Prognostication of the high-risk WM patient.

Waldenström's macroglobulinemia is characterized by a protracted course in most patients and the median survival may be long. However, a subset of patients may present with more aggressive disease that is associated with short survival. In order to better characterize these "poor-risk" patients, we identified patients who died within 2 years from the initiation of front-line treatment. These patients were older and had more often features of aggressive disease, such as elevated LDH and low serum albumin than the standard-risk population. Furthermore, only a minority of poor-risk patient had a response to initial therapy. However, conventional clinical factors or even the lack on response could not adequately identify poor-risk patients, indicating the need for novel molecular or other markers that would be able to effectively recognize patients at greatest need for aggressive therapies.

Validation of the International Prognostic Scoring System (IPSS) for Waldenstrom's macroglobulinemia (WM) and the importance of serum lactate dehydrogenase (LDH).

The recently proposed, ISSWM staging system for symptomatic patients with WM was based on patients treated with alkylating agents and nucleoside analogs and has not been externally validated nor has been validated for cause-specific survival (CSS). We independently validated ISSWM both for overall survival (OS) and for CSS and assessed whether addition of elevated serum LDH may add to the strength of ISSWM in 335 patients treated upfront mainly with alkylating agents (43%), and rituximab-based therapies (47%). ISSWM could discriminate three groups with significantly different OS and CSS (p<0.01 for both). High serum LDH was predictive of shorter OS and CSS (p<0.01). The combination of high risk according to ISSWM and elevated serum LDH identified a subset of patients for whom innovative treatment approaches are needed.