Bone cancer on the skull is a rare condition. It refers to a group of cancers, with the most common being chordoma.

Chordomas develop in the spine’s bones or at the base of the skull. They usually grow in the remnants of the notochord, which is a part of a developing embryo that eventually becomes the spinal cord.

While several genes may contribute to their development, researchers have not yet identified a definitive genetic marker.

According to the American Cancer Society (ACS), primary bone cancers account for 1% of all cancers. They tend to grow slowly but can be aggressive. Survival rates are highest with prompt, early treatment that removes the entire tumor.

Other types of bone cancer can also affect the skull, including chondrosarcoma and osteosarcoma. Cancer from elsewhere in the body may also metastasize or spread to the bones of the skull.

This article will explain what bone cancer on the skull is, including symptoms, causes, and treatments.

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Bone cancer develops in the bones on or around the skull or in the cartilage.

Like other types of bone cancer, bone cancer on the skull comes in two forms: Primary bone cancer and secondary bone cancer.

Primary bone cancer is bone cancer that begins in the bones of the skull. Secondary bone canceris bone cancer that begins somewhere else in the body, then metastasizes or spreads to the bones of the skull.

Primary bone cancer is very rare, and bone cancer on the skull is even rarer.

The most common type of cancer on the skull base is a chordoma tumor.

Chordomas are soft tumors that may contain hemorrhages. They tend to spread slowly but are aggressive locally, so they can quickly attack nearby regions. They also frequently regrow even after surgical removal.

Chordomas develop along the spine from the remnants of the notochord. They can also affect the base of the skull. The notochord is the tissue in an embryo that gives rise to the spinal cord. This type of cancer is most common in people aged 40–60 but can occur in children and older people.

Other cancers that affect bone may also affect the skull. They include:

  • Osteosarcoma: More common in children and young adults, this cancer most frequently affects the arms, legs, and pelvis. It can, however, develop in any bone. It is the most common bone cancer in young people.
  • Ewing sarcoma: This usually affects the bones but can also affect soft tissue. It is the second most common bone cancer in children and the third most common in adults.
  • Chondrosarcoma: This cancer begins in cartilage cells. The risk increases as people age. In rare cases, it affects the bones of the skull or the skull base.

The symptoms of bone cancer on the skull vary depending on the exact location and size of the cancer, as well as the type of cancer. The most common symptoms of chordomas include:

Many people with chordomas do not have symptoms in the early stages of the tumor.

Other types of bone cancer may cause:

Researchers do not fully understand what causes bone cancer, including on the skull. Chordomas are more common in midlife, and males are twice as likely to get them than females. Scientists have identified several genetic mutations that increase the risk, and sometimes chordomas cluster in families.

Paget disease of the bone and prior treatment with radiation may increase the risk of developing other types of bone cancer.

Treatment for bone cancer on the skull depends on several factors, including the tumor’s location and whether it is safe to operate.

In most cases, surgically removing the tumor is a primary treatment goal. Thereafter, a doctor may recommend:

  • chemotherapy
  • radiation
  • a combination of the two

In some cases, targeted therapies or immunotherapy may be available.

Chordomas are generally resistant to most types of chemotherapy and most targeted treatments. Because the tumors can regrow, doctors generally recommend ongoing follow-up even after surgical removal.

The outlook depends on multiple factors, such as:

  • the stage of cancer
  • whether it has spread
  • the size of the tumor
  • whether it is possible to operate on the tumor
  • how healthy a person is because this may determine which types of treatment they can tolerate

For chordomas, the overall 5-year survival rate is 50%. If a doctor can completely remove the tumor, this figure rises to 65%. However, tumors often regrow. If a tumor is inoperable, the 5-year survival rate is around 40%.

The cancer survival rate means the percentage of people who are still alive after that particular amount of time.

Researchers have not identified any specific strategy to prevent skull bone cancers. People with a history of radiation treatment may need ongoing screenings for cancer.

People who have previously had a chordoma may need ongoing magnetic resonance imaging (MRI) scans to look for signs of cancer recurrence.

Bone cancer can be a scary diagnosis, and some bone cancers are aggressive. Many types occur in young and otherwise healthy people. The outlook in all forms of bone cancer is more favorable if a person gets an early diagnosis and proper treatment.

A person should see a doctor for any signs of bone cancer.

Bone pain, bone weakness, broken bones, and neurological symptoms such as headaches may signal bone cancer. People should discuss their treatment options with a specialist.