Chronic lymphocytic leukemia: a new vision of an old disease (II Brazilian Consensus Meeting on CLL-B)

EDITORIAL

Chronic lymphocytic leukemia: a new vision of an old disease (II Brazilian Consensus Meeting on CLL-B)

Carlos Sergio Chiattone^I; Roberto Passetto Falcão^II

^IPresident of the Sociedade Brasileira de Hematologia e Hemoterapia

^IIPresident of the Colégio Brasileiro de Hematologia

^{Correspondence to}

Knowledge about chronic lymphocytic leukemia (CLL-B), the most frequent type of leukemia in Western countries, has undergone a veritable transformation over the last few years.

The classic vision of CLL-B as a homogeneously indolent disease with a slow and progressive accumulation of lymphocytes in the organism and normally seen in elderly individuals who have a short expected biological survival time no longer is readily applicable to all patients stricken with the disease. CLL-B is seen today as a heterogeneous disease having a variable clinical course.

Much information on the nature of the neoplastic cell, including chromosomal and molecular alterations, as well as mechanisms which participate in the survival of the leukemic clone, has recently been published.

Although clinical staging, by Rai or Binet, still continues to be the principal foundation in the forecast of prognosis, guiding the therapeutic decision, it is known today that approximately 50% of the patients who present the initial stage of the disease will evolve aggressively, with a rapid progression towards a premature death.

Among the most important recent advances in the understanding of CLL-B is the identification, beyond clinical staging, of new prognostic factors. Among them the following stand out: the cytogenetic alteration subgroup, the mutational state of immunoglobulin, the expression of ZAP-70 and the expression of CD38.7 These new factors can contribute towards the identification of patients in a non-advanced clinical stage, but with a high risk of a rapid progression of the disease.

The range of therapeutic options for CLL-B has been greatly extended over the last few years, including alkylating agents, purine analogs and, more recently, monoclonal antibodies. The combinations of these agents (chemoimmunotherapy), based principally on the observation of the synergic effect in vitro, have been studied in depth recently, resulting in an enormous improvement in the response rates.

The support treatment, such as a vaccination strategy against infectious agents and the correction of anemia, the systematic follow-up for the precocious identification of a second neoplasia and the adequate handling of infections, has made a marked improvement in the quality of life of these patients possible.

Last, but not least, there is the definition of the minimum criteria for the diagnosis of CLL-B. The identification ever more frequent of incipient monoclonal lymphocytosis in the peripheral blood by routine hematological exams performed on asymptomatic individuals is a relatively new situation in the hematological practice, incurring a diversity of opinions as to the conduction and orientation of these “patients”, including from an ethical point of view.

In light of this enormous quantity of new knowledge, through the initiative of the SBHH and the CBH, the “II Brazilian Consensus Meeting on CLL-B” was held in Salvador, Bahia, on October 7-8, 2005.

Many Brazilian specialists were invited to report on different aspects of CLL-B. Professor Guillaume Dighiero, of the Pasteur Institute of Paris, France, renowned researcher on the theme, was invited to assist in the mediation of discussions and in the conclusions of the consensus.

The main objective of the encounter, once the consensus among the members of the group had been obtained, was to prepare an updated manuscript for the orientation of Brazilian specialists on CLL-B, above all providing a rational focus on the diagnosis and therapy for CLL-B adapted to the Brazilian setting.

The result of the II Brazilian Consensus Meeting on CLL-B is presented in this issue of the RBHH.

Publication Dates

• Publication in this collection
  17 July 2006
• Date of issue
  Dec 2005