Angiosarcoma of the breast is a rare and aggressive cancer that begins in the cells lining the blood or lymphatic vessels within breast tissue. This malignancy differs from more common breast cancers, such as ductal or lobular carcinoma, which originate in the milk ducts or lobules. Angiosarcoma can grow rapidly and spread quickly, making early detection particularly challenging.
Understanding Angiosarcoma of the Breast
Angiosarcoma of the breast originates from endothelial cells, which form the inner lining of blood and lymphatic vessels. It is a very rare condition, accounting for less than 0.05% of all breast cancer cases.
There are two primary types of breast angiosarcoma: primary and secondary. Primary angiosarcoma arises spontaneously in the breast tissue without a clear cause, often affecting younger women, between 30 and 50 years old. This type usually starts deep within the breast parenchyma and may not initially involve the skin.
Secondary angiosarcoma, also known as radiation-induced angiosarcoma (RIAS), develops after prior radiation therapy for breast cancer. It appears in older women, with a median onset age of around 67-71 years, often 5 to 10 years after radiation treatment. This type frequently affects the skin and superficial tissues in the irradiated area, sometimes presenting as reddish-purple lesions. The incidence of secondary angiosarcoma has increased due to the wider adoption of breast-conserving therapy, which often includes radiation.
Recognizing Symptoms and Diagnostic Methods
The signs and symptoms of angiosarcoma of the breast can be subtle, making early identification difficult. For primary angiosarcoma, a rapidly growing, painless lump or mass in the breast is a common initial symptom. Other signs include thickened skin, a feeling of fullness, or breast swelling.
Secondary angiosarcoma often presents with skin changes in the previously irradiated area, such as discolored patches resembling bruises, reddish-purple lesions, or nodules. Swelling in the breast or arm and a painful lump can also occur with secondary angiosarcoma. These symptoms can easily be mistaken for benign skin conditions or post-radiation changes, which can delay diagnosis.
Diagnosis typically begins with imaging studies, though angiosarcoma can be challenging to detect with standard methods. Mammography, ultrasound, and MRI are commonly used. Imaging findings can be nonspecific; for instance, mammograms may be obscured by dense breast tissue in younger patients with primary angiosarcoma or by post-treatment changes in secondary cases. MRI can be more effective in characterizing these tumors, often showing skin thickening and enhancing nodules. A PET scan may also be used to detect the spread of cancer.
A definitive diagnosis relies on obtaining tissue for pathological examination through a biopsy. For primary angiosarcoma, a core needle biopsy is often performed, while a skin punch biopsy may be used for secondary angiosarcoma if the lesions are superficial. An incisional or excisional biopsy might be necessary to get a sufficient tissue sample. Specialized pathological review is important due to the rarity of angiosarcoma, as its cells can sometimes resemble normal tissue or other types of cancer. Pathologists use specific endothelial markers, such as CD31 and CD34, to confirm the diagnosis by identifying the vascular origin of the tumor cells.
Treatment Strategies
Surgical removal is the main treatment for localized angiosarcoma of the breast. A mastectomy, which involves removing the entire breast, is often recommended due to the infiltrative nature of the tumor, aiming for wide, clear margins. Lymph nodes in the armpit are typically not removed unless there is evidence of involvement, as angiosarcoma rarely spreads to these nodes.
The role of radiation therapy is complex and varies depending on the type of angiosarcoma. For primary angiosarcoma, radiation may be considered after surgery, especially if margins are not clear or the tumor is large. However, its use in secondary angiosarcoma is debated due to the patient’s prior radiation exposure. Some studies suggest that adjuvant radiation might benefit certain patients, but there is no universal consensus.
Chemotherapy is a systemic treatment option, particularly for advanced or recurrent angiosarcoma. Taxanes and liposomal doxorubicin are commonly used agents, with overall response rates estimated around 30%. Complete responses to chemotherapy are less common, occurring in approximately 6% of cases. Targeted therapies, such as anti-angiogenic drugs, and immunotherapy are also being investigated for their potential role in treatment, especially given the expression of c-KIT in some angiosarcomas. Managing angiosarcoma often requires a multidisciplinary team approach, involving surgical oncologists, radiation oncologists, and medical oncologists, to develop a tailored treatment plan.
Outlook and Post-Treatment Care
The prognosis for angiosarcoma of the breast can be challenging. Outcomes vary based on factors such as tumor size, type (primary versus secondary), and stage at diagnosis. Early detection and complete surgical removal with clear margins are important for improving the outlook.
Long-term follow-up and surveillance are important after treatment to monitor for any signs of local recurrence or distant metastasis. This typically involves regular physical examinations of the breast and chest wall. Imaging studies, such as MRI or CT scans, are also frequently used to detect any new growth or spread. Angiosarcoma has a propensity for hematogenous spread, meaning it can travel through the bloodstream to distant sites, most commonly the lungs, liver, and bones.
The recurrence rates for breast angiosarcoma can be high, with local recurrence rates ranging from approximately 54% to 92%. Patients are encouraged to be vigilant for any new skin changes or lumps and report them promptly to their healthcare team. A supportive care team can also help patients navigate the complexities of post-treatment life.