Investigation of the Accompaniment of Cancer in Rheumatic Diseases in Mashhad, Iran, from 2007-2018: A Retrospective, Descriptive, Cross-Sectional Study

Background: The present study aimed to investigate the association between rheumatic diseases and cancer in patients referred to two medical-training centers and private clinics over 10 years in Mashhad, Iran. Methods: This study, which was retrospective, descriptive, and cross-sectional in nature, involved 1,036 rheumatic patients who were referred to Imam Reza and Ghaem Hospitals, as well as rheumatology clinics in Mashhad, Iran, between 2007 and 2018. For each patient, data was collected on demographics, laboratory results, type of rheumatic disease, duration of the disease, frequency of malignancy among rheumatic patients, type of malignancy, and the drug treatments administered up until the final diagnosis of malignancy. The study concluded with a comparison between rheumatic patients with malignancy and those without. Results: The incidence of malignancy was found to be higher in women (p=0.005) and in older age groups (p=0.005). Furthermore, patients with malignancy were observed to use biological drugs (p=0.001), Adalimumab (p=0.02), and Infliximab (p=0.01) less frequently. Upon examination of laboratory data, it was noted that the Erythrocyte Sedimentation Rate (ESR) was higher in cases of malignancy (p<0.005), while the serum hemoglobin level was lower in such cases (p=0.009). Conclusion: The study’s findings suggest a higher incidence of malignancy was observed in women and older age groups. Additionally, patients with malignancy were less likely to use biological drugs, including Adalimumab and Infliximab. These insights could potentially guide future research and therapeutic strategies in the management of rheumatic diseases.