Breast cancer stems from a mutation of normal breast cells that allows the cells to evade cell death and proliferate uncontrollably, giving rise to unlimited cancer cells. There are several types of breast cancer, which originate in different tissues within the breast, that can be characterized depending on the invasiveness of the cancer. Aggressive breast cancers exhibit highly invasive properties, and many forms of aggressive breast cancer can prove fatal.
Inflammatory Breast Cancer
Inflammatory breast cancer, also alled IBC, is a relatively rare and very aggressive type of breast cancer, accounting for up to 5 percent of breast cancer cases, according to the National Cancer Institute. IBC develops when normal breast cells develop mutations and begin to proliferate out of control, eventually blocking lymph vessels and preventing the draining of lymph fluid out of the breast. When the flow of lymph fluid is disrupted, fluid builds up in the breast, leading to swelling and inflammation. A patient with IBC experiences a red, swollen and sore breast without any palpable lump. IBC cells exhibit invasive properties and can readily spread to other tissues. Patients with IBC have a 20 to 50 percent five-year survival rate, according to the National Cancer Institute.
Metaplastic Breast Cancer
Another form of breast cancer is metaplastic breast cancer, a rare form of cancer accounting for between 0.2 and 5 percent of breast cancer diagnoses, according to a study published in Australasian Radiology in 2004. The study also indicates that metaplastic breast cancer cells exhibit aggressive properties, and patients with metaplastic breast cancer have a five-year survival rate as low as 38 percent. Cancer cells in metaplastic breast cancer have undergone a process called metaplastic differentiation--they change from glandular breast tissue into a less specialized cell type. These unspecialized cells undergo uncontrolled proliferation and exhibit the ability to invade into other tissues. Metaplastic breast cancer may occur in conjunction with other forms of breast cancer, such as ductal breast cancer, and may also present with calcified masses within the breast. The Australasian Radiology study indicates that the variance in metaplastic breast cancer from patient to patient can present difficulty in diagnosing the disease.
Paget's Disease
Another aggressive type of breast cancer is Paget's disease of the nipple, a breast cancer that affects nipple cells but may spread to other parts of the breast and to the lymph nodes. The cause of Paget's disease is still unknown, but it may develop when normal nipple cells mutate to become cancerous. Paget's disease may also develop as a result of another underlying breast cancer, such as ductal breast cancer that spreads to the duct tissue in the nipple. Patients with Paget's disease of the nipple experience dry, scaly and red skin on the nipple, which eventually leads to severe skin defects around the nipple. As many patients with Paget's disease also have another form of breast cancer, patients may also have a palpable mass in the breast. The National Cancer Institute Indicates that Paget's disease is commonly treated with breast-removal surgery combined with other cancer therapies.
