Increased Risk of Local Recurrence in Cutaneous Squamous Cell Carcinoma Arising in Sun-Exposed Skin: A Retrospective Cohort Study.

Simple Summary: The aim of this study is to compare the risk of local recurrence and metastases in patients with cSCC based on the presence or absence of prior sun exposure in the region of tumor development. A retrospective observational epidemiological study including 558 patients from January 2017 to December 2020 was conducted. Among the 463 patients with cSCC in highly sun-exposed areas, 73 (15.8%) were diagnosed with local recurrence versus only 7 of 95 patients (7.4%) in less sun-exposed areas. No differences were found in terms of metastasis between both groups. In regions with low sun exposure, the variables linked to a heightened risk of recurrence include tumor depth and the involvement of surgical margins. Our results suggest that highly sun-exposed areas could have a greater risk of developing local recurrence, conferring a worse prognosis for the patients. Background: The incidence of cutaneous squamous cell carcinoma (cSCC) is increasing over the years. Risk factors for local recurrence and metastasis have been widely studied in highly sun-exposed areas of the body but less data exist about less sun-exposed ones. The main objective of this study is to compare the risk of local recurrence and metastases in patients with cSCC in highly sun-exposed areas compared to cSCC in less sun-exposed areas. Material and methods: A retrospective observational study was carried out, including 558 patients with histopathologically confirmed cSCC at the Reina Sofía University Hospital (HURS), Córdoba, during the period from 1 January 2017 to 31 December 2020. Demographic, clinical and anatomopathological data were collected. Results: Local recurrence occurs more often in highly sun-exposed areas (15.8%) compared to less sun-exposed ones (7.4%) (p < 0.05). However, no differences in the rate of metastases in both groups were found. The presence of affected surgical margins and tumor thickness were identified as independent risk factors for cSCC in low sun-exposure areas. Conclusions: cSCC located in anatomical areas of high sun exposure presented a greater risk of developing local recurrence in our population, which could suggest that these tumors have worse prognosis than those that lie in areas that do not receive chronic sun exposure. [ABSTRACT FROM AUTHOR]