Recurrent Osteosarcoma

Recurrent osteosarcoma is cancer that has returned after initial treatment or has not responded to therapy. It occurs in 30-50% of patients who initially had cancer confined to one area, and in 80% of patients who had cancer that had already spread at diagnosis.

Table of contents

• What is recurrent osteosarcoma?
• Where does osteosarcoma recur?
• Factors affecting outlook
• Treatment approach
• Types of treatment for recurrence
• Survival and outcomes

What is recurrent osteosarcoma?

Recurrent osteosarcoma means the cancer has come back after treatment or has not responded to the initial treatment. This is a challenging situation that affects a significant number of patients with osteosarcoma. Understanding what recurrence means and how it is treated can help patients and families make informed decisions about care.^[4]

Osteosarcoma is a type of bone cancer that most commonly affects adolescents and young adults. When the cancer returns, it requires different treatment strategies than were used for the original diagnosis. The patterns of recurrence and where the cancer returns play an important role in determining treatment options and outcomes.^[4]

Where does osteosarcoma recur?

The most common site where osteosarcoma spreads and recurs is the lungs. This is because cancer cells can break away from the original tumor in the bone and travel through the bloodstream to the lungs.^[4]

A smaller number of patients experience local recurrence, which means the cancer comes back in or near the same area where it started. Some patients may have only local disease with no evidence that the cancer has spread to other parts of the body. In these cases, surgical removal or amputation is typically the first treatment option. If surgery is not possible, radiation therapy may be the best approach.^[4]

Most patients with recurrent osteosarcoma actually have micrometastases, which are tiny clusters of cancer cells that have spread beyond the original cancer site but are too small to be detected by current imaging tests. These hidden cancer cells are why the disease can return even after the primary tumor appears to have been completely removed.^[4]

Factors affecting outlook

Several factors influence how well a patient with recurrent osteosarcoma may respond to treatment. The most important factor is whether the cancer can be completely removed with surgery.^[4]

The time between the original diagnosis and when the cancer returns also matters. A longer interval between the first diagnosis and recurrence is associated with a better outlook. Patients whose cancer takes longer to return tend to have more favorable outcomes than those whose cancer recurs quickly after treatment.^[4]

The location of the recurrence is also significant. Patients with recurrence in the lungs generally have a better prognosis than patients with cancer that has spread to other distant sites. This is because lung tumors can sometimes be cured if the cancer can be completely removed with surgery, followed by chemotherapy.^[4]

Before chemotherapy became standard treatment in the 1970s, more than 80% of osteosarcoma patients developed recurrent disease, typically appearing as lung tumors. This showed that most patients had hidden cancer cells at the time of diagnosis that could not be detected with available tests.^[7]

Treatment approach

Effective treatment of recurrent osteosarcoma requires both local and systemic therapy. Local therapy consists of surgery directed at removing the recurrent tumor. Systemic therapy is treatment aimed at eliminating cancer cells throughout the body, and usually consists of chemotherapy.^[4]

Systemic therapy is necessary in addition to local treatment to maximize a patient’s chance of cure. Because micrometastases may be present but undetectable, treatment with chemotherapy is needed to target these hidden cancer cells. Without systemic treatment, the presence of micrometastases can cause osteosarcoma to recur again following surgery alone.^[4]

The approach to treating recurrent osteosarcoma requires a team of specialists working together. This multi-disciplinary team may include a primary care physician, an orthopedic surgeon experienced in bone tumors, a pathologist, radiation oncologists, pediatric oncologists, rehabilitation specialists, pediatric nurse specialists, and social workers.^[4]

An experienced team is best found in a specialty cancer center that treats many patients with osteosarcoma. Working with a multidisciplinary team at one of these centers helps ensure that patients receive treatment, supportive care, and rehabilitation that will achieve the best possible survival and quality of life.^[4]

Typically, patients undergo chemotherapy followed by surgery and then additional chemotherapy after the surgery. This multi-step approach addresses both visible tumors and potential microscopic disease.^[4]

Types of treatment for recurrence

Treatment plans for recurrent osteosarcoma depend on whether the cancer has returned only locally or has spread to distant sites like the lungs. Each situation requires a different approach.

For patients with only local recurrence and no evidence of spread, the first line of treatment is surgical removal or amputation of the affected area. If surgery is not feasible, local radiation therapy is usually the best option. Research from the United Kingdom found that patients with only local recurrence who were treated with surgical removal, radiation therapy, or amputation had a five-year survival rate of 41%.^[4]

For patients with cancer that has spread or returned in multiple locations, treatment is more complex. The ability to completely remove all visible cancer with surgery remains the most important factor determining whether treatment will be successful. In some cases, surgery may not be possible. When this occurs, chemotherapy becomes the main treatment option.^[4]

Because osteosarcoma is not particularly responsive to radiation therapy, surgery is considered the only option for definitive removal of tumors when possible. Surgeons may need to perform complex procedures involving special types of joint replacements or bone reconstruction following tumor removal.^[7]

In some cases, participation in a clinical trial using new, innovative therapies may provide the most promising treatment option. Clinical trials test new treatments that are being developed to improve outcomes for patients with recurrent disease.^[4]

Survival and outcomes

The outlook for patients with recurrent osteosarcoma is challenging. Patients with a recurrence face lower survival chances compared to those whose cancer has not returned. Treatment of metastatic or locally recurrent osteosarcoma remains an incompletely answered challenge, and patients in such cases find themselves in a particularly difficult situation.^[7]

Despite the challenges, some patients can achieve long-term survival, especially when surgery can completely remove all visible cancer. The combination of surgery to remove tumors and chemotherapy to target hidden cancer cells offers the best chance for controlling the disease.^[4]

The potential benefits of treatment, including multi-modality care or participation in a clinical trial, must be carefully balanced with the potential risks. Circumstances unique to each patient’s situation influence how treatment principles are applied and whether a patient decides to pursue treatment. The information about treatment options is intended to help patients make shared decisions with their treating cancer physician.^[4]