Outcomes of early onset colorectal cancer (EOCRC) with synchronous liver oligometastasis.

Abstract

e15599 Background: Screening and removal of pre-malignant adenomas has reduced CRC incidence in adults older than 50 years (later onset CRC [LOCRC]), but EOCRC incidence has increased by 1-2% annually since the 1990s. The liver is the commonest site of CRC metastasis, and EOCRC presents with more advanced stage compared with LOCRC. Oligometastasis (OM) refers to potentially resectable CRC, and complete resection of CRC primary and OM is associated with improved survival and potential cure. Here, we examined treatment outcomes of EOCRC with synchronous liver oligometastases (sLiOM) at our institution. Methods: We performed a retrospective review of institutional electronic health records and identified 160 EOCRC patients with sLiOM treated with curative intent in the last decade. Demographics, treatment, and follow up data were recorded, and analysis for survival outcomes performed. The study protocol was exempt after review by Mayo Clinic institutional review board. Results: Of 160 patients, median age at diagnosis was 43 years. Primary tumor was in the left colorectum in 73% and right colon in 26% of patients. Metastasis was limited to the liver only in 64%, and liver metastasis was solitary in 14% of patients (table 1). Fluoropyrimidine doublet backbone (81%) was more commonly used compared to triplet (19%), with doublet + bevacizumab (41%) as the most common regimen. Hepatectomy only (59%), combined hepatectomy with ablation (32%), ablation only (5%), transarterial radioembolization (2%), and trans arterial embolization (1%) were the modalities employed for sLiOM. Of the 148 patients who underwent hepatectomy, R0 resection was achieved in 51%. After a median follow-up of 37 months, progression-free survival was 11.6 mos (95% CI 9-14mos) and median overall was 83.6 mos (95% CI 62-105mos). The median time to liver progression was 16 mos (95% CI 12-20 mos). At data cut off, 41 patients (26%) were alive and disease-free, and 60 patients (38%) were alive and disease free in the liver only. Conclusions: This multi-site, retrospective analysis of EOCRC patients demonstrates excellent survival outcomes with localized treatment of sLiOM. Median OS in this cohort compares favorably to previously reported mOS of 36 months in EOCRC patients (Arhin et al, 2021). Cure is not often achieved even after treatment of sLiOM in this cohort, suggesting aggressive disease biology and the need for improved patient selection. [Table: see text]