The Biome Study is investigating a possible link between viruses and bacteria in the breast ducts to breast cancer

In 2012, Dr. Susan Love Foundation for Breast Cancer Research (DSLRF) began collaborating with Delphine Lee, MD, PhD, from the John Wayne Cancer Institute in Santa Monica, California, on a study investigating bacteria and viruses in ductal fluid. Many other types of cancers have been linked to viruses and bacteria, including cervical cancer which is caused by human papillomavirus (HPV). The bacteria Helicobacter pylori (H. pylori) can cause stomach cancer, and hepatitis C, a virus that causes inflammation of the liver, is one of the primary causes of liver cancer. This suggests it is possible that breast cancer also has an infectious origin.

Since breast cancer begins in the lining of the milk ducts, the first place to look for an infectious agent is in the ductal fluid. This fluid is collected easily, by massaging the breast and squeezing the nipple. For this study, we analyzed bacteria and viruses present in the ductal fluid collected from 48 women.

Study participants

Forty-eight women, half with and half without a history of breast cancer, were recruited for the study using DSLRF’s Army of Women®.

To be included in the study, participants were required to be:

  • female.
  • greater than 18 years of age.
  • have at least one intact nipple.
  • be able to provide informed consent.

Participants were excluded if they:

  • had been diagnosed with metastatic breast cancer.
  • had taken antibiotic therapy less than six months from the date of consent.
  • had taken oral contraceptives, hormone replacement therapy, any form of estrogen, any selective estrogen receptor modulators (SERMs), or any aromatase inhibitors within 12 months from the date of consent.
  • were currently lactating or had lactated within 12 months from the date of consent.
  • had any known abnormal levels of sex hormones or prolactin.
  • had received chemotherapy or radiation less than 12 months from the date of consent.
  • had any subareolar or other surgery (papilloma resections, biopsies or fine needle aspirations) within 2 centimeters of the nipple.
  • had any active infections or inflammation in the breast; or were unwilling to sign an informed consent.

Study procedures

Study participants completed a brief questionnaire and had ductal fluid collected from their breasts. Nipple aspirate fluid collection was attempted in both breasts of women without a history of breast cancer, and only in the healthy breast women with a history of breast cancer.

Click here to read an interview with Drs. Susan Love and Delphine Lee, in which they discuss why the study is unique and the potential impact on breast cancer prevention and treatment.

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