Mayo Clinic Health Manager

Get free personalized health guidance for you and your family.

Get Started

Free

E-Newsletter

Subscribe to receive the latest updates on health topics. About our newsletters

  • Housecall
  • Alzheimer's caregiving
  • Living with cancer

Causes

By Mayo Clinic staff

Cancer is a group of abnormal cells that grow more rapidly than do normal cells. Cancer cells also have the ability to invade and destroy normal tissues, either by growing directly into surrounding structures or after traveling to another part of your body through your bloodstream or lymphatic system. Microscopic cancer cells form small clusters that continue to grow, becoming more densely packed and hard.

In most cases it isn't clear what triggers abnormal cell growth in breast tissue in men. But doctors do know that about one in six cases of breast cancers in men are inherited, compared with about 5 percent to 10 percent of breast cancers in women. Defects in breast cancer gene 1 or 2 (BRCA 1 or BCRA 2) put you at greater risk of developing breast cancer. Other inherited genes also may increase your risk of developing breast cancer. Knowing your family history is important to determine your chance of inheriting an abnormal gene.

Most genetic mutations related to breast cancer aren't inherited, but instead develop during your lifetime. These acquired mutations may result from radiation exposure, such as receiving chest radiation therapy in childhood, or from other, as yet unknown, factors.

DS00661

Jan. 17, 2008

© 1998-2009 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Reliable tools for healthier lives," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

Print Share Reprints

Text Size: smaller largerlarger