Dynamic predictive power of TP53 signatures in breast cancer prognosis: Pre- and post-neoadjuvant chemotherapy insights

Background

The TP53 signature determined using a biopsy specimen before neoadjuvant chemotherapy (pre-NAC biopsy specimens) predicts NAC response and prognosis in breast cancer. We aimed to compare the clinical utility of the TP53 signature determined using pre-NAC biopsy specimens and surgical specimens after NAC (post-NAC surgical specimens).

Methods

This observational cohort study included patients with paired pre-NAC biopsy and post-NAC surgical specimens, analyzing the association between the TP53 signature from each specimen and prognosis (UMIN000042055).

Results

Pre-NAC biopsy specimens classified 71 patients into those having a TP53 mutant signature (pre-mt, n = 47) and wild-type signature (pre-wt, n = 24), with the same for post-NAC surgical specimens (post-mt, n = 16 and post-wt, n = 55). Among the 47 pre-mt patients, 31 became post-wt (pre-mt/post-wt), whereas 16 remained post-mt (pre-mt/post-mt). All pre-wt patients remained post-wt (pre-wt/post-wt). Recurrence-free survival (RFS) was significantly shorter in the pre-mt group than in the pre-wt group, although no significant difference was observed between the post-mt and post-wt groups. Change in the TP53 signature following NAC did not affect predictive ability of the TP53 signature determined using pre-NAC biopsy specimens.

Conclusions

The TP53 signature status should be determined using pre-NAC biopsy specimens.