Epidemiological landscape of young patients with multiple myeloma diagnosed before 40 years of age: the French experience
Alexis Caulier, Murielle Roussel, Pierre Morel, Naëlle Lombion, Benoît Branco, Jean Galtier, Cyrille Hulin, Aurore Perrot, Valentine Richez, Anne-Victoire Michaud-Robert, Cyrille Touzeau, Chantal Doyen, Clara Mariette, Denis Caillot, Stéphanie Harel, Pascal Lenain, S. S. Ivanoff, Jean Fontan, Anne Marie Stoppa, Salomon Manier, Laurent Garderet, Xavier Leleu, Jean‐Pierre Marolleau, Bertrand Arnulf, Hervé Avet‐Loiseau, Bruno Royer
Abstract
Multiple myeloma (MM) is rare in young patients, especially before age 40 years at diagnosis, representing <2% of all patients with MM. Little is known about the disease characteristics and prognosis of these patients. In this study, we examined 214 patients diagnosed with MM at age ≤40 years over 15 years, in the era of modern treatments. Among them, 189 patients had symptomatic MM. Disease characteristics were similar to older patients: 35% had anemia, 17% had renal impairment, and 13% had hypercalcemia. The staging was ISS-1 in 52.4%, ISS-2 in 27.5%, and ISS-3 in 20.1%. Overall, 18% of patients had high-risk cytogenetics [del 17p and/or t(4;14)]. Ninety percent of patients received intensive chemotherapy followed by autologous stem cell transplant, and 25% of patients had allogeneic stem cell transplant predominantly at time of relapse. The median follow-up was 76 months, the estimated median overall survival was 14.5 years, and the median progression free-survival was 41 months. In multivariate analysis, bone lesions (hazard ratio [HR], 3.95; P = .01), high ISS score (HR, 2.14; P = .03), and high-risk cytogenetics (HR, 4.54; P < .0001) were significant risk factors for poor outcomes. Among predefined time-dependent covariables, onset of progression (HR, 13.2; P < .0001) significantly shortened overall survival. At 5 years, relative survival compared with same age- and sex-matched individuals was 83.5%, and estimated standardized mortality ratio was 69.9 (95% confidence interval, 52.7-91.1), confirming that MM dramatically shortens the survival of young patients despite an extended survival after diagnosis.