Abstract: Objective: To determine the related factors of bullous pemphigoid (BP) complicated with malignant tumors and establish clinical prediction model. Methods: One hundred and nine BP patients hospitalized in our hospital from January 2018 to June 2023 were collected. According to whether there was a concomitant malignant tumor, the patient were divided into BP simple group and BP combined tumor group. Statistical analysis of clinical features and laboratory tests were performed in both groups. Related factors of BP complicated with malignant tumor were analyzed by binary logistic regression, R software was used to construct a clinical prediction model. Results: Of 109 patients, 19 (17.43%) were complicated with malignant tumor, and lung cancer was the most common (6 cases). The univariate analysis and binary logistic regression analysis showed that erythrocyte sedimentation rate and carbohydrate antigen 199 were risk factors of malignancy in BP patients, albumin was a protective factor. The AUC of ROC curve of the nomogram prediction model established based on the above risk factors was 0.917 (95% CI 0.8573-0.9766). The correction curves of the predictive model set indicated that the predictive model had good calibration ability. Conclusion: Erythrocyte sedimentation rate and carbohydrate antigen 199 are risk factors for malignancy in BP patients. The prediction model shows good predictive ability, which can provide a reference for systemic tumor screening in patients with BP.

Key words: bullous pemphigoid, malignant tumor, related factors, prediction model, nomogram model