Breast cancer second most common for American women

Other than skin cancer, breast cancer is the most common cancer in American women, according to the Office on Women's Health at the U.S. Department of Health and Human Services.

Every woman has a chance of getting breast cancer, with about one in eight being diagnosed with breast cancer at some point in her life. This risk was about one in 11 in 1975, according to the Office on Women's Health.

The U.S. National Cancer Institute at the National Institutes of Healthestimates 232,340 new cases of breast cancer will be diagnosed in U.S. women in 2013. This sounds scary, but many women with breast cancer do survive it. With screening including mammograms, doctors often can find cancer early. Treatment has the best chance of success when found early, according to Office on Women's Health.

Breast cancer begins in breast tissue, where cancer cells may form a mass, or tumor; yet not all tumors are cancerous. These cancer cells also may invade nearby tissue and spread to lymph nodes and other parts of the body. With screening, breast cancer can be found before it spreads.

There are a number of types of breast cancer; however, two of the main categories are noninvasive and invasive.

Noninvasive (in situ) breast cancer refers to cancer in which the cells have remained within their place of origin - they have not spread to other areas of the breast. If the cancer has spread, it is termed invasive and is diagnosed as Stage I, II, III or IV.

"There are aggressive and non-aggressive types of breast cancer. Breast cancers that feed off estrogen are non-aggressive, are called estrogen-positive, and have a lower growth rate and are more easily treated. Estrogen-negative breast cancers do not live off estrogen, are more aggressive and create more challenges for treatments," said Julie Nangia, MD, assistant professor in the Lester and Sue Smith Breast Center at Baylor College of Medicine.

On Jan. 1, 2009, in the U.S. there were approximately 2,747,459 women alive who had a history of breast cancer, according to the National Cancer Institute.

Older women, 50 percent, are more likely to be diagnosed with breast cancer than younger women, with age being one of the contributing factors of the disease.

"Women who have had complete hysterectomies before the age of 40 have a lower incident rate of estrogen-positive breast cancer than those who had hysterectomies after 40 or not (at all). Women who have had hysterectomies have a lower estrogen level than those who have not, and those who had hysterectomies at a younger age have a lower estrogen level moving into their 60s," Nangia said.

Prevention of estrogen-positive breast cancer includes exercise, and to maintain a healthy weight. Obesity and excess fat increases estrogen, which alcohol does as well. Therefore, limiting alcohol consumption to no more than three drinks a week is suggested, according to Nangia.

According to the National Cancer Institute, from 2005-2009, the median age for a breast cancer diagnosis was 61.

Diagnoses are: Approximately 0.0 percent less than age 20; 1.8 percent between 20 and 34; 9.9 percent between 35 and 44; 22.5 percent between 45 and 54; 24.8 percent between 55 and 64; 20.2 percent between 65 and 74; 15.1 percent between 75 and 84; and 5.7 percent at 85-plus years. Regarding cases of breast cancer and ethnicity, caucasian women have the highest rate of 127.4 per 100,000, with African-Americans close behind at 121.4 per 100,000. Asian/Pacific islanders follow at 91.8, Hispanics at 90.8 and Native Americans at 77.1.

Mammography has led to a dramatic increase in the incidence of ductal carcinoma in situ (DCIS). The diagnosis was relatively rare before the early 1980s and the widespread use of mammography. Today, approximately one woman is diagnosed with DCIS for every four women diagnosed with invasive breast cancer.