Rare cancers

When we talk about a rare cancer, we mean a type of cancer that doesn’t happen very often. In fact, there are less than 6 cases of each type of rare cancer for every 100,000 people in Australia each year. Rare cancers can arise in many different parts of the body.

A cancer is considered rare if it:

• is seen in very few people
• affects people who are much older or younger than those normally diagnosed with that type of cancer
• affects children – all childhood cancers are considered rare
• is a common cancer histologic type in an unlikely part of the body or with a specific gene change which makes it a rare subset of a more common cancer

The following rare cancer types are included in WEHI’s core research focus:

• rare gynaecological cancers eg. ovarian cancer, rare types of uterine cancer and cervix cancers, vaginal and vulval cancers
• blood vessel cancers such as Epithelioid Haemangioendothelioma (EHE)
• squamous cell cancers of very rare sites such as the rectum or ovary
• neuroendocrine cancers of the small cell variety

Rare cancers are hard to find early because there are no screening programs. This means they’re often found late, which makes them harder to treat.

Doctors also face challenges in recognising the symptoms of rare cancers because there is limited information available about them.

They often have specific but very rarely seen changes eg under the microscope and additional expertise may be required to reach the correct diagnosis.

Treatments for people with rare cancers have not advanced at the same pace as treatments for more common cancers, such as breast or prostate cancers.

Unlike many people with a common cancer, most people with rare cancers usually don’t have support, treatments and resources that are specific to their cancer. They often have to rely on information and treatments meant for more common cancers.

WEHI is increasing the genetic matching of rare cancers to existing cancer therapies that are used for more common cancers.

Some types of rare cancers respond to treatments, but effective therapies have not been developed for many types of rare cancers.

There are a number of reasons for this.

• Less money and attention is given to finding cures for rare cancers, compared to more common cancers.
• Scientists have limited clinical samples of rare cancers, which restricts their ability to discover how these cancers respond to treatment.
• Testing new therapies for rare cancers is difficult because there aren’t many people with the same kind of cancer. Current strategies to test treatments rely on large groups of patients who all have a similar condition.
• It’s hard to get new treatments approved for a small group of patients. Our clinical translational research aims to better understand a disease, and the development of new diagnostic tests or treatments to help get medications approved for people to use.

International Rare Cancers Initiative
Rare Cancers Australia
Cancer Council Australia