What is the prognosis of breast cancer with extensive bone (bony) metastases and solid organ involvement?

From the Guidelines

The prognosis for breast cancer with extensive bone metastases and solid organ involvement is generally poor, with median survival typically ranging from 1-3 years, though individual outcomes vary significantly. Treatment focuses on extending life while maintaining quality of life through systemic therapies like hormone therapy (tamoxifen, aromatase inhibitors, or fulvestrant), targeted therapies (trastuzumab for HER2+ disease), chemotherapy (taxanes, anthracyclines, capecitabine), and CDK4/6 inhibitors (palbociclib, ribociclib, abemaciclib) 1.

Key Considerations

• Bone-directed therapies such as bisphosphonates (zoledronic acid 4mg IV monthly) or denosumab (120mg subcutaneously monthly) are essential to reduce skeletal complications 1.
• Prognosis depends on several factors including tumor subtype (hormone receptor and HER2 status), treatment response, performance status, extent of metastases, and prior treatments 1.
• Triple-negative breast cancer generally has a worse prognosis than hormone-positive disease.
• While metastatic breast cancer remains incurable, advances in treatment have improved survival rates, with some patients living significantly longer than the median, particularly those with hormone-positive disease who respond well to therapy 1.

Treatment Approach

• The choice of therapy should be made after consideration of factors such as previous therapies and response to them, disease-free interval, endocrine responsiveness, HER2 status, tumour burden, menopausal status, biological age, and co-morbidities 1.
• Patients’ preferences should always be taken into account not only about treatment options but also methods of treatment administration (intravenous or oral) 1.
• Radiation therapy is an integral part of palliative treatment, especially for bone metastases that are painful or carry a risk of fractures and/or neurological complications 1.

Bone Health

• Bisphosphonates have shown treatment benefits for breast cancer patients with bone metastases, reducing the frequency of skeletal morbidity and delaying the onset of skeletal-related events 1.
• The optimal duration of bisphosphonate therapy has not been well defined, but continuation of therapy should be reconsidered at 2 years, taking into account the presence of active cancer or existing focus of bone metastasis 1.

From the FDA Drug Label

The majority of patients on study were White (74%), all patients had an ECOG PS of 0 or 1, and 80% were postmenopausal. All patients had received prior systemic therapy, and 75% of patients had received a previous chemotherapy regimen Twenty-five percent of patients had received no prior therapy in the metastatic disease setting, 60% had visceral metastases, and 23% had bone only disease.

The prognosis of breast cancer with extensive bony mets and solid organs is poor.

• Median OS for patients with visceral metastases was not explicitly stated in the label for the specific case of extensive bony mets and solid organs.
• Overall survival results from PALOMA-2 and PALOMA-3 were not statistically significant, but the studies did not specifically address the prognosis of breast cancer with extensive bony mets and solid organs 2.

From the Research

Prognosis of Breast Cancer with Extensive Bony Mets and Solid Organs

The prognosis of breast cancer with extensive bony metastases and solid organs is generally poor. According to 3, bone metastases account for 3.5% of the entire cohort and 56.7% of all metastatic cases in HER2-positive breast cancer patients.

Factors Affecting Prognosis

Several factors can affect the prognosis of breast cancer patients with bone metastases, including:

• Age: Older patients tend to have a poorer prognosis 3
• Presence of brain, liver, or lung metastases: These can significantly worsen the prognosis 3
• PR status: Patients with positive PR status may have a better prognosis 3
• Surgery and chemotherapy: These treatments can improve the prognosis 3
• Extent of bone metastases: More extensive bone metastases can worsen the prognosis 4

Treatment Options

Treatment options for breast cancer patients with bone metastases include:

• Local therapies such as surgery, radiation therapy, and radiofrequency ablation (RFA) 4
• Systemic therapies such as endocrine therapy, chemotherapy, monoclonal antibody-based therapy, bone-enhancing therapy, and radioisotope therapy 4
• Combination therapies such as trastuzumab plus anastrozole or letrozole 5, 6
• Novel bone-specific targeted therapies 4

Survival Prediction

A nomogram can be constructed based on the Cox proportional hazards regression model to predict cancer-specific survival (CSS) for HER2-positive breast cancer patients with bone metastases 3. The nomogram can include factors such as age, brain metastases, liver metastases, lung metastases, PR status, surgery, and chemotherapy. The C-index of the nomogram can be used to evaluate its accuracy, and the calibration curve can be used to evaluate its reliability.

Case Reports

There are case reports of patients with HER2-positive and hormone receptor-positive metastatic breast cancer achieving durable and drastic responses to combination therapies such as trastuzumab, letrozole, abemaciclib, and goserelin 7. These reports suggest that combination therapies can be effective in treating breast cancer patients with bone metastases and solid organs.