There may be a link between breast cancer and bacteria in the breasts?

"The researchers found that several types of bacteria were more common in the women with tumors in their breasts than in those without tumors. Women with tumors had higher levels of three types of bacteria —Enterobacteriaceae, Staphylococcus and Bacillus — compared with women who did not have tumors. For example, E. coli, which is a type of Enterobacteriaceae, was more common in the breasts of women with tumors."

"In the study, the researchers also did a small laboratory experiment using the bacteria found in the women with tumors: They added the bacteria to human breast cells growing in lab dishes, to see if the bacteria caused DNA damage. DNA damage can lead to the development of cancer, the researchers wrote."

"The experiment showed that two of the bacterial strains (Enterobacteriaceae and Staphylococcus) from the breast tissue damaged the DNA, at least in the lab, Reid said. However, doing this experiment in animals or humans would lead to more definitive results, he said."

Is There a Link Between Bacteria and Breast Cancer?

http://www.livescience.com/55221-microbiome-breast...

Before I was diagnosed with DCIS, I had breast infections (both breasts). Maybe DCIS starts with an infection and continues to fester even after treatment with antibiotics. Is this why some DCIS is comedo-necrosis and is pus-like when the pathologists look at it and squeeze it?

According to the American Cancer Society, some bacteria can cause cancer, and Wikipedia has a list of some bacteria that are believed to cause cancer. I just read that mycoplasma may be associated with ovarian cancer.

Maybe not all DCIS begins with infection, but maybe chronic inflammation from infection mutates the cells in those who have an infection. Some doctors think DCIS and breast cancers are caused by certain viruses that stay in the system forever. One doctor whose work I follow thinks that almost all breast cancers are caused by viral infection, sort of like how HPV causes cervical cancer. There is a study in Australia where they found HPV in the breast cells of breast cancer patients.

New Research Linking Human Papillomavirus And Breast Cancer: 'Who Would Have Thought Breast Cancer Is An Infectious Disease?'

http://www.huffingtonpost.com.au/2016/01/29/hpv-br...

Human papilloma virus is associated with breast cancer

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC273712...

I read that scientists can cause something that appears to be identical to human DCIS in lab rats by using a certain virus. It may be that anything that causes damage to the DNA of the cells and causes chronic inflammation can cause DCIS. It sure seems interesting to me that they found specific bacteria (that apparently damages DNA) in higher amounts in people with breast cancer.

I read about the bovine leukemia-lymphoma virus and its possible link to breast cancer (and now I don't drink milk or eat dairy foods, just in case):

Exposure to Bovine Leukemia Virus Is Associated with Breast Cancer: A Case-Control Study

http://journals.plos.org/plosone/article?id=10.137.../journal.pone.0134304

Virus in cattle linked to human breast cancer

http://news.berkeley.edu/2015/09/15/bovine-leukemi...

Apparently, there are other viruses that scientists think are associated with getting breast cancer, not just HPV and Bovine Leukemia Virus.

Role of viruses in the development of breast cancer

https://infectagentscancer.biomedcentral.com/artic...

Human Papilloma Viruses and Breast Cancer

"HPV type 18 was the most common type identified in breast cancer specimens (55% of 40 IDC and DCIS breast cancer specimens) followed by HPV 16 (13%) and uncommonly HPV high-risk types 45, 58, and 73. Low-risk HPV types 3, 78, and 124 plus three different new HPV types were also identified."

http://journal.frontiersin.org/article/10.3389/fon...

I was dx with dcis in the exact place that I had a breast infection. I totally think they are related. Will be interesting to hear about more studies on this topic.

I had a bad case of mastitis while breastfeeding 13 years ago on the same breast that's been diagnosed with LCIS. Mastitis is usually caused by staphylococcus aureus bacteria, and yes, I do think there's a link.

Hi all,

I certainly believe there is a direct connection with HPV and the rise of breast cancer. If HPV can cause cervical cancer, and oral cancer, it is not confined to an area. I've read a number of British and Australian studies that connect it, but curiously not a great deal of scholarly American studies have addressed it. One paper indicated that it showed up in breast milk so HPV certainly migrates to that area. One would think scientists would jump all over this topic with the increasing number of women diagnosed each year with breast cancer, and HPV the #1 STD. Common sense indicates there is a connection. I wrote 2 radiologists asking their opinions about the connection, yet both denied there is a link. HPV is proliferative and can reappear again and again, just like ADH.

In my mind from everything I've read, there is a direct link between the two and I think pathologists need to start specifically testing for it in abnormal/cancerous breast tissue. If a vaccine can be developed to prevent getting HPV, then surely one can be developed to eradicate it from the body.

Here is an interesting paper I came across in the British Journal of Cancer titled Human Papilloma Virus Is Associated With Breast Cancer

http://www.nature.com/bjc/journal/v101/n8/full/6605282a.html