Autoimmune hemolytic anemia as a paraneoplastic phenomenon in solid tumors: A critical analysis of 52 cases reported in the literature.

Autoimmune hemolytic anemia (AIHA) is a well known paraneoplastic phenomenon in lymphoproliferative disorders but there are also a number of case reports of such an association with solid tumors. We have analysed 52 cases of this association reported in the literature. We found that AIHA may occur prior to, concurrent with cancer or well after end of treatment, either as a sign of recurrence or in complete remission of the cancer. 70% of the patients had warm antibody and 30% cold antibody AIHA. Some patients had additional antibodies such as platelet antibodies (Evans syndrome), lupus anticoagulants or antibodies to C1 esterase inhibitor. AIHA occurred in almost all types of cancers, but it was relatively more common in renal cell cancer and Kaposi sarcoma compared to other cancers. In early stage cancers, in particular in renal cell cancers, curative resection of the cancers led to complete, often sustained remission of AIHA within a short time in a number of patients. Resection of the tumor had also beneficial effects in some metastatic cancers. Patients who had a response to resection of the tumor were often refractory to steroid treatment before surgery, while some responses to steroids were observed in patients with metastatic cancer. The study of cancer patients with autoimmune diseases may provide important insights into the biology of tumors.