[A retrospective case-control study of immunoglobulin G₄-related disease combined with malignancy]

IgG₄-related disease (IgG₄-RD) has been proved to be associated with malignancy.The incidence and risk factors of malignancy development in IgG₄-RD were not clear. Nine IgG₄-RD patients with malignancies and 27 IgG₄-RD control cases were analyzed for risk factors and clinical features. The incidence of malignancy in IgG₄-RD was 3.3%, higher than age-controlled general population. Smoking history was significantly more common in patients with malignancies than in the control group (9/9 vs 16/27, P<0.05). A total of 6/9 malignancies occurred within the first year after the diagnosis of IgG₄-RD. Colorectal, biliary and thyroid cancers were the leading types. Smoking history is a risk factor for IgG₄-RD associated malignancy. Careful vigilance to monitor malignancy needs to be paid during follow-up.