Acta Dermato-Venereologica 99-9CompleteContent | Page 13

CLINICAL REPORT Interest in Skin Cancer in Urban Populations: A Retrospective Analysis of Google Search Terms in Nine Large German Cities Linda TIZEK 1,2 , Maximilian C. SCHIELEIN 1,2 , Melvin RÜTH 1 , Rolf-Markus SZEIMIES 3 , Wolfgang G. PHILIPP-DORMSTON 4,5 , Stephan A. BRAUN 6 , Christine HECKER 7 , Bernadette EBERLEIN 1 , Tilo BIEDERMANN 1 and Alexander ZINK 1 1 Department of Dermatology and Allergy, School of Medicine, Technical University of Munich, 2 The Institute for Medical Information Processing, Biometry, and Epidemiology, LMU Munich, Munich, 3 Department of Dermatology and Allergology, Vest Clinic, Recklinghausen, 4 Hautzentrum Koeln, Klinik Links vom Rhein, Cologne, 5 Faculty of Health, University Witten-Herdecke, Witten, 6 Department of Dermatology – General Dermatology and Venereology, Münster University Medical Center, Muenster, and 7 Department of Dermatology, Nuremberg Hospital North, Nuremberg, Germany Skin cancer is a major public health issue, which could be reduced through prevention programmes. How­ ever, prevention utilization is not very prevalent. It is therefore important to understand individuals’ interest in skin cancer. Google AdWords Keyword Planner was used to identify the search volume of terms relating to skin cancer in 9 German cities between July 2014 and June 2018. From a total of 1,203 identified keywords, 1,047 search terms were related to skin cancer, which had a search volume of 3,460,980 queries for the study period. Most terms referred to “identifying skin can- cer”. For melanoma, the number of Google searches per 100,000 inhabitants correlated with the cancer registry data for melanoma incidence rates (men: r = 0.810, women: r = 0.569). Assessment of this data for the different cities further enabled identification of regional variations, which could help to identify areas with a high need for targeted prevention campaigns. Key words: skin cancer; melanoma; non-melanoma skin can- cer; Google; search analysis; retrospective study; keratinocyte; risk assessment. Accepted May 9, 2019; E-published May 10, 2019 Acta Derm Venereol 2019; 99: 797–804. 797 Corr: Alexander Zink, Department of Dermatology and Allergy, School of Medicine, Technical University of Munich, Biedersteiner Str. 29, DE-80802 Munich, Germany. E-mail: [email protected] S kin cancer, including non-melanoma skin cancer (NMSC) and melanoma, is the most common carci­ noma among Caucasians worldwide (1–4), with increa­ sing incidence during recent decades (5–9). While the incidence of NMSC is 18–20 times higher than that of melanoma (1, 3), melanoma is more often fatal (10, 11). Thus, skin cancer presents an enormous socioeconomic burden (12–14), which could be reduced by early detec­ tion, diagnosis and treatment (15, 16). Specifically, the in­ cidence of NMSC can be reduced through sun-protection measures (17–19). Despite substantial efforts to compre­ hensively implement primary prevention strategies (e.g. seeking shade, wearing sun protective clothing, using sun-screen) and secondary prevention strategies (e.g. regular self-examination, regular dermatological check- ups, skin cancer screening campaigns) (20), studies have SIGNIFICANCE This study examined the Google search volume for skin- cancer-related terms in 9 German cities. Overall, 3.5 mil- lion searches related to skin cancer were observed between July 2014 and June 2018. Most of these searches focused on the identification of skin cancer (e.g. ABCD and pictures of skin cancer). In general, the number of search queries per 100,000 inhabitants was lower in larger cities, such as Berlin or Hamburg, in comparison with Stuttgart or Muens- ter. Analysis of the differences in search behavior between cities could help to identify areas with a high need for tar- geted prevention campaigns. shown that utilization of such strategies is not highly prevalent (21–23), particularly among individuals who spend a lot of time outdoors (24–27). One way to investigate reasons for not using skin cancer prevention measures is to focus on the interest in skin cancer among the general population (28). As the Internet is a commonly used source of health information, search engine analysis represents a novel tool for investigating the general interest in various topics (16, 28–33). In Ger­ many, approximately 90% of inhabitants use the Internet (34). More specifically, 95% use Google as their primary search engine (35), and 57% have used the Internet to search for health-related information (36). For example, a German study among patients with melanoma reported that 63% indicated the Internet as the most important source of media information (37). One US study revealed a positive correlation between Internet search volume and the incidence and mortality rates of melanoma and other common cancers (38). Additional studies have revealed an increasing number of Google searches related to health information in recent years (30, 39). The aim of the present study was to investigate German inhabitants’ interest in skin cancer, and whether geogra­ phical differences in interest have emerged, by analyzing Google search volumes in 9 German cities. Furthermore, the number of search queries within each city was com­ pared with data from respective cancer registers in order to determine whether there was a correlation between interest and cancer incidence rates. This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3214 Acta Derm Venereol 2019; 99: 797–804