Adult Bone Cancer: Patient Guide

Cancer found in a bone is usually not bone cancer. ACS puts it plainly. Primary bone cancer starts in the bone. Bone metastasis starts somewhere else. It may begin in the breast, lung, or prostate, then spread to bone.

The two are treated by different teams with different drugs. Before anything else, ask which one your report describes. The answer sits in the pathology, not the scan.

Age narrows the list quickly. ACS describes six main types.

• Chondrosarcoma is the second most common primary bone cancer. It is rare before age 20, and risk climbs with age. It usually forms in cartilage of the pelvis, leg, or arm.
• Chordoma develops in the bones of the spine and is most often seen in older adults.
• Osteosarcoma is the most common primary bone cancer overall. It mainly affects ages 10 to 30. Still, ACS notes that about 1 in 5 cases occur in people over 60.
• Fibrosarcoma usually appears in middle-aged adults, mostly in the leg bones.
• Giant cell tumor of bone is most common in people in their 20s and 30s, usually in the arms or legs near the knee.
• Ewing sarcoma is the third most common type overall, but rare after age 30.

NCI describes chondrosarcoma as a group of bone tumors. The cells in them make too much cartilage. It strikes about 1 person per 200,000 each year in the United States. It is more common in adults.

The conventional type grows slowly. Rarer subtypes move faster, and NCI names four: dedifferentiated, myxoid, clear cell, and mesenchymal.

Symptoms NCI lists are pain that does not go away with rest, swelling, and a large mass on the affected bone.

Treatment leans on surgery. NCI notes that small conventional tumors may be cured by removing them. Cryosurgery, which freezes tumor tissue, is an option in some cases. Radiation is used when a tumor cannot be removed. Chemotherapy has limited effect here. NCI gives the reason. These tumors grow slowly, and chemotherapy works best on fast-dividing cells.

That last point explains a common confusion. Being offered no chemotherapy is not undertreatment in chondrosarcoma. It reflects how the tumor behaves.

NCI describes chordoma as a slow-growing cancer. It arises from notochord cells left over after birth. The notochord is an early structure that helps form the spine.

Chordomas grow along the spine, most often near the tailbone or at the base of the skull. Most people are diagnosed in their 50s and 60s. Only 5% occur in children.

Symptoms depend on location. Skull base tumors can cause headaches or double vision. Tailbone tumors can cause leg pain and problems with bladder or bowel control.

Workup uses MRI to size and locate the tumor. CT looks for spread. A biopsy confirms notochord cells under the microscope. Surgery is preferred when it is possible. Radiation follows surgery, or replaces it when surgery cannot be done. NCI reports average survival of about 10 years after diagnosis. It varies with location and with how completely the tumor was removed.

NCI puts osteosarcoma at 5.4 cases per million per year for ages 0 to 19. That is roughly 440 cases a year in that group. NCI also notes a harder course in the older teen and young adult range, usually defined as ages 18 to 40.

More than 50% of tumors arise in the long bones around the knee. The pelvis accounts for 7% to 9%.

NCI lists specific risk factors. They include past radiation exposure and Paget disease of bone. Inherited conditions raise risk too. Li-Fraumeni syndrome comes from TP53 variants. Hereditary retinoblastoma comes from RB1 variants. Rothmund-Thomson syndrome comes from RECQL4 variants. If any of those apply to you, say so before the workup starts.

This is the step people underestimate. NCI recommends a core needle biopsy or an open surgical biopsy. It should be done by a surgeon skilled in limb-sparing techniques.

The reason is practical. The biopsy track has to come out with the tumor at the real operation. A biopsy placed wrong can turn a limb-sparing surgery into an amputation.

So ask one question before any needle goes in: will the surgeon who would eventually operate be the one planning this biopsy?

The standard sequence is chemotherapy first, then surgery, then more chemotherapy. NCI names three standard drugs. They are methotrexate, doxorubicin, and cisplatin. NCI calls complete removal with clear margins essential for cure.

After the first round of chemotherapy, the pathologist measures how much of the tumor died. NCI reports that patients with at least 90% necrosis in the primary tumor have a better prognosis than those with less.

Below 90% is not a dead end. NCI reports event-free survival of 40% to 50% in that group. For patients who got no chemotherapy at all, it was 11%. With surgery alone, fewer than 20% of patients with local disease survive without relapse.

The overall trend has moved. NCI reports 5-year survival rising from 40% in 1975 to 72% in children under 15. For teens aged 15 to 19 it is about 71%.

Ewing sarcoma is defined by a genetic event. NCI names the translocation t(11;22)(q24;q12). It creates the EWSR1::FLI1 fusion gene. That fusion is present in 85% to 90% of pediatric cases.

Common primary sites are soft tissue at 19%, pelvis at 18%, the tibia, fibula, patella, or foot at 14%, rib at 11%, and femur at 11%.

Treatment combines chemotherapy with local control. NCI names five agents used. They are vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide. For teens aged 15 to 19, NCI reports the 5-year survival rate rising from 20% to 69%.

• Bone pain that does not ease with rest, or that wakes you at night.
• A firm swelling or mass over a bone, whether or not it hurts.
• Pain in the same spot lasting weeks without a clear injury.
• New leg pain with bladder or bowel changes. NCI lists this pair for chordoma near the tailbone. Loss of bladder or bowel control is an emergency. Call 911 or go to an emergency department.
• A bone that breaks after a minor fall. Ask whether the imaging showed anything abnormal in the bone itself.

• Is this a primary bone cancer or cancer that spread to bone?
• What exact type and subtype does the pathology name?
• Is this center a sarcoma center, and how many of these cases does it treat a year?
• Will the surgeon who would operate plan my biopsy?
• Is chemotherapy expected to help in my specific type?
• If chemotherapy comes first, when will the necrosis percentage be measured?

For related reading, see Pathology Reports, Getting a Second Opinion, and Cancer Staging.

• National Cancer Institute — Osteosarcoma and Undifferentiated Pleomorphic Sarcoma of Bone Treatment (PDQ), Health Professional Version
• National Cancer Institute — Ewing Sarcoma and Undifferentiated Small Round Cell Sarcomas of Bone and Soft Tissue Treatment (PDQ), Health Professional Version
• National Cancer Institute — Chondrosarcoma
• National Cancer Institute — Chordoma
• American Cancer Society — What Is Bone Cancer?