Ovarian cancer can spread to bones, though it does so less frequently than many other cancers. Bone metastasis from ovarian cancer is considered uncommon compared to the more typical spread patterns, which favor the peritoneum (the lining of the abdominal cavity), liver, and lungs. When it does reach bone, the spine and pelvis are the most frequent targets, and the diagnosis carries a median survival of about 7 months from the time the bone spread is identified.
Where It Typically Spreads in the Skeleton
Ovarian cancer has a strong preference for certain bones over others. In a clinical analysis of 26 patients with confirmed bone metastasis from ovarian cancer, the cervical spine (neck area) was involved in 12 cases, the lumbar spine (lower back) in 10, the pelvis in 8, and the thoracic spine (mid-back) in 7. The limbs were affected in 5 cases, while the ribs and sternum were rarely involved.
This pattern makes sense biologically. Bones with a rich blood supply and active marrow, like the vertebrae and pelvis, are more hospitable to circulating cancer cells. This is also why back pain and pelvic pain are often the first signs that ovarian cancer has reached bone.
Symptoms of Bone Metastasis
The most common symptom is bone pain that doesn’t go away with rest and tends to worsen over time. It often feels different from arthritis or a pulled muscle because it can be present at night and may intensify gradually over weeks. Some patients first discover bone involvement only after a fracture occurs from minimal trauma, called a pathological fracture, because the cancer has weakened the bone from within.
When the spine is involved, the consequences can be more serious. Pressure on the spinal cord can cause pain and stiffness in the neck or back, weakness in the arms or legs, loss of bladder or bowel control, or sudden urinary urgency. These symptoms require immediate medical attention because spinal cord compression can lead to permanent damage if not treated quickly.
High blood calcium levels (hypercalcemia) are another complication. As cancer breaks down bone tissue, calcium floods the bloodstream, which can cause nausea, confusion, excessive thirst, fatigue, and constipation. Hypercalcemia is treatable but needs to be caught early.
How Bone Spread Is Detected
Not all imaging is equally good at finding bone metastases. The most accurate method is a specialized PET/CT scan using a sodium fluoride tracer, which has a sensitivity of 100% and specificity of 97% in clinical studies. MRI is also highly effective, with 95% sensitivity and 90% specificity, and it can detect cancer inside the bone marrow before the outer bone shell shows any damage.
Standard bone scans, which have been used for decades, are considerably less reliable, picking up only about 78% of bone metastases and producing frequent false positives. Regular CT scans fall in a similar range at roughly 74% sensitivity. If your doctor suspects bone involvement, asking about PET/CT or MRI is reasonable, as these provide a much clearer picture.
What Timing Means for Prognosis
When bone metastasis appears relative to the original ovarian cancer diagnosis makes a dramatic difference in outcomes. In a study of patients with epithelial ovarian cancer, those who developed bone involvement within the first 12 months of their primary diagnosis had a mean overall survival of just 11.2 months from the time of their original cancer diagnosis. Patients whose bone metastases appeared later, more than 12 months after diagnosis, had a mean overall survival of 78.4 months from primary diagnosis. That gap is enormous and reflects the underlying aggressiveness of the cancer rather than the bone spread itself.
Once bone metastasis is identified, the median survival across all patients is about 7.2 months. This is a median, meaning half of patients live longer than this, sometimes substantially so, depending on how the cancer responds to treatment and how many other sites are involved.
Managing Pain and Preventing Fractures
Treatment for bone metastases focuses on two goals: controlling the cancer itself and protecting the skeleton from further damage.
Radiation therapy is one of the most effective tools for bone pain relief. About 70% of ovarian cancer patients treated with radiation for painful bone lesions experienced improvement within one month. However, bony sites respond less well than soft tissue sites, with a clinical response rate of around 44% for bone compared to 89% for soft tissue or lymph node locations. Common treatment schedules involve sessions spread over one to two weeks.
Bone-strengthening medications play an important role in reducing complications like fractures. These fall into two categories:
- Bisphosphonates work by embedding into bone and blocking the cells that break it down. They are given as an infusion or taken orally and have been the standard treatment for years.
- Denosumab is an injectable medication that targets the same bone-destroying process through a different mechanism. It is FDA-approved specifically for preventing fractures and other skeletal complications in patients with bone metastases from solid tumors, given as an injection every four weeks.
Both options slow the rate of bone destruction, reduce fracture risk, and can help with pain. Your oncologist will choose between them based on kidney function and other individual factors, since bisphosphonates can be harder on the kidneys.
Fracture Risk and Bone Weakness
Pathological fractures are one of the most feared complications of bone metastases. The more lesions present, the higher the likelihood of a painful break that limits mobility and often requires surgery. Doctors assess fracture risk by looking at how much of the bone’s outer wall has been destroyed by the tumor. When more than 50% of the bone cortex is affected, the risk of fracture rises substantially.
Weight-bearing bones like the femur (thigh bone) are particularly concerning. Scoring systems help doctors decide whether a weakened bone needs preventive stabilization with a rod or plate before it actually breaks, which leads to a much better recovery than treating a fracture after it happens. If you have known bone metastases and notice new or worsening pain in a limb, especially with weight-bearing activities, that warrants prompt evaluation.