Division of Epidemiology and Public Health, University of Nottingham, Nottingham, United Kingdom.
PLoS Med. 2012;9(7):e1001275. doi: 10.1371/journal.pmed.1001275. Epub 2012 Jul 31.
People with cancer are known to be at increased risk of venous thromboembolism (VTE), and this risk is believed to vary according to cancer type, stage of disease, and treatment modality. Our purpose was to summarise the existing literature to determine precisely and accurately the absolute risk of VTE in cancer patients, stratified by malignancy site and background risk of VTE.
We searched the Medline and Embase databases from 1 January 1966 to 14 July 2011 to identify cohort studies comprising people diagnosed with one of eight specified cancer types or where participants were judged to be representative of all people with cancer. For each included study, the number of patients who developed clinically apparent VTE, and the total person-years of follow-up were extracted. Incidence rates of VTE were pooled across studies using the generic inverse variance method. In total, data from 38 individual studies were included. Among average-risk patients, the overall risk of VTE was estimated to be 13 per 1,000 person-years (95% CI, 7 to 23), with the highest risk among patients with cancers of the pancreas, brain, and lung. Among patients judged to be at high risk (due to metastatic disease or receipt of high-risk treatments), the risk of VTE was 68 per 1,000 person-years (95% CI, 48 to 96), with the highest risk among patients with brain cancer (200 per 1,000 person-years; 95% CI, 162 to 247). Our results need to be considered in light of high levels of heterogeneity, which exist due to differences in study population, outcome definition, and average duration of follow-up between studies.
VTE occurs in greater than 1% of cancer patients each year, but this varies widely by cancer type and time since diagnosis. The absolute VTE risks obtained from this review can aid in clinical decision-making about which people with cancer should receive anticoagulant prophylaxis and at what times.
已知癌症患者发生静脉血栓栓塞症（VTE）的风险增加，并且据信这种风险因癌症类型、疾病分期和治疗方式而异。我们的目的是总结现有文献，以准确确定癌症患者 VTE 的绝对风险，按恶性肿瘤部位和 VTE 的背景风险分层。
我们从 1966 年 1 月 1 日至 2011 年 7 月 14 日检索了 Medline 和 Embase 数据库，以确定包括以下八种特定癌症类型之一的患者或参与者被认为代表所有癌症患者的队列研究。对于每项纳入的研究，我们提取发生临床明显 VTE 的患者人数和总随访人年数。使用通用倒数方差法对研究间的 VTE 发生率进行汇总。总共纳入了 38 项独立研究的数据。在一般风险患者中，VTE 的总体风险估计为 13/1000 人年（95%CI，7 至 23），其中胰腺癌、脑癌和肺癌患者的风险最高。在被认为高风险（转移性疾病或接受高风险治疗）的患者中，VTE 的风险为 68/1000 人年（95%CI，48 至 96），其中脑癌患者的风险最高（200/1000 人年；95%CI，162 至 247）。由于研究人群、结局定义和平均随访时间的差异，我们的结果存在高度异质性。
VTE 每年发生在超过 1%的癌症患者中，但这在很大程度上取决于癌症类型和诊断后时间。本综述获得的绝对 VTE 风险可以帮助临床决策，决定哪些癌症患者应接受抗凝预防以及何时进行。
