CPC15 Vulval squamous cell carcinoma is an under-reported cancer associated with poor outcomes: a national cohort study of the incidence and survival in England

Abstract Epidemiological data are limited for vulval squamous cell carcinoma (VSCC). This retrospective, national cohort study reports the incidence and survival of VSCC from 2013 to 2020 in England. Data were extracted from the National Disease Registration Service ‘Get Data Out – Skin’ dataset. Crude incidence rates (CIRs) were reported per 100 000 person-years (PY). Trends were assessed using SEER Joinpoint regression analysis (version 5.2.0; US National Cancer Institute) and annual percentage change (APC), from 2013 to 2019. Incidence rate ratios (IRRs) with Poisson regression were used to evaluate the impact of the first year of the COVID-19 pandemic on CIRs. Crude net survival rates were reported from 2014 to 2016. In total, 6929 cases of VSCC were registered from 2013 to 2020 (mean 866 cases per year). The 2013–2020 CIR was 3.09 per 100 000 PY [95% confidence interval (CI) 3.02–3.17]; it was 3.03 (95% CI 2.83–3.24) in 2013, and 2.87 (95% CI 2.67–3.07) in 2020. Over the study period, 4171 cases were diagnosed at stage 1–2 (60.2%), 1543 were stage 3–4 (22.3%) and 1215 were stage unknown (17.5%). The 2013–2019 APC showed a nonsignificant upward trend of +0.97% (95% CI −1.08 to 3.23), P = 0.31. During the early pandemic, the CIR fell significantly from 3.15 per 100 000 PY (95% CI 2.95–3.67) in 2019 to 2.87 (95% CI 2.67–3.07) in 2020 [IRR 0.91, P = 0.05 (0.0498)]. The 5-year net survival for stage 1–2 VSCC was 78%, compared with 33% for stage 3–4. This is the first and largest national dataset to report the incidence and survival of VSCC in England. A nonsignificant upward trend in incidence coincides with the high prevalence of high-risk human papillomavirus (HPV) genotypes, an ageing population, increasing awareness campaigns, and incidental detection through the cervical cancer screening programme. During the early COVID-19 pandemic, VSCC incidence fell significantly. The published epidemiological literature often amalgamate all vulval cancer histological subtypes. In 2015, the National Cancer Intelligence Network reported an 18% increase in incidence of vulval cancer from 1990–92 to 2007–09, while mortality rates decreased by 25% from 1990–92 to 2008–10. The Netherlands Cancer Registry reported an increasing APC of VSCC, of +5.0% (95% CI 2.7–7.7) between 2002 and 2010, while Italian registries reported a decreasing APC of −0.96% (95% CI −1.43 to −0.48) between 1990 and 2015. VSCC net survival is worse than that of melanoma, breast cancer or prostate cancer, and presents at later stages, emphasizing the need for better awareness and therapeutic options. These essential data contribute to an under-researched area of women’s health, laying foundations to discover the future impact of the HPV vaccine, and supporting ongoing research.