Used in the treatment of various solid tumors, lymphomas, and leukemias. Also used in some autoimmune disorders such as rheumatoid arthritis (cyclophosphamide, methotrexate). Often used in combinations to minimize individual toxicities and increase response. Chemotherapy may be combined with other treatment modalities such as surgery and radiation therapy. Dosages vary greatly, depending on extent of disease, other agents used, and patient's condition. Some new formulations (daunorubicin, doxorubicin) encapsulated in a lipid membrane have less toxicity with greater efficacy.