Breast Cancer Link with Benign Breast Disease Defined

< July 27, 2005 > -- Women with benign breast disease face an elevated risk for developing breast cancer, and a new study reported in the New England Journal of Medicine clarifies which women within that group have higher and lower risks.

"It has been known for a long time that women with benign breast disease had an increased risk of breast cancer," says study author Dr. Lynn Hartmann, a medical oncologist with the Mayo Clinic in Rochester, Minn. "Our contribution is to provide more precise risk estimates."

There are a number of benign, or non-cancerous, breast conditions a woman can and probably will experience during her lifetime, according to the National Cancer Institute (NCI). Many of these are caused by changes in a woman’s hormone levels and are a normal part of getting older, the NCI states.

Study Findings Help Physicians Predict Risk

According to an accompanying editorial in the journal, some 20 percent of US women have undergone a breast biopsy within a decade of starting annual screening. Women who have had a biopsy are at about a 50 percent increased risk of developing breast cancer.

But it has not been clear how risk may differ within this group of women.

"Clearly there are gradations within that large group of women," Dr. Hartmann notes. "We're trying to take a first step towards doing a better job of risk prediction for women."

Dr. Hartman and her colleagues looked at 9,087 women with benign breast disease who had been followed for a median of 15 years.

Overall, the women in the group were at about a 56 percent increased risk of developing breast cancer, a risk that persisted for 25 years after the biopsy was performed.

Learning Precise Measurements

When the different lesions seen in the women were divided into categories, however, a different picture emerged.

"Clearly, the subsequent risk varies quite significantly within those [categories]," Dr. Hartmann says.

Women with non-proliferative cysts were at no increased risk. "Not in the near term, not in the long term," Dr. Hartmann emphasizes.

Women with cysts who also had a strong family history were at increased risk, however.

At the other end of the spectrum, women with atypia or atypical hyperplasia (too many cells, and too many abnormal cells) faced more than four times the increased risk of later breast cancer.

In between those two extremes were women with "proliferative findings" (too many cells, but the cells still looked normal) who were at about twice the increased risk.

Family history was an independent risk factor, the study shows.

"This is excellent work," says Dr. Jay Brooks, chairman of hematology/oncology at the Ochsner Clinic Foundation in New Orleans. "This shows us that it's very important to have the pathology of the abnormality reviewed to make sure it's correct, to take a very detailed family history and then counsel women on how to reduce their risk of developing breast cancer."

Dr. Brooks adds, "This is a very significant study that should tell physicians how to help women understand their risk for developing breast cancer and the many ways that we can offer them to prevent the disease."

Always consult your physician for more information.

Benign Breast Conditions Explained

The two most common types of benign breast lumps are cysts and fibroadenomas. In addition, there are several other conditions that can present themselves as lumps, such as fat necrosis and sclerosing adenosis.

A cyst is a fluid-filled sac that develops in the breast tissue. Such cysts typically occur in women between the ages of 35 and 50 and are most common in those approaching menopause.

Cysts often enlarge and become tender and painful just before the menstrual period and may seem to appear overnight. Cysts are rarely malignant and may be caused by a blockage of breast glands.

Cysts can feel either soft or hard. When close to the surface of the breast, cysts can feel like a large blister, smooth on the outside, but fluid-filled on the inside. However, when they are deeply imbedded in breast tissue, cysts will feel like hard lumps because they are covered with tissue.

A physician may identify a lump as a cyst by physical examination, but many physicians confirm the diagnosis by mammography or ultrasound examination. The physician may then perform a fine-needle aspiration as the next step in diagnosing the cyst.

A fine-needle aspiration procedure involves guiding a very fine needle into the cyst and drawing fluid from it. This procedure also serves as the treatment for this condition, as once the cyst is aspirated, it collapses and disappears.

Cysts can reappear at a later date, in which case they are simply drained again. Cysts are seldom malignant.

Fibroadenomas are solid, smooth, firm, benign lumps that are most commonly found in women in their late teens and early 20s. They are the most common benign lumps that occur in women and can occur in women of any age. Increasingly, they are being seen in postmenopausal women who are taking hormone replacement therapy.

The painless lump feels rubbery and moves around freely and very often is found by the woman herself. They vary in size and can grow anywhere in the breast tissue.

While most physicians can recognize this type of lump simply by feeling it, generally, the diagnosis is confirmed by mammography or ultrasound and fine-needle aspiration. Sometimes, in very young women, the fibroadenoma is not removed.

However, since sometimes these tumors enlarge with pregnancy and breastfeeding, physicians may recommend surgically removing the fibroadenoma.

While fibroadenoma does not lead to cancer, there is a type of fibroadenoma that has been associated with an increased risk of cancer, particularly in women with a family history of the disease.

Fat necrosis is a condition in which painless, round, firm lumps caused by damaged and disintegrating fatty tissues form in the breast tissue.

Fat necrosis often occurs in women with very large breasts or in response to a bruise or blow to the breast. This condition may also be the result of a lumpectomy and radiation from a previous cancerous lump.

In some cases, physicians will watch the lump through several menstrual cycles, and may perform a mammogram before deciding whether or not to remove it. These lumps are not malignant and there is no reason to believe that they increase a woman's risk of cancer.

Sclerosing adenosis is a breast condition that involves excessive growth of tissues in the breast's lobules, often resulting in breast pain. While these changes in the breast tissue are microscopic, they may show up on mammograms as calcifications and can produce lumps.

Usually a biopsy is necessary to distinguish this condition from cancer. In addition, because fat necrosis can be mistaken for cancer, the lumps are usually removed through surgical biopsy.

Always consult your physician for a diagnosis.