What exactly is breast cancer?

The Centers for Disease Control and Prevention defines it as a disease in which cells in the breast grow out of control. A new lump in the breast or armpit, thickening or swelling of part of the breast, or breast pain can be symptoms of this disease.

The main risk factors a person can’t control include being a woman, getting older, a family history of breast cancer and having dense breasts.

Lifestyle changes can reduce the risk of breast cancer. They include maintaining a healthy weight, regular exercise and avoiding or limiting alcohol intake.

Where is breast cancer usually located?

Most breast cancers begin in the ducts, the tubes that carry milk to the nipple, or the lobules, the glands that produce milk, according to the CDC. Breast cancer can spread to other parts of the body.

Is breast cancer malignant or benign?

Breast cancer tumors are malignant and different from benign, non-cancerous breast conditions.

What is the survival rate of breast cancer?

The five-year survival rate for women diagnosed with localized breast cancer — where the disease hasn’t spread outside the breast — is 99 percent, according to the American Cancer Society.

In cases where the disease has spread to the lymph nodes or nearby tissue, the five-year survival rate is 85 percent. It drops to 27 percent for patients whose cancer has spread to the lungs, liver, bones or other distant parts of the body.

Who does breast cancer affect?

It affects mostly women. Breast cancer is the second most common cancer in women after skin cancer, according to the National Cancer Institute.

Men can get it, too, but male breast cancer makes up less than 1 percent of all cases of the disease.

The risk increases as people get older. The average age when women are diagnosed is 61, while men are usually diagnosed when they’re between 60 and 70 years old.

How common is breast cancer?

A woman in the U.S. has a one in eight chance of developing breast cancer.

About 268,600 new cases of invasive breast cancer will be diagnosed in women this year, according to the American Cancer Society.