Cutaneous comorbidities in patients with multiple myeloma: A 10-year retrospective cohort study from a Korean population

Multiple myeloma (MM) is a common hematologic malignancy characterized by the presence of the clonal proliferation of tumor cells. Studies on cutaneous comorbidities in Asian patients with MM have yet to be conducted. This study aimed to analyze the prevalences, characteristics, overall survivals, and risk factors of various cutaneous comorbidities in patients with MM. A retrospective cohort study using medical records from January 1, 2008, to December 31, 2017, in patients with MM was conducted. Of 1438 patients with MM, 354 patients (24.61%) had one or more cutaneous comorbidities. Among them, herpes zoster infection was found to be the most common cutaneous comorbidity. The development of herpes zoster was found to be a possible candidate for good prognostic factor for overall survival [hazard ratio, 0.62; 95% confidence interval (95% CI), 0.44–0.86], while the occurrence of cutaneous malignant tumor was found to be a possible candidate for poor prognostic factor for overall survival (hazard ratio, 3.13; 95% CI, 1.76–5.56). The development of some cutaneous comorbidities heralds the prognostic importance in patients with MM. A better understanding of the prevalences, clinical characteristics, and risk factors of various cutaneous comorbidities in patients with MM may help clinicians identify the clinical course and prognosis of the disease.