Supplementary Material for: Liver resection in synchronous bilobar versus unilobar colorectal liver metastases: A retrospective analysis of oncological outcomes and patient survival

Background: Resection of colorectal liver metastasis has emerged as the standard treatment. Our study compares oncological outcomes of patients with resected synchronous bilobar versus unilobar colorectal liver metastasis.
Methods: This retrospective study presents long-term follow-up data of 105 consecutive patients with primary colorectal cancer and synchronous liver metastasis. All patients underwent primary tumor and metastasis resections between 2007 and 2019.
Results: 55 patients with bilobar and 50 patients with unilobar colorectal liver metastases were included. No significant difference in overall, tumor-specific or recurrence-free survival was observed between patients with bilobar and unilobar metastases. After case-control matching, the results were confirmed in patients with similar tumor burden. In the multivariate analysis, chemotherapy following liver metastasis resection was a significant prognostic factor associated with poor overall survival (HR 0.518, 95%CI 0.302-0.888, p=0.017).
Conclusion: Overall survival, as well as tumor-specific and recurrence-free survival did not differ between patients with unilobar and bilobar liver metastasis. These findings add to the knowledge that primary tumor and metastasis resection in eligible patients improve the long-term outcome.

背景：结直肠癌肝转移（colorectal liver metastasis）切除术已成为标准治疗手段。本研究旨在对比接受手术切除的同步性（synchronous）双叶（bilobar）与单叶（unilobar）结直肠癌肝转移患者的肿瘤学结局。
方法：本项回顾性研究纳入了105例连续入组的原发性结直肠癌伴同步肝转移患者的长期随访数据。所有患者均于2007年至2019年间接受了原发肿瘤及肝转移灶切除术。
结果：本研究共纳入55例双叶结直肠癌肝转移患者与50例单叶结直肠癌肝转移患者。双叶与单叶转移患者的总生存期、肿瘤特异性生存期及无复发生存期均无显著差异。经病例对照匹配后，在肿瘤负荷相似的患者亚组中，上述结果得到了验证。多因素分析显示，肝转移灶切除术后化疗是与不良总生存期相关的独立预后因素（风险比（HR，hazard ratio）0.518，95%置信区间（95%CI，95% confidence interval）0.302~0.888，p=0.017）。
结论：单叶与双叶肝转移患者的总生存期、肿瘤特异性生存期及无复发生存期均无显著差异。本研究结果进一步证实，对符合适应证的患者实施原发肿瘤及转移灶切除术可改善其长期预后。