Validation of the International Prognostic Index in Working Formulation group A low-grade non-Hodgkin's lymphoma: retrospective analysis of 137 patients from the Gruppo Italiano per lo Studio dei Linfomi registry
C. Stelitano et al., Validation of the International Prognostic Index in Working Formulation group A low-grade non-Hodgkin's lymphoma: retrospective analysis of 137 patients from the Gruppo Italiano per lo Studio dei Linfomi registry, HAEMATOLOG, 85(2), 2000, pp. 154-159
Background and Objectives. The subset of non-follicular non-Hodgkin's lymph
oma (NHL) includes patients with varied prognoses, thus suitable for differ
ent therapeutic approaches. The International Prognostic index (IPI), origi
nally proposed for aggressive NHL, has been demonstrated to be of prognasti
c relevance also in follicular NHL, The main aim of the study was to valida
te the IPI in this histologic category; in addition, the specific prognosti
c classification, currently employed in the Gruppo Italiano per lo Studio d
ei Linfoml (GISL) prospective therapeutic trials and based on different fea
tures, more similar to those applied to chronic lymphocytic leukemia, was a
nalyzed.
Design and Methods, The present series consists of 137 evaluable patients a
ffected by Working Fomrulation group A NHL out of 256 cases referred to the
GISL Registry. The retrospective prognostic study included the evaluation
by bath univariate and multivariate analyses of overall survival, response
to therapy and response duration. The IPI was applied as originally propose
d. The GISL definition of Indolent and aggressive disease at diagnosis was
based on the presence of B symptoms, bulky disease, anemia and thrombocytop
enia.
Results. The distribution of patients In IPI risk groups was rather unbalan
ced with 18%, 47%, 28% and 7% of cases classified as low (L), intermediate-
low (IL), intermediate-high (IH) and high (H) risk, respectively. The media
n overall survival was not reached In either L or IL risk groups, and was 8
4.1 and 7.4 months for IH and H risk groups, respectively (p=0.0005). A sim
plified IPI model was designed merging patients in both intermediate risk g
roups and the statistical difference of survival retained its significance.
GISL prognostic stratification was demonstrated to have a Significant asso
ciation with survival, with a median survival of 71.3 months In aggressive
disease and a median survival not reached at 152 months In Indolent disease
. Both the simplified IPI model and the GISL risk definition retained their
significance In multivariate analysis for overall survival, while for resp
onse to therapy only the simplified IPI model resulted to be of stattistica
l significance. In addition, the GISL prognostic stratification identified
patients with different outcomes within the IPI intermediate risk group, wi
th a median survival of 70.2 months for patients with aggressive disease wh
eras the median survival for those with Indolent disease was not reached. F
inally, a prognostic score resulting from the Integration of the simplified
IPI and the GISL system was statistically validated.
Interpretation and Conclusions. The retrospective analysis of this series d
emonstrates the validity of the IPI in non-follicular Indolent NHL and the
usefulness of integrating the IPI parameters with disease specific prognost
ic variables. (C) 2000, Ferrata Storti Foundation.