Page 17 - Wondergem

Observational Studies (PHAROS), covering 40% of the Dutch population. The data 1 from PHAROS are sufficiently detailed to allow specific analyses on the prognostic
value of patient- and disease related factors as well as the outcome reached with
different treatment regimens. Moreover, by using data from a population based registry
the selection bias that is present in observational or cohort studies is minimised (35,38).
Treatment
Treatment of FL
Because the choice of treatment for TFL is often dictated by previous treatment for FL, a brief outline of treatment guidelines for FL in the Netherlands is given here. Stage I FL is generally treated by local radiotherapy with curative intent (40Gy). Newly diagnosed FL stage II-IV is, when possible, initially managed with a watch and wait policy. If B symptoms, bulky disease, organomegaly or cytopenia because of bone marrow invasion arise, R-chemotherapy is given: R-CVP (rituximab, cyclophosphamide, vincristine and prednisone) for fit patients and R-chlorambucil for unfit patients. As second line treatment R-Fludarabine is generally used, however, in case of a late relapse (occurring >2 years after the end of previous treatment) the initial regimen is often being repeated. For subsequent relapses, there are no specific guidelines. At that stage anthracyclines can be used, especially as induction therapy for autologous or allogeneic transplant. Although the use of rituximab is implemented at every stage of the disease, the use of rituximab maintenance therapy varies. In some centers rituximab maintenance is given following first line, based on the data from the PRIMA study (39). However, because long term follow-up of the PRIMA study showed no OS advantage, which suggests that re-treatment at relapse is as effective as maintenance therapy (40), many Dutch centers now mainly use maintenance therapy with rituximab after second line treatment (www.hovon.nl). International guidelines are similar, although in many countries anthracyclines are incorporated more frequently in first line with the goal of prolonging progression free survival (41).
Overview of studies on treatment of transformed FL
Patients with TFL are often excluded both from first line DLBCL studies and from indolent lymphoma studies resulting in a scarcity of objective data upon which treatment decisions can be based. To check the number and type of studies that have been published on treatment of transformed follicular lymphoma we performed a search using Pubmed and Embase*. This search was done by two independent investigators (DE Issa and MJ
Introduction and scope of this thesis
15