢 (n = 1069) ,但是,由於是小規模樣本,不能決定哪種方法更好 (已探測到HCC數量: OR 0.74; 95% CI 0.26 2.12)。

作者結論

沒有夠品質的試驗支持或反對對HCC的HBsAg 陽性病人進行篩檢。可能因為,篩檢或許有效,但是篩檢或治療引起的傷害將會得不償失。需要更多設計合宜的大規模隨機試驗。

翻譯人

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

沒有足夠的證據指出可以使用Alphafetoprotein和肝臟超聲波篩檢慢性B型肝炎病人。Alphafetoprotein和肝臟超聲波篩檢肝癌是否比無篩檢的方法更有利於受B型肝炎病毒感染的人群,我們還沒有得到充分的證據證明。只有2項隨機試驗。一項實驗AFP結合US1年2次篩檢與5年內接受篩檢相比較。 篩檢組探測出更多的肝癌,但兩組在因肝癌死亡率上沒有顯著差別。另外一項試驗比較了AFP結合US篩檢和單獨使用AFP篩檢。由於收樣數目不足,兩組在探測的肝癌偵測數量兩組沒有顯著差異。

Plain language summary

Inadequate evidence on screening with alpha-fetoprotein and/or ultrasound of the liver for patients with chronic hepatitis B

There is inadequate evidence to decide whether screening for liver cancer with alpha-fetoprotein and/or ultrasound of the liver compared to no screening is beneficial to patients infected with the hepatitis B virus. Only two randomised trials could be included. One trial compared bi-annual screening with alpha-fetoprotein plus ultrasound against no screening for five years. More liver cancers were detected in the screened group, but the two groups did not differ significantly regarding liver cancer mortality. Another trial compared alpha-fetoprotein plus ultrasound screening against alpha-fetoprotein screening. This trial, with an inadequate sample size, showed no significant difference between the groups regarding number of cancers detected.

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