Breast cancer is a malignant (cancerous) growth that begins in the tissues of the breast. Breast cancer is classified by the location of the tumor in the breast and whether or not the cancer has spread to the surrounding tissue and lymph nodes. Most breast cancers develop in the milk lobules or milk ducts, but they may also develop in the fatty tissue or connective tissue of the breast. The type of breast cancer determines its rate of progression.
Breast cancer risk factors include age, sex, family history, age at first menstruation, age at menopause, and use of oral contraceptives or hormone replacement therapy. Lifestyle risk factors for breast cancer include alcohol consumption, smoking, obesity, and chemical or radiation exposure.
Breast cancer may be detected during a breast exam, which includes a breast self-exam, an exam by a doctor or other healthcare professional, and a mammogram.
The first symptom of breast cancer may be a breast lump. In many women, breast lumps come and go with normal hormonal fluctuations. Not all breast lumps are cancerous; a lump may be a benign (noncancerous) cyst. However, a breast lump that is persistent, or a swelling or mass in the breast that feels distinctly different from surrounding breast tissue, may be a sign of breast cancer.
Breast abnormalities may also be detected on a mammogram. A mammogram is an x-ray of the breast used to show abnormalities in breast tissue. A mammogram is an important tool in detecting breast cancer because breast cancer rarely produces symptoms in its earliest stages. A mammogram can help detect breast cancer earlier in its progression, possibly leading to a better outcome.
Breast cancer guidelines recommend an annual mammogram for women aged 40 and older or more frequent mammograms depending on individual risk factors. A breast self-exam can be performed regularly, when the breasts are not swollen or tender. Regular breast self-exams allow a woman to become familiar with how her breasts normally feel. Any irregularities or changes found during a breast self-exam should be discussed with a doctor or healthcare professional right away. Women should also have regular clinical breast exams performed by a doctor or other healthcare professional.
