Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer that progresses rapidly. Unlike many other breast cancers, IBC often does not present as a distinct lump that can be felt. Instead, it manifests with unique visual and physical changes to the breast, such as redness, swelling, and a distinct “orange peel” texture of the skin. Its aggressive nature and distinct presentation differentiate it from more common types of breast cancer.
Understanding Inflammatory Breast Cancer
Inflammatory breast cancer is characterized by its rapid onset of symptoms, developing within weeks or months. It does not typically form a palpable lump, which can lead to it being mistaken for a breast infection like mastitis. The defining symptoms include sudden swelling, warmth, and redness that covers at least one-third of the breast. The skin may also appear pitted or dimpled, resembling the surface of an orange, a condition known as peau d’orange. Nipple changes, such as inversion or flattening, and a feeling of heaviness or tenderness in the breast, can also occur.
These distinctive symptoms arise because cancer cells block the small lymphatic vessels within the skin of the breast. The lymphatic system is a network of vessels that typically drain fluid from tissues, and when these vessels are blocked, fluid accumulates, causing the breast to become inflamed and swollen.
Staging System for Inflammatory Breast Cancer
Cancer staging provides a standardized way to describe the extent of cancer within the body, guiding treatment decisions. For breast cancer, the TNM (Tumor, Node, Metastasis) system is widely used. The “T” describes the primary tumor’s size and extent, “N” indicates spread to nearby lymph nodes, and “M” signifies metastasis to distant parts of the body. In the context of IBC, the “T” component is always classified as T4d, specifically indicating inflammatory carcinoma.
Inflammatory breast cancer is inherently considered a locally advanced cancer. This is because the cancer cells have already invaded the skin and lymphatic system of the breast, by definition. Consequently, IBC is never classified as Stage I or Stage II. All diagnoses of non-metastatic IBC begin at Stage III, reflecting its diffuse nature and involvement of the skin.
Specific Stages of Inflammatory Breast Cancer
Inflammatory breast cancer is primarily categorized into two main stages: Stage III and Stage IV. Stage III indicates that the cancer is locally advanced, meaning it has spread within the breast and to nearby lymph nodes but not to distant organs. This stage is further divided into sub-classifications, IIIB and IIIC.
Stage IIIB signifies cancer spread to the breast skin and potentially the chest wall, including ribs and chest muscles. It may also involve lymph nodes in the armpit. Stage IIIC indicates more extensive regional spread. This means the cancer has spread to lymph nodes above or below the collarbone, or to lymph nodes inside the chest near the breastbone.
Stage IV represents metastatic disease. At this stage, the cancer cells have spread beyond the breast and regional lymph nodes to distant parts of the body. Common sites for distant spread include the bones, lungs, liver, or brain. Approximately one-third of IBC cases have already metastasized when first diagnosed.
Implications of Staging
The assigned stage of inflammatory breast cancer significantly influences the treatment approach. Because IBC is always at least locally advanced, treatment begins with systemic therapies aimed at shrinking the cancer throughout the body. This often includes neoadjuvant chemotherapy, given before surgery to reduce tumor size and disease extent.
Following initial systemic treatment, surgery, usually a modified radical mastectomy, is performed to remove the affected breast tissue and often nearby lymph nodes. Radiation therapy is also a standard part of treatment for both Stage III and Stage IV IBC, targeting any remaining cancer cells in the breast area and lymph nodes. Targeted therapies may also be used if the cancer cells have specific characteristics, such as HER2 overexpression.
The stage also provides an indication of the likely course of the disease, or prognosis. Higher stages, such as Stage IV, indicate more advanced disease requiring more intensive and prolonged treatment. While survival statistics are based on large populations and individual outcomes can vary, advanced stages suggest a more aggressive disease that is harder to treat successfully.