Orphan Diseases in Oncology: A Hidden Healthcare Challenge




  • There’s no specific definition for rare cancers.
  • 24% of all new cancer cases are rare.
  • Their specificities are closer to not so rare cancers.
  • European Union defines rare diseases as “diseases with a prevalence of fewer than 5 cases out of a population of 10,000.”
  • Since the prevalence is affected by mortality, it has been proposed that the incidence of disease should be used instead
  • According to the above definition, rare cancers are the ones with incidence of less than 6 per 100,000 persons per year.
  • This definition helps in avoiding the common cancers with high mortality to be included in the list
  • It makes rare cancer with high survival rate are also included in the list.
  • Im the year 2016, Joint Action on Rare Cancers (JARC) re-examined the list of rare cancers comprising of 1968 cancers made by the RARECARE project.
  • The cancers were classified into 12 families
  • The rare cancers were categorized them into 3 tiers according to the International Classification of Diseases for Oncology (ICD-O) classification:
    • First tier: These are supposed to be major cancer entities clinically. (e.g. soft tissue sarcoma etc.)

They play am important role in referral policy and hence have some organizational significance.

    • Second tier: These are based upon morphologies and topographies (e.g. soft tissue 16 sarcoma of limb etc.)

It has clinical significance.

Have significance in forming trial protocols

The Tier-2 diseases are assembled into a smaller number of Tier-1 diseases.

    • Third tier: corresponds to the morphological classification.