Genetic susceptibility to Hodgkin's disease and secondary neoplasias: FISH analysis reveals patients at high risk of developing secondary neoplasia

Background: Cytotoxic drugs administered before high-dose therapy (HDT) represent a significant factor in the development of leukemic complications in patients with lymphoid malignancies. This retrospective study was used to detect evidence of abnormal therapy-related myelodysplasia/secondary acute myeloid leukaemia (tMDS/sAML) clones before HDT in a subset of patients who subsequently developed secondary neoplasia. Patients and methods: 230 patients with non-Hodgkin's lymphoma (NHL) underwent HDT comprising cyclophosphamide and total body irradiation (TBI) with autologous hematopoietic progenitor-cell support. Thirty-three patients have developed tMDS/sAML and 20 of these were screened for the presence of emerging therapy-related abnormalities before HDT. A further 24 patients without evidence of secondary neoplasia were screened using fluorescence in situ hybridisation (FISH). Results: Significant levels of abnormal cells were identified in 20/20 patients screened who have developed secondary neoplasia compared with only three of 24 patients in the HDT control group who have not. The latter three patients have since died. Conclusions: The triple FISH assay was developed to detect loss of chromosomal material from 5q31, 7q22 and 13q14. It can potentially identify those patients at risk of alkylating agent-induced leukaemia before they proceed to HDT. Used in a prospective manner, the triple FISH assay could permit more informed clinical management.