Advances in the diagnosis and treatment of acute and chronic leukemia in Mexico

Up to half of patients diagnosed with chronic lymphocytic leukemia in México may not require treatment

“…In this study, despite the use of medications that were not especially expensive, we observed good patient outcomes in patients with newly diagnosed CLL, with an OS of more than 20 years (median not yet reached): these data suggest that the clinical course of CLL patients in México is less aggressive than in Caucasian populations, as it has been shown in multiple myeloma [9][10][11]. Genetic differences have been suggested to explain the differences in the prevalence of CLL in México [4], but the precise explanation has not been found.…”

“…The diminished aggressiveness of CLL in México may stem from several facts: (a) Most patients (80%) presented in this study in early stages of the disease (Rai stages 0-2); (b) 89% of patients were ZAP-70 negative, whereas in Caucasians the negativity of ZAP-70 is around 60% [12]; (c) There were no cases of T-CLL; (d) Genetic factors may be involved as has been shown in multiple myeloma [4,[9][10][11], and (e) Other unknown reasons.…”

“…CLL is substantially less frequent in Mexican mestizos than in other populations [3,4] and there is data which suggest that the clinical course of some hematological malignancies is less aggressive in México and Latin American mestizos [3,4,8] than in Caucasians or Africans. The genetic admixture of Mexican Mestizos is 56% amerindian genes, 40% white genes and 4% black genes [4]; it is interesting that in the cohort of CLL patients which we are informing here, 18% were either born in European countries or had an immediate European ancestor, this indicating that this CLL cohort has more persons with Caucasian origin than the general Mexican population. As far as the age of the patients is concerned, the median age was found to be lower than that informed in Caucasian populations (65 versus 70 years) [8].…”

“…Chronic lymphocytic leukemia (CLL) is a lymphoid neoplasm which represents the most frequent hematologic malignancy in Caucasians [1]: Every year, there are 15,000 new diagnoses and 5000 CLL deaths in the United States [2]. Its prevalence in México and other non-Caucasian populations is substantially lower [3] and the clinical course of CLL patients has been described to be less aggressive [4]. Although therapeutic choices were once limited, treatment of this disease has vastly improved in the last decades [2]: The initial treatment of CLL relied in a single drug approach, using alkylators such as chlorambucil and cyclophosphamide, later on purine analogs combined or not with alkylators, then chemoimmunotherapy employing anti-CD20 monoclonal antibodies in combination with other agents and, more recently novel therapeutic agents such as the BCR kinase inhibitors, Bcl2 antagonists and new anti-CD20 monoclonal antibodies [1].…”

“…On the other hand, it seems clear that not all patients with CLL need treatment [1,2] and that, in circumstances of underprivileged economy, withholding treatment, specifically with the novel drugs, may be associated with a better cost-benefit ratio. We have previously suggested that, with the main goal of obtaining personal and/or institutional rewards, physicians in developing countries are indicating unnecessary treatments to patients with hematological diseases [4,5], thus contributing to the alarming rises in costs of the hematological care [6]. We review here, the 32year experience of a single center in treating persons with CLL.…”