Clinical and epidemiological features of multiple myeloma patients from a low socio-economic region of Brazil

Multiple myeloma (MM) represents 1% of all new cases of cancer worldwide. 1 The International Myeloma Foundation estimates that about 30,000 MM patients are currently under treatment in Brazil. Since few studies have reported the clinical and epidemiological features of MM in this country, 2,3 we aim to contribute to the clinical panorama of the disease by describing a series of 65 patients (median age: 64 years; range: 35–80 years) diagnosed with MM between 2006 and 2014 at the Hospital da LIGA (n = 55) and Oncoclínica São Marcos (n = 10), Natal, RN. Patients diagnosed with monoclonal gammopa-thy of undetermined significance, asymptomatic MM, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes), solitary plasma-cytoma, and primary plasma cell leukemia were excluded. The majority of myeloma proteins were of the IgG isotype (69.2%). The Kappa light chain was associated with the heavy chain isotypes in 64.7% of cases. Most patients were in stage IIIA of were submitted to conventional chemotherapy based on cyclophosphamide, thalidomide and dexamethasone (CTD), with 16 of them undergoing autologous hematopoietic stem cell transplantations. Sixteen patients (24.6%) were treated with a melphalan, prednisone and thalidomide (MPT) protocol. Eight (12.3%) patients were treated with thalidomide with dexamethasone and eight (12.3%) with vincristine, dox-orubicin and dexamethasone (VAD). Sixteen patients took bortezomib as second line treatment after disease progression. In our cohort, the clinical presentation and response to treatment revealed gender-related differences not found worldwide, with women being more frequently affected than men (gender ratio M/F = 0.6) and exhibiting lower creatinine levels at diagnosis than men (<1.3 mg/dL) (p-value = 0.032). These epidemiological and clinical characteristics are not similar to the disease descriptions in the more developed southern regions of Brazil. 2,3 In fact, in most countries, MM is more frequent in men than in women. 4,5 The causes of the gender bias herein reported, whether related to referral (for instance, due to women's health campaigns which have been intensified in Brazil over the last decades) or biological characteristics of the population, are not evident and warrant further studies. Regarding biological factors, Boyd et al. 6 analyzed cytogenetic alterations in a large MM cohort and suggested that gender differences are influenced by the primary genetic events, with immunoglobulin translocations being more common in women and hyperdiploidy in men. In the southern regions of Brazil, where genetic alterations have been studied in MM, no such bias was described. 7 …