Hydroxychloroquine (Plaquenil) and Cancer: Is there an increased risk?

No Clear Increased Risk of Cancer with Hydroxychloroquine

Hydroxychloroquine (Plaquenil and generics) is an immune modulating medication frequently used in treating a variety of immune-mediated diseases. In hair loss, we use this medication for treating lichen planopilaris, lupus, discoid lupus, frontal fibrosing alopecia and pseudopelade.

Concerns about cancer are always important with drugs that affect the immune system. Surprisingly, most larger scale epidemiologic studies of hydroxychloroquine have not shown an increased risk of cancer in patients using these drugs.

Current data would suggest there is no increased risk of cancer with hydroxychloroquine

Studies by Fardet and colleagues in 2017 found that the use of hydroxychloroquine was not associated with an increased cancer risk. The authors even proposed the users of hydroxychloroquine may have a reduced risk of metastatic cancer. Other studies including recent studies by Mao and colleagues in 2018 did not show any increased cancer risk among hydroxychloroquine users.

Continued studies are needed - especially as they pertain to certain groups. For example the risk of cancer in a patient with systemic lupus or rheumatoid arthritis may be quite different than those with lichen planopilaris or frontal fibrosing aloepcia. Studies in animals have suggested that these drugs may have anti-cancer effects for some types of cancers. Although there is ongoing interest as to whether these drugs could actually reduce the risk of some cancers- to date, this has not been seen in bigger studies. Overall, compared to immunosuppressives like methotrexate, hydroxychloroquine seems to have a lower cancer risk and this fact is important to keep in mind when treating patients at high risk for cancer.

Reference

Fordet et al. Clin Epidemiol 2017
Mao et al. Ther Clin Risk Manag 2018