Bingham George, Shetye Alysha, Suresh Reena, Mirnezami Reza
Department of General Surgery, St. Thomas's Hospital, Lambeth, London SE1 7EH, United Kingdom.
Department of Colorectal Surgery, Royal Free Hospital, Hampstead, London NW3 2QG, United Kingdom.
World J Clin Oncol. 2020 May 24;11(5):294-307. doi: 10.5306/wjco.v11.i5.294.
Colorectal cancer (CRC) is the third most common cause of cancer-related death worldwide. Despite significant advances in screening, surgical management and adjuvant therapies, average 5-year survival seldom exceeds 60% in most developed nations. Metastatic disease represents the primary cause of mortality in patients with CRC, and the liver is the most common location for distant tumour spread. Up to 25% of patients are found to have synchronous liver metastases at the time of diagnosis and a further 30%-40% will develop metachronous disease in the course of follow-up. It has been suggested that primary tumour location [right side versus left side, primary tumour location (PTL)] can influence oncological outcomes in this patient group and that this should be considered in prognostic models and therapeutic decision-making algorithms. This suggestion is not universally accepted and there have been conflicting reports in the literature to date.
To provide a comprehensive summary of the available evidence regarding the impact of PTL on oncological outcomes in patients with colorectal cancer liver metastases (CRCLM).
MEDLINE, EMBASE and COCHRANE were searched for relevant publications using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology. Data on oncological outcomes was then extracted from full text articles that met the predefined inclusion criteria.
A total of 41 studies were identified that met predefined inclusion criteria for this review. In 21 out of 38 studies that provided data on overall survival, a statistically significant improvement in overall survival was reported in patients with left sided primary tumours. These studies included a total of 13897 patients compared with 4306 patients in the studies that did not show a significant difference. Eight studies noted a similar trend towards improved disease-free or progression-free survival. Several authors observed distinct patterns of relapse after treatment of hepatic metastases according to PTL; for example hepatic recurrence after treatment of CRCLM appears to occur more aggressively with right-sided CRC.
Taken together, the findings of the present review indicate that PTL may have a role as an independent prognostic factor when determining treatment and disease surveillance strategies in CRC. The mechanisms responsible for this variation remain poorly understood, but are likely to relate to molecular, histological and embryological differences, as well as inherent differences in therapeutic sensitivity.
结直肠癌（CRC）是全球癌症相关死亡的第三大常见原因。尽管在筛查、手术治疗和辅助治疗方面取得了重大进展，但在大多数发达国家，5年平均生存率很少超过60%。转移性疾病是CRC患者死亡的主要原因，肝脏是远处肿瘤转移最常见的部位。高达25%的患者在诊断时被发现有同步肝转移，另外30%-40%的患者在随访过程中会发生异时性疾病。有人提出，原发肿瘤位置[右侧与左侧，原发肿瘤位置（PTL）]会影响该患者群体的肿瘤学结局，并且在预后模型和治疗决策算法中应考虑这一点。这一观点并未得到普遍认可，迄今为止文献中存在相互矛盾的报道。
全面总结关于PTL对结直肠癌肝转移（CRCLM）患者肿瘤学结局影响的现有证据。
使用系统评价和Meta分析的首选报告项目方法在MEDLINE、EMBASE和COCHRANE中检索相关出版物。然后从符合预定义纳入标准的全文文章中提取肿瘤学结局数据。
共确定了41项符合本综述预定义纳入标准的研究。在提供总生存数据的38项研究中的21项中，报告左侧原发肿瘤患者的总生存有统计学显著改善。这些研究共纳入13897例患者，而未显示显著差异的研究中有4306例患者。八项研究指出无病或无进展生存改善有类似趋势。几位作者观察到根据PTL治疗肝转移后不同的复发模式；例如，CRCLM治疗后肝复发在右侧CRC中似乎更具侵袭性。
综上所述，本综述的结果表明，在确定CRC的治疗和疾病监测策略时，PTL可能作为一个独立的预后因素发挥作用。造成这种差异的机制仍知之甚少，但可能与分子、组织学和胚胎学差异以及治疗敏感性的内在差异有关。
