DNA content in high and intermediate grade non-Hodgkin's lymphoma-prognostic significance and clinicopathological correlations

Abstract

Summary Flow cytometric (FCM) estimation of DNA content has been performed on tumour tissue from 197 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 non-diploid 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 13/81 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 presentation. There was no significant difference in response rate, relapse-free survival (RFS) or overall survival rate between the different ploidy categories. Tumour proliferative index (PI) varied markedly between patients (range 2-51%, median 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 significantly 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%). Despite this correlation with CR, PI was not significantly 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 significance 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 patients, and there was a significant rise in tumour PI at relapse compared with the initial pre treatment biopsy (P = 0.017). We conclude that in high and intermediate grade NHL, DNA ploidy as assessed using conventional 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.With the advent of intensive combination chemotherapy, durable remissions have been achieved in over 50% of patients with high grade NHL (Fisher et al., 1983;Connors & Klimo, 1988;Coleman et al., 1988). However, these patients comprise a heterogenous group with varied patterns of disease and differing clinical outcome. The problems associated with the histological classification of NHL are well recognised (NCI Non-Hodgkin's Lymphoma Classification Project Writing Committee, 1985), and reproducible quantitative methods of tumour classification are required to confer additional prognostic informa...

Tumor proliferative activity and response to first-line chemotherapy in advanced breast carcinoma

“…In general, there is a correlation between the rate of proliferation and the grade of lymphoma, with low-grade lymphomas expressing a low growth fraction and vice-versa [38][39][40]. In this disease, the impact of proliferation on survival is generally reported as being negative [41][42][43][44], and only rarely it is positively associated with response [45].…”

An investigation of different methods of cell cycle analysis by flow cytometry in rectal cancer

“…The comparable performance of these methods in measuring computer synthesised histograms suggests that the differences observed in the clinical series do not reflect operator error, but rather that there exists subtle differences between synthesised and experimentally derived histograms which lead to a greater variation in values for cell proliferation as determined by different analysis programs. This may partly explain the variable results described for non-Hodgkin's lymphoma by several authors (Bauer et al, 1986;McLaughlin et al, 1988;Wooldridge et al, 1988;Cowan et al, 1989).…”

Proliferating cell nuclear antigen (PCNA) as a prognostic factor in non-Hodgkin's lymphoma

“…The biological behaviour of lymphoma may also be assessed by determining the rapidity of cell proliferation using various methods, such as measuring the size of the S phase fraction (SPF) by flow cytometry (Christensson et al, 1986, Young et al, 1987Lenner et al, 1987;Cowan et al, 1989;Lehtinen et al, 1989), assessing expression of Ki-67 antigen (Gerdes et al, 1984;Grogan et al, 1988;Hall et al, 1988;Brown et al, 1989), or by immunocytochemical detection of 5-bromodeoxyuridine (BrdUrd) incorporation in the DNA (Witzig et al, 1989).…”

“…Lymphomas where >50% of cells showed positive staining for PCNA had inferior 5-year survival as compared with those with less than 50% of positive cells (57% vs 41%, P = 0.008). The presence of > 50% of positively staining cells for PCNA was strongly associated with a larger than the median size of the SPF (median, 8.3%) (Christensson et al, 1986, Young et al, 1987Lenner et al, 1987;Cowan et al, 1989;Lehtinen et al, 1989), assessing expression of Ki-67 antigen (Gerdes et al, 1984;Grogan et al, 1988;Hall et al, 1988;Brown et al, 1989), or by immunocytochemical detection of 5-bromodeoxyuridine (BrdUrd) incorporation in the DNA (Witzig et al, 1989).Proliferating cell nuclear antigen (PCNA), also known as cyclin, is a 36 kD nuclear protein (Bravo & Celis, 1980;Bravo et al, 1987) that was originally detected by using autoantibodies from sera of patients with SLE (Miyachi et al, 1978). PCNA is expressed in a high concentration during the S phase fraction of the cell cycle in the nuclei of proliferating cells, and in a lesser amount during the GI and G2/mitosis phases (Kamel et al, 1991).…”