Hodgkin's Lymphoma in Systemic Lupus Erythematosus
Objective: In systemic lupus erythematosus (SLE), there is a well-documented increased risk of non-Hodgkin's lymphoma (NHL), but little is known about the risk of Hodgkin's lymphoma (HL). The purpose of our work was to describe the phenomenon of HL in SLE.
Methods: A multi-site cohort of 9547 SLE subjects was assembled; HL cases were ascertained through cancer registry linkage, and the standardized incidence ratio (SIR) for HL was determined. We also performed a literature search for HL cases in SLE, and compared these with our sample. Finally, we pooled results from our cohort study with two large population-based cohort studies providing SIR estimates for HL in SLE.
Results: Five cases of HL occurred in our SLE cohort during the observation interval, for an SIR of 2.4 (95% CI 0.8, 5.5). The literature review documented 13 HL case reports developing in patients with SLE. A pooled analysis combining our data with the other large cohort studies yielded a standardized incidence ratio of 3.16 (95% CI, 1.63-5.51) for HL in SLE.
Conclusions: Data suggest that risk in SLE is increased not only for NHL, but also for other malignancies arising from B-lymphocytes, including HL.

Interest is quickly growing regarding the increased risk of malignancies in autoimmune conditions such as systemic lupus erythematosus (SLE). We recently completed a multi-site international cohort study that calculated standardized incidence ratios (SIRs) for cancer in SLE vs the general population. In that study, the most dramatic increased risk of cancer was seen in haematological malignancies, with an SIR of 2.8 [95% confidence interval (CI) 2.1, 3.5]. The data suggested that most types of haematological malignancies were increased, although the most precise estimates were produced for non-Hodgkin's lymphoma (NHL), since this is by far the most frequent haematological malignancy (both in the general population and in autoimmune rheumatic conditions).

Some have suggested that malignancy risk in SLE is increased also for other haematological malignancies, particularly those arising from B-lymphocytes. For example, case reports of Hodgkin's lymphoma (HL) in SLE patients have been noted in the literature for many decades. To date, clear summary data are lacking regarding the magnitude of risk, the distribution of pertinent demographic factors, and the outcomes in the HL cases that arise in SLE. We, therefore, provide in this concise report the details of the HL cases in our multi-centre SLE cohort, in conjunction with a summary of literature published on HL in SLE, both from case reports and in two other very large recent cohort studies.