Abstract 3364
Background
RAS mutational status is an essential criterion to guide first-line treatment in metastatic colorectal cancer (mCRC). MORE-RAS was a multicenter, multicountry, observational, ambispective (retrospective + prospective) study conducted in the Middle East and North Africa (MENA) region to assess RAS testing practices and tumor characteristics in newly diagnosed patients (pts) with mCRC. Results of the retrospective analysis are presented here.
Methods
Eligible pts included adults aged ≥18 with mCRC who had already initiated first-line therapy, had at least 1 post-baseline visit for disease evaluation, and had available survival data. Pts with incomplete and unavailable data or presence of other coexisting malignancies were excluded. Data from eligible pts were retrospectively analysed 2 years back from the day of patient consent.
Results
A total of 495 pts (median age: 57 y) were enrolled; majority were male (55.6%), with adenocarcinoma histology, stage IV disease (86.8%) and left-sided tumors (79%). Primary tumor site was sigmoid (40.9%), followed by rectal (26.1%), ascending (17.2%), descending (12.1%), and transverse (3.8%) colon. RAS testing was requested in 417 (78%) pts; reasons for not prescribing included test unavailability, financial/medical decision, or other. Testing samples were mostly paraffin-embedded (91.7%) primary tumors (92.5%); sequencing was the most common test method used. RAS testing found that 33.9% of tumors harbored mutations and 66.1% carried wild-type (WT) sequences. The most common mutation was KRAS (94.1%), occurring largely in Exon2-Codon12 (70.5%). RAS testing was typically prescribed after initiation of first-line treatment, significantly more in pts with stage IV disease (p < 0.005), resulted in addition of targeted therapy (41.8% anti EGFR, 30.2% anti VEGF) in WT mCRC, and significantly impacted treatment strategy of left-sided tumors (p = 0.037).
Conclusions
RAS testing for mCRC in the MENA region was often performed after first-line treatment. The dominance of WT RAS in this region is distinct from the mutational pattern reported in Western countries.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Amgen.
Funding
Amgen.
Disclosure
M. Oukkal: Advisory / Consultancy, Speaker Bureau / Expert testimony: Amgen; Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (self): Roche; Advisory / Consultancy: Novartis; Advisory / Consultancy: Pfizer; Speaker Bureau / Expert testimony: Bayer; Speaker Bureau / Expert testimony: Ipsen. H. Mahfouf: Advisory / Consultancy, Speaker Bureau / Expert testimony: Amgen; Advisory / Consultancy, Speaker Bureau / Expert testimony: Roche; Advisory / Consultancy, Speaker Bureau / Expert testimony: Merck; Advisory / Consultancy, Speaker Bureau / Expert testimony: Bayer; Advisory / Consultancy: Ipsen. A. Ouamer: Full / Part-time employment: Amgen. L. Bashir: Full / Part-time employment: Amgen. All other authors have declared no conflicts of interest.
Resources from the same session
5203 - Novel fusion genes identified from matched primary and recurred breast cancers by RNA-sequencing
Presenter: Soojeong Choi
Session: Poster Display session 2
Resources:
Abstract
5873 - Association between PIK3CA mutation status and development of brain metastases in HR+/HER2- metastatic breast cancer
Presenter: Donna Fitzgerald
Session: Poster Display session 2
Resources:
Abstract
3588 - The role of AXL as mechanism of resistance to trastuzumab and a prognostic factor in breast cancer HER2 positive: a translational approach.
Presenter: Anna Adam-Artigues
Session: Poster Display session 2
Resources:
Abstract
5640 - Untargeted assessment of tumor fractions in plasma for monitoring and prognostication from metastatic breast cancer patients undergoing systemic treatment
Presenter: Marija Balic
Session: Poster Display session 2
Resources:
Abstract
2616 - Clinical application of mutational analysis in breast cancer patients: the relevance of PIK3CA analysis for precision medicine.
Presenter: Juan Miguel Cejalvo
Session: Poster Display session 2
Resources:
Abstract
3870 - A retrospective gene expression analysis of surgically-removed Breast Cancer Brain Metastasis (BCBM)
Presenter: Meritxell Mallafré-Larrosa
Session: Poster Display session 2
Resources:
Abstract
1240 - Endocrine therapy alone versus targeted combination strategy as first line treatment in elderly patients with hormone receptor-positive advanced breast cancer: meta-analysis of Phase II and III randomized clinical trials
Presenter: Claudia Omarini
Session: Poster Display session 2
Resources:
Abstract
5535 - Alpelisib (ALP) + fulvestrant (FUL) for patients with hormone receptor–positive (HR+), HER2− advanced breast cancer (ABC): management and time course of key adverse events of special interest (AESIs) in SOLAR-1
Presenter: Hope Rugo
Session: Poster Display session 2
Resources:
Abstract
3093 - Changes in Hormone-Receptor status in Luminal breast cancers between primary tumor and metastases: results of the observational cohort GIM-13 AMBRA Study
Presenter: Marina Cazzaniga
Session: Poster Display session 2
Resources:
Abstract
1378 - MONARCH 3: Updated time to chemotherapy and disease progression following abemaciclib plus aromatase inhibitor (AI) in HR+, HER2- advanced breast cancer (ABC)
Presenter: Miguel Martín
Session: Poster Display session 2
Resources:
Abstract