The high frequency and exclusive occurrence of deletions involving p16 in the progressed DLCLs suggests that genetic loss at 9p21 targeting p16 and/or p15 is an important secondary genetic event in the histologic progression of FCL.
Interestingly, the methylation frequency of the CDH13 gene was comparable to those of the tumor suppressor genes p15 (68%) and p16 (74%) detected in B-DLCLs.
Among all patients with DLBCL, there was no significant difference in the overall survival between those with hypermethylated and unmethylated p15 (P=0.442) or between those with hypermethylated and unmethylated p16 (P=0.468).