P211 Evolving patterns of cutaneous squamous cell carcinoma: a retrospective study of tumour complexity and the role of adjuvant radiotherapy
Natasha Boylan, Matthew Nicol, Cara Beattie, Charis Thompson, Lisa Ranaghan, Cathryn Crockett, Keith Rooney, Collette McCourt, Olivia DolanAbstract
The NICE/BAD guidelines 2020 on the management of cutaneous squamous cell carcinoma (cSCC) highlight the importance of risk stratification into low-risk, high-risk and very high-risk tumours. Since the COVID pandemic, it is our impression that patients are presenting with higher-risk tumours. Our aim is to evaluate changes in tumour complexity and the potential role of adjuvant radiotherapy (ART) in improving outcomes in high-risk cSCC. cSCCs (ICD-10 code C44) diagnosed in 2019 and 2023 were identified using the regional cancer management system and electronic care record. Demographic, histological and outcome data were collected, excluding unresectable tumours and cases with < 1 year of follow-up from outcome analysis. Statistical analysis was performed using Jamovi. A separate retrospective analysis of high-risk, node-negative cSCC treated with ART at the regional cancer centre from 2017 to 2023 was completed. In total, 342 cSCCs were identified (180 in 2023; 162 in 2019). The patients’ mean age was 77 years in both cohorts. The male-to-female ratios were 2 : 1 and 3 : 1, respectively. In 2023, immunosuppression rates (31.1% vs. 19.8%, P = 0.03) and very high-risk (pT3) SCCs (38.3% vs. 27.8%, P = 0.04) were significantly higher than for 2019. Overall, 44 patients met the criteria for ART but were treated with surgery alone. Local recurrence occurred in 9%, locoregional recurrence in 11.4% and DSM in 6.8%. Those with recurrence were older (mean 83 vs. 77 years) and 37.5% were immunosuppressed. In the ART cohort (n = 72), immunosuppression was present in 29%. The follow-up duration was 3–7 years. Local recurrence occurred in 13%, locoregional recurrence in 21% and DSM in 11%. In total, 38% of recurrences were in immunosuppressed patients. These findings demonstrate a shift towards more immunosuppressed patients and very high-risk tumours postpandemic. Recurrence rates and DSM remain considerable in patients with high-risk tumours. Future work will compare surgery alone vs. surgery plus ART within matched risk groups, which would complement the important question being addressed in the ongoing SCC-AFTER trial.