Background/Objectives: The increasing incidence rates of keratinocyte carcinoma (KC), particularly in fair-skinned populations, call for efforts to intensify health education of the general population in addressing this prevalent skin cancer type. As a preparatory step, this systematic review summarizes the published research on the knowledge and risk perception regarding KC among individuals without medical training. Methods: The review was registered in PROSPERO (CRD42024618851) and adheres to PRISMA guidelines. The databases PubMed, Scopus, Web of Science, PsycArticles, and PsycINFO were searched on 30 July 2024. Studies were eligible if knowledge and/or risk perception was assessed in lay people. Risk of bias (ROB) was assessed with the Joanna Briggs Institute checklist for prevalence studies. Comparable outcomes (e.g., awareness of terms for KC) were meta-analyzed. Results: Included reports (n = 17) were published between 1991 and 2024 with 16,728 individuals assessed. Awareness for the most common type of KC, basal cell carcinoma (BCC), was low (20.75% of respondents (95% confidence interval (CI): 15.24–27.61)), while more respondents were familiar with colloquial terms (60.9–72.8%). Meta-analysis indicated an underestimation of the frequency of KC, with only 7.21% (CI: 4.03–12.58) identifying BCC as the most common type of skin cancer. Furthermore, concern about developing KC as assessed in only two overlapping studies was reported by only 25–30% of respondents, indicating a significant gap in risk awareness and a lack of research on risk perception regarding KC. Conclusions: This review highlights the need for targeted health education interventions to improve knowledge and preventive behaviors regarding KC. Given the limitations of the included studies, characterized by high ROB, heterogeneity of results, and a lack of standardized assessment tools, further research is essential to enhance the understanding and awareness of KC in diverse populations.

Immunosuppressed patients have a substantially increased risk for developing skin cancer. Therefore, it is mandatory that such patients are adequately informed and aware of skin cancer and their increased risk to modify their behavior. Numerous studies have evaluated the topic, but no synthesis of their findings exists. The protocol of this systematic review was registered on PROSPERO (CRD42024618851) and its reporting followed the PRISMA-2020 guideline. To identify all studies assessing knowledge or perception of skin cancer in immunosuppressed patients, forward and backward citation tracking was employed in addition to an electronic literature search across five databases. For the risk of bias (ROB) assessment, the Joanna Briggs Institute checklist for prevalence studies was used. Quantitatively comparable outcomes were meta-analyzed, while all others were qualitatively synthesized. Thirty-two reports comprising 4214 patients were included. Acknowledging substantial heterogeneity between studies, just over two thirds of patients recalled having been informed about their increased skin cancer risk (pooled proportion: 68.34%, 95% confidence interval (CI): 55.48–78.90). Awareness of the increased risk for skin cancer varied widely (34.5–100%), and pooled mean Skin Cancer and Sun Knowledge scores were 14.77 (CI = 8.57–20.96). About half of those patients asked about risk factors for skin cancer knew that immunosuppression was among them. This indicates that immunosuppressed patients are insufficiently educated about their increased skin cancer risk. However, the high heterogeneity in the synthesized outcomes and the minimal proportion (3%) of low ROB ratings for the included studies call for further research to better understand the awareness of skin cancer risk in this vulnerable population.