WANG Qin
（Hebei Medical University, Shijiazhuang,Hebei.）
Abstract：
Flow cytometric (FCM) estimation of DNA content has been performed on tumour tissue from 1 97 patients with high and intermediate grade non - Hodgkin's lymphoma (NHL) to investigate the clinicopathological correlations and prognostic significance of DNA ploidy and proliferative activity. Fifty-one per cent of tumours were diploid; the remaining nondiploid tumours were near diploid (14%) aneuploid (28%) and tetraploid (7%). In 81 tumours multiple analyses were performed from different regions of the tumour, ploidy discrepancy was seen within the same tumour in 1 3/81 tumours (16%), and intra - tumour variation in proliferative index (PI) in 72 tumours was estimated at ±5%. Ploidy status did not correlate with histological subtype (Kiel or Rappaport), Ann Arbor stage or the site of disease at present ation. There was no significant difference in response rate,relapsefree survival (RFS) or overall survival rate between the different ploidy categories. Tumour proliferative index (PI) varied markedly between patients (range 2-51%,medi an 14%). A significant association was observed between PI and histological subtype in the Kiel classification (P=0.001). The median PI for the lymphoblastic lymphomas was 20% compared with 10% for the centrocytic tumours.An elevated PI was signifcantly associated with a reduced response rate(P=0.023), with 71% of patients with a low PI (<20%) achieving complete remission (CR) compared with 49% patients with a high PI (>20%). Despi te this correlation with CR, PI was not signifcantly associated with overall survival. When the DNA data was combined with over 20 other potential prognostic factors in multivariate analysis, ploidy and proliferative activity did not prove to be of independent prognostic signifcance for response, RFS or overall survival. In 20 patients additional biopsy material was available from the site of subsequent relapse. In these cases, although the histology at relapse remained unchanged, ploidy status altered in 13/20 pat i ents, and there was a significant rise in tumour PI at relapse compared with the initial pre treatment biopsy (P=0.0 17). We conclude that in high and intermediate grade NHL, DNA ploidy as assessed using conven - tional FCM analysis is not significantly associated with clinical outcome. However, proliferative activity does correlate with histological subtype and response to therapy, and this parameter warrants further evaluation in future studies.
Key Words：
DNA; clinicopathological correlations
