Prognostic value of Bcl2 and p53 in Hodgkin lymphoma: A systematic review and meta-analysis

Aims: Several studies suggested that high expression of Bcl2 and/or p53 in Hodgkin/Reed-Sternberg cells is an unfavorable prognostic factor in Hodgkin lymphoma (HL). However, results in this field appear contrasting. We aimed to assess the prognostic value of p53 and Bcl2 in HL through a systematic review and meta-analysis. Methods: Electronic databases were searched from January 2000 to December 2020 for all studies assessing the prognostic value of p53 and Bcl2 in HL. The association of high p53 or Bcl2 expression with overall survival (OS), progression-free survival (PFS) and response to treatment was assessed by using hazard ratio (HR) and odds ratio (OR). Results: Eighteen studies were included. Bcl2 overexpression was significantly associated with decreased PFS (HR = 2.202; p < 0.0001), while the associations with decreased OS (HR = 1.565; p = 0.257) and refractoriness to treatment (OR = 0.482; p = 0.068) were non-significant. p53 overexpression was not significantly associated with refractoriness to treatment (OR = 0.904; p = 0.155); the analysis of OS and PFS was not feasible, but published data suggested the absence of a significant association. Conclusions: In HL, Bcl2 overexpression is associated with decreased PFS, while a significant prognostic value could not be demonstrated for p53. Defining optimal criteria for interpreting Bcl2 and p53 immunostaining is necessary to draw definitive conclusions.