Carcinoma of the breast is the most common non-skin malignancy in women. The most common type of breast cancer is ductal carcinoma, but breast cancer can also begin in other tissues of the breast.
Breast cancer is rare in women younger than 25, but the incidence increases rapidly after age 30.
Risk factors for developing breast cancer include:
Germline mutations, first-degree relatives with breast cancer, race ethnicity, age, estrogen exposure, radiation exposure etc.
Almost all malignancies of the breast are adenocarcinomas that first arise as carcinoma in situ in ductal/lobular system. Carcinoma in situ refers to neoplastic proliferation of epithelial cells without invading (eroding) the basement membrane. Invasive carcinoma has penetrated the basement membrane and spread in the stroma.
Based on expression of estrogen receptor and HER2 breast malignancies can be divided into three major subgroups:
- Estrogen receptor (ER)-positive, HER2 negative
- HER2 positive ( which can be either ER negative or positive)
- ER-negative and HER2 negative
Early breast cancer usually does not cause symptoms but as cancer grows symptoms may include:
- Breast lump, which usually doesn’t have regular confines
- Change in the size, shape of the breast nipple
- Fluid from the nipple (bloody, clear to yellow)
Most common locations of metastasis include:
A group of scientists have discovered a mechanism that might stop breast cancer from releasing metastasis to bones. This team of scientists found out that the tumor secretes an enzyme that breaks down bone tissue forming holes, preparing in this way for the arrival of tumor cells. The enzyme which is secreted is LysYI Oxidase or LOX.
Lysyl oxidase is an extracellular copper enzyme that catalyzes the formation of aldehydes from lysine residues in collagen and elastin precursors.
The researchers hope that by blocking the activity of this enzyme they might be able to stop the progression of the cancer in a specific group of patients. The discovery can only be applied to the patients that have estrogen receptor negative (ER-negative) breast cancer.
The next step is to find out how the tumor that secretes LOX interacts with bone cells in order to develop the new drug that prevents bone lesions.
Finding out this new mechanism is an important progress in the fight against breast cancer metastasis, increasing the chances of survival for thousands of patients.
This team of researchers also proved in mice that a drug class called bisphosphonates was also able to prevent bone lesions and stop breast cancer. Bisphosphonates are a class of drugs that are used to treat bone mass loss in osteoporosis.
This new approach is a big step closer in defeating breast cancer, which is a very common and aggressive disease.