Is there an association between cutaneous leishmaniasis and skin cancer? A systematic review

Background: Cutaneous leishmaniasis is a prevalent communicable disease in low- and middle-income countries, where non-communicable diseases like skin cancer are on the rise. However, the study of multi-morbidity or co-morbidity between communicable and non-communicable diseases is limited, and even null for some tropical or neglected diseases. Nevertheless, looking at these conditions together instead of as isolated entities in places where these illnesses exist, could show new prevention and treatment paths. We aimed to summarize and critically appraise the epidemiological evidence on the association between cutaneous leishmaniasis and skin cancer. Methods: Following the PRISMA guidelines, we conducted a systematic review using five search engines (Embase, Medline, Global Health, Scopus and Web of Science). We sought observational studies in which the outcome was skin cancer whilst the exposure was cutaneous leishmaniasis; these conditions should have had laboratory or pathology confirmation. Results: No epidemiological investigations have studied the association between cutaneous leishmaniasis and skin cancer. Most of the evidence about the association of interest is still based on case reports and other clinical observations rather than strong epidemiological observational studies. Conclusions: Research is much needed to verify the repeatedly clinical observation that cutaneous leishmaniasis may be a risk factor for skin cancer. This evidence could inform and guide early diagnosis or prevention of skin cancer in survivors of cutaneous leishmaniasis or where cutaneous leishmaniasis is still highly prevalent. Registration: PROSPERO ID CRD42018111230; registered on 16/10/18.