RENAL MEDULLARY CARCINOMA AND ABL GENE AMPLIFICATION

Abstract

We characterized the clinical course of renal medullary carcinoma (RMC) and performed an expanded analysis of BCR-ABL. The literature was searched for all reports of RMC. New cases at Northwestern University are described and relevant clinical information was abstracted. BCR and ABL genes, and ABL protein were evaluated by fluorescence in situ hybridization and immunohistochemical analysis, respectively. A total of 95 cases were identified. Mean age at diagnosis was 19 years, the male-to-female ratio was 1.9:1.0, 90% of all patients were black, 98% had an abnormality in a least 1 hemoglobin gene (ie sickle cell trait, SC disease or sickle cell disease) and mean survival was 19 weeks. Two patients (3%) without metastasis were long-term survivors. The response to chemotherapy was poor. One patient treated with thalidomide survived for 52 weeks. The ABL gene was amplified a mean +/- SEM of 1.9 +/- 0.1-fold in all 3 cases evaluated, while ABL protein was increased in 2 of 3 evaluated. No evidence of BCR-ABL translocation was detected. RMC is typically seen in young individuals with the sickle cell trait. It is diagnosed when metastatic, is not responsive to systemic therapy and rapidly causes death. Because cure appears possible with early diagnosis, increased awareness of the disease could make an impact. The use of thalidomide or newer anti-angiogenesis agents should be considered for advanced disease. The role of ABL amplification with respect to etiology and as a therapeutic target should be investigated further.