Department of Community Based Medicine, NIHR School for Primary Care Research, University of Bristol, 25-27 Belgrave Road, Bristol, UK.
Br J Cancer. 2009 Dec 3;101 Suppl 2(Suppl 2):S80-6. doi: 10.1038/sj.bjc.6605396.
This paper reviews the background to five primary care case-control studies, collectively known as the CAPER studies (Cancer Prediction in Exeter). These studies, on colorectal, lung, prostate and brain tumours, sought to identify the particular features of cancer as reported to primary care. They also sought to quantify the risk of cancer for symptoms and primary care investigations, both individually and paired together.
Two studies were on colorectal cancer: the former with 349 cases used hand searching and coding of entries, while the latter obtained 6442 cases from a national electronic database. The lung and prostate studies had 247 and 217 cases, respectively, and used manual methods. The brain study also used a national electronic database, which provided 3505 cases.
Generally, the symptoms matched previous series from secondary care, though the risks of cancer, expressed as positive predictive values, were lower. Rectal bleeding in colorectal cancer, and haemoptysis in lung cancer both had positive predictive values of 2.4%. The risk of a brain tumour with headache was one in a thousand.
The results identify areas where current guidance on urgent referral for investigation of suspected cancer could be improved.
本文回顾了五项初级保健病例对照研究的背景，这些研究统称为 CAPER 研究（埃克塞特的癌症预测）。这些研究涉及结直肠癌、肺癌、前列腺癌和脑肿瘤，旨在确定向初级保健报告的癌症的特定特征。它们还试图量化症状和初级保健调查的癌症风险，包括单独和配对的风险。
两项研究涉及结直肠癌：前者有 349 例，使用手工搜索和条目编码，后者则从国家电子数据库中获得 6442 例。肺癌和前列腺癌的研究分别有 247 例和 217 例，采用手工方法。脑肿瘤研究也使用国家电子数据库，提供了 3505 例病例。
一般来说，症状与二级保健的先前系列相符，但癌症的风险（表示为阳性预测值）较低。结直肠癌的直肠出血和肺癌的咯血的阳性预测值均为 2.4%。头痛伴脑肿瘤的风险为千分之一。
研究结果确定了当前关于紧急转介疑似癌症调查的指南可以改进的领域。
