There have been several studies looking at whether having SLE increases your risk of cancer. For most cancers it isn't clear if there is an increased risk or not. Some researchers have suggested a small increase in risk for some cancers such as lung and cervical cancers but other studies have not found any difference. The main exception is for lymphomas especially non-Hodgkin lymphomas (NHL).

The average incidence of lymphoma in the UK general population is 11 cases per 100 000 women and 15 cases per 100 000 men. Some studies have found that among people with SLE the risk of NHL may be as much as 3 to 4 times higher than for the general population. But, this still means that most people with SLE will never develop lymphoma.

We don't understand why people with SLE may have a higher risk of lymphoma.

Reference

• Bernatsky et al 2005 An international cohort study of cancer in systemic lupus erythematosus. Arthritis and Rheumatism 1481-1490.