What You Should Know About Research into Rare Pediatric Cancers

by Becky C. Weaver, Chief Mission Officer, St. Baldrick's Foundation
September 30, 2020

Rare Cancer Day is September 30th, but the St. Baldrick’s Foundation fights rare cancers year-round.

baby smiling

What is rare disease?

When it comes to cancer, or even diseases as a whole, “rare” is a misleading word.

A rare disease is defined as “any disease or condition that affects fewer than 200,000 people in the United States, or about 1 in 1,500 people.” About 72% of rare diseases are genetic, and of those, 70% start in childhood.

Worldwide, people with rare diseases make up less than 6% of the population. But more than 6,000 rare diseases have been identified so far, and they affect more than 300 million around the world. If these people were a country, they would be the world’s third largest nation.

What about cancer, in particular?

There are cancers that are not rare. Almost all of us know people who have fought breast, colon, lung or prostate cancer, for instance. But according to the National Cancer Institute, most cancers are rare – meaning they occur in fewer than 15 out of 100,000 people each year. That includes all forms of childhood cancer.

Yet in the U.S., more children die of cancer than any other disease; about one in five diagnosed do not survive. That’s a collective number for all childhood cancers, so it doesn’t really apply to any one child facing his or her specific type of cancer. The reality is that some childhood cancers have treatments that work for most patients, and other types leave no survivors.

The cancers studied by the Rare Tumor Committee of the Children’s Oncology Group account for about 15% of all childhood cancers, a proportion that jumps to nearly 30% for adolescents. Committee Chair Theodore Laetsch, MD, says, “So as a group, these cancers are not quite so rare, but individually, given the wide variety of subtypes, it is difficult to study any one of them individually.”

Challenges of Rare Cancer Types

How rare or how common a particular type of childhood cancer is can be a big deal.

Rare cancers are often hard to recognize, and a misdiagnosis or a delay in the correct diagnosis can be critical to the patient’s outcome.

”Our daughter had a type of cancer only diagnosed in 15-20 kids per year, extrarenal rhabdoid,” says Melissa Loudon, a two-time shavee, volunteer event organizer, Speak Up advocate, and now a St. Baldrick’s staff member. “The only reason she was diagnosed within two weeks is that our treatment facility had seen another child with a very similar type just a few months prior. That family had to wait over a month for diagnosis, and there were starkly different outcomes for our families. I have no doubt that the time frame from diagnosis to treatment played a role in that difference.”

Not only are more common cancer types easier to diagnose, they also have a better track record for progress.

In a more common cancer type, researchers have more scientific knowledge to build upon, and they are able to learn more from the larger number of patients on a higher number of clinical trials, to find more successful treatments, faster. When only a handful of children are diagnosed with a type of cancer each year, opportunities and resources for research are also limited.

When a cancer is found in both adults and children, often it behaves differently in children. Research funded by St. Baldrick’s proved this to be the case in acute myeloid leukemia (AML), for instance. In other cancers found more often in adults, like melanoma, there is not yet enough research to understand the differences that may exist, so children are often treated on adult protocols.

Because rare cancers have historically been neglected by industry, support from non-profits like the St. Baldrick’s Foundation is critical to learning how to treat these cancers.

Rare diseases are sometimes called orphan diseases, because most pharmaceutical companies do not focus on developing new drugs for them. The Orphan Drug Act of 1983 created some financial incentive for companies to do so. Since then, the Food and Drug Administration (FDA) has approved more than 400 new therapies for rare diseases, but the challenge remains.

What is St. Baldrick’s doing about rare cancers?

The St. Baldrick’s Foundation makes grants for all types of childhood cancer, including the most rare.

Here are a few examples:


The St. Baldrick’s Foundation has supported the North American Consortium for Histiocytosis (NACHO) since 2014. Histiocytosis is a group of rare disorders, most common in children, in which there is an over-production of white blood cells known as histiocytes that can lead to organ damage and tumor formation. Before NACHO, there was little progress in knowledge and new therapy development for this wide variety of conditions. NACHO has 49 member institutions working together and aims to keep expanding so that children all over North America will have access to clinical trials that could save their lives.

