Britt K, Short R. Lancet online 7 December 2011. http://dx.doi.org/10.1016/S0140-6736(11)61746-7 [accessed 7 February 2012]

This comment,1 published in The Lancet, has evoked a plethora of response in the popular press and revisits the contentious issue of the Catholic Church and the combined oral contraceptive pill (COCP). It focuses on the increased risks of breast, ovarian and uterine cancers in Catholic nuns, the titular ‘hazards of nulliparity’.

It reflects on Fraumeni's work, who reviewed cancer mortality data of nuns in the USA for the period 1900–1954, which showed an increase in mortality in nuns from breast cancer at all ages, and an increase in later life of uterine and ovarian cancer.2 It then succinctly covers the data on the link between parity and these cancers, before moving to the effect of the COCP on their incidence – reduction in ovarian and endometrial cancer without increasing the relative risk of breast cancer, but accepts that further evidence is required.

Finally it turns to the religious aspect; the Humanae Vitae condemns all contraceptive methods except abstinence, but permits “therapeutic means considered necessary to cure organic disease, even though they have a contraceptive effect”.3 Britt then concludes if the COCP was freely available to nuns, the risk of ovarian and uterine cancer would be reduced.

The press predictably ran with ‘Nuns should go on the pill, says Lancet’,4 and some Catholic groups were upset, not least with the ill-advised publication on the feast day of the immaculate conception. But Britt's argument has much to recommend it – overall ovarian cancer mortality remains high, largely due to late presentation and lack of a feasible screening programme. Uterine cancers have better survival, but nuns may have less outpatient endometrial sampling obtained due to virgo intacta. Recourse to hysteroscopy may delay diagnosis and so upstage disease. In an aetiologically high-risk group, with potential delays in management, the use of the COCP is worth rational discussion.