Etiology and Pathogenesis > Molecular Oncology | Staging and Prognosis  

Meeting Abstract

Clinical correlation of histologic and genetic features in primary CNS lymphoma (PCNSL)

L. E. Abrey, D. A. Filippa, L. M. DeAngelis

Memorial Sloan-Kettering Cancer Center, New York, NY

Specific histologic features of PCNSL have not yet been found to have prognostic importance.
Prior reports have described bcl-2 expression ranging from 35-72%, p53 0,16 and 57%, apoptosis 34%, Ki67 10-80% (53% >20%MIB1).
None of these features has been clearly described to have any significant clinical correlation.
We examined PCNSL tumor specimens from 45 immunocompetent HIV-1 negative patients.
All tumors were examined for CD 20, EBV, apoptosis, necrosis, bcl-2, p53, and Ki67.
These results were then correlated with response to therapy (complete response or less), risk of relapse (any v. none) and survival (calculated from date of diagnosis).
Chi squared analysis was used to analyze discrete variables; Yates correction was applied for expected values less than 5.
The Kaplan Meier product limit method was used to assess survival.
All patients had CD20+, EBV negative tumors; 44 tumors had a large cell histology.
Necrosis was seen in only 8 tumors (18%); apoptosis was present in 36 (80%). 37 tumors (82%) expressed bcl-2 and 10 (22%) expressed p53.
Ki67 ranged from <5% to >80% with a median value of 20-30%.
Patients with p53 negative tumors had a higher risk of relapse (p = 0.08).
There was a trend suggesting that patients with bcl-2 positive tumors were less likely to have a complete response (p=0.1) but also less likely to relapse(p=0.1).
Overall survival was not significantly affected by any factor.
However, median survival varied with the percent of Ki67 positive cells: <10%: 26.8months, 11-49%: 50.7months, >50%: 12.5months.
These preliminary results suggest that the prognostic importance of bcl-2, p53 and Ki67 in PCNSL merit further study.

© Copyright 2003 American Society of Clinical Oncology All rights reserved worldwide