Ann Oncol. 2024 May 02. pii: S0923-7534(24)00128-5. [Epub ahead of print]
S Pignata,
D Califano,
D Lorusso,
L Arenare,
M Bartoletti,
U De Giorgi,
C Andreetta,
C Pisano,
G Scambia,
D Lombardi,
A Farolfi,
S Cinieri,
A Passarelli,
V Salutari,
C De Angelis,
C Mignogna,
D Priolo,
E D Capoluongo,
S Tamberi,
G L Scaglione,
V Arcangeli,
R De Cecio,
G Scognamiglio,
F Greco,
A Spina,
M Turinetto,
D Russo,
V Carbone,
C Casartelli,
C Schettino,
F Perrone.
BACKGROUND: Immunotherapy combined with chemotherapy significantly improves progression-free survival compared to first-line chemotherapy alone in advanced endometrial cancer, with a much larger effect size in microsatellite-instability high (MSI-H) cases. New biomarkers might help to select patients that may have benefit among those with a microsatellite-stable (MSS) tumor.
METHODS: In a pre-planned translational analysis of the MITO END-3 trial, we assessed the significance of genomic abnormalities in patients randomized to standard carboplatin/paclitaxel without or with avelumab.
RESULTS: Out of 125 randomized patients, 109 had samples eligible for next-generation sequencing (NGS) analysis, and 102 had MSI tested. According to The Cancer Genome Atlas (TCGA), there were 29 cases MSI-H, 26 MSS TP53 wild-type (wt), 47 MSS TP53 mutated (mut), and one case with POLE mutation. Four mutated genes were present in more than 30% of cases: TP53, PIK3CA, ARID1A, and PTEN. Eleven patients (10%) had a BRCA1/2 mutation (five in MSI-H and six in MSS). High TMB (≥10 Muts/Mb) was observed in all MSI-H patients, in four out of 47 MSS/TP53 mut, and no case in the MSS/TP53 wt category. The effect of avelumab on progression-free survival significantly varied according to TCGA categories, being favorable in MSI-H and worst in MSS/TP53 mut (P interaction=0.003); a similar non-significant trend was seen in survival analysis. ARID1A and PTEN also showed a statistically significant interaction with treatment effect, which was better in the presence of the mutation (ARID1A P interaction=0.01; PTEN P interaction=0.002).
CONCLUSION: The MITO END-3 trial results suggest that TP53 mutation is associated with a poor effect of avelumab, while mutations of PTEN and ARID1A are related to a positive effect of the drug in patients with advanced endometrial cancer.
Keywords: Avelumab; Cancer Genome Atlas; Chemotherapy; Endometrial Cancer; Next Generation Sequencing