Breast Cancer

Breast Cancer

Learn more about breast cancer, risk factors, diagnosis and treatment.

Cancer occurs as a result of mutations, or abnormal changes, in the genes responsible for regulating the growth of cells and keeping them healthy. Breast cancer usually begins in the cells of the lobules, which are the milk-producing glands, or the ducts, the passages that drain milk from the lobules to the nipple. Less commonly, breast cancer can begin in the stromal tissues, which include the fatty and fibrous connective tissues of the breast.

When the cells in the ducts or the lobules suffer a transformation, a malignancy can occur, giving rise to ductal carcinoma or lobular carcinoma, the two most common forms of breast cancer in women. Breast Cancer appears more frequently after menopause, but can occur in younger women. Families with a history of breast or ovarian cancer can increase the risk for women under 30 years old.

Risk factors

Risk factors increase the possibility of developing a certain disease. There are various risk factors associated with development of breast cancer including advancing age, family history, the age when menstruation began, radiation to the chest, late or no childbirth, excess weight, lack of physical activity, smoking and alcohol consumption.


Breast cancer may be suspected if a nodule is detected in the breast or arm pit. In addition, a change of breast size, or in the appearance of the skin of the breast or nibble, or an usual discharge from the nipple (yellow, green, or bloody) may also raise the suspicion for breast cancer.

Sometimes, breast cancer may be suspected following routine breast ultrasounds or mammography, where results show alterations suggestive of the disease. Ideally, all breast cancers should be detected during routine examinations rather than when changes are noticeable to the patient since early detection raises the possibility for a cure. Therefore, international recommendations for breast cancer screening now support a mammogram in women over 50 years old annually or every two years (or more frequently in certain circumstances).

If breast cancer if suspected, a biopsy is recommended in order to confirm or exclude the diagnosis. A breast biopsy consists of collecting a small piece of breast tissue in the suspected zone (sometimes also from the auxiliary lymph node), after administration of a local anesthetic. The procedure is fast and produces minimal discomfort. It is performed by a radiologist, anatomical pathologist or surgeon. If malignant cells are identified, this will confirm the diagnosis of breast cancer.

It may also be necessary to take additional breast exams (MRI) or for other parts of the body (ultrasound, radiography, bone scintigraphy, or CT)


Treatment of breast cancer may involve various therapeutic modalities: surgery, radiotherapy, chemotherapy, hormone therapy, among others. The decision of which therapeutic option is best indicated or the sequence of their application is often based on the results of the exams as explained above.

The majority of breast cancers possess hormone receptors (estrogen and/or progesterone). These cancers respond to medications that block the hormone receptors (hormone therapy). Chemotherapy may be applied to all types of cancer, with or without hormone receptors presents.

These days, with early diagnosis and appropriate intervention, breast cancer is curable in the majority of cases.