Characteristics of malignant melanoma in patients with Inflammatory Bowel Diseases

Abstract

Background and AimS: Malignant melanoma (MM) is associated with significantmorbidity and mortality, and MM cases worldwide are increasing faster thanany other cancer. Patients with inflammatory bowel diseases (IBD) are known tobe at increased risk of non-melanoma skin cancer (NMSC) due to abnormalities ininnate immunity, immunosuppressive medications, or both. However, little isknown about the overall risk, clinical characteristics, and course of MM in patientswith IBD. We sought to describe clinical characteristics of MM in patients withIBD, and evaluate whether these characteristics differ over time, by patient age, and concurrent use of immunosuppressive medications. Methods: At 2 tertiary care centers, University of North Carolina and Duke UniversityMedical Center, we identified patients with at least 1 ICD-9 code for bothmelanoma (172.x or V10.82) and IBD (555.x and 556.x), and reviewed clinicalrecords to confirm these diagnoses. Those without definitive diagnosis of MM ofthe skin or IBD were excluded. Characteristics of the MM, such as site, depth, andtherapy, as well as characteristics of the IBD, such as duration of disease, type ofIBD, and medication use, were abstracted from the medical record. Descriptivestatistics and bivariate analyses were used to compare characteristics by age, bytime, and by immunosuppressive medication use at the time of MM. Results: A total of 80 patients were included. The median age at the time ofmelanoma was 51 (IQR 38-65), median age of IBD diagnosis was 43 (29-58). The populationwas 42.5% female. A total of 42.5% had Crohn's disease (CD), 53.7% had ulcerativecolitis (UC), and 3.8% unknown type. Immunosuppressive medications (thiopurine, methotrexate, or biologic) were used at the time of MM in 24.2% of patients.When compared to the United States population with melanoma, as reported in Surveillanceand End Epidemiology Results (SEER) database, patients with IBD wereyounger at the time of MM diagnosis. Sites of MM in the IBD population included26.0% head/neck, 44.2% trunk, 13.0% upper extremity, 16.9% lower extremity, 18.2%metastatic at presentation. Those on immunosuppression at the time of MM diagnosiswere significantly younger than those not on immunosuppression (42.6 v. 53.2, p=0.03). When comparing those in the youngest quartile of age at MM diagnosis toothers, younger patients had significantly fewer in-situ melanomas (9.1% v. 40.4%, p=0.05). When melanoma was evaluated by year of diagnosis, subjects diagnosed after2000 were diagnosed with melanoma at an older age (56.5 v. 40.0, p=0.02), theirtherapy more often included sentinel node biopsy (p<0.01), and a higher percentagewere on immunosuppression (32.6 v. 7.1, p=0.06). Conclusions: This large, multi-institutional case series suggests that MM maydevelop earlier in life in IBD patients, as compared with the general population, particularly in patients treated with immunosuppressive medications. Additionally, in our series, melanomas diagnosed early in life were more often deeper thanmelanomas occurring in older individuals. As sunscreen use has been shown toprevent melanoma and reduce nevi development in children, counseling on sunprotection at an early age may be indicated.