Critical response to ‘adjunctive’ dutasteride

A trial published in the Lancet suggesting that dutasteride could be a useful adjunct to active surveillance in men with low-risk prostate cancer has been criticised by an editorial in the same journal (Lancet 2012; published online 24 Jan. doi:10.1016 /S0140-6736(11)61619-X and doi:10.1016/S0140-6736(12)60066-X).

The REDEEM trial followed up 289 men randomised to receive placebo or dutasteride 0.5mg daily who had a biopsy during active surveillance. The primary endpoint was prostate cancer progression, defined as a composite of pathological progression or ‘therapeutic progression’ – ie undergoing more aggressive treatment. After three years, the incidence of the composite endpoint was significantly lower among men taking dutasteride (38 vs 48 per cent).

The editorial casts doubt on the validity of therapeutic progression as an endpoint and notes that the difference in the incidence of pathological progression was small (29 per cent with dutasteride and 33 per cent with placebo). Furthermore, the REDEEM finding appears to conflict with that of the REDUCE trial (NEJM 2010;362:1192–202), in which dutasteride was associated with a higher incidence of high-grade tumours compared with placebo.