Is pyoderma gangrenosum associated with solid malignancies? Insights from a population-based cohort study.

Background The question of whether solid malignancies (SMs) are associated with pyoderma gangrenosum (PG) remains to be conclusively answered. Objective To evaluate the risk of SM among patients with PG and the odds of PG after a diagnosis of SM. Methods A population-based retrospective cohort study was conducted to study the risk for SM in patients with PG (n = 302) as compared with age-, sex- and ethnicity-matched control subjects (n = 1799). A case-control design was used to estimate the odds of PG in those with a preexisting history of SM. Results The prevalence of a preexisting SM was comparable in patients with PG and controls (7.5% vs. 8.8%, respectively; P = 0.490). The odds of having PG following a diagnosis of a SM was not statistically increased (OR, 0.85; 95% CI, 0.53-1.36). The incidence of SM was 6.8 (95% CI, 3.5-12.2) and 7.9 (95% CI, 6.1-10.1) per 1000 person-years among patients with PG and controls, respectively. Patients with PG were not more likely to develop SM as compared to controls (HR, 0.86; 95% CI, 0.44-1.69). Patients with a dual diagnosis of PG and SM were older and had more frequent comorbid conditions and increased mortality. Conclusions SM is not associated with provoking PG, and patients with PG are not at an increased risk of developing SM. A thorough routine screening for SM in patients with new-onset PG is an unnecessary approach based on the study findings.