Malignancy Risk in Systemic Lupus Erythematosus
Author:
Christie Bartels, MD, MS
Assistant Professor, Department of Medicine and Division of Rheumatology at University of Wisconsin School of Medicine and Public Health
Member of the Lupus Foundation of America Medical Scientific Advisory Council
Citation: Bartels C. Malignancy risk in systemic lupus erythematosus [published online March 29, 2019]. Rheumatology Consultant.
Previous studies have shown an increased risk of lymphoma and skin cancers, as well as lung, liver, head and neck, vaginal, and cervical dysplasia, among persons with systemic lupus erythematosus (SLE).1 In a cross-sectional study, Bae and colleagues2 evaluated malignancy risk among patients with SLE compared with the general population using a very large, comprehensive, national insurance database with 21,000 patients with lupus in South Korea. The findings support the results of previous meta-analyses and studies in the United States and Canada that have shown an increased risk of lymphoma, head and neck, lung, liver, and cervical dysplasia in SLE. Surprisingly, ovarian cancer and male leukemia rates were increased in Bae and colleagues’ study, although ovarian cancer rose after a few years of observation, which might reflect treatment effects or treatment differences in South Korea. These findings contrast with the reported decrease in breast and ovarian cancer risk among persons with SLE in a meta-analysis by Bernatsky and colleagues.3
Bae and colleagues also found that leukemia was predominant among men with SLE. Leukemia in SLE has been reported in the North American literature, but it is interesting that this risk could be gender-specific. These findings merit further global epidemiologic investigations, since they could be based on regional smoking hazards, environmental exposures, immunosuppression patterns, and/or the use of different therapeutic agents—risk factors that were not discussed in the study.
Significance
One of the consistent findings in the study by Bae and colleagues and other studies is cervical dysplasia—an important finding, given that SLE disproportionately affects young women. Higher rates of human papillomavirus (HPV) vaccination and vigilant cervical cancer screening are a relevant global issue in the care of patients with SLE. In the United States, expert medical organizations state that cervical cancer screening may be decreased to every 3 to 5 or even every 10 years, depending on the age group. High-risk populations are an exception in whom continued annual screening is advised. Although not mentioned specifically, patients with SLE on immunosuppressive medications are in that higher-risk category. Therefore, this should be discussed with such patients, and clinicians should make sure they receive HPV vaccination and advise a possible annual Papanicolaou smear and cervical examination.
Limitations, screening >>
Limitations
In Bae and colleagues’ study, the authors did not describe how the patients had been treated or for how long. The researchers reported that cross-sectionally at entry patients with SLE had a higher rate of previous cancer diagnosis; it might have been interesting had the authors done a short prospective analysis excluding participants with a previous cancer diagnosis, but that perspective is limited with a cross-control study. Also, smoking rates were not discussed in the article. This is an important gap because SLE damage and prognosis can be worse among people who smoke, which is also a risk factor for cancer. This reminds rheumatologists that tobacco cessation is recommended for patients with SLE.
Screening
In Canada, rheumatology groups have specifically called for annual cervical cancer screening for patients with SLE. In the United States, we borrow the language for people at high-risk or immunosuppressed populations (eg, patients with HIV), and persons with SLE on immunosuppression are part of the population needing annual screening. Guidelines are less explicit in the United States, which requires more education for primary care providers and patients. In a bold move, the Canadian Rheumatology Association recently recommended annual cervical cancer screening in its general guidelines for maintenance care of patients with SLE. Regardless of whether this recommendation is incorporated into American College of Rheumatology guidelines or other North American guidelines, annual cervical cancer screening for patients with SLE is a best practice that should be discussed and further investigated so as to make clear recommendations for health care providers and patients.
References:
1. Choi MY, Flood K, Bernatsky S, Ramsey-Goldman R, Clarke AE. A review on SLE and malignancy. Best Pract Res Clin Rheumatol. 2017;31(3):373-396. doi:10.1016/j.berh.2017.09.013.
2. Bae EH, Lim SY, Han K-D, et al. Systemic lupus erythematosus is a risk factor for cancer: a nationwide population-based study in Korea. Lupus. 2019;28(3):317-323. doi:10.1177/0961203319826672.
3. Bernatsky S, Ramsey-Goldman R, Foulkes WD, Gordon C, Clarke AE. Breast, ovarian, and endometrial malignancies in systemic lupus erythematosus: a meta-analysis. Br J Cancer. 2011;104(9):1478-1481. doi:10.1038/bjc.2011.115.
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