Abstract 117P
Background
First-line (1L) treatment options for LS RASwt mCRC include the addition of epidermal growth factor receptor inhibitors (EGFRi) to chemotherapy (CT), supported by the overall survival advantage versus CT + bevacizumab (BEV) demonstrated recently in PARADIGM, the first phase 3 trial with pre-planned analysis by tumour side. Treatment selection and outcomes in Australasian routine practice has yet to be described.
Methods
Data from 1/2015 – 5/2023 on patients with LS RASwt mCRC who received 1L doublet CT for palliative intent was reviewed from TRACC, a prospective, multi-site Australasian registry. Baseline clinicopathological characteristics and survival outcomes were analysed with p ≤0.05 denoted as statistical significance.
Results
Of 676 LS RASwt, palliative intent, mCRC patients, 573 (85%) were actively treated, 404 (60%) receiving 1L doublet CT. Of these, 193 (48%) also received EGFRi and 120 (30%) also received BEV. Compared to BEV, patients receiving 1L EGFRi trended towards younger age (57 vs 61 years, p=0.07), were more often Stage IV at diagnosis (80% vs 70%, p=0.05), and less likely to have a BRAF mutant tumour (5% vs 17%, p=0.002). Median progression-free survival (PFS) was 11.7, 9.7 and 10.9 months for EGFRi + doublet CT, BEV + doublet CT and doublet CT alone respectively (HR 0.86 [0.67-1.12], p=0.06 for EGFRi + doublet CT versus BEV + doublet CT). Median overall survival (OS) was 38.1, 29.8 and 31.0 months for EGFRi + doublet CT, BEV + doublet CT and doublet CT alone respectively (HR 0.78 [0.58-1.07], p=0.12 for EGFRi + doublet CT versus BEV). Second-line (2L) PFS was similar for initial EGFRi (n=50 patients) then BEV versus opposite (n=32 patients) sequence (9.7 vs 8.0 months, p=0.55). Notably 24% of patients did not receive an EGFRi in 1L or 2L.
Conclusions
In Australasian practice, 1 in 2 patients with LS RASwt mCRC received 1L treatment with EGFRi + doublet CT, with trends toward improved PFS and OS versus BEV + doublet CT. 1 in 4 patients never received an EGFRi in 1L or 2L treatment, with further research required to understand clinician rationale for reserving active targeted treatments to later line settings.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
WEHI.
Funding
Merck.
Disclosure
V. Wong, B.B.Y. Ma: Financial Interests, Institutional, Research Funding: Merck Serono. All other authors have declared no conflicts of interest.
Resources from the same session
271P - Prostate cancer with histone modifier UTX mutations can benefit from olaparib
Presenter: NOBUHITO MURAMOTO
Session: Poster Display
Resources:
Abstract
272P - Comparison between MRI-targeted and standard biopsy for prostate cancer detection: A systematic review and meta-analysis
Presenter: Andree Kurniawan
Session: Poster Display
Resources:
Abstract
273P - The diagnostic performance of cognitive MRI-targeted biopsy in biopsy-naïve patients undergoing systematic 14-region 18-core biopsy: Do the three areas affect the results?
Presenter: Yuka Toyama
Session: Poster Display
Resources:
Abstract
274P - Index tumor location influencing early biochemical recurrence after radical prostatectomy in patients with negative surgical margins
Presenter: Jun Akatsuka
Session: Poster Display
Resources:
Abstract
275P - Prognosis of metastatic castration-resistant prostate cancer in response to chemotherapy and PSMA expression in circulating tumor cells
Presenter: Naoya Nagaya
Session: Poster Display
Resources:
Abstract
276P - Prognostic significance of p53 mutation in metastatic hormone-sensitive prostate cancer
Presenter: Lakshmi Kamala
Session: Poster Display
Resources:
Abstract
277P - Vasohibin-1 expression as a biomarker of aggressive growth in prostate ductal adenocarcinoma
Presenter: Murad Salomov
Session: Poster Display
Resources:
Abstract
278P - Full-coverage radiotherapy for prostate cancer patients with oligometastases
Presenter: Bichun Xu
Session: Poster Display
Resources:
Abstract
279P - Hypofractionated radiotherapy protocol implementation and early outcomes for prostate cancer patients: A single institution retrospective review
Presenter: Thu Nguyen
Session: Poster Display
Resources:
Abstract
280P - Radium-223 for patients with metastatic castration-resistant prostate cancer with symptomatic bone metastases progressing after first-line abiraterone or enzalutamide: One institutional experience
Presenter: Keng Man Chiang
Session: Poster Display
Resources:
Abstract