Abstract 120P
Background
Cetuximab (Cet) plus chemotherapy (CT) has been approved as preferred first-line (1L) treatment for left-sided (LS) metastatic colorectal cancer (mCRC) with wild-type (wt) RAS/BRAF gene. However, it remains uncertain whether Cet is beneficial as maintenance therapy after 1L treatment. This study aimed to investigate the clinical outcomes for maintenance therapy in pts with LS RAS/BRAF wt mCRC who responded to 1L Cet plus CT.
Methods
We performed a retrospective review of pts with LS RAS/BRAF wt mCRC who had disease controlled (CR, PR or SD) after 6 cycles of Cet based induction therapy from JAN 2018 to JUN 2022 at HuNan Cancer Hospital. The 1L regimen consists of Cet plus mFOLFOX6 or FOLFIRI, based on pts selection, followed by maintenance therapy with Cetuximab with or without chemotherapy (cohort A) or chemotherapy alone (cohort B). Death data were obtained from the government's death registry. Kaplan-Meier methods were employed to describe overall survival (OS) and progression-free survival (PFS).
Results
A total of 125 pts were included in this study, with 72 (57.6%) in cohort A and 53 (42.4%) in cohort B. The median age was 58 years (range: 23-76), and 86 (68.8%) were male. The most common site of metastasis was the liver (90 patients, 72.0%). During a median follow-up of 32.6 m, the median OS from the start of 1L therapy was significantly longer in cohort A (46.4 m, 95% CI 40.1-NA) than in cohort B (31.1 m, 95% CI 27.6-38.0; p < 0.0001). Similarly, cohort A (14.2 m, 95% CI 12.4-17.0) had a significantly longer median PFS than cohort B (11.0 m, 95% CI 9.6-11.7; p=0.021). The Cox proportional hazards model, after adjusting for age, sex, primary tumor location, metastatic site, and whether the primary tumor and metastases were resected or not, showed that compared with cohort B, cohort A was associated with a statistically significant longer OS (HR 0.43, 95% CI 0.25-0.73) and a longer PFS, although the difference was not statistically significant (HR 0.70, 95% CI 0.44-1.12).
Conclusions
Maintenance therapy with Cet can significantly improve OS in pts with LS RAS/BRAF wt mCRC and lead to a clinically meaningful improvement in PFS, although the statistical difference was not reached.
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
383P - Pre-treatment body mass index and neutrophil lymphocyte ratio predict 3-years progression free survival in locally advanced stage nasopharyngeal carcinoma
Presenter: Ni Putu Pusvita Dewi
Session: Poster Display
Resources:
Abstract
384P - Sequential multi-modality strategies for locally advanced betel-nuts related hypopharyngeal cancer in Taiwan
Presenter: Wei-Chen Lu
Session: Poster Display
Resources:
Abstract
385P - The prognostic factors of induction chemotherapy followed by concurrent chemoradiotherapy in patients with HPV associated with oropharyngeal cancer
Presenter: Hyun Jin Bang
Session: Poster Display
Resources:
Abstract
386P - FOLR1 stabilized beta-catenin promotes laryngeal carcinoma progression through EGFR signal
Presenter: Huawei Tuo
Session: Poster Display
Resources:
Abstract
387P - A comprehensive analysis of the oral health status, tobacco use, and cancer prevalence among the tribal communities in India
Presenter: Delfin Lovelina Francis
Session: Poster Display
Resources:
Abstract
388P - Clinicopathological correlation of P53 expression in oral cancers
Presenter: Venkata Madhavi Bellala
Session: Poster Display
Resources:
Abstract
389P - Lack of cross-resistance to erlotinib in human head and neck cancer cells with acquired resistance to cetuximab
Presenter: James A. Bonner
Session: Poster Display
Resources:
Abstract
390P - Epidemiological aspects of the development of oral cancer in the Republic of Uzbekistan
Presenter: Akhrorbek Yusupbekov
Session: Poster Display
Resources:
Abstract
391P - Lip cancer: Racial disparities, treatment modalities and long-term survival outcome in young and adults versus older age patients
Presenter: FathAlrahman Ibrahim
Session: Poster Display
Resources:
Abstract
392TiP - A prospective phase II study of individualized adjuvant therapy in patients with locally advanced hypopharyngeal cancer after neoadjuvant therapy
Presenter: Juyi Wen
Session: Poster Display
Resources:
Abstract