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TP53 Sequencing and p53 Immunohistochemistry Predict Outcomes When Bevacizumab Is Added to Frontline Chemotherapy in Endometrial Cancer: An NRG Oncology/Gynecologic Oncology Group Study
Journal article   Open access   Peer reviewed

TP53 Sequencing and p53 Immunohistochemistry Predict Outcomes When Bevacizumab Is Added to Frontline Chemotherapy in Endometrial Cancer: An NRG Oncology/Gynecologic Oncology Group Study

Kristina W Thiel, Eric J Devor, Virginia L Filiaci, David Mutch, Katherine Moxley, Angeles Alvarez Secord, Krishnansu S Tewari, Megan E McDonald, Cara Mathews, Casey Cosgrove, …
Journal of clinical oncology, Vol.40(28), pp.3289-3300
06/03/2022
DOI: 10.1200/JCO.21.02506
PMCID: PMC9553389
PMID: 35658479
url
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9553389View
Published (Version of record) Open Access

Abstract

The status of p53 in a tumor can be inferred by next-generation sequencing (NGS) or by immunohistochemistry (IHC). We examined the association between p53 IHC and sequence and whether p53 IHC alone, or integrated with NGS, predicts the outcome. From GOG-86P, a randomized phase II study of chemotherapy combined with either bevacizumab or temsirolimus in advanced endometrial cancer, 213 cases had p53 protein expression data measured by IHC and NGS data. An analysis was designed to integrate p53 expression by IHC with the presence or absence of a mutation. These variables were further correlated with progression-free survival (PFS) and overall survival (OS) in the chemotherapy plus bevacizumab arms versus the chemotherapy plus temsirolimus arm. In the analysis of p53 IHC, the most striking treatment effect favoring bevacizumab was in cases where p53 was overexpressed (PFS hazard ratio [HR]: 0.46, 95% CI, 0.26 to 0.88; OS HR: 0.31, 95% CI, 0.16 to 0.62). On integrated analysis, patients with missense mutations and p53 protein overexpression had a similar treatment effect on PFS (HR: 0.41, 95% CI, 0.22 to 0.83) and OS (HR: 0.28, 95% CI, 0.14 to 0.59) favoring bevacizumab plus chemotherapy relative to temsirolimus plus chemotherapy. Concordance between NGS and p53 IHC was 88%. Concordance was 92% when cases with mutations and mutations or mismatch repair deficiency were removed. IHC for p53 alone or when integrated with sequencing for identifies a specific, high-risk tumor genotype/phenotype for which bevacizumab is particularly beneficial in improving outcomes when combined with chemotherapy.

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