Factors that may increase your risk of invasive lobular carcinoma include:

  • Being female. Women are more likely to develop breast cancer, but men can also develop breast cancer.
  • Older age. Your risk of breast cancer increases as you age. Women with invasive lobular carcinoma tend to be a few years older than women diagnosed with other types of breast cancer.
  • Lobular carcinoma in situ (LCIS). If you've been diagnosed with LCIS — abnormal cells confined within breast lobules — your risk of developing invasive cancer in either breast is increased. LCIS isn't cancer, but is an indication of increased risk of breast cancer of any type.
  • Postmenopausal hormone use. Use of the female hormones estrogen and progesterone during and after menopause has been shown to increase the risk of invasive lobular carcinoma. Researchers believe the hormones may stimulate tumor growth and also make tumors more difficult to see on mammograms. It's not clear whether newer hormone regimens, including lower dose combinations, could also increase the risk of invasive lobular carcinoma.
  • Inherited genetic cancer syndromes. Women with a rare inherited condition called hereditary diffuse gastric cancer syndrome have an increased risk of both stomach (gastric) cancer and invasive lobular carcinoma. Women with certain inherited genes may have an increased risk of breast and ovarian cancers.
May. 22, 2012