A systematic review on Richter syndrome: what is the published evidence?

A systematic and comprehensive search of literature was performed using MEDLINE databases from 1st January 1978 to 2nd November 2009 and hand search of references. A search performed by combining the Medical Subject Headings (MESH) terms 'Richter's syndrome' and 'chronic lymphocytic leukemia' (CLL) yielded 143 citations. Ten additional case-control studies judged relevant for the purpose of study were also included. In total, 45 case reports, 18 case series, and 9 case-control studies were identified. For the purpose of this review, only case series and case-control studies were considered. The following conclusions could be drawn from the studies analyzed in this review: (i) some biological markers (i.e. CD38 expression and genotype, absence of del13q) or clinical features (i.e. bulky lymph node involvement), although not validated in prospective trials, may be considered for close monitoring and a careful biopsy policy; (ii) PET, is not yet standardized in RS, however, it may be useful in the diagnosis and to choose the site for biopsy; (iii) when diagnosed RS should be treated with a combination of rituximab and polychemotherapy; (iii) younger patients who respond to initial therapy should be offered allogeneic SCT, if feasible. Despite the paucity of data, it is important to note that this article represents the first systematic review of the entire body of available clinical evidence useful for an appropriate management of Richter transformation.