Wilson M J, van Haaren M, Harlaar J J, Park Hee Chul, Bonjer H J, Jeekel J, Zwaginga J J, Schipperus M
TRIP Hemovigilance and Biovigilance Office, Leiden, The Netherlands; Erasmus University Medical Center Rotterdam, Department of Surgery, The Netherlands.
OLVG Amsterdam, Department of Internal Medicine, The Netherlands.
Surg Oncol. 2017 Mar;26(1):96-104. doi: 10.1016/j.suronc.2017.01.005. Epub 2017 Feb 2.
To evaluate the long-term prognostic factor of preoperative anemia in colorectal cancer patients.
Anemia is frequently observed in colorectal cancer patients, with a case incidence of 30 to 67 percent. Besides an indicator of tumor-induced blood loss and inflammation, anemia in cancer is also suggested to be a cause of inferior outcome, possibly via worsening of tumor hypoxia. As surgery is likely to enhance anemia, the long-term prognostic value of preoperative anemia seems most interesting.
Comprehensive searches were carried out in all relevant databases, including MEDLINE, Embase and Web-of-Science. To include studies addressing overall survival, follow-up had to be at least 24 months or till death. For pooling of survival results, a mixed-linear (fixed-effects) model was fit to the reported hazard ratios (HRs) to calculate a pooled estimate and confidence interval.
We included 12 studies comprising 3588 patients to estimate the association between preoperative anemia and overall survival (OS) and disease-free survival (DFS). In a fixed-effects meta-analysis of eight studies, including both colon and rectal cancer, preoperative anemia was significantly associated with poor OS (HR 1.56; 95% CI 1.30 to 1.88; p < 0.001). A meta-analysis of seven studies also showed that preoperative anemia was significantly associated with poor DFS (HR 1.34; 95% CI 1.11 to 1.61; p = 0.002). Restricted to studies exclusively on colon cancer or rectal cancer, HRs for OS were 1.25 (95% CI 1.00 to 1.55; p = 0.05) and 2.59 (95% CI 1.68 to 4.01; p < 0.001), respectively, while HRs for DFS were 1.21 (95% CI 0.96 to 1.52; p = 0.11) and 1.61 (95% CI 1.18 to 2.21; p = 0.003).
The present meta-analysis reveals that preoperative anemia is significantly associated with decreased long-term OS and DFS in rectal cancer, but not in colon cancer patients, although this meta-analysis is mainly based on retrospective studies with high heterogeneity. These results justify raised awareness about the impact of preoperative anemia on long-term survival.
评估结直肠癌患者术前贫血的长期预后因素。
结直肠癌患者中贫血较为常见，病例发生率为30%至67%。除了作为肿瘤引起的失血和炎症指标外，癌症患者的贫血也被认为是导致预后较差的原因，可能是通过加重肿瘤缺氧。由于手术可能会加重贫血，术前贫血的长期预后价值似乎最值得关注。
在所有相关数据库中进行全面检索，包括MEDLINE、Embase和Web of Science。为纳入涉及总生存期的研究，随访时间必须至少为24个月或直至死亡。为汇总生存结果，对报告的风险比（HRs）拟合混合线性（固定效应）模型以计算汇总估计值和置信区间。
我们纳入了12项研究，共3588例患者，以评估术前贫血与总生存期（OS）和无病生存期（DFS）之间的关联。在包括结肠癌和直肠癌的8项研究的固定效应荟萃分析中，术前贫血与较差的OS显著相关（HR 1.56；95%CI 1.30至1.88；p<0.001）。7项研究的荟萃分析还表明，术前贫血与较差的DFS显著相关（HR 1.34；95%CI 1.11至1.61；p = 0.002）。仅限于专门针对结肠癌或直肠癌的研究，OS的HR分别为1.25（95%CI 1.00至1.55；p = 0.05）和2.59（95%CI 1.68至4.01；p<0.001），而DFS的HR分别为1.21（95%CI 0.96至1.52；p = 0.11）和1.61（95%CI 1.18至2.21；p = 0.003）。
本荟萃分析表明，术前贫血与直肠癌患者长期OS和DFS降低显著相关，但与结肠癌患者无关，尽管该荟萃分析主要基于异质性较高的回顾性研究。这些结果证明有必要提高对术前贫血对长期生存影响的认识。
