Ewing’s Sarcoma vs. Osteosarcoma

Ewing’s sarcoma and osteosarcoma are both rare and aggressive forms of bone cancer. While the two conditions are similar in some ways, they differ markedly in others. A thorough understanding of the differences is crucial to ensure a tailored diagnosis and effective treatment strategy.

Ewing’s sarcoma

Ewing’s sarcoma is a highly aggressive bone cancer that predominantly affects adolescents and young adults. Often originating in the pelvis, chest wall or long bones of the extremities, the cancer is marked by its rapid growth and potential to spread or metastasize.

When viewed under a microscope, Ewing’s sarcoma cells are small, round, blue and often arranged in solid sheets. The cancer’s defining feature is specific chromosomal translocations involving the EWSR1 gene. Specifically, the genetic material in chromosomes #11 and #22 is mismatched. The chromosomal change is not inherited but rather takes place in a single cell after birth. Central to the diagnosis of Ewing’s sarcoma, this genetic aberration can help a physician distinguish the cancer from other bone tumors.

Clinical presentation and diagnosis of Ewing’s sarcoma

Common symptoms of Ewing’s sarcoma include localized pain, tenderness and swelling at the tumor site. Because the cancer may develop deep within the pelvis or chest wall, early detection can be challenging. Additionally, many symptoms of Ewing’s sarcoma are specific to the affected area of the body. For instance, a tumor in the chest wall may cause difficulty breathing.

The diagnostic process for Ewing’s sarcoma typically involves imaging tests, such as X-rays, computed tomography (CT) scans and magnetic resonance imaging (MRI) scans, which are combined with a biopsy to confirm the diagnosis.

Treatment of Ewing’s sarcoma

Usually, Ewing’s sarcoma is treated with a combination of surgery and chemotherapy. The goal of surgical treatment is to remove the tumor in its entirety. The procedure may be preceded by chemotherapy to shrink the tumor and make it easier to remove, and/or followed by aggressive chemotherapy to target any remaining cancer cells and help prevent a recurrence. In some cases, particularly where complete surgical resection is challenging, radiation therapy may be considered to manage further cancer growth.

Osteosarcoma

Like Ewing's sarcoma, osteosarcoma primarily affects adolescents and young adults. However, its origin lies in the metaphysis, the rapidly growing end of long bones.

More common than Ewing’s sarcoma, osteosarcoma is characterized by an overproduction of abnormal bone-forming cells, which amass and form cancerous bone tumors. While the cancer can occur in any bone, it most commonly arises in the upper leg bone (femur) and shinbone (tibia) near the knee, and the upper arm bone (humerus) near the shoulder.

Clinical presentation and diagnosis of osteosarcoma

The hallmark sign of osteosarcoma is persistent and unexplained bone pain, which may be accompanied by tenderness, swelling and redness. Sometimes, a lump can be felt near the affected bone.

Diagnostic images, such as X-rays, CT scans and MRI scans, are often used to help a physician visualize the tumor and assess its characteristics. A biopsy confirmation is necessary for a definitive diagnosis, allowing for the precise classification of the tumor. This information is essential for planning treatment.

Treatment of osteosarcoma

The cornerstone of osteosarcoma treatment is a combination of surgery and chemotherapy. Surgery involves removing the tumor and affected bone with the goal of preserving limb function when possible. Limb-sparing surgery, which involves replacing the removed bone segment with a prosthesis or bone graft, is a common approach. Chemotherapy may be administered before surgery to shrink the tumor or after surgery to target any remaining cancer cells and reduce the risk of recurrence. The collaboration of orthopedic surgeons, oncologists, and other specialists is crucial for tailoring the treatment plan to the unique aspects of each case.

Benefit from world-class care at Moffitt Cancer Center

If you would like to learn more about the similarities and differences between Ewing’s sarcoma and osteosarcoma, you can talk with a specialist in Moffitt’s Sarcoma Program. To request an appointment, call 1-888-663-3488  or submit a new patient registration form online. We do not require referrals.