Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford.
Medical School, University of Exeter, Exeter.
Br J Gen Pract. 2018 May;68(670):e311-e322. doi: 10.3399/bjgp18X695801. Epub 2018 Apr 9.
Weight loss is a non-specific cancer symptom for which there are no clinical guidelines about investigation in primary care.
To summarise the available evidence on weight loss as a clinical feature of cancer in patients presenting to primary care.
A diagnostic test accuracy review and meta-analysis.
Studies reporting 2 × 2 diagnostic accuracy data for weight loss (index test) in adults presenting to primary care and a subsequent diagnosis of cancer (reference standard) were included. QUADAS-2 was used to assess study quality. Sensitivity, specificity, positive likelihood ratios, and positive predictive values were calculated, and a bivariate meta-analysis performed.
A total of 25 studies were included, with 23 (92%) using primary care records. Of these, 20 (80%) defined weight loss as a physician's coding of the symptom; the remainder collected data directly. One defined unexplained weight loss using objective measurements. Positive associations between weight loss and cancer were found for 10 cancer sites: prostate, colorectal, lung, gastro-oesophageal, pancreatic, non-Hodgkin's lymphoma, ovarian, myeloma, renal tract, and biliary tree. Sensitivity ranged from 2% to 47%, and specificity from 92% to 99%, across cancer sites. The positive predictive value for cancer in male and female patients with weight loss for all age groups ≥60 years exceeded the 3% risk threshold that current UK guidance proposes for further investigation.
A primary care clinician's decision to code for weight loss is highly predictive of cancer. For such patients, urgent referral pathways are justified to investigate for cancer across multiple sites.
体重减轻是非特异性癌症症状，初级保健中没有关于其检查的临床指南。
总结在初级保健中出现的体重减轻作为癌症患者的临床特征的现有证据。
诊断测试准确性综述和荟萃分析。
纳入了报告体重减轻（索引测试）在向初级保健就诊并随后诊断为癌症（参考标准）的成年人中进行的 2×2 诊断准确性数据的研究。使用 QUADAS-2 评估研究质量。计算了敏感性、特异性、阳性似然比和阳性预测值，并进行了二变量荟萃分析。
共纳入 25 项研究，其中 23 项（92%）使用初级保健记录。其中，20 项（80%）将体重减轻定义为医生对症状的编码；其余的则直接收集数据。有一项研究使用客观测量来定义不明原因的体重减轻。在 10 个癌症部位发现了体重减轻与癌症之间的阳性关联：前列腺、结直肠癌、肺癌、胃食管、胰腺、非霍奇金淋巴瘤、卵巢、骨髓瘤、肾和胆道。癌症部位的敏感性范围为 2%至 47%，特异性范围为 92%至 99%。所有年龄≥60 岁的男性和女性患者中，有体重减轻的患者中癌症的阳性预测值均超过了当前英国指南建议的 3%风险阈值，需要进一步进行调查。
初级保健临床医生决定对体重减轻进行编码高度提示癌症。对于此类患者，有理由通过紧急转介途径对多个部位的癌症进行调查。
