Abstract 5123
Background
Hotspot mutations (HSM) in TP53 (R175, Y220, G245; R248, R273) have been recognized as potential immunoreactive neoantigens able to achieve intratumoral T cell responses in advanced ovarian cancer, particularly in high-grade serous ovarian cancer (HGSOC). The purpose of this study was to assess if HSM, Non-HSM (missense non-HSM) and Other (INDELs, stop gained, splice site) somatic mutations in TP53, confer differential survival outcomes. Presence of circulating p53-autoantibodies (p53-AAbs) was also tested and correlated with TP53 mutation spectra.
Methods
A series of 83 patients (71 HGSOC) with advanced (III-IV stage, G2-3) ovarian cancer, treated with primary debulking surgery and platinum-based therapy, were retrospectively enrolled. Characterization of TP53 mutations in chemo-naïve tumours was performed with a targeted next-generation sequencing approach. An ELISA kit was used to detect p53-AAbs. Platinum-free interval (PFI), progression-free survival (PFS) and Overall survival (OS) were compared using Kaplan-Meier, Log-rank test and Cox proportional hazard models (adjusted for age, stage, serous subtype, residual tumour).
Results
Somatic mutations in TP53 were found in 74.7% of patients; among them, 71% was -p53-AAbs and 29% was +p53-AAbs. The repertoire of TP53 mutations was significantly different according to p53-AAbs (p = 0.005), with prevalence of Other mutations (50%) in patients -p53-AAbs. In multivariate analysis (WT as the ref. category), patients with: i) Non-HSM mutations had reduced PFI (p = 0.026), PFS (p = 0.014) and OS (p = 0.048); ii) Other mutations had reduced PFI (p = 0.002) and PFS (p = 0.007), but not OS (p = 0.062); iii) HSM mutations were not associated with PFI (p = 0.605), PFS (p = 0.681) and OS (p = 0.437).
Conclusions
Molecular profile of chemo-naïve tumours in advanced ovarian cancer showed different outcomes coupled to specific TP53 signatures. A more aggressive mutational profile in TP53 was observed in patients without p53-AAbs. Non-synonymous mutated neoantigens arised from tumour clones, appear to be critical to identify patients best suited to immunotherapy. Further investigations in the tumour microenvironment are needed to confirm these preliminary findings.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Giorgio Giorda.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3879 - Efficacy of derazantinib (DZB) in patients (pts) with intrahepatic cholangiocarcinoma (iCCA) expressing FGFR2-fusion or FGFR2 mutations/amplifications
Presenter: Michele Droz Dit Busset
Session: Poster Display session 2
Resources:
Abstract
4679 - It’s Not Only About Weight Loss: Tackling Pancreatic Cancer-Associated Cachexia
Presenter: Ana Leonor Matos
Session: Poster Display session 2
Resources:
Abstract
2276 - Frequency and clinicopathological characteristics of biliary tract carcinomas harboring the FGFR2-fusion gene: a prospective observational study (PRELUDE study)
Presenter: Masafumi Ikeda
Session: Poster Display session 2
Resources:
Abstract
2773 - Post-hoc analyses of a subgroup of patients with advanced biliary tract cancer (BTC) who crossed over to treatment with etoposide toniribate (EDO-S7.1) in a randomized Phase II study
Presenter: Ulrich-Frank Pape
Session: Poster Display session 2
Resources:
Abstract
4479 - Capecitabine +Best supportive care (BSC) or Erlotinib +BSC has Overall survival (OS) benefit over BSC alone in unresectable/metastatic Gall bladder cancer(GBC) patients with ECOG PS-III. Results from a phase II Randomised controlled trial (RCT)
Presenter: Babita Kataria
Session: Poster Display session 2
Resources:
Abstract
4843 - FGFR2 fusions and its effect of patient (pt) outcomes in intrahepatic cholangiocarcinoma (iCCA)
Presenter: Daniel Almquist
Session: Poster Display session 2
Resources:
Abstract
2324 - The Clinical Outcomes of Systemic Chemotherapy in Patients with Unresectable or Metastatic Combined Hepatocellular-cholangiocarcinoma (HCC-CCA): Retrospective Study of 120 Patients
Presenter: Eojin Kim
Session: Poster Display session 2
Resources:
Abstract
3678 - High PD-L1 expression is associated with treatment response to pembrolizumab in patients with advanced biliary tract cancer.
Presenter: Gilhyang Kim
Session: Poster Display session 2
Resources:
Abstract
3901 - Genomic profiling in Chinese biliary tract cancer patients with PI3K/AKT/mTOR pathway and RAS gene mutations
Presenter: Jingyu Cao
Session: Poster Display session 2
Resources:
Abstract
4390 - Phase II trial of trifluridine/tipiracil (TAS-102) in patients with advanced refractory biliary tract cancer (BTC)
Presenter: Sakti Chakrabarti
Session: Poster Display session 2
Resources:
Abstract