PD08 Developing an effective intervention to improve photoprotection behaviour in xeroderma pigmentosum: results of the XPAND trial

Abstract Premature death in patients with xeroderma pigmentosum (XP) is most commonly due to metastatic skin cancer. In total, 80% of the skin cancers in XP are on the face, head and neck. So rigorous ultraviolet protection, especially of the face, is crucial in managing patients with XP. We recently developed a new methodology for the accurate estimation of the daily dose of ultraviolet (UV) reaching the skin of the face over a prolonged period. We then used this to study photoprotection behaviour in detail over a 3-week period in 36 patients with XP in the UK. We identified a wide range of UV protection behaviours (i.e. daily UV dose to the face), with around 35% of adult patients with XP protecting significantly worse than the rest. We then found that their poor photoprotection correlated closely with nine variables, seven of them potentially reversible psychological or social factors. We went on to design a personalized behaviour change intervention (‘XPAND’) to target these psychological factors that correlated with poor photoprotection (i.e. high daily UV dose to the face). It consists of seven one-to-one sessions delivered by a nurse or psychologist. We tested the efficacy of this intervention in 16 patients with XP with poor photoprotection, in a randomized controlled trial. The design was a two-arm parallel-group randomized control trial with a delayed-intervention control arm who received XPAND the following year. The primary endpoint was mean daily UV dose to the face during a 3-week period in June or July following XPAND (or no intervention in the control group). Sixteen patients were randomized. There were sufficient data for primary outcome analysis in 13 of them. The XPAND group (n = 8) had a lower mean daily UV dose to the face than the control group (P < 0.001). The delayed-intervention control group also had a lower mean daily dose to the face after the intervention than before, although not at a statistically significant level. Secondary endpoints were also analysed. Health economic analysis was carried out and showed that XPAND was a potentially cost-effective treatment, as it would reduce long-term treatment costs associated with UV exposure. This small randomized controlled trial has shown that XPAND is effective at improving UV protection in poorly protecting patients with XP, and should be incorporated into the clinical management of XP.