How Does Breast Cancer Start?

Ask a Doctor

I have a couple female relatives who have battled breast cancer, including my aunt who had a mastectomy. I want to be hypervigilant because I know it runs in families. Are there early signs or symptoms of breast cancer? What are the early stages, and how does breast cancer start?

Doctor's Response

Early breast cancer has no symptoms. It is usually not painful.

Most breast cancer is discovered before symptoms are present, either by finding an abnormality on mammography or feeling a breast lump. A lump in the armpit or above the collarbone that does not go away may be a sign of cancer. Other possible symptoms are breast discharge, nipple inversion, or changes in the skin overlying the breast.

  • Most breast lumps are not cancerous. All breast lumps, however, need to be evaluated by a doctor.
  • Breast discharge is a common problem. Discharge is most concerning if it is from only one breast or if it is bloody. In any case, all breast discharge should be evaluated.
  • Nipple inversion is a common variant of normal nipples, but nipple inversion that is a new development needs to be of concern.
  • Changes in the skin of the breast include redness, changes in texture, and puckering. These changes are usually caused by skin diseases but occasionally can be associated with breast cancer.

Staging of a cancer refers to the determination of how much of the cancer there is and how far the cancer has spread at the time of diagnosis. Staging helps determine both a woman's prognosis and guides her treatment plan options. Staging is determined by a variety of methods, including results from surgical procedures, lymph node biopsy, and imaging tests.

Cancer in situ (DCIS or LCIS) is referred to as stage 0, because the tumor cells have not even begun to spread outside the ducts or lobules into the adjacent breast tissue. Invasive breast cancers are staged I through IV, with stage I being the earliest stage and easiest to treat, while stages II and III represent advancing cancer, with stage IV representing breast cancer cells that have spread (metastasized) to distant organs like the bones, lungs, or brain. Upon spreading these metastases become detectable when they have divided enough times to form detectable masses or metastatic tumors.

For more information, read our full medical article on breast cancer.

Health Solutions From Our Sponsors

American Cancer Society. "Breast Cancer." <

"HER2 Testing for Breast Cancer." <>.

United States. National Cancer Institute. "General Information About Breast Cancer." Sept. 25, 2014. <

United States. National Cancer Institute. "SEER Stat Fact Sheets: Breast Cancer." <