Association of Leukemia Cutis With Survival in Acute Myeloid Leukemia

IMPORTANCE: Leukemia cutis (LC) is an important yet understudied extramedullary manifestation of leukemia. Previous reports have suggested poor prognosis for patients with LC, but these reports have largely consisted of descriptive studies with a limited number of patients. OBJECTIVES: To identify patient factors associated with LC and characterize the association of LC with the course of acute myeloid leukemia (AML). DESIGN, SETTING, AND PARTICIPANTS: This retrospective, matched-cohort study included 1683 patients with AML diagnosed from January 1, 2005, to April 1, 2017, with and without biopsy-proven LC seen at a single-center, tertiary care hospital in St Louis, Missouri. To specifically evaluate differences in survival, propensity scoring was used to match patients with AML with LC to patients with AML without LC off the logit of propensity score based on age, race/ethnicity, sex, and leukemia type. Kaplan-Meier methods were used to compare cumulative probability survival. Matched survival analysis was performed with extended Cox regression to determine factors associated with leukemia-specific and overall survival. MAIN OUTCOMES AND MEASURES: Leukemia-specific survival and overall survival. RESULTS: A total of 1683 patients were reviewed, including 78 patients with biopsy-proven LC of the AML type and 1605 patients with AML without LC. A total of 62 of the patients with AML and LC (mean [SD] age, 58.2 [11.7] years; 33 [53.2%] male) were matched in a 1:3 ratio to 186 patients with AML without LC (mean [SD] age, 58.2 [13.5] years; 103 [55.4%] male). The 5-year survival among the 62 patients with AML with LC was 8.6%, shorter than the 28.3% among the 186 matched patients with AML without LC. Matched survival analysis revealed that patients with AML and LC compared with those without LC had hazard ratios of 2.06 (95% CI, 1.26-3.38; P = .004) for leukemia-specific death and of 1.66 (95% CI, 1.06-2.60; P = .03) for all-cause death. In addition, matched patients with LC had greater odds of extramedullary organ burden (odds ratio, 3.48; 95% CI, 1.72-7.05; P