– Background/Purpose:  Cancer is one of the main causes of morbidity and mortality worldwide. The overall risk of cancer in SLE is higher than in the general population (SIR 1.14). Objectives: To determine the incidence and prevalence of cancer in patients with SLE. To identify prevalent types of cancer and associated risk factors. To estimate mortality of patients with SLE due to neoplastic etiology.

– Methods: A cohort study was conducted, all medical charts of patients diagnosed with SLE (ACR 1982/97 classification criteria) by different Rheumatology Services from January 2000 to June 2016 were reviewed. We studied sociodemographic variables and those related to SLE and to cancer. Statistical analysis: Descriptive, Prevalence, Incidence, Chi²-exact test, T Test and Mann Whitney, ANOVA, Multiple Linear Regression, Kaplan-Meier curves.

– Results: We included 303 SLE patients, 88.4% women.  Twenty-two cancers were diagnosed in 18 patients, determining a prevalence of 5.9% [IC95% 3.3-8.6] and an annual incidence rate of 5.2 / 1000 inhabitants, both rates being higher compared to the general population (p= 0.0001, p = 0.02 respectively), and a risk of cancer of 2.4. The mean age at diagnosis of cancer was 46 ± 12.9 years, 94.4% were women and 16.6% (3/18) had a family history of cancer. Five types of cancers were observed: 8 cervical, 3 breast, 3 ovarian, 3 thyroid, 1 non-Hodgkin’s lymphoma. All patients received treatment (14 surgeries, 1 chemotherapy and 3 combined), 15 remitted and 2 developed metastases. Three patients had 2 cancers and 1 patient had 3. There was no association between the presence of cancer and smoking, alcoholism, obesity or immunosuppressive treatment. Patients with cancer had more comorbidities such as arterial hypertension (55.5% vs 44.5%, p = 0.031) and diabetes (22.2% vs 3.9%, p = 0.009) compared with those who did not have cancer. In the regression analysis, greater cumulative damage, older age at diagnosis of SLE, longer disease duration and HPV infection were significantly associated with cancer.  The mean survival time in patients with SLE who had cancer was 10.8 years. Thirty   six patients died, 33 due to other causes and 3 due to cancer. The cancer mortality rate per year was 3.9%.

– Conclusion: The prevalence of cancer in patients with SLE was 5.9%, with an annual incidence of 5.2 / 1000 inhabitants.  The most frequent types of cancer were: cervix, breast, ovarian, thyroid and lymphoma. The risk factors that were associated with cancer were HPV infection, higher SLICC/SDI, older age at diagnosis of SLE and longer time of evolution of SLE.  The death rate due to cancer was 3.9%.