The burden of rare cancers in the United States

Abstract

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.

Increasing Incidence of Liposarcoma: A Population-Based Study of National Surveillance Databases, 2001–2016

“…A rare cancer, by definition, affects a small number of people. The RARECARE project dedicated to the surveillance of rare cancers in Europe defines a rare cancer as having incidence rate <6 cases per year per 100,000 population [1], while the U.S. National Cancer Institute defines it as <15 cases per year per 100,000 population [2,3]. Despite the low rate of each individual malignancy, overall rare cancers affect a significant proportion of cancer patients.…”

“…In Europe, rare cancer incidence is estimated as 108 cases per 100,000, or 22% of all new annual cancer diagnoses [1]. In the U.S., 20% of all new cancer diagnoses have an incidence rate of <6 cases per 100,000 population per year [3]. Ignored by the pharmaceutical industry as well as epidemiological and clinical research, rare cancers…”

“…Limited treatment options, high costs of existing treatments, and frequent misdiagnosis of rare cancers burden patients, physicians, and health systems [4]. The lack of epidemiological knowledge about the risk factors associated with many rare cancers precludes the development of viable prevention, making it one of the most dramatic unresolved public health problems [1,3,5]. In comparison, well-studied cancers such as colorectal cancer, which constitutes a smaller portion of the overall cancer cases (13%), has had significant progress in cancer control and prevention [5,6].…”

How cancer patients perceive clinical trials (CTs) in the era of CTs: Current perceptional status and differences between common and rare cancers

“…Newly developed CTs designs based on the advancement of sequencing technologies have broadened opportunities of CTs in patients with rare cancers(19, 25). Accordingly, numbers of currently registered and ongoing CTs for rare cancers on ClinicalTrials.gov have decently increased compared with last three decades (Table S4) (14,20,26). However, we do not exactly know what make patients with rare cancers participating in CTs and what make them refraining from it.…”

“…Meanwhile, patients with rare cancers have been frequently excluded from conventional types of CTs due to their inherent barriers of small populations and minimal evidences of standardized treatments (8)(9)(10). Necessarily, they have suffered from relative therapeutic deprivation compared with patients with common cancers, more obviously in case of young and adolescent patients (11)(12)(13)(14)(15). However, with development of newer molecular targets and multi-omics, CTs have evolved into more intuitive and comprehensive forms (16), and they particularly benefited patients with rare cancers by potentiating opportunities of enrollments (10,(17)(18)(19)(20).…”