Compiled by:
Salina Khatoon, Senior Evidence and Knowledge Analyst, Hannah Shaw, Principal Evidence and Knowledge Analyst, Public Health Wales.
Non-melanoma skin cancers (NMSC) are the most common type of cancer in Wales, making up 94% of all skin cancers during 2019. Age-standardised incidence rates of NMSC have risen by 7.1% between 2016 and 2019 to 469.8 per 100,000 in Wales1. The reason for this increase within Wales remains largely unclear. The Evidence Service sought to identify why rates of NMSC might be rising in Wales. Using agile scope methodology, we sought to identify if a correlation with one or more of the known risk factors exists over time. Specifically, we sought to establish why cases of non-melanoma skin cancer are increasing in Wales.
Agile scope methodology was developed by the Evidence Service in Public Health Wales (PHW). Seven electronic databases were searched and limited to English language and systematic reviews published between 2010 and 2024. Title and abstract screening were conducted by two reviewers independently screening the first 10% for relevance. Full text screening decisions were made by two reviewers. Quality assessment was undertaken by one reviewer, using a tool developed by PHW.
No systematic reviews were identified examining the association between the trend in historic risk factor exposure with a trend in NMSC rates. However, seven systematic reviews examining the association between specific risk factors and NMSC were included and generally conducted as part of sub-group analysis. Long term exposure to UV radiation, antihypertensive medication use, menopausal hormone therapy use, topical corticosteroids use, sunscreen use, and smoking were key risk factors identified as having a potential relationship with NMSC and may contribute to the increased incidence rates seen in Wales. The relationship between risk factors and NMSC appears to be extremely complex and may vary according to the type of skin cancer. For example, some primary studies identified smoking as protective among men, but not women. Also, the relationship appears to differ across different skin cancer sub-types. There was a lack of good quality systematic reviews investigating sunburn, foreign travel, and the use of indoor tanning exposure and the potential dose response relationship with NMSC. Findings identified are likely to be generalisable to the UK population, as most included studies were conducted across Europe and USA. However, it is important to highlight that trends associated with the identified risk factors are likely to vary across countries, for example sun exposure.
It was not possible to draw firm conclusions about the relationship between a dose-response or duration of exposure to certain factors and the risk of NMSC due to the limited evidence base and lack of longitudinal data at systematic review level. However, evidence suggests that the relationship between risk factors and NMSC is complex, and this review highlights several potential risk factors that may warrant further investigation, at primary study level.
If you wish to read the full report, please request a copy from the Evidence Service at evidence.service@wales.nhs.uk.
1. Public Health Wales (2023) Non-Melanoma Skin Cancer Incidence in Wales, 2016-2019. Available from: https://publichealthwales.shinyapps.io/nmsc_incidence_wales_2016_2019/ [accessed 12/04/24]
© 2024 Public Health Wales NHS Trust (June 2024)
Material contained in this document may be reproduced under the terms of the Open Government Licence (OGL) www.nationalarchives.gov.uk/doc/open-governmentlicence/version/3/ provided it is done so accurately and is not used in a misleading context.
Acknowledgement to Public Health Wales NHS Trust to be stated.
ISBN: 978-1-83766-410-8