Cytogenetic abnormalities in patients with newly diagnosed multiple myeloma as a secondary primary malignancy: a retrospective study.

Objectives: Multiple myeloma (MM) often develops as a secondary primary malignancy (SPM). The retinoblastoma susceptibility gene (RB1) was the first tumour suppressor gene to be identified. We pooled and analyzed available data to compare the incidence of RB1 gene deletions and other cytogenetic abnormalities in patients with MM alone or as an SPM.Methods: We conducted a retrospective study of 475 patients. The experimental group comprised 18 patients with MM as an SPM, and the control group comprised 457 MM patients. We analyzed the baseline information in both groups, and used the odds ratio (OR), 95% confidence interval (CI), and forest plot to determine the incidence of SPMs with and without cytogenetic abnormalities.Results: The incidence of RB1 gene deletion was higher in the experimental group. There was no significant difference in other cytogenetic abnormalities.Conclusions: RB1 gene deletions appear to be associated with MM that develops as an SPM.