# Rare cancers

Source: https://onco.cc/terms/rare-cancers/  
OnCo record `rare-cancers` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Rare cancers are those with fewer than about 6 new cases per 100,000 people per year. Individually rare, together they are a quarter of all cancers and have worse survival because of late diagnosis, few trials and scattered expertise.

## Summary

RARECARE (EU) defines rare cancers as incidence <6/100,000/year; there are ~200 such entities making up ~24% of European cancers, with 5-year survival ~48% versus ~63% for common cancers. Causes of the gap: diagnostic delay and misdiagnosis, absence of standard treatments, difficulty running trials (basket/umbrella designs, registries, real-world evidence help), and dispersed care. Responses: European Reference Networks (EURACAN, EuroBloodNet, PaedCan), centralisation (e.g. sarcoma centres), the NCI Rare Tumor Patient Engagement Network, Rare Cancers Europe, orphan-drug incentives and tumour-agnostic approvals (NTRK, MSI-H, RET, BRAF) that serve rare histologies. Paediatric cancers are all rare cancers.

## Fields

- Kind: Term
- Last checked: 2026-09-08
- Also known as: rare cancer
- Tags: gap-fill

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Rare_disease
- RARECARE / RARECAREnet: https://www.rarecarenet.eu/
- Rare Cancers Europe: https://www.rarecancerseurope.org/
- NCI MyPART: https://www.cancer.gov/pediatric-adult-rare-tumor

## Connected records

- cancers: [Adrenocortical carcinoma](https://onco.cc/cancers/adrenocortical/), [Appendiceal cancer and pseudomyxoma peritonei](https://onco.cc/cancers/appendiceal/), [Blastic plasmacytoid dendritic cell neoplasm (BPDCN)](https://onco.cc/cancers/bpdcn/), [Chordoma](https://onco.cc/cancers/chordoma/), [Dermatofibrosarcoma protuberans](https://onco.cc/cancers/dermatofibrosarcoma-protuberans/), [Desmoid tumour](https://onco.cc/cancers/desmoid-tumour/), [Epithelioid sarcoma](https://onco.cc/cancers/epithelioid-sarcoma/), [Esthesioneuroblastoma (olfactory neuroblastoma)](https://onco.cc/cancers/esthesioneuroblastoma/), [Gastrointestinal stromal tumour (GIST)](https://onco.cc/cancers/gist/), [Gestational trophoblastic neoplasia](https://onco.cc/cancers/gestational-trophoblastic/), [Hereditary pheochromocytoma and paraganglioma (SDHx, VHL, RET, NF1, MAX and TMEM127)](https://onco.cc/cancers/hereditary-ppgl/), [Inflammatory myofibroblastic tumour (IMT)](https://onco.cc/cancers/inflammatory-myofibroblastic-tumour/), [Merkel cell carcinoma](https://onco.cc/cancers/merkel-cell-carcinoma/), [Metastatic pheochromocytoma and paraganglioma](https://onco.cc/cancers/metastatic-ppgl/), [Nasal cavity and paranasal sinus cancers (including esthesioneuroblastoma)](https://onco.cc/cancers/sinonasal/), [NUT carcinoma (midline carcinoma with NUTM1 rearrangement)](https://onco.cc/cancers/nut-carcinoma/), [Parathyroid carcinoma](https://onco.cc/cancers/parathyroid-carcinoma/), [Pheochromocytoma and paraganglioma (PPGL)](https://onco.cc/cancers/pheochromocytoma-paraganglioma/), [Pituitary tumours (pituitary neuroendocrine tumours) and pituitary carcinoma](https://onco.cc/cancers/pituitary-tumours/), [Salivary gland cancers](https://onco.cc/cancers/salivary-gland/), [Sinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinoma](https://onco.cc/cancers/sinonasal-undifferentiated-carcinoma/), [Tenosynovial giant cell tumour (TGCT)](https://onco.cc/cancers/tenosynovial-giant-cell-tumour/), [Thymoma and thymic carcinoma](https://onco.cc/cancers/thymic-epithelial/), [Uterine sarcoma](https://onco.cc/cancers/uterine-sarcoma/), [Uveal melanoma](https://onco.cc/cancers/uveal-melanoma/), [Vascular tumours (angiosarcoma, epithelioid haemangioendothelioma, kaposiform haemangioendothelioma)](https://onco.cc/cancers/vascular-tumours/)
- terms: [Accrual and enrolment](https://onco.cc/terms/accrual/), [Basket, umbrella, and platform trials](https://onco.cc/terms/basket-umbrella-platform/), [Centralisation and high-volume centres](https://onco.cc/terms/centralisation/), [Off-label](https://onco.cc/terms/off-label/), [Orphan drug](https://onco.cc/terms/orphan-drug/), [Orphan Drug Act 1983](https://onco.cc/terms/orphan-drug-act/), [Orphan drug designation](https://onco.cc/terms/orphan-designation/), [Real-world evidence](https://onco.cc/terms/real-world-evidence/), [Regulation (EC) No 141/2000: EU orphan medicines](https://onco.cc/terms/eu-orphan-regulation/), [Regulation (EC) No 1901/2006: EU paediatric medicines](https://onco.cc/terms/eu-paediatric-regulation/), [Sarcoma (tissue type)](https://onco.cc/terms/sarcoma-type/), [Tumour-agnostic (tissue-agnostic) approval](https://onco.cc/terms/tumour-agnostic/)
- trials: [ComboMATCH (EAY191)](https://onco.cc/trials/combomatch/), [DART (SWOG S1609): nivolumab plus ipilimumab in rare tumours](https://onco.cc/trials/dart-s1609/), [DETERMINE](https://onco.cc/trials/determine-trial/), [DETERMINE arm 04: trastuzumab with pertuzumab in HER2-amplified or mutated rare cancers](https://onco.cc/trials/determine-arm04/), [I-PREDICT](https://onco.cc/trials/i-predict/), [MyPathway](https://onco.cc/trials/mypathway/), [NCI-MATCH (EAY131)](https://onco.cc/trials/nci-match/), [ROAR (Rare Oncology Agnostic Research) basket: BRAF V600E biliary tract cancer cohort](https://onco.cc/trials/roar/), [TAPUR (Targeted Agent and Profiling Utilization Registry)](https://onco.cc/trials/tapur/), [WINTHER](https://onco.cc/trials/winther/)
- institutions: [Garvan Institute of Medical Research / Kinghorn Cancer Centre](https://onco.cc/institutions/garvan-institute/), [Peking Union Medical College Hospital](https://onco.cc/institutions/pumch/)

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JSON: https://onco.cc/api/v1/entities/rare-cancers.json