What is inflammatory breast cancer and its treatment?

Inflammatory Breast Cancer: Diagnosis and Treatment

Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer requiring prompt diagnosis and multimodality treatment with neoadjuvant chemotherapy, surgery, and radiation therapy to optimize survival outcomes. 1

Clinical Presentation and Diagnosis

IBC presents with distinctive clinical features that differentiate it from other breast cancers:

• Rapid onset of breast erythema, edema, and/or peau d'orange (orange peel appearance)
• Duration of symptoms typically less than 6 months
• Erythema occupying at least one-third of the breast
• Often presents without an underlying palpable mass 1

Diagnostic Criteria

The American Joint Committee on Cancer (AJCC) defines IBC as "a clinicopathological entity characterized by diffuse erythema and edema of the breast, often without an underlying palpable mass." 2

Minimum requirements for diagnosis include:

• Clinical presentation with rapid onset of symptoms
• Pathological confirmation of invasive carcinoma 2

Dermal lymphovascular tumor emboli seen on skin punch biopsy is pathognomonic but not required for diagnosis. 1

Common Pitfalls in Diagnosis

• IBC is frequently misdiagnosed as mastitis or generalized dermatitis, leading to critical delays in treatment 1
• IBC accounts for only 1-5% of all breast cancer cases in the United States, making it a rare condition that clinicians may not immediately recognize 1
• Neglected locally advanced breast cancer may be confused with true IBC 2

Biological Characteristics

IBC has unique biological features:

• Higher prevalence of triple-negative and HER2-positive subtypes
• Upregulated inflammatory signaling pathways
• Dermal lymphovascular tumor emboli 1

Treatment Approach

1. Neoadjuvant Systemic Therapy

• First-line treatment is neoadjuvant chemotherapy with anthracycline and taxane-based regimens 1
• Add trastuzumab for HER2-positive disease 1
• Clinical response should be assessed using dynamic contrast-enhanced MRI before proceeding to surgery 3

2. Surgery

• Modified radical mastectomy is the standard surgical approach 1
• Breast-conserving therapy may be considered in selected patients who demonstrate good response to neoadjuvant chemotherapy, though this remains controversial 3

3. Radiation Therapy

• Mandatory post-surgery radiation therapy to chest wall and regional lymph nodes 1
• Radiation targets include chest wall, supraclavicular region, infraclavicular region, internal mammary lymph nodes, and axillary bed at risk 1
• Total dose escalation to 66 Gy recommended for high-risk patients 1

Follow-up and Prognosis

Despite advances in treatment, IBC remains a disease with poor prognosis:

• Regular imaging during and after treatment to assess response
• Physical examinations every 3-6 months after completing treatment
• Yearly mammogram of the contralateral breast
• Consider yearly ultrasound of locoregional lymph nodes 1

Historically, IBC had less than 5% survival rate beyond 5 years when treated with surgery or radiation therapy alone 4. With modern trimodal therapy, 5-year survival rates have improved to 40-50% 5, though outcomes remain inferior to non-IBC breast cancers.

Evolution of Treatment

The management of IBC has evolved substantially over the last several decades. Before the introduction of multimodality treatment, survival rates were dismal. The addition of neoadjuvant chemotherapy has significantly improved outcomes, making the coordination of systemic therapy, surgery, and radiation critical to continued improvements in treating this aggressive disease 6.