Who this is for
Denosumab and breast cancer recurrence are often discussed together, but the evidence is not straightforward.
This article is for women with early breast cancer who want to understand whether denosumab can protect their bones and whether it may also reduce the chance of breast cancer returning.
“I’ve done the surgery. I’m willing to do chemotherapy. I’ll take hormone tablets for 10 years. What else can I do to reduce my chance of the cancer coming back?”
This is one of the most common—and most important—questions I hear in my clinic.
Clinical observation
A 48-year-old mother of two teenagers came to see me after surgery for hormone receptor-positive breast cancer.
Her pathology showed 6 of 16 lymph nodes contained cancer, placing her in a higher-risk group.
She understood she would undergo chemotherapy, ovarian suppression, endocrine therapy and radiotherapy.
Then she asked a question that stopped the consultation for a moment.
“Doctor… is there anything else I can do? I want to see my children grow up. I want to meet my grandchildren.”
The names and details change.
The question rarely does.
What surprised me
Most people know denosumab as a medication that strengthens bones.
What surprised me was that researchers have also studied whether denosumab might do more than strengthen bones. By blocking a protein called RANKL, it may also affect the chance of breast cancer returning, although this has not yet been proven.
Although the evidence remains mixed, this pathway has generated enormous scientific interest and continues to be investigated, including in women with inherited BRCA1 mutations.
Why denosumab and breast cancer recurrence research matters
Patients often hear denosumab discussed in very different situations.
One woman may receive it for osteoporosis.
Another may receive it to protect her bones during breast cancer treatment.
A patient with breast cancer that has spread to bone may receive a much higher dose.
The doses, goals and evidence are different in each situation.
Understanding these differences helps patients know what denosumab can—and cannot—do.
What is denosumab?
Denosumab is a monoclonal antibody that blocks RANK Ligand (RANKL).
RANKL stimulates osteoclasts, the cells responsible for breaking down bone.
By blocking RANKL, denosumab:
- strengthens bone
- reduces fractures
- reduces skeletal complications from cancer that has spread to bone
- may influence the tumour microenvironment, an area of ongoing research.
There are three very different reasons we use denosumab
Understanding these differences is extremely important because patients often hear different doses from others in support groups.
Osteoporosis during breast cancer treatment
This is the most common indication in early breast cancer.
Many women receiving:
- aromatase inhibitors
- ovarian suppression
- early menopause induced by treatment
develop accelerated bone loss.
If a bone density (DEXA) scan shows osteoporosis or significant bone thinning, denosumab may be recommended. The decision depends on the patient’s risk of fractures, medical history and other available treatments.
Standard dose – 60 mg injected under the skin every 6 months.
In Australia, PBS subsidy may be available for eligible patients who meet the current osteoporosis criteria.
Preventing fractures during adjuvant breast cancer therapy
The ABCSG-18 trial studied postmenopausal women with hormone receptor-positive early breast cancer who were receiving aromatase inhibitor treatment.
The study used denosumab:
60 mg every 6 months
Denosumab significantly reduced the risk of clinical fractures and improved bone mineral density.
Longer follow-up also showed a possible improvement in disease-free survival. However, preventing breast cancer recurrence was not the study’s primary purpose, so this finding needed confirmation.
The larger D-CARE trial studied a higher-risk early breast cancer population using a more intensive denosumab schedule.
D-CARE did not demonstrate an improvement in bone metastasis-free survival, disease-free survival or overall survival.
Because the two major trials produced different results, current guidelines do not recommend denosumab solely to prevent breast cancer recurrence.
Its established role in early breast cancer remains protecting bone health in appropriately selected patients.
Does being high risk change the recommendation?
Several positive lymph nodes, a larger tumour or higher-risk tumour biology can increase the chance of breast cancer returning.
However, high recurrence risk alone does not currently make denosumab a standard treatment for preventing recurrence.
The decision to use denosumab in early breast cancer is generally based on factors such as:
- Bone density
- Osteoporosis or fracture risk
- Menopausal status
- Aromatase inhibitor or ovarian suppression treatment
- Other medical conditions affecting bone health
For some postmenopausal patients, adjuvant bisphosphonate treatment may also be discussed because the evidence for reducing breast cancer recurrence is stronger than it is for denosumab.
A woman with six positive lymph nodes would clearly be considered at higher risk of recurrence. However, this would not automatically mean that she should receive denosumab.
Breast cancer that has spread to bone
This is a completely different situation.
When breast cancer has spread to the bones, treatment usually aims to control the cancer for as long as possible while preventing complications such as:
- fractures
- spinal cord compression
- surgery to bone
- radiotherapy to painful bone lesions
The standard starting dose is:
120 mg every 4 weeks
Some oncologists—including in my own practice—may consider extending the interval between doses after prolonged disease stability. However, the evidence is still evolving, particularly for denosumab, so this decision must be individualised.
