AbstractBackgroundCachexia has significant impact on the patients' quality of life and prognosis. It is frequently observed in patients with cancer, especially in advanced stages, but prevalence data for the overall population are lacking. Good quality estimates of cancer cachexia in general and for each of the major cancer types would be highly relevant for potential treatment development efforts in this field. Both the USA and European Union (EU) have implemented special clinical development rules for such rare disorders what are called ‘orphan diseases’. The cut‐off level for a disease to be considered an orphan disease in the USA is 200 000 people (0.06% of the population) and EU is 5 per 10 000 people (0.05% of the population).MethodsFor this systematic review, we searched at PubMed (from inception to 31 January 2018) to identify clinical studies that assessed the prevalence of cachexia in cancer patients at risk. Studies reporting the prevalence of either cancer cachexia or wasting disease in the top‐10 cancer types and 4 other selected cancer types known to be particularly commonly complicated by cachexia were included in this analysis (i.e. prostate cancer, breast cancer, colorectal cancer, melanoma, endometrial cancer, thyroid cancer, urinary bladder cancer, non‐hodgkin lymphoma, lung cancer, kidney and renal pelvis cancer, head and neck cancer, gastric cancer, liver cancer, and pancreatic cancer). We calculated the current burden of cancer cachexia, disease by disease, in the USA and in the EU and compared them to the current guidelines for the definition of orphan disease status.ResultsWe estimate that in 2014 in the USA, a total of 527 100 patients (16.5 subjects per 10 000 people of the total population), and in 2013 in the EU, a total of 800 300 patients (15.8 subjects per 10 000 people of the total population) suffered from cancer cachexia (of any kind). In the 14 separately analysed cancer types, the prevalence of cancer cachexia in the USA ranged between 11 300 (0.4/10 000, gastric cancer) and 92 000 patients (2.9/10 000, lung cancer) and in the EU between 14 300 (0.3/10 000, melanoma of the skin) and 150 100 (3.0/10 000, colorectal cancer).ConclusionsThe absolute number of patients affected by cancer cachexia in each cancer group is lower than the defined thresholds for orphan diseases in the USA and EU. Cancer cachexia in each subgroup separately should be considered an orphan disease.

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美国和欧盟癌症恶病质的孤儿病状况：系统评价

摘要背景恶病质对患者的生活质量和预后有显着影响。它经常在癌症患者中观察到，尤其是晚期癌症患者，但缺乏总体人群的患病率数据。对一般癌症恶病质和每种主要癌症类型的良好质量估计将与该领域潜在的治疗开发工作高度相关。美国和欧盟 (EU) 都针对此类罕见疾病（即所谓的“孤儿疾病”）实施了特殊的临床开发规则。在美国，一种疾病被视为孤儿疾病的临界水平是 20 万人（占人口的 0.06%），而欧盟是每 1 万人中 5 人（占人口的 0.05%）。方法在本次系统评价中，我们在 PubMed 上进行了检索（从成立到 2018 年 1 月 31 日），以确定评估高危癌症患者恶病质患病率的临床研究。该分析中纳入了报告前 10 种癌症类型和其他 4 种已知特别容易并发恶病质的选定癌症类型（即前列腺癌、乳腺癌、结直肠癌、黑色素瘤、子宫内膜癌、甲状腺癌、膀胱癌、非霍奇金淋巴瘤、肺癌、肾癌和肾盂癌、头颈癌、胃癌、肝癌和胰腺癌）。我们计算了美国和欧盟当前癌症恶病质的负担（按疾病分类），并将其与当前孤儿疾病状态定义指南进行比较。结果我们估计，2014 年美国共有 527 100 名患者（总人口中每 10 000 人有 16.5 名受试者），2013 年欧盟共有 800 300 名患者（总人口中每 10 000 人有 15.8 名受试者）。总人口）患有癌症恶病质（任何类型）。在 14 种单独分析的癌症类型中，美国癌症恶病质的患病率介于 11 300 名患者（0.4/10 000，胃癌）和 92 000 名患者（2.9/10 000，肺癌）之间，而欧盟则介于 14 300 名患者（2.9/10 000，肺癌）之间。 0.3/10 000，皮肤黑色素瘤）和 150 100（3.0/10 000，结直肠癌）。结论每个癌症组中受癌症恶病质影响的患者绝对数量低于美国和欧盟规定的孤儿疾病阈值。每个亚组中的癌症恶病质应分别被视为孤儿疾病。