Abstract 124P
Background
BRAF V600E is identified approximately 5-9% of colorectal cancer (CRC) patients. Non-V600E BRAF mutation is characterized a rare molecular subtype. The clinical characteristics and prognostic impact of non-V600 BRAF mutants are not well defined.
Methods
We recruited 829 patients with CRC from our institution. Tissue samples were molecularly tested. Clinical data was retrospectively reviewed and analyzed using Chi-square and t-test. Overall survival (OS) was compared by log-rank test.
Results
All BRAF mutation was detected in 50 (6%) patients including 24 (3%) patients with non-V600 mutations. Patient characteristics and BRAF testing technique were not significantly different based on BRAF status and it was comparable between BRAF V600E and non-V600 groups. There were significantly more ALL RAS and PIK3CA mutations in non-V600 mutant patients. Patients with non-V600 mutation had median OS of 82 months which was longer than BRAF WT, 66 months, and 31 months of BRAF V600E group, respectively (P=0.067). OS according to treatment with anti-EGFR in metastatic CRC patients was not significantly different in both V600E and non-V600 BRAF mutant groups. Table: 124P
| BRAF-MT (n=50) | |||||||
| BRAF-WT (n=779) | BRAF-MT (n=50) | p-value | V600 (n=26) | non-V600 (n=24) | p-value | ||
| Age | 63 (18 - 93) | 65 (19-85) | 66 (19 - 85) | 65 (24 - 83) | |||
| Sex | |||||||
| Male | 471 (60) | 32 (64) | 0.62 | 15 (58) | 17 (71) | 0.333 | |
| Female | 308 (40) | 18 (36) | 11 (42) | 7 (29) | |||
| Sidedness | |||||||
| Left | 591 (76) | 33 (66) | 0.289 | 12 (70) | 15 (62) | 0.878 | |
| Right | 168 (22) | 15 (30) | 7 (27) | 8 (33) | |||
| non-specify | 20 (3) | 2 (4) | 1 (4) | 1 (4) | |||
| Technique | |||||||
| NGS | 547 (70) | 38 (76) | 0.466 | 18 (69) | 20 (83) | 0.26 | |
| Pyrosequencing | 84 (11) | 6 (12) | 5 (19) | 1 (4) | |||
| PCR | 148 (19) | 6 (12) | 3 (12) | 2 (12) | |||
| All RAS mutation | 418 (54) | 8 (16) | <0.001 | 0 | 8 (33) | 0.001 | |
| PIK3CA mutation | 94 (12) | 9 (18) | 0.218 | 1 (4) | 8 (33) | 0.009 | |
| Recur/Met | (n=575) | (n=35) | (n=19) | (n=16) | |||
| Anti-VEGF | 105 (18) | 7 (20) | 0.796 | 2 (11) | 5 (31) | 0.207 | |
| Anti-EGFR | 162 (28) | 6 (17) | 0.156 | 3 (16) | 3 (19) | 1 |
Conclusions
Non-V600 BRAF mutation may indicate better prognosis. The difference in treatment effect was not demonstrated in patients with BRAF mutation.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Faculty of medicine Ramathibodi Hospital.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
602P - COLUMBUS 7-year update: A randomized, open-label, phase III trial of encorafenib (Enco) + binimetinib (Bini) vs vemurafenib (Vemu) or Enco in patients (Pts) with BRAF V600-mutant melanoma
Presenter: Andrew Haydon
Session: Poster Display
Resources:
Abstract
603P - An individualised postoperative radiological surveillance schedule for IDH-wildtype glioblastoma patients (HK-GBM Registry)
Presenter: Jason Chak Yan Li
Session: Poster Display
Resources:
Abstract
604P - Cabozantinib versus placebo in patients with radioiodine-refractory differentiated thyroid cancer who progressed after prior VEGFR-targeted therapy: Outcomes from COSMIC-311 by BRAF status
Presenter: Marcia Brose
Session: Poster Display
Resources:
Abstract
606P - BRAF and NRAS mutations are associated with poor prognosis in Asians with acral-lentiginous and nodular cutaneous melanoma
Presenter: Sumadi Lukman Anwar
Session: Poster Display
Resources:
Abstract
607P - Single institutional outcomes of radiotherapy and systemic therapy for melanoma brain metastases in Japan
Presenter: Naoya Yamazaki
Session: Poster Display
Resources:
Abstract
608P - The efficacy of immune checkpoint inhibitors and targeted therapy in mucosal melanomas: A systematic review and meta-analysis
Presenter: Andrea Teo
Session: Poster Display
Resources:
Abstract
609P - The association between thyroid function abnormalities and vitiligo induced by pembrolizumab regarding prognosis in patients with advanced melanoma
Presenter: Moez Mobarek
Session: Poster Display
Resources:
Abstract
610P - Analyzing the clinical benefit of the evidence presented at these congresses and utilizing a standardized scale to quantify it will significantly enhance our understanding of the studies showcased, allowing for more objective evaluation and interpretation
Presenter: Charles Jeffrey Tan
Session: Poster Display
Resources:
Abstract
611P - ESMO-magnitude of clinical benefit scale (MCBS) scores for phase III trials of adjuvant and curative therapies at the 2022 ASCO annual meeting (ASCO22)
Presenter: Thi Thao Vi Luong
Session: Poster Display
Resources:
Abstract
612P - Is the juice worth the squeeze? Overall survival gain per unit treatment time as a metric of clinical benefit of systemic treatment in incurable cancers
Presenter: Vodathi Bamunuarachchi
Session: Poster Display
Resources:
Abstract