Oral contraceptives and cervical cancer: critique of a recent review.

A recent review article by Smith et al. in The Lancet purports to find a causal relationship between long-term use of oral contraceptives (OCs) and cervical cancer. While we endorse the search for such a relationship, we felt it important to critically examine Smith et al.'s review process and, as a result, we have questions about the validity of their conclusions. In our view, the findings of published articles as presented by Smith et al. do not confirm a causal connection between long-term use of OCs and cervical cancer. Our goal is not to conduct another formal review of the evidence, but to evaluate whether Smith et al. have met the burden of proof for establishing a causal relationship. Given the importance of OCs to women the world over, we urge reproductive health professionals to consider this issue carefully before accepting that a causal relationship exists.