Studying the genetic code of rare cancers

Samara Potter, M.D., a Baldrick’s Fellow at Baylor College of Medicine, is using technology to look at the genetic code of rare tumors, to learn more about why and how they occur, as well as how they change over time. This knowledge will help to create tests to diagnose patients, as well as to develop more effective, less toxic treatments.

Her funding is generously supported by two St. Baldrick’s Hero Funds. The Invictus Fund honors the memory of Holden Gilkinson, who was diagnosed at the age of three with Stage IV anaplastic Wilms tumor, and passed away just days before his 7th birthday. The other is Oh Danny Boy I Love You So: The Danny O’Brien Rhabdoid Tumor Research Fund. Danny was just five months old when he was diagnosed with an extremely rare and aggressive rhabdoid tumor on his liver. He passed away at the tender age of nine months.

The Children’s Oncology Group (COG) is in a unique position to study rare cancers, with more than 200 member institutions across North America and beyond. Progress in rare cancers benefits from an international approach.

Adrenocortical carcinoma

The COG has published results of a St. Baldrick’s supported clinical trial for adrenocortical carcinoma, a rare cancer seen mostly in children. It was important to include patients from Brazil, particularly the Curitiba area, where the incidence is much higher than in the U.S.

From this trial, researchers were able to improve outcomes for patients with small tumors that could be removed (often very young patients) and those whose tumors could not be removed but had spread only locally. Another trial is being planned to seek improvements for those with large tumors or tumors that had spread to other organs.

Using tissue contributed by patients on this study, researchers have also identified several genetic mutations that commonly drive adrenocortical carcinoma tumors. It appears that patients with some types of mutations are less likely to be cured, and researchers hope to use this discovery to better define which patients need aggressive therapy.

Nasopharyngeal cancer

This rare type of cancer that starts in the upper part of the throat, behind the nose, is very different in children from adults. A COG study has shown very good outcomes for children given chemotherapy before and during radiation, even when the tumor had already spread. However, there are many long-term side effects of this therapy including a risk of hearing loss. A new trial is being designed that may test whether an immunotherapy may allow doctors to decrease the dose of radiation to reduce side effects.

St. Baldrick’s also partners with the COG on strategic initiatives that make an impact in the study of rare pediatric cancers.

High-Impact Initiative

Because there is a significant cost to research institutions to open a clinical trial, institutions lose money if they open a trial and then have no patients – or only one or two – who qualify. To solve this problem, the St. Baldrick’s Foundation supported the COG’s High-Impact Initiative. The COG chose a group of 3-5 clinical trials that have a low chance of enrollment. Each institution opening the entire set of these trials received $10,000 from the St. Baldrick’s grant to the COG. This balanced the financial risk to institutions, giving more kids access to potentially lifesaving trials, and shortening the time needed to complete these studies.


The cornerstone of the COG’s precision medicine research platform is Project:EveryChild. For those participating, researchers take extra tissue whenever the child must undergo a diagnostic procedure, and that tissue is stored in the COG’s biorepository. The COG also collects and securely maintains key information about the child, their cancer, treatment and outcomes. The key to discovery is this connection between the biospecimens and the data about each patient’s treatment and its effectiveness.

Through this initiative, for the first time, scientists will have the information on the biology and treatment outcomes they need to accelerate progress, especially for ultra-rare childhood cancers.

“Biobanking through Project:EveryChild is an invaluable resource to pediatric cancer researchers throughout the world,” says Douglas S. Hawkins, MD., Chair of the Children’s Oncology Group. “The St. Baldrick’s Foundation is the largest contributor to Project:EveryChild and an essential partner with COG.”

These are only a few examples of how St. Baldrick’s supporters are making an impact in all childhood cancers, even those most rare.

Join us today and #GiveKidsALifetime!


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