There are limited published data on the burden of rare cancers in the United States. By using data from the North American Association of Central Cancer Registries and the Surveillance, Epidemiology, and End Results program, the authors provide information on incidence rates, stage at diagnosis, and survival for more than 100 rare cancers (defined as an incidence of fewer than 6 cases per 100,000 individuals per year) in the United States. Overall, approximately 20% of patients with cancer in the United States are diagnosed with a rare cancer. Rare cancers make up a larger proportion of cancers diagnosed in Hispanic (24%) and Asian/Pacific Islander (22%) patients compared with non‐Hispanic blacks (20%) and non‐Hispanic whites (19%). More than two‐thirds (71%) of cancers occurring in children and adolescents are rare cancers compared with less than 20% of cancers diagnosed in patients aged 65 years and older. Among solid tumors, 59% of rare cancers are diagnosed at regional or distant stages compared with 45% of common cancers. In part because of this stage distribution, 5‐year relative survival is poorer for patients with a rare cancer compared with those diagnosed with a common cancer among both males (55% vs 75%) and females (60% vs 74%). However, 5‐year relative survival is substantially higher for children and adolescents diagnosed with a rare cancer (82%) than for adults (46% for ages 65‐79 years). Continued efforts are needed to develop interventions for prevention, early detection, and treatment to reduce the burden of rare cancers. Such discoveries can often advance knowledge for all cancers. CA Cancer J Clin 2017. © 2017 American Cancer Society. CA Cancer J Clin 2017;67:261–272. © 2017 American Cancer Society.

中文翻译：

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美国罕见癌症的负担

关于美国罕见癌症负担的已发表数据有限。通过使用北美中央癌症登记协会和监测、流行病学和最终结果计划的数据，作者提供了 100 多种罕见癌症（定义为发生率较低的癌症）的发病率、诊断分期和存活率的信息。在美国，每年每 100,000 人中超过 6 例）。总体而言，美国约有 20% 的癌症患者被诊断出患有罕见癌症。与非西班牙裔黑人 (20%) 和非西班牙裔白人 (19%) 相比，罕见癌症在西班牙裔 (24%) 和亚洲/太平洋岛民 (22%) 患者中诊断出的癌症比例更大。超过三分之二 (71%) 的儿童和青少年癌症是罕见的癌症，而在 65 岁及以上的患者中诊断出的癌症不到 20%。在实体瘤中，59% 的罕见癌症在区域或远处阶段被诊断出来，而常见癌症的这一比例为 45%。部分由于这种分期分布，与男性（55% 对 75%）和女性（60% 对 74%）诊断为常见癌症的患者相比，罕见癌症患者的 5 年相对生存率较低。然而，诊断为罕见癌症的儿童和青少年的 5 年相对生存率（82%）明显高于成人（65-79 岁的 46%）。需要继续努力开发预防、早期检测和治疗的干预措施，以减轻罕见癌症的负担。这样的发现通常可以促进对所有癌症的了解。CA Cancer J Clin 2017。© 2017 美国癌症协会。CA Cancer J Clin 2017；67：261-272。© 2017 美国癌症协会。