At a median follow-up of 15.6 years, BCL2 and TP53 (in both TU and LN) were significantly associated with OS but only in the first 5 years. Likewise, BCL2 and TP53 (in both TU and LN) were associated with EFS in the first 2 years after randomization, with no association after 2 years. BCL2 and TP53 remained statistically significant after adjustment for the standard clinical–pathological characteristics in regard to OS and EFS in the respective first years after randomization, (p value < 0.001 for both markers).
Furthermore, an interaction was found between high BCL2 expression in the TU (but not in LN) and benefit to CMF over anthracycline-based chemotherapy (interaction p value EFS: 0.042; OS = 0.01). No interaction was found for TP53 expression neither in TU nor in LN.
We conclude that BCL2 and TP53 were predictive biomarkers for better and worse survival respectively, but only in the first two to five years after diagnosis. BCL2 expression in the TU but not in the LN was predictive of increased benefit to CMF vs anthracycline-based chemotherapy.