Mieloma múltiple en Chile. Características clínicas y sobrevida

Abstract

Background: Mortality rate records are the only data available in Chile about the prognosis of patients with multiple myeloma (MM). Aim: To characterize clinical features, survival rate and factors related to mortality in cases with MM treated in six large medical centers in Chile. Material and Method: Retrospective analysis of demographic data, clinical features and survival rate records of patients with MM, collected between 1998 and 2002. Survival curves were generated and a multivariate analysis of factors associated to early mortality was carried out. Results: Data from 245 patients aged 38 to 95 years (129 women) was collected. Fifty two percent had an IgG myeloma, 25% had and IgA and 6.1% had light chains myeloma. According to Durie and Salmon staging system, 8,2% were in Stage I 12.6% in Stage II, 60.5% in Stage III and in 18.8% the information about staging was not available. Fifty percent had an hemoglobin level below 10 g/dL, 30% had a serum creatinine over 2 mg/dL and 28% had a serum calcium level over 10.5 mg/dL. Median survival was 33 months. Twenty percent of patients died within the first six months after diagnosis (early mortality). Predictive factors for early mortality were male sex, thrombocytopenia, anemia, renal failure, hypercalcemia, a beta2-microglobulin ≥5.5 mg/L and a serum albumin level <3.5 g/dL. There was a correlation between the number of bad prognosis factors present and the probability of early mortality. Conclusions: This group of Chilean patients with MM presented a short survival time, and 20% died within the first six months after diagnosis. More than a half of cases were diagnosed at an advanced stage (Durie and Salmon Stage III). Several factors were associated to early mortality, two of which (beta 2-microglobulin and serum albumin), are included in the new International Staging System for MM.