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
529P - Ramucirumab plus docetaxel after combination chemoimmunotherapy in patients with non-small cell lung cancer: A prospective observational study
Presenter: Tadaaki Yamada
Session: Poster Display
Resources:
Abstract
530P - MYC recruits tumor-associated macrophage to sustain metastatic malignancy of lung adenocarcinoma micropapillary subtype through epigenetic reprogramming
Presenter: Xuming Song
Session: Poster Display
Resources:
Abstract
531P - Effect of combinational targeted therapy for AXL and ATR against malignant mesothelioma cells
Presenter: Soichi Hirai
Session: Poster Display
Resources:
Abstract
532P - The changes of the serum SMRP levels is useful to predict the antitumor efficacy of ipilimumab plus nivolumab combination therapy in patients with malignant pleural mesothelioma
Presenter: Taiichiro Otsuki
Session: Poster Display
Resources:
Abstract
533P - Efficacy in the elderly NSCLC patients in SCORPION study: Phase II study of DTX plus RAM following platinum-based chemotherapy plus ICIs
Presenter: Teppei Yamaguchi
Session: Poster Display
Resources:
Abstract
534P - DSC2 promotes the proliferation, metastasis and drug resistance of lung cancer by activating the PI3K/AKT pathway
Presenter: Qi Li
Session: Poster Display
Resources:
Abstract
535P - Alteration in NKX2-1 CN reshapes the oncogenic, immunologic, and prognostic landscapes in NSCLC
Presenter: Herdee Gloriane Luna
Session: Poster Display
Resources:
Abstract
536P - The evaluation and long-term outcome of pulmonary metastasectomy for osteosarcoma: A 20-year experience of Shanghai Rujin Hospital
Presenter: Zhusheng Zhang
Session: Poster Display
Resources:
Abstract
537P - The impact of treatment-free interval on patient outcome after pulmonary metastasectomy for sarcoma
Presenter: Po-Kuei Hsu
Session: Poster Display
Resources:
Abstract
538P - First-line chemoimmunotherapy for metastatic thymic carcinoma
Presenter: Victoria Andreas
Session: Poster Display
Resources:
Abstract