The Cochrane Library – Feedback
Oral anticoagulation for prolonging survival in patients with cancer
Elie A Akl, Ganesh Kamath, Seo Young Kim, Victor E D Yosuico, Maddalena Barba, Irene Terrenato, Francesca Sperati, Holger Schünemann
DOI:10.1002/14651858.CD006466
Date received: July 22, 2008
Cite this comment as: http://www.cochranefeedback.com/cf/cda/citation.do?id=9847#9847
I thank Drs. Akl and Schünemann for their reply to my previous comment.
Regarding the interpretation of the subgroup analysis of SCLC, there would be two ways of treating the results statistically:
1. An a priori determined subgroup along with all 100+ other cell types of cancer (let alone the various stages) -- the p value, adjusted for multiple comparisons (e.g., Bonferroni Adjustment), would not be significant
2. A post hoc analysis that should not be emphasized in the implications of practice, abstract, or plain language summary
In either case, oral anticoagulants are not evidence-based to benefit patients with SCLC.
Few patients with SCLC or their loved ones will be subscribing to the Cochrane Library for the full text of reviews such as this one. Instead, they will find the abstract and plain language summaries freely available on the Cochrane website. The plain language summary states, “Oral anticoagulation with vitamin K antagonists does improve mortality in the subgroup of patients with extensive small cell lung cancer.” Inclusion of this statement in the plain language summary is not justified by the data. Likewise, the authors’ conclusions in the abstract regarding SCLC would only be appropriate if another sufficiently powered RCT of SCLC patients confirmed the finding in the subgroup analysis. Unfortunately, the conclusion of this Cochrane review would make it virtually impossible to recruit patients with SCLC for a placebo controlled RCT with oral anticoagulants.
Thanks for the additional clarification of the potential competing financial interests.