November 14, 2011

expert reaction to association between the contraceptive pill and prostate cancer, as published in BMJ Open

A study from a Canadian team found that countries where the contraceptive pill is more common also showed higher levels of prostate cancer. Along with quotes the SMC sent out a before the headlines analysis.

Dr Kate Holmes, Research Manager at The Prostate Cancer Charity, said:

“This study does not present a strong evidence case for an association between the use of the contraceptive pill and prostate cancer, nor does it intend to. It is intended to explore the possibility that release of endocrine disruptive chemicals (EDCs) into the environment, a process which is not unique to the pill, might impact on the incidence of the disease. However, for all of the 87 countries in the study, there is no information on the level of these chemicals in the environment, with the focus on the contraceptive pill as the sole source, which we know is not the case.

“Other types of contraceptive use are investigated too, to rule out the potential that increased levels of sexual activity are related to prostate cancer, or that a sexually transmitted infection could be linked to the disease. However, it would not be a surprise that countries which have a higher use of the contraceptive pill also have a higher detection level of prostate cancer, as this would be a reflection of a higher quality health care system in that country.

“While this study raises some interesting questions about the presence of EDCs in the environment, it does not contribute to our overall understanding of the development of prostate cancer.”

‘Oral contraceptive use is associated with prostate cancer: an ecological study’. BMJ Open 2011;1:e000311. doi:10.1136/bmjopen-2011-000311. Before The Headlines analysis: Oral contraceptive use is associated with prostate cancer: an ecological study. Before The Headlines is a service provided to the SMC by volunteer statisticians: members of the Royal Statistical Society and Statisticians in the Pharmaceutical Industry. A list of contributors, including affiliations, is available here.