Risk factors

For breast cancer survivors, factors that increase the risk of a recurrence include:

• Lymph node involvement. Finding cancer in nearby lymph nodes at the time of your original diagnosis increases your risk of the cancer coming back.
• Larger tumor size. People with larger tumors have a greater risk of recurrent breast cancer.

• Positive or close tumor margins. During breast cancer surgery, the surgeon tries to remove the cancer along with a small amount of the normal tissue that surrounds it. A pathologist examines the edges of the tissue to look for cancer cells.

  If the borders are free of cancer when examined under a microscope, that's considered a negative margin. If any part of the border has cancer cells (positive margin), or the margin between the tumor and normal tissue is close, the risk of breast cancer recurrence is increased.

• Lack of radiation treatment following a lumpectomy. Most people who choose a lumpectomy (wide local excision) for breast cancer undergo breast radiation therapy to reduce the risk of recurrence. Those who don't undergo the radiation therapy have an increased risk of local breast cancer recurrence.
• Younger age. Younger people, particularly those under age 35 at the time of their original breast cancer diagnosis, face a higher risk of recurrent breast cancer.
• Inflammatory breast cancer. People with inflammatory breast cancer have a higher risk of local recurrence.
• Lack of endocrine therapy for hormone receptor-positive breast cancer. In people who have a certain type of breast cancer, not receiving endocrine therapy can raise their risk of recurrence.
• Cancer cells with certain characteristics. If your breast cancer wasn't responsive to hormone therapy or treatments directed at the HER2 gene (triple negative breast cancer), you may have an increased risk of breast cancer recurrence.
• Obesity. Having a higher body mass index increases your risk of recurrence.