AB0394 DOES HIGH DISEASE ACTIVITY IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS INCREASE THE RISK OF CANCER INCIDENCE?

Abstract

Background:Cancer is known as one of the causes of morbidity and mortality in systemic lupus erythematosus (SLE) patients. It has been thought that SLE activity and stimulation of the immune system predisposes the risk of cancer (1).Objectives:To investigate the correlation between SLE disease activity and the cancer incidence.Methods:The study included a cohort of SLE patients, diagnosed according to the American College of Rheumatology classification criteria(2)attending the Rheumatology department, Aswan University in the period from January 2018 to June 2019. We used a questionnaire to screen patients who were diagnosed with cancer. We collected demographic and laboratory data on all screened patients and their disease activity using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)(3). For the patients diagnosed with cancer, we recorded age of onset of SLE, age of diagnosis of cancer, type of cancer, treatment received, immunosuppressive regimen (dosage and duration) and cancer outcomes.Results:The study included 117 patients (95 female, 22 male), mean age (25.6 ± 6.5) years with mean SLE duration(7.3 ±6.3) years and mean SLEDAI(9± 8.9). 76% had lupus nephritis, 62.2% had hematological abnormalities and 17.8%had neurophsycatric lupus. 91% were on corticosteroids (CCS), 33% on mycophenolate mofetil (MMF), 43% on azathioprine, 14% on cyclosporin. 56.8% were either receiving or had received intravenous cyclophosphamide (CYC) with a mean cumulative dose (7.5 ± 4.7) gm. We found 18 (15.3%) patients (13 female and 5 males) were diagnosed with cancer during the course of SLE with mean age at onset (31±3.7), mean age at cancer diagnosis (39.28±10.77), mean SLE duration(18.17±6.02) and mean SLEDAI (7.39±4.19). Most of SLE patients with cancer had lupus nephritis (89%) and all cancer patients were on a median dose of CCS 10 (2.5- 20) mg daily for median 10 (4-24) years. 83.5% of them had received intravenous CYC prior to the development of cancer with mean total cumulative dose of (6.7±4.6) gm, 67% received MMF, 33% received cyclosporine and 50% received azathioprine. Types of cancer were as follow; 22.2% lymphoma, 16.7% cancer cervix, 16.7% cancer breast, 11.1% colorectal cancer, 11.1% squamous cell carcinoma, 5.6% leukemia, 5.6% bronchogenic carcinoma, 5.6% prostate cancer and 5.6% cancer thyroid. 66.7% of them had been successfully treated, 27.8% had metastasis, 5.6% had died. There was no significant difference in SLEDAI between patients with cancer and patients without. Whereas malignancy is correlated to longer disease duration (p= 0.01) and older age of SLE onset with significant difference (p= 0.001).Conclusion:Although we have detected an increasing incidence of cancer in SLE patients in comparison to normal population, our study didn’t find a signficant correlation between SLE disease activity and the risk of cancer. We should closely observe SLE patients with old age at onset and/or long disease duration because of their higher risk for cancer development.