P53 AND BCL-2 EXPRESSION IN HIGH-GRADE B-CELL LYMPHOMAS - CORRELATIONWITH SURVIVAL-TIME

B-cell high-grade lymphomas are heterogeneous in terms of histology, c linical presentation, treatment response and prognosis. As bcl-2 and p 53 gene deregulations are frequencly involved in several types of lymp hoid malignancies, we aimed our investigation at the study of the rela tion between bcl-2 and p53 expression and survival probability in a gr oup of 119 patients with B-cell high-grade lymphoma. These were obtain ed from the Virgen de la Salud Hospital, Toledo, Spain (73 cases), Joh n Radcliffe Hospital, Oxford, UK (31 cases), and the Istituto Nazional e dei Tumori, Milan, Italy (15 cases). The relation between bcl-2 prot ein expression and survival was small, depending on the primary locali sation of the tumour (in lymph node of mucosae), and lacked a signific ant correlation with overall survival. In contrast with this, p53 expr ession was related to survival probability in our series, this relatio n being both significant and independent of histological diagnosis. p5 3-positive patients showed a sudden decrease in life expectancy in the first months after diagnosis. Multivariant regression analysis confir med that the only parameters significantly related with survival were extranodal origin, which is associated with a better prognosis, and p5 3 expression, which indicates a poor prognosis. Simultaneous expressio n of bcl-2 and p53 was associated with a poorer prognosis than p53 alo ne. This is particularly significant for large B-cell lymphomas presen ting in lymph nodes. The cumulative poor effect of both p53 and bcl-2 in large B-cell lymphomas, which is more significant in nodal tumours, could confirm the existence of a multistep genetic deregulation in no n-Hodgkin's lymphoma. This indicates that the genetic mechanisms contr olling apoptosis and their disregulation are critical steps in the pro gression of lymphomas.