BCL2 expression in DLBCL: reappraisal of immunohistochemistry with new criteria for therapeutic biomarker evaluation

Abstract

Overexpression of the BCL2 is associated with a poor prognosis in diffuse large B-cell lymphoma (DLBCL). The assessment of MYC immunohistochemistry (IHC) is becoming optimized, whereas the criteria for BCL2 positivity are highly variable. Furthermore, data on the frequency and prognostic value of BCL2 positivity are conflicting. We aimed to evaluate BCL2 expression by IHC and assess the prognostic significance of the histopathologically scored BCL2 expression in 456 patients with DLBCL uniformly treated with standard immunochemotherapy (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone, R-CHOP). We initially designed 4-grade BCL2 scoring criteria, from 0 to 3+, and found that ∼40% of DLBCL showed strong BCL2 expression (score 3+). The scores from the pathologist's visual estimation were confirmed to be reliable using a digital image analysis. A retrospective survival analysis revealed that BCL2 score 3+ was a significant prognostic factor independent of the international prognostic index (IPI), the IHC-determined cell of origin, and the MYC protein/rearrangement status in a training set (n = 218). The adverse prognostic impact of BCL2 score 3+ was confirmed in a validation set (n = 238). We also developed a prognostic model consisting of 3 groups with a combined BCL2 score and MYC protein/rearrangement status. Patients with BCL2 score 3+ showed a higher treatment failure rate; therefore, alternative therapeutic strategies should be considered for these patients. A highly selective BCL2 inhibitor, venetoclax, was recently introduced as breakthrough therapy. Our BCL2 scoring system could readily be used by pathologists to evaluate patients with DLBCL who might benefit from BCL2-targeted therapies.

In situ BCL2 expression is an independent prognostic factor in HIV‐associated DLBCL, a LYMPHOVIR cohort study

“…Our findings reveal a strong independent unfavourable prognostic impact of BCL2 expression in PLHIV with DLBCL (HR: 4·48 95% CI: [1·00; 20·10], P = 0·05). These data are consistent with those of several studies in the HIV‐uninfected individuals with DLBCL in which patients were treated with a combined rituximab and doxorubicin‐based regimen (Hermine et al , ; Wilson et al , , ; Rosenwald et al , ; Hu et al , ; Tsuyama et al , ). In the light of our data, BCL2 expression determined by IHC, may allows the stratification of outcomes (Wilson et al , ; Barrans et al , ; Johnson et al , ).…”

“…Several tumour pathological markers are associated with overall survival in HIV‐negative DLBCL (Alizadeh et al , ; Hans et al , ; Nyman et al , ; Wilson et al , ; Lenz et al , ). BCL2 protein overexpression is a well‐established pejorative prognostic feature in HIV uninfected individuals with DLBCL, especially when combined with MYC overexpression or rearrangement (Hermine et al , ; Wilson et al , ; Rosenwald et al , ; Johnson et al , ; Horn et al , ; Tsuyama et al , ). However, the prognostic impact of BCL2 expression on outcomes in PLHIV and DLBCL is still a subject of debate (Little et al , ; Chadburn et al , ).…”

Risk Stratification Using Multivariable Fractional Polynomials in Diffuse Large B-Cell Lymphoma

“…A major limitation of the IPI system is that it does not allow the incorporation of newly discovered prognostic factors, most notably BCL2 and MYC. BCL2 and/or MYC expression in DLBCL is associated with aggressive behavior and poor prognosis (9,35,36,53). However, the proportional cut-off points of their expressions are still arbitrary, and a recent study has shown the importance of intensity of BCL2 expression as well as its extent (36).…”

“…BCL2 and/or MYC expression in DLBCL is associated with aggressive behavior and poor prognosis (9,35,36,53). However, the proportional cut-off points of their expressions are still arbitrary, and a recent study has shown the importance of intensity of BCL2 expression as well as its extent (36). To overcome this limitation and produce an objective, the continuous variable for measuring protein expression, multiplex IF for BCL2 and MYC with tumor marker CD20 was exploited.…”

“…We selected BCL2 and MYC as candidates for predictors because numerous studies on DLBCL have reported their association with poor prognosis (9,35,36). Although the proportions of 40 and 50% were generally considered as cut-off points for positivity in MYC and BCL2 IHC, respectively (2), it was mostly dependent on visual observation, and there have been controversies regarding various proportional cut-off points (36,37). Therefore, we employed a digital quantitative acquisition and analysis for the objective measurements of BCL2 and MYC expressions without dichotomization.…”