Community Spotlight: Rare Cancers

Rare cancers affect fewer than 40,000 people per year in the United States. These cancers make up about a quarter of all cancers and account for about a quarter of all cancer deaths. Because they are less common than other cancers, they can be harder to diagnose. Overall, information on rare cancers can be tricky to find.¹

Which cancers are rare cancers?

Some cancers are considered rare because of the people they occur in. For example, all children’s cancers (in those aged 0 to 15) are considered rare. There are about 10,500 cases of children’s cancer per year in the United States. Cancers that can occur in children include:^1-3

• Brain tumors
• Neuroblastoma, a type of cancer that affects nerve cells
• Leukemia, a type of blood cancer
• Immune cell tumors, such as Hodgkin and non-Hodgkin lymphoma
• Kidney tumors, such as Wilms tumor or clear cell renal cell carcinoma
• Retinoblastoma, a cancer of the eye
• Bone cancers, such as adamantinoma or chordoma
• Rhabdomyosarcoma, a type of cancer that normally develops in muscle cells

Also, researchers have learned that more common cancers can have rare subtypes. For example, lung cancer, ovarian cancer, and cervical cancer can have rare subtypes. Mesothelioma is a rare type of lung cancer. Small cell cancer of the cervix is a rare type of cervical cancer.^4-6

Other types of cancer that are rare in adults include:^4,7

• Thyroid cancer
• Acute lymphoblastic leukemia (ALL)
• Mouth cancer
• Breast cancer in men

Diagnosing rare cancers

Rare cancers are difficult to diagnose and treat. The main reasons for this include:^1,8

• Doctors see fewer people with rare cancers, so they have less experience diagnosing those cancers.
• It is hard to find doctors that know about a specific rare cancer.
• Symptoms of rare cancers can be difficult to spot if they are the same as symptoms of other, more common conditions.

Much of what experts know about cancer has been learned from clinical trials or research studies. But there are fewer research studies and clinical trials for rare cancers because they are harder to conduct. There are fewer people who can take part in the research studies. There also may not be animal or cell models available to study for a certain type of cancer.^1,8

Treating rare cancers

It can be hard to find doctors or specialist centers that treat a specific rare cancer. You may have to travel farther to find a doctor who knows more about the cancer. And different doctors may disagree about how to treat or manage a rare cancer.^1,8,9

Also, people with symptoms of a rare cancer may not know what the symptoms mean. They may not see a doctor until the cancer has already progressed to a later stage and is harder to treat. Many rare cancers do not have an established treatment.⁷

Some rare subtypes of common cancers may be able to be treated the same way the common cancer would. Others may be treated differently. For example, small cell cancer of the cervix is treated differently than other cervical cancers.⁹

Living with a rare cancer

Useful information about rare cancers can be hard to find. Ask your doctor about websites where you can find more information online. There may be several names that describe your cancer type. Your doctor can give you more details about these names.⁸

Your doctor also may be able to help you find research studies and clinical trials for your specific type of rare cancer.