Symptomatic Multiple Myeloma in Young Adults ≤ 40 Years of Age.

Introduction: Multilple myeloma (MM) rarely occurs in patients ≤ 40 years of age. Thus, information regarding disease features and outcome is limited. We performed a retrospective analysis of the database of GMSG which includes 1162 patients with symptomatic MM who were diagnosed since 1987.

Patients and methods: Multiple clinical and laboratory variables were evaluated in patients ≤ 40 years of age and in older patients including the recently proposed International Staging System (ISS) for MM. Furthermore, the same variables were assessed for possible correlation with prognosis in patients ≤ 40 years of age. Patients with asymptomatic MM were not included.

Results: Forty seven (4%) patients were ≤ 40 year old when treatment was initiated. Clinical and laboratory parameters were similar among the two groups of patients with the exception of ISS which was lower in younger patients (p=0.03). Despite a similar response to primary treatment the median survival of younger patients was significantly longer than that of older patients (65 months versus 37 months; p=0.001). Among younger patients, hypercalcemia, thrombocytopenia, bone marrow plasmacytosis and elevated serum LDH were associated with impaired survival on univariate analysis. ISS was not statistically significant (p=0.1) but the median survival of patients with ISS 1,2 and 3 was 154 months, 60 months and 33 months respectively. A Cox regression analysis showed that only elevated serum LDH was significant and was associated with a median survival of 9 months.

Conclusions: Young patients with symptomatic myeloma have similar disease features with older patients but present with a lower ISS. Patients ≤ 40 years of age live twice as long when compared to older patients with symptomatic MM. Elevated serum LDH identified a subgroup of patients (23%) who had an extremely poor outcome. 40% of young patients presented with ISS 1 and survived for more than a decade. This information may be of value when designing therapeutic strategies for young patients with myeloma especially when allogeneic stem cell transplantation is considered.