What about BRCA1?
One of the most exciting areas of research involves women carrying BRCA1 mutations.
Laboratory studies suggest the RANK/RANKL pathway may play an important role in BRCA1-associated breast cancer development.
Clinical studies such as BRCA-P are investigating whether denosumab could reduce the future risk of breast cancer in these women.
This research is ongoing and should currently be regarded as investigational rather than established standard of care.
What this means for my patients
For women with hormone receptor-positive early breast cancer, the treatments with the strongest evidence for reducing recurrence may include:
- appropriate surgery
- Chemotherapy when indicated
- radiotherapy
- endocrine therapy
- ovarian suppression when appropriate
Maintaining a healthy weight, staying physically active and protecting bone health also support long-term health and recovery.
Denosumab is an important medication for protecting bone health.
However, the evidence that it prevents breast cancer recurrence remains conflicting.
For this reason, denosumab is not routinely recommended solely as an anticancer treatment in early breast cancer.
For patients at higher risk of recurrence, it may be more useful to discuss bone density, menopausal status and whether another bone-strengthening medicine called a bisphosphonate may be appropriate.
Key takeaways
- Denosumab has several different roles in breast cancer care
It may be used for osteoporosis, treatment-related bone loss or complications from cancer that has spread to bone. - Denosumab is effective at protecting bones
It can reduce fractures and improve bone strength in appropriately selected patients. - Its effect on breast cancer recurrence remains uncertain
Research findings have been conflicting, so it is not routinely recommended solely to prevent recurrence. - Treatment must be individualised
Bone density, menopausal status, cancer treatment, fracture risk and dental health all need to be considered.
Key evidence
- Gnant M, Pfeiler G, Dubsky PC, et al. Adjuvant denosumab in breast cancer (ABCSG-18): a multicentre, randomised, double-blind, placebo-controlled trial. Lancet. 2015;386(9992):433-443. doi:10.1016/S0140-6736(15)60995-3
- Gnant M, Pfeiler G, Steger GG, et al. Adjuvant denosumab in postmenopausal patients with hormone receptor-positive breast cancer (ABCSG-18): disease-free survival results from a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Oncol. 2019;20(3):339-351. doi:10.1016/S1470-2045(18)30862-3
- Coleman R, Finkelstein DM, Barrios C, et al. Adjuvant denosumab in early breast cancer (D-CARE): an international, multicentre, randomised, controlled, phase 3 trial. Lancet Oncol. 2020;21(1):60-72. doi:10.1016/S1470-2045(19)30687-4
- Eisen A, Somerfield MR, Accordino MK, et al. Use of adjuvant bisphosphonates and other bone-modifying agents in breast cancer: ASCO-OH (CCO) guideline update. J Clin Oncol. 2022;40(7):787-800. doi:10.1200/JCO.21.02647
- Early Breast Cancer Trialists’ Collaborative Group. Adjuvant bisphosphonate treatment in early breast cancer: meta-analyses of individual patient data from randomised trials. Lancet. 2015;386(10001):1353-1361. doi:10.1016/S0140-6736(15)60908-4
- Stopeck AT, Lipton A, Body JJ, et al. Denosumab compared with zoledronic acid for the treatment of bone metastases in patients with advanced breast cancer: a randomized, double-blind study. J Clin Oncol. 2010;28(35):5132-5139. doi:10.1200/JCO.2010.29.7101
- Nolan E, Vaillant F, Branstetter D, et al. RANK ligand as a potential target for breast cancer prevention in BRCA1-mutation carriers. Nat Med. 2016;22(8):933-939. doi:10.1038/nm.4118
Frequently asked questions (FAQs)
- I have several positive lymph nodes. Should I receive denosumab?
Not necessarily.
The decision depends on your bone health, menopausal status, fracture risk, current treatment and whether the cancer has spread to bone.
Positive lymph nodes alone are not a reason to receive denosumab.
- Is denosumab chemotherapy?
No. It is a targeted monoclonal antibody that works on bone metabolism by blocking the RANKL pathway.
- Does everyone receiving hormone tablets need denosumab?
No. Many women do not. A bone density (DEXA) scan helps determine who is most likely to benefit.
- Can denosumab cure breast cancer?
No. It is not a substitute for surgery, chemotherapy, endocrine therapy or radiotherapy. Its established role is protecting bone health, while its potential anticancer effects continue to be studied.
Dr Dilanka De Silva
MBBS, MRCP(UK), MRCP(UK SCE Oncology), FRACP, PhD
Medical Oncologist & Cancer Genetics Physician
Memorial Sloan Kettering Cancer Center Fellow (New York, USA)