Epidermal Growth Factor Immunotherapy: Exploring the Effects of NB-UVB Exposure.

Introduction: Inflammatory skin reactions are the most common issue in Cetuximab-treated patients. Many evidences show the correlation with NB-UVB exposure, but the mechanisms are not completely understood. The aim of this study is the evaluation of the effects of NB-UVB exposure on inflammatory cytokines modulation during EGFR immunotherapy.Materials and methods: Human immortalized keratinocytes, HaCaT cells, were treated with 10 g/ml of Cetuximab for 24 hrs and NB-UVB exposed. Viability, ROS production and pro-inflammatory cytokines gene expression and release were assessed. An additional, in vivo evaluation of Minimal Erythema Dose in Cetuximabtreated patients was performed.Results: NB-UVB exposure activates the inflammatory skin response in HaCaT cells, inducing the overexpression of pro-inflammatory mediators. Reduced cells viability, ROS production and expression and release of selected cytokines after Cetuximab-treatment. The co-treatment, with NB-UVB and Cetuximab, show the recovery with baseline conditions. In vivo evaluation underline that patient’s skin reactions are not changed after NB-UVB exposure.Conclusion: In conclusion, NB-UVB doesn't exacerbate papulopustular reactions developed during anti-EGFR treatment, both in vivo and in vitro evaluations. A better understanding of this relationship, between NB-UVB exposure and dermatological side effects, could throw a new light on sun exposure limitation, improving Cetuximabtreated patients QoL and favoring therapeutic adherence.