Abstract 283P
Background
Neoadjuvant therapy in early triple-negative breast cancer (eTNBC) with pembrolizumab and chemotherapy has become the new standard following the publication of KEYNOTE-522 study. While immune-related effects are expected with this treatment combination, it remains unclear if there are specific subgroups associated with increased risk of endocrine adverse events (AEs). We aimed to assess the risk of endocrine AEs in key patient subgroups undergoing neoadjuvant treatment for eTNBC.
Methods
We included consecutive pts between March 2022 and November 2023 in 11 centers across Argentina who underwent neoadjuvant chemotherapy and immunotherapy for eTNBC. Univariate and multivariate analyses including logistic regression were conducted to determine whether the rate of endocrine therapy AEs was associated with key specific subgroups, including age, pathological response, germinal BRCA status, tumor size, axillary clinical staging, and dose-dense anthracycline regimens. p < 0.05 was considered for statistical significance.
Results
A total of 143 pts were included from 13 centers. The median age was 47,2 years [IQR 23-79]. The incidence of all grade, G3/4, and immune-related adverse events (irAEs) were 89.5%, 41.2%, and 27.2%, respectively. 17 (11.8%) pts had treatment-associated hypothyroidism, and 12 (8.3%) cases reported secondary adrenal insufficiency/hypophysitis (SAI). No specific statistical associations were observed between specific subgroups and the incidence of irAEs, except for SAI. SAI was associated with younger patient age, with median ages of 38 [IQR 33.5-40.8] and 46 [38-56], for patients with and without a diagnosis of SAI, respectively (p=0.012).
Conclusions
In our real-world cohort, the incidence of secondary adrenal insufficiency/hypophysitis was higher than the reported results of the pivotal clinical trial. An interesting correlation was evidenced between patient age and this particular irAE. We anticipate that our discoveries will enhance recognition of this particular side effect. Additional research is required to assess the long-term impact of this irAE on quality of life.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
334P - Cardiovascular events related to CDK4/6 inhibitors: A systematic review and safety meta-analysis of randomized controlled trials
Presenter: Louis Boismoreau
Session: Poster session 14
335P - First-in-human phase I/IIa clinical trial of ZV0203, a novel pertuzumab-based antibody-drug conjugate (ADC), in patients (pts) with Her2 positive advanced solid tumors
Presenter: Fengjuan Lin
Session: Poster session 14
336P - Determination of the most common hereditary mutations associated with breast cancer and ovarian cancer in the population of Ukrainian women
Presenter: Dmytro Nehrulia
Session: Poster session 14
337P - Is presence of molecular residual disease after pathologic complete response associated with relapse in inflammatory breast cancer?
Presenter: Jennifer Chen
Session: Poster session 14
338TiP - EORTC-2129-BCG: Elacestrant for treating ER+/HER2- breast cancer patients with ctDNA relapse (TREAT ctDNA)
Presenter: Michail Ignatiadis
Session: Poster session 14
339TiP - A randomized trial of trastuzumab deruxtecan and biology-driven selection of neoadjuvant treatment for HER2-positive breast cancer (ARIADNE)
Presenter: Theodoros Foukakis
Session: Poster session 14
351P - Abemaciclib plus fulvestrant for HR+, HER2- advanced breast cancer following progression on a prior CDK4/6 inhibitor plus endocrine therapy: Subgroup analyses from the phase III postMONARCH trial
Presenter: Giampaolo Bianchini
Session: Poster session 14
352P - Cost-effectiveness of CDK4/6 inhibitors in first- vs second-line for advanced breast cancer (ABC) in the phase III SONIA trial (BOOG 2017-03)
Presenter: Noor Wortelboer
Session: Poster session 14
353P - Clinical outcomes of treatment with CDK4/6 inhibitors in metastatic breast cancer among carriers of germline pathogenic variants in ATM, BRCA1, BRCA2, CHEK2, and PALB2
Presenter: Robert Scheel
Session: Poster session 14