Prognostic value of Bcl2 and Bcl6 in primary cutaneous large B-cell lymphoma: A systematic review and meta-analysis

Aims: To assess the prognostic value of Bcl2 and Bcl6 in primary cutaneous diffuse large B-cell lymphoma (pcDLBCL), through a systematic review and meta-analysis. Methods: Electronic databases were searched from their inception to April 2021 for studies reporting Bcl2 and Bcl6 expression and survival outcomes in pcDLBCL series. Kaplan-Meier and Cox regression survival analyses with hazard ratio calculation were performed for overall survival (OS), with a significant p-value< 0.05. Results: Eight studies with 148 patients were included. OS was significantly decreased in Bcl2-pos itive pcDLBCLs (5-year OS= 52.9 +/- 5.2%) compared to Bcl2 negative pcDLBCLs (5-year OS= 86.6 +/- 7.2%), with a HR of 4.615 (95% CI, 1.827-11.657; p = 0.001); no significant difference in OS was found between Bcl6-positive pcDLBCLs (5-year OS= 61.3 +/- 6.5%) and Bcl6-negative pcDLBCLs (5-year OS= 56.8 +/- 7.2%), with a HR of 0.789 (95% CI, 0.462-1.350; p = 0.388). Conclusions: In pcDLBCL, Bcl2 expression is a strong unfavourable prognostic marker; Bcl6 does not seem to be associated with survival instead. Further studies are necessary in this field.