On 2017 Dec 12, Jose M. Moran commented:

None

On 2017 Dec 12, Jose M. Moran commented:

Dear Alvaro, I think that your comments deserve a Letter to the Editor.

On 2017 Nov 09, Alvaro Alonso commented:

This paper reports that warfarin users had lower overall incidence rates of cancer than non-users in a large population-based cohort. The association was present for most cancers.

One major limitations in this analysis, that puts into question the validity of the results, is the lack of adjustment for potential confounders. The reported models seem to only adjust for age and sex. The authors did not consider any other factor that may influence the decision to prescribe or not warfarin. It has been established that frail and sicker individuals are less likely to receive oral anticoagulation with warfarin, even if indicated, and to discontinue treatment (see for example PMID 19151165, 26277091 and 27471198).

In summary, before concluding that a particular medication has a blanket anticancer effect, I would expect a more careful consideration of confounding.

On 2017 Nov 09, Alvaro Alonso commented:

This paper reports that warfarin users had lower overall incidence rates of cancer than non-users in a large population-based cohort. The association was present for most cancers.

One major limitations in this analysis, that puts into question the validity of the results, is the lack of adjustment for potential confounders. The reported models seem to only adjust for age and sex. The authors did not consider any other factor that may influence the decision to prescribe or not warfarin. It has been established that frail and sicker individuals are less likely to receive oral anticoagulation with warfarin, even if indicated, and to discontinue treatment (see for example PMID 19151165, 26277091 and 27471198).

In summary, before concluding that a particular medication has a blanket anticancer effect, I would expect a more careful consideration of confounding.

On 2017 Dec 12, Jose M. Moran commented:

None