Abstract

Background: Rheumatoid arthritis (RA) patients have an increased risk of malignancy with postulated risk factors that include chronic inflammation, smoking and the use of immunosuppressants have been postulated as drivers of higher malignancies rates. Our study aimed to describe the prevalence and type of malignancies encountered in an urban, predominantly Black RA patient population.
Methods: Cross sectional analysis of 1142 patients with RA diagnosis by ICD-codes of which 501 cases met the inclusion criteria for the study. Blacks accounted for 88.4% of the study population. Fifty-six patients had cancer recorded in their medical records and these cases were further reviewed for tumor type, timing of diagnosis and patient clinical characteristics.
Results: The cancer prevalence was 11.2% (56/501) in our Black RA population being studied. Mean age at cancer diagnosis was 59.9 ± 5.2 for the patients who developed cancer before RA diagnosis and 58.25 ± 16.02 for those who developed malignancy after RA diagnosis. There were 18 breast cancers, 4 colon and 4 cervical cancers; for lung, multiple myeloma, thyroid, squamous cell carcinoma and pancreas there were 3 cases each; for endometrial, Non-Hodgkin's lymphoma, meningioma and prostate, 2 cases each and 1 each for urinary bladder, esophageal adenocarcinoma, lymphoma, glioblastoma, liver, Hodgkin's lymphoma, sarcoma, ovary and renal cell carcinoma. No differences were found in years of RA duration, joint erosion, joint space narrowing or SENS score except for significantly higher ESR among the cancer group and RF seropositivity in the non-cancer group.
Therapeutic modalities were not significantly different between the cancer and no cancer groups.
Conclusion: Breast cancer was the most prevalent malignancy among our Black RA population. Further studies are needed to identify the contributing factors to the malignancy risk of breast cancer in our Black RA population and whether it is gender-related since RA is more prevalence in women