Patients Under 50 Years of Age Do Not Present Specific Prognostic Characteristics: An IFM Study in 1897 Patients Under 65 Years of Age.

Abstract 2837

Poster Board II-813

Age is a critical prognostic factor in many hematological malignancies. The reasons for this major prognostic impact are not univocal. For a large part, its prognostic value is in fact related to the therapy intensity tolerated by the patients. Because of frequent renal, hepatic, cardiac impairments, intensive therapies are not tolerated after 60 or 65 years, leading physicians to dramatically reduce treatment intensity in elderly patients. The question of a specific prognostic value of age in a more homogeneous population is an unresolved issue. In myeloma, it has been suggested that patients under 50 years of age presented more favorable features, explaining the better outcome observed in these patients (Ludwig et al., Blood 2008). However, the population was highly heterogeneous, treated both with conventional and intensive therapeutic strategies. In order to address this question, we reviewed the files of 1897 patients under 65 years of age, homogeneously treated within the IFM with high-dose melphalan, from 2000 to 2007. The median age was 56 years (range=23-65), the sex-ratio male/female was 54%. We addressed the issues of the prognostic impact of young age (<50), but also of older patients (60 to 65). The following prognostic parameters were tested: b2-microglobuline, high creatinine (>177 μmol/l), hypercalcemia, low hemoglobin (<10 g/dl), thrombocytopenia (<130 G/l), ISS, del(13), t(4;14), and del(17p). In the first comparison (<50 vs others), the only statistically different parameters were b2-microglobuline (p=.009) and ISS distribution (p=.004). All the other parameters were not significantly different. Similar results were observed in the second comparison (<60 vs 60-65). Only b2-microglobuline values (p=.0001) and ISS distribution (p<.0001) were different. These differences in b2-microglobuline levels probably reflect the decrease of glomerular filtration with age. We then looked at the impact of age on outcome. We found that patients under 50 years of age displayed a better overall survival than patients between 50 and 65 (p=.007), with no difference in PFS. We also found that patients between 60 and 65 presented a poorer outcome than younger patients (OS, p=0.002, EFS, p=0.01). However, when patients under 50 were compared with those between 50 and 60, no difference was observed, both for OS and EFS. Thus, in conclusion, young age is not a prognostic factor in multiple myeloma. In contrast, older age (60 to 65) remains an adverse prognostic parameters, even in patients treated with high-dose melphalan.