Table 2.

Biologic Factors Associated with Outcomes in Patients with DLBCL.^*

Biomarker	Methodology	Prognostic Significance	Other Implications
Cell-of-origin molecular classification	Various technologies (gene array, digital expression profiling, multiplex RT-PCR-based methods)	ABC subtype is associated with poor prognosis	ABC subtype may be associated with an increased risk of CNS relapse
Cell-of-origin IHC-based algorithms	Various IHC-based algorithms to assign molecular subtype; most commonly the Hans algorithm†	Non-GCB subtype is associated with poor prognosis, although this is not confirmed in some studies	Dichotomizes patients into GCB and non-GCB subgroups and represents an approximation of molecular subtype as assessed by GEP
Double- or triple-hit rearrangement involving MYC and either BCL2 or BCL6 or both	FISH is used primarily in clinical practice; the use of break-apart probes is recommended; GEP-based assays may identify additional cases with double-hit signature undetected by FISH with similar biologic features and outcome‡	Double- or triple-hit cases are associated with poor prognosis; poor prognosis may be limited to cases in which the MYC translocation partner is an immunoglobulin gene locus	Now classified by the WHO as high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements; majority of cases are GCB subtype; may benefit from more intensive therapies
MYC and BCL2 protein expression	IHC measurement to estimate the percentage of cells expressing MYC or BCL2 protein or both; 40% cutoff threshold for MYC and 50% for BCL2	Double expression of MYC and BCL2 or expression of BCL2 alone is associated with worse prognosis	May have prognostic significance mainly in GCB-type DLBCL; MYC-BCL2 double expression may be associated with an increased risk of CNS relapse
Proliferation index	IHC measurement of proliferation marker Ki67; no established cutoff threshold	Higher proliferation may be associated with poorer prognosis, although it has not consistently been shown to be an independent prognostic marker	High proliferation rate (>80%) may increase suspicion that patient has high-grade B-cell lymphoma (with or without double- or triple-hit rearrangements)
TP53	PCR, NGS, or gene array for detection of mutation or deletion of TP53	TP53 mutations in the DNA-binding domain are associated with poor prognosis	May cluster with a genetic subset of DLBCL
CDKN2A	Gene array, FISH, or PCR for detection of deletion of the CDKN2A locus or loss of the 9p21 region	Deletion of the CDKN2A locus or loss of the 9p21 is associated with poor prognosis	May cluster with some genetic subsets of DLBCL
MHC class II	IHC measurement of partial or complete loss of MHC class II expression	Loss of expression of MHC class II may be associated with a poor prognosis (more frequent in non-GCB subtype)	Primarily observed in primary mediastinal B-cell lymphoma and in tumors with EZH2 mutations
Lymphocyte count and lymphocyte:monocyte ratio	Measured in peripheral blood; low lymphocyte count (<1 × 109/liter) or low lymphocyte:monocyte ratio (various cutoff thresholds)	Low lymphocyte count or low lymphocyte:monocyte ratio is associated with poor prognosis	May have implications for immunebased therapies
Host genetics	Single nucleotide variation in 5q23.2 or 6q21 (PCR or single nucleotide polymorphism array)	Single nucleotide variation in 5q23.2 or 6q21 is associated with poor prognosis	Further investigation is needed

^*The list of select biologic factors correlated with outcomes in patients with DLBCL is based on reproducible observations, including validation in independent patient cohorts. NGS denotes next-generation sequencing, and RT-PCR reverse-transcriptase polymerase chain reaction.

^†The Hans algorithm is as follows: GCB: CD10+ or CD10−BCL6+MUM1−; non-GCB: CD10−BCL6−MUM1+ or CD10−BCL6+MUM1+ or CD10− BCL6−MUM1−.

^‡The information on methods for detecting additional cases with the use of a double-hit gene-expression signature is from Ennishi et al.⁴