Can metastasis of breast cancer cause fever?

Metastatic Breast Cancer and Fever

Yes, metastasis of breast cancer can cause fever, particularly in cases of extensive liver metastases or progressive disease. Fever may be a manifestation of cancer progression or recurrence and can sometimes be the first sign of disease recurrence in breast cancer patients 1.

Mechanism and Presentation of Cancer-Associated Fever

Fever in metastatic breast cancer can occur through several mechanisms:

• Direct tumor-associated fever (paraneoplastic syndrome)
• Extensive liver involvement
• Tumor necrosis during treatment
• Viral reactivation in immunocompromised state due to progressive disease

Clinical Characteristics of Tumor-Associated Fever

• Often occurs with extensive liver metastases 2
• May present without significant elevation in inflammatory markers (CRP <5 mg/dl in many cases) 2
• Can persist for more than one week
• Not typically associated with significant leukocytosis (WBC <10,000/mm³) 2
• May be the first manifestation of disease recurrence in some patients 1

Diagnostic Approach

When evaluating fever in a patient with metastatic breast cancer, it's important to:

1. Rule out other causes of fever - Tumor-associated fever is a diagnosis of exclusion 1

2. Assess disease status - New sites of metastases or progression of existing disease should be evaluated, particularly focusing on:

   • Liver metastases (most common site associated with fever) 2
   • Bone marrow involvement
   • Lung metastases 1

3. Monitor tumor markers - Rising tumor markers (CEA, CA15-3, CA27.29) may indicate disease progression 3

Prognostic Significance

The presence of tumor-associated fever in metastatic breast cancer has prognostic implications:

• Patients whose fever responds to systemic therapy (along with tumor response) have better overall survival 1
• Patients with progressive disease and persistent fever despite treatment have poorer outcomes 1, 2
• In one study, 4 out of 5 patients with liver metastases and fever who did not respond to chemotherapy died within 6 months 2

Management Considerations

The primary approach to managing tumor-associated fever in metastatic breast cancer is treating the underlying malignancy:

• Systemic therapy - Chemotherapy or hormonal therapy that results in tumor response often leads to resolution of fever 1
• Supportive care - For patients with progressive disease and DNR orders, palliative care focusing on symptom management should be prioritized 4
• Monitoring - Regular assessment of disease status through imaging and tumor markers is essential 3

Special Considerations

In patients with oligometastatic disease (single or few detectable metastatic lesions), a more aggressive multidisciplinary approach may be considered, as this subset represents potentially curable stage IV disease (estimated at 1-10% of newly diagnosed metastatic breast cancer patients) 3.

Pitfalls to Avoid

1. Misattribution of fever - Don't assume all fevers in metastatic breast cancer patients are infection-related; tumor-associated fever is a real entity
2. Overlooking disease progression - Unexplained fever may be the first sign of disease recurrence or progression
3. Inadequate monitoring - Regular assessment of disease status is crucial in patients with metastatic breast cancer who develop fever

In conclusion, fever can be a significant manifestation of metastatic breast cancer, particularly with liver involvement, and often indicates disease progression. Response of fever to systemic therapy correlates with tumor response and overall survival.