Malignancy in Systemic Lupus Erythematosus (SLE) Patients

Background: Malignancies are among the leading causes of death in Systemic Lupus Erythematosus (SLE) patients with studies reporting a higher prevalence of malignancy in SLE patients compared to the general population. We wanted to determine the frequency of cancer in a cohort of SLE patients and identify its associated risk factors. Methods: Cross-sectional study involving SLE patients attending the nephrology outpatient clinic, Universiti Kebangsaan Malaysia Medical Centre between January and June 2014. Results: We recruited 228 patients (207 female, 21 male), aged 40.48 ± 12.86 years with mean SLE duration of 11.65 ± 6.46 years. Majority (87%) had lupus nephritis and were in remission with a median SLEDAI score 2 (0, 14). Majority (89%) were on corticosteroid with either a steroid sparing agent like mycophenolate mofetil (15.4%), azathioprine (36.8%) or ciclosporin (15.4%). One hundred and sixty (70.2%) patients were either receiving or had received intravenous cyclophosphamide with median dose of 5,173.6 ± 3,242.4 mg. Seven female patients were diagnosed with cancer during the course of their SLE with 56 (34-78) years being median age at malignancy and SLE duration of 4 (0-12) years. Majority (5/7) had lupus nephritis and all patients a median dose of prednisolone 10 (2.5, 10) mg with 10 (4-24) years of steroids. Two patients had a family history of cancer with majority developing cancer after the diagnosis of SLE. Two patients received intravenous cyclophosphamide prior to the development of cancer for their SLE compared to overall cohort of 160. Three patients had colorectal cancer, 2 had cervical cancer, 1 had breast cancer, and one patient had germ cell tumour and one thyroid cancer. All patients had their cancer successful treated with no signs of recurrence. Conclusion: We found a lower occurrence of cancer in our SLE patients as compared with the reported literature.