While a single rare cancer might affect a small number of patients, rare cancers—as a whole—actually make up about 1 out of every 4 new cancer diagnoses and an estimated 25 percent of all cancer deaths every year.1 Here’s what you need to know about rare cancers and how you can help conquer them.

It’s one of the most persistent and challenging realities of cancer research: Rare cancers—at an individual level—affect fewer people than more common cancers and, as a result, often receive less exposure, less awareness, and less research funding. 

It makes sense: After all, the more common a cancer type is, the more people learn about it and feel motivated to help conquer it. The reverse is also true, however: The rarer or more obscure a cancer is, the less likely it is to receive the critical funding and resources necessary to pursue research breakthroughs. 

For people with rare cancers, this often means fewer treatment options and, subsequently, poorer outcomes.

First things first: What are rare cancers?

While there isn’t one universal definition for what makes a cancer rare, researchers around the world quantify these cancers using similar approaches. 

In the U.S., a rare cancer is typically one diagnosed in fewer than 15 per 100,000 people each year or with fewer than 40,000 new diagnoses annually. (By comparison, out of the 2 million new cancer diagnoses predicted for 2025, an estimated 319,750 will be breast cancer and 313,780 will be prostate cancer.)

In Europe, a cancer type is widely deemed rare when it is diagnosed in fewer than six per 100,000 people each year. Besides numerical thresholds, cancers might also be considered rare when they:

• Make up a specific subtype of a more common cancer (triple-negative breast cancer, for instance).
• Occur in an unusual part of the body (such as the appendix).
• Are diagnosed in demographics in which they are not usually found (pediatric cancers, for example).

While the number of people with a rare cancer type might be small, rare cancers—on the whole—aren't uncommon. As a group they make up 1 out of every 4 cancer diagnoses each year. Further still, out of the 613,349 cancer-related deaths predicted for 2025, approximately 25 percent will be the result of rare cancers.

Despite the immense burden rare cancers place on patients and families—whether from limited treatment options, poor access to care, or the emotional toll of navigating a diagnosis—these diseases are often under-researched and underfunded. What’s more, these cancers often have poorer outcomes and higher fatality rates compared to other more common types. 

This creates an urgent and significant challenge for scientists, doctors, and, most importantly, patients—particularly for those with aggressive cancers that still an approved drug or standard treatment protocol. 

Why fund rare cancer research?

Whether they need a vaccine to prevent recurrence or care tailored to their specific diagnosis or tumor type, every patient with cancer deserves access to the best possible treatment options and potential cures. Of course, the less research is conducted behind a given cancer, the less we’re able to know about that disease and, subsequently, the less likely those treatments and cures are to emerge. 

Take, for example, the soft tissue sarcoma research from Conquer Cancer-funded oncologist Abdulazeez Salawu. In addition to having a high rate of recurrence, soft tissue sarcomas are genetically diverse, making them harder to monitor and detect. With his Conquer Cancer funding, Dr. Salawu was able to test patients for signs of circulating tumor DNA (ctDNA), ultimately identifying a potentially new and better way diagnose cancer recurrence in people who’ve experienced soft tissue sarcoma. 

But the benefits of researching rare cancers go beyond any single patient population or diagnosis: No matter how uncommon individually, these diseases combined affect countless people each year, and, without deeper study, will continue to affect countless more in the future. Moreover, rare cancer studies often lead to breakthroughs in other diseases as well—including other rare cancers. 

For instance, knowledge gained from studying genetic mutations, tumor behavior, and new treatment strategies in one rare cancer could apply to other rare cancers, too—or even other more common cancers. The result? Treatments, cures, and perhaps even prevention strategies that offer hope for people with a wide range of cancers.  

Learn about some of the incredible rare cancer research funded by Conquer Cancer and our donors.

What challenges do researchers face when studying rare cancers?

Scientists face a wide range of unique challenges in rare cancer research—challenges that extend into the lives of patients and their loved ones.

Limited resources and data: Rare cancers often lack the robust body of information that exists for more common cancers, making it harder for researchers to identify potential treatment options.

Scarce tumor samples: Since fewer people are diagnosed with rare cancers, investigators often struggle to collect enough tumor samples for laboratory analysis, making it difficult to conduct meaningful studies.

Small patient populations: Clinical trials are a cornerstone of cancer research—and patient participation is critical to clinical trials. But researchers studying rare cancers often struggle to enroll enough people to test new therapies. Additionally, rare cancers have fewer specialists focused on them, limiting clinical trial access for people who can’t travel long distances.

Lack of support: Whether because of limited participation or lower financial incentives, funding agencies and pharmaceutical companies often focus resources on cancers affecting the highest number of people. For researchers dedicated to conquering uncommon cancers, this often means more limited funding for rare cancer research—and thus fewer opportunities to pursue even the most promising ideas.  

How can individuals and organizations advance rare cancer research?

The importance of funding rare cancer research is clear: No matter how obscure a single rare cancer might be, these diseases affect hundreds of thousands of real people and their families every year. It’s why funding rare cancer research cannot wait—and neither can the patients actively facing these diseases. 

Here are some ways individuals and organizations can play a critical role in driving progress:

• Give. Donate to places like Conquer Cancer®, the ASCO Foundation, which funds promising studies into all types of cancer, including rare cancers.
• Advocate and spread awareness. Share personal stories, statistics, or information about rare cancers on social media, in your community, or with lawmakers to draw attention to the need for more funding and drive public interest in supporting the cause.

Organizations can: 

• Fund grants for scientists studying rare cancers to help advance critical discoveries.
• Partner with universities and hospitals to co-fund rare cancer research.
• Help raise awareness of rare cancers by sponsoring events, public service announcements, or social media campaigns to educate the public and encourage support for research.
• Match employee donations to support rare cancer research and multiply the impact of individual contributions.

For patients with rare cancers, one breakthrough can change everything.

Rare cancers may be uncommon, but a single discovery can have a ripple effect and lead to discoveries that benefit countless people with other cancers. By contributing to rare cancer research, we can unlock lifesaving treatments, bring hope to people with cancer, and create progress that transforms the future of cancer care. Learn more about rare cancers, discover inspiring people conquering these diseases, and make a gift that makes an impact around the world. 

Related Content:

• Meet Dr. Bahar Ladarian, who’s using her Conquer Cancer funding to treat rare neuroendocrine tumors.
• Sean Swarner is a rare cancer survivor with a rare list of achievements—including conquering the Seven Summits, the highest mountain on every continent. Hear his story.
• Get more stories like these from Conquer Cancer. Sign up for our emails.

References:

1.   Global Burden of Rare Cancers: Insights from GLOBOCAN 2022 Estimates 
https://pmc.ncbi.nlm.nih.gov/articles/PMC12110169/#:~:text=3.,for%20all%20rare%20cancer%20estimations 
2.    About Rare Cancers 
https://www.cancer.gov/pediatric-adult-rare-tumor/rare-tumors/about-rare-cancers