When it comes to cancer, the sheer numbers can be overwhelming. For example, consider the fact that roughly 2 million people will be diagnosed with cancer this year, and they could be impacted by 100 different types of cancer.

Of those cancers, many are rare and may sound unfamiliar. One of those less-talked-about cancers is called sarcoma, and July is recognized as Sarcoma Awareness Month with the intent to educate people and support those who have been diagnosed with this kind of cancer.

In honor of Sarcoma Awareness Month, here’s what you should know.

1. There are many different types of sarcomas, including more than 100 subtypes. This type of cancer starts in a person’s bones or soft tissue, such as their muscles, fat, blood vessels, blood vessels, nerves, tendons or joint lining, according to the Mayo Clinic. 

2. It’s known as the forgotten cancer. That’s because sarcomas are rare, amounting to about 1% of cancer diagnoses in adults and 15% in children. About 16,000 cases are diagnosed in a year, according to the Cleveland Clinic.

3. Sarcomas may present as lumps and bumps. Because there are so many different subtypes of sarcomas, it’s best not to generalize about signs and symptoms. However, some can appear as lumps or bumps on your skin, so it’s important to bring any swelling or new appearances to the attention of your healthcare provider. 

4. They’re more common in some areas of the body than others. Those include the legs, ankles and feet (40%); the trunk, chest, abdomen and pelvis (30%); shoulders, arms, wrists and hands (15%); and the head and neck (15%), according to the Cleveland Clinic.

5. Scientists don’t fully understand what causes sarcomas to develop. Still, there are some risk factors for sarcomas to be aware of, says the Sarcoma Foundation of America, including DNA mutations, inherited syndromes, radiation therapy, chronic swelling from lymphedema, exposure to certain chemicals and even exposure to certain viruses, like herpesvirus 8, which may increase the risk for a type of sarcoma called Kaposi’s sarcoma in some individuals.

6. Early detection is critical. Identifying sarcomas early can help improve the odds of successful treatment and prognosis, according to the American Oncology Institute. Generally, sarcomas are diagnosed using imaging tests, such as MRI, CT scans and X-rays, along with biopsies and lab work. That’s why it’s important to have regular check-ups with your primary care provider so they can detect any changes and you can ask any and all health-related questions you might have.

7. You can wear yellow in July to show support. Grab a yellow ribbon or throw on a yellow shirt and show you care. You may see others on social media doing the same as a way of standing in solidarity with family and friends who have sarcoma. 

When should you ask for help? If you notice a mass on your body that’s larger than a golf ball (5 centimeters), or you’re experiencing bone pain not related to an injury that doesn’t go away, make an appointment with your doctor.