Relationship between initial clinical presentation and the molecular cytogenetic classification of myeloma.

Multiple myeloma (MM) consists of several distinct cytogenetic subtypes, and we hypothesized that each subtype may have a unique mode of initial presentation and end-organ damage. We studied 484 patients with newly diagnosed MM to determine the relationship between specific myeloma-defining event (MDE) and the cytogenetic subtype. Patients were divided into four non-overlapping groups based on the MDE at diagnosis: isolated renal failure, isolated anemia, isolated lytic bone disease or a combination (mixed). MM with translocations without trisomies accounted for 30% of all patients, but accounted for 50% of patients with renal failure. Specifically, the t(14;16) translocation accounted for only 5% of all MM patients, but was present in 13.5% of patients with renal failure as MDE. Among patients with t(14;16), 25% presented with renal failure only as MDE. Patients with isolated renal failure as MDE had significantly poorer survival compared with all other groups, whereas patients with bone disease as MDE had the best outcome (P<0.001). Our findings support the hypothesis that in addition to prognostic differences, there is significant heterogeneity in clinical presentation associated with the cytogenetic subtype, suggesting that MM encompasses a group of cytogenetically and phenotypically distinct disorders rather than a single entity.