Simultaneous breast cancer and Kaposi's sarcoma complicating rheumatoid arthritis

For a number of years we have been following the medical literature to find a relationship between chronic treatment with methotrexate and breast cancer occurrence, because we had had in our clinic a female patient who had had two consecutive cancers following methotrexate treatment for rheumatoid arthritis (RA). We were much surprised to find in some papers that breast cancer incidence is low in women with RA. Since then, we have found several papers explaining the low incidence of breast cancer among women being under NSAIDs, but those papers are not univocal. Methotrexate is a known antifolate agent and it has been demonstrated that dietary shortage of folate is a risk factor for breast cancer development.