Common Viruses and Breast Cancer

I am surprised that viruses are still dismissed as a cause of breast cancer!

There are a number of common viruses that, despite having a connection to breast cancer, are dismissed as causes of the disease. Infectious organisms can cause chronic disease and this creates, if nothing else, a predisposition to cancer. Not too many people are going to argue with this hypothesis. But let be more specific and point out that viruses have multiple consequences. For example, the HIV virus that causes AIDS can also cause Kaposi’s Sarcoma and central nervous system lymphoma. The HPV, human papilloma virus, can also cause cervical, penile, anal cancers. Hepatitis B and C can cause liver cancer. Helicobacter Pylori causes ulcers but also stomach cancers and Epstein-Barr (causing mononucleosis) can cause Burkitt’s lymphoma and nasopharyngeal carcinoma. 

Some studies suggest that a virus similar to the mouse mammary tumor virus (MMTV) is associated with breast cancer in humans. In North America, Europe and Australia, where the species is common, incidentally where we also have the highest incidence of breast cancer, this virus was detected in 30 - 40% of breast cancer tissue samples. Interestingly, in Asia where the incidence of breast cancer is much lower than in North America, infected samples were many times lower too. Remember, that the development of cancer is a multi-step process with several contributing factors, infections by herpesvirus, polyomavirus, papillomavirus and retrovirus families definitely associate with breast cancer. 

In my own experience, I’ve found that people who have had mononucleosis (caused by Epstein Barr Virus) have a much higher incidence of all cancers, including breast cancer. So whenever I see Epstein Barr or mononucleosis in patient’s medical history, I immediately start thinking about immune support to prevent cancer. The role of viruses in most common cancers is certainly important, and in my opinion, highly underestimated. Viruses can directly act as catalysts of disease and of course also as triggering co-factors. 

I believe that approximately 30% of cancer has a viral aetiology––in other words, the origin is viral or bacterial. Already, we know that between 15% and 20% of known viruses and bacteria’s cause cancer. This likely explains the random and so-called rampant cases of cancers that don’t seem to have any other obvious causes. 

I propose that by preventing and treating infections properly we may possibly stop or even eliminate many breast cancers.