Public concern has once again been raised over the link between underarm deodorants and cancer, after a recent report that frequent underarm shaving combined with deodorant use could increase the risk of breast cancer.

The study, which was carried out by Kris McGrath from Northwestern University, USA, surveyed the underarm-hygiene habits of 437 women with breast cancer. Women who shaved their underarms more than twice a week and applied deodorant more than once a week were almost 15 years younger when they were diagnosed with breast cancer than those who used neither regimen. Consistent with previous studies, McGrath found no link with a younger age of breast cancer diagnosis when either shaving or deodorant was used alone.

This finding was published shortly after a report from Philippa Darbre, Reading University, UK, that found traces of parabens — preservatives used in cosmetics, food and pharmaceutical products — in breast tumours. Although there is no proof that parabens cause cancer and most deodorants no longer contain these compounds, Darbre said “Their detection in human breast tumours is of concern since parabens have been shown to mimic the action of the female hormone oestrogen, [which] can drive the growth of human breast tumours” (Reuters, 12 January 2004).

Darbre is excited by McGrath's work and claims “It is a landmark publication because it provides the first epidemiological evidence for a link between the use of antiperspirants/deodorants and breast cancer development” (NewScientist.com, 24 January 2004). It is clear that more studies will be needed to resolve this controversial issue.