This review was withdrawn on 16 November 2020. The withdrawal notice originally cited a comment received and other methodological problems as the reason for withdrawal. An additional statement by the Editor in Chief of the Cochrane Library has been added (12 October 2021).

Statement by the Editor in Chief:

In February 2021, an article was posted by Retraction Watch describing the submission of a comment and the subsequent process leading to the withdrawal of this review: retractionwatch.com/2021/02/11/leading-evidence-based-group-blames-pandemic-for-9-month-delay-pulling-flawed-cancer-review. The statement attributed to the Cochrane Hepato‐Biliary Group cited the methodological quality of the published review and the COVID 19 pandemic as reasons for delay in the withdrawal of the review. Having examined the process of the correction and the editorial process, the Editor in Chief is satisfied that the principal reason for the delay in withdrawal of the review relates to a disagreement between the two parties over the methods and data in the review. There were no concerns regarding the integrity of the author team and the authors will be invited to resubmit the corrected review for editorial consideration with a view to reinstatement in the Cochrane Database of Systematic Reviews.

Previous withdrawal statements relating this review:

16 November 2020: Due to a comment received and due to some other identified methodological problems, the present review is withdrawn.

22 June 2021: This review has been withdrawn due to the way in which mortality has been framed, analysed, and reported in the review. The approach to the analysis of the primary outcome of survival has not been consistently applied, leading to potential confusion for the reader.

The editorial group responsible for this previously published document have withdrawn it from publication.