Abstract

Background: We reported that addition of rituximab (R) to chemotherapy significantly improves outcome in DLBCL patients (pt) >60 years (

JCO
24
:
3121
–27,
2006
). Although the IPI is a robust clinical prognostic tool in DLBCL, Sehn et al (ASH 2005: abstract 492) reported that a revised (R) IPI more accurately predicted outcome in pt treated with rituximab-chemotherapy.

Methods: We evaluated outcomes of the Intergroup study with respect to the standard IPI, R-IPI, age-adjusted (aa) IPI for evaluable pt treated with R-CHOP alone or with maintenance rituximab. We further assessed a modified IPI (mIPI) using age ≥ 70 y as a cutoff rather than age 60 y.

Results: The 267 pt in this analysis were followed for a median of 4 y. Pt characteristics were: age > 70 (48%) (median=69), male 52%, stage III/IV 75%, >1 EN site 30%, LDH elevated 60%, PS ≥2 15%. On univariate analysis all of these characteristics were significant for 3 y failure-free survival (FFS) and overall survival (OS). The IPI provided additional discrimination of risk compared to the R-IPI with significant differences in FFS and OS for 3 vs 4–5 factors. The aa-IPI defined relatively few pt as low or high risk. The impact of age was studied using a cut-off of 70 years in a modified IPI, yielding 4 risk groups as shown below.

Conclusions: For pt ≥ 60 treated with rituximab-chemotherapy the distinction between 3 vs 4,5 factors in the IPI was significant.The IPI also provided additional discrimination of risk compared to the R-IPI. In this older group of pt, use of an age cutoff ≥70 y placed more patients in the low risk category. It is of interest to apply the mIPI in other datasets with DLBCL pt >60 y.

Group# Factors #Pt% 3y FFS*% 3y OS*
*All risk groups significantly different; logrank p < 0.001 
**95 % CI: FFS (0.46,0.66), OS (0.58,0.78) 
***95 % CI: FFS (0.21,0.45), OS (0.31,0.55) 
L: Low, LI: Low Intermediate, HI: High Intermediate, H; High 
IPI     
0–1 12 78 83 
LI 28 70 80 
HI 33 56** 68** 
4–5 37 33*** 43*** 
R-IPI     
Very Good 
Good 1–2 40 72 81 
Poor 3–5 60 46 57 
aa-IPI     
12 78 83 
LI 35 68 78 
HI 44 47 59 
31 35 
mIPI (age ≥ 70)     
0–1 27 77 86 
LI 28 62 74 
HI 29 47 58 
4–5 16 28 36  
Group# Factors #Pt% 3y FFS*% 3y OS*
*All risk groups significantly different; logrank p < 0.001 
**95 % CI: FFS (0.46,0.66), OS (0.58,0.78) 
***95 % CI: FFS (0.21,0.45), OS (0.31,0.55) 
L: Low, LI: Low Intermediate, HI: High Intermediate, H; High 
IPI     
0–1 12 78 83 
LI 28 70 80 
HI 33 56** 68** 
4–5 37 33*** 43*** 
R-IPI     
Very Good 
Good 1–2 40 72 81 
Poor 3–5 60 46 57 
aa-IPI     
12 78 83 
LI 35 68 78 
HI 44 47 59 
31 35 
mIPI (age ≥ 70)     
0–1 27 77 86 
LI 28 62 74 
HI 29 47 58 
4–5 16 28 36  

Disclosure: No relevant conflicts of interest to declare.

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