Introduction
Diffuse large B cell Lymphoma (DLBCL) is the most common subtype of
Non-Hodgkin Lymphoma (NHL). DLBCLs constitute 30-40% of NHL and more
than 80% of aggressive lymphomas(1). Among the treatment targets of
lymphomas is angiogenesis, which is increasingly important and is the
main subject of many cancer treatment researches. Angiogenesis is
regulated by the balance between angiogenic and anti-angiogenic factors.
Microvascular density and tumor angiogenesis were found to be poor
prognostic factors in patients with DLBCL receiving anthracycline-based
chemotherapy(2). VEGF (Vascular endothelial growth factor), PDGF
(Platelet derivated growth factor) are the leading angiogenic factors,
and thrombospondin-1 is the leading antiangiogenic factor. In studies
conducted with serum VEGF levels of patients with a diagnosis of DLBCL,
those with high serum VEGF levels were found to be associated with poor
prognosis(3). In mice models with DLBCL, apoptosis in pericytes, one of
the important elements of angiogenesis, and a decrease in tumor volume
were observed with imatinib treatment targeting PDGFR-β(4). It was
observed that high level of thrombospondin expression in many tumor cell
lines inhibits tumor cell angiogenesis and progression(5, 6). Our aim in
this study is to immunohistochemically investigate the relationship
between the staining rates of mainly antiangiogenic factor
thrombospondin-1, VEGF and PDGFR-in tissue preparations in patients
diagnosed with DLBCL as a result of lymphadenopathy biopsy and their
clinical features at the time of diagnosis, response to treatment and
prognosis.