Personal history of psoriasis and risk of incident cancer among women: a population-based cohort study
Abstract
We systematically examined the association between a personal history of psoriasis and risk of incident cancer (other than keratinocyte carcinoma, also known as nonmelanoma skin cancer, i.e. SCC and basal cell carcinoma), based on a prospective analysis of the Nurses' Health Study (Appendix S1).
In 2008 we queried Nurses' Health Study participants as to whether they had physician-diagnosed psoriasis and if so the year of diagnosis (1997 or before, 1998-2001, 2002-5, 2006-7 or 2008).[4] We confirmed self-reported psoriasis using the Psoriasis Screening Tool questionnaire, which was 99% sensitive and 94% specific for psoriasis in a hospital-based pilot study.[5] We asked about the involved body surface area (BSA) when psoriasis was at its worst, measured using the palm (i.e. the subject's flat hand and thumb together, fingers not included). For cancer outcomes, only confirmed invasive cases after medical record review were included, except for breast cancer and bladder cancer, which included both invasive and in situ cases.