Prevalence, Spectrum and Clinical Implications of Malignancies in Patients with Bullous Pemphigoid

Current research on the malignancy rate and spectrum of malignancies in patients with bullous pemphigoid is contradictory. The aims of this study were to determine the prevalence and spectrum of malignancy in patients with bullous pemphigoid and to compare demographic, clinical, therapeutic and outcome data between bullous pemphigoid patients with and without malignancy. This retrospective cohort study enrolled 335 patients (194 women and 141 men; mean age at diagnosis of bullous pemphigoid 77.5 ± 12 years) followed up at an Israeli tertiary centre between January 2009 and December 2019: 107 (32%) had malignancy and 228 (68%) did not. Malignancy occurred before and after bullous pemphigoid diagnosis in 82 (77%) and 25 (23%) patients, respectively. Bullous pemphigoid patients with cancer were older (p = 0.02) and had a higher mortality rate (p < 0.0001) than those without malignancy. The 2 groups did not differ in terms of sex, comorbidities, or clinical characteristics. Those who developed malignancy before bullous pemphigoid were younger than those who developed malignancy after bullous pemphigoid (mean age 69.3 vs 82.4 years, p < 0.0001). Overall malignancy rates did not differ between patients with bullous pemphigoid and the general population; therefore, comprehensive malignancy workup may be unnecessary. However, patients with bullous pemphigoid had a greater risk of melanoma (10.7% vs 4.3%, p = 0.0005); therefore, routine skin screening may be recommended. SIGNIFICANCE The aims of this study were to determine the prevalence and spectrum of cancer in patients with bullous pemphigoid (BP), and to compare BP patients with and without cancer. The results show that there is no increased rate of overall malignancy in BP, while the frequency of melanoma increases. Patients with both BP and cancer are older, but there are no differences in severity or clinical features. These results suggest that routine skin screening in patients with BP is necessary to improve treatment and outcomes.