Benign breast disease and breast cancer

Some of the benign breast lesions have been long recognized as risk factors for the development of breast cancer. Benign breast cancers have been incorporated into the Gale model of calculation of breast cancer risk. Now we have more evidence from a large study to have this conclusion.

A new study that was published in New England Journal of Medicine gives information about the risk of benign disease for the future development of breast cancer. The Researchers from Mayo Clinic, H. Lee Moffitt Cancer Center and University of California have studied identified all women who have been diagnosed with benign breast disease at the Mayo Clinic between 1967 and 1991. The lead investigators Lynn C. Hartmann, M.D and colleagues studied all such patients using medical records and questionnaires distributed to all these women. They have studied 9087 women who have been diagnosed with benign breast disease for a median period of 15 years. Researchers compared the number of observed breast cancers with the number expected on the basis of the rates of breast cancer. Among these patients the following types of histologies were seen

• Non-proliferative lesions 67%
• Proliferative lesions 30%
• Atypical hyperplasia 4%

Researchers noted that breast cancer developed in 707 patients of the total of 9087 women who have been diagnosed with benign breast disease. This represents 1.56-fold increase in the risk of development of breast cancer compared to the general population. The increased risk was noted for at least 25 years following biopsy for the benign breast disease. The following is the break down of increased risk in different sub groups of the study population.

• Atypia: 4.24 fold
• Proliferative changes without atypia: 1.88 fold
• Non-proliferative lesions: 1.27 fold

Women who had no family history of breast cancer and had only non-proliferative benign breast lesions were not at increased risk of breast cancer. The breast cancer tend to occur in the same breast especially in women with history of atypia.

"Our findings indicate a link between select types of benign breast lesions and the later development of breast cancer," said Lynn Hartmann. "Women who have a breast biopsy that is benign must discuss the possibility of additional risks with their doctors," Hartmann said.

Cancer terms:
Antibody: A substance formed by the body cells that guard against invading organisms or substances. Example: It is rare for someone to get two attacks of chicken pox. With the first episode of chickenpox the body cells creates antibodies that defends the body against a second attack of chickenpox. See cancer terms for more cancer related terms.