Among younger patients with Waldenström macroglobulinemia (WM), modern treatments, early diagnosis, and the absence of high-risk features in symptomatic patients are all contributing factors to excellent overall survival (OS), according to research published in the American Journal of Hematology.

Less than 10% of all patients with WM are aged 50 years or younger at time of diagnosis, with a median age of WM diagnosis of 70 years. Both the International Prognostic Scoring System for WM (IPSSWM; developed using data from patients treated almost exclusively with chemotherapy) and the revised IPSSWM (rIPSSWM; developed using data from patients treated with rituximab-based chemoimmunotherapy or proteasome inhibitors) relied on data from patients who were around the median age of WM diagnosis. However, there is a lack of information about prognostic factors and the most common outcomes among younger patients with WM.

To address the lack of understanding, a team of researchers evaluated data from 160 younger patients with WM to determine features that predict outcomes in this younger patient population.

The median patient age was 49 years (range, 23-55), and all patients were diagnosed between 2000 and 2019 at 1 of 14 centers in Italy. The majority (66%) of patients were men and 12% had family history of WM. Overall, median follow-up was 5.6 years.


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At the time of diagnosis, the majority of patients (70%) were asymptomatic. According to IPSSWM criteria, 63% of patients were low risk, 27% of patients were intermediate risk, and 10% of patients were high risk; according to rIPSSWM criteria, 92% of patients were very low or low risk and 8% of patients were considered intermediate risk.

Using IPSSWM criteria, patients classified as high risk had inferior 5-year OS to those considered low or intermediate risk (92.9% vs 100%; P =.002); however, using rIPSSWM criteria, patients in the intermediate-risk group had worse 5-year OS compared with those in the very low/low group (87.5% vs 100%; P =.028).

Compared with the general population, the OS among young patients with WM was not significantly worse. Early diagnosis, lack of high-risk symptoms, and improved therapies appear to contribute to improved outcomes in this group.

“Our study indicates that the life expectancy of young WM patients diagnosed in the last two decades is comparable to that of the age and sex matched general population,” the authors wrote.

“Early diagnosis, reflected by the high proportion of asymptomatic patients, the absence of high-risk features in symptomatic patients and the high efficacy of modern treatments are the main determinants of the excellent outcome of young WM patients,” concluded the investigators.

Reference

Varettoni M, Ferrari A, Frustaci AM, et al. Younger patients with Waldenström Macroglobulinemia exhibit low risk profile and excellent outcomes in the era of immunotherapy and targeted therapies. Am J Hematol. Published online August 11, 2020. doi:10.1002/ajh.25961