More evidence that strains of the human papilloma virus (wart virus) are associated with breast cancer

June 18, 2010

There are more than 100 strains of HPV (human papilloma virus – the wart related virus). Many are harmless but about 30 types put you at risk for cancer. The strains that cause cervical and other cancers are classified as high-risk. Low-risk HPV can cause genital warts. High-risk HPV can lead to cancers of the cervix, vulva, vagina, and anus in women. In men, it can lead to cancers of the anus and penis. These viruses also are connected with cancers of the pharynx and throat.

Sexually transmitted, high-risk HPV strains include types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68, and 73. These high-risk types of HPV cause growths on the cervix that are usually flat and nearly invisible, as compared with the external warts caused by low-risk types HPV–6 and HPV–11. HPV types 16 and 18 together cause about 70 percent of cervical cancers. It is important to note, however, that the great majority of high-risk HPV infections go away on their own and do not cause cancer.

It has long been hypothesized that high risk HPVs have causal roles in some breast cancers. In this study using more refined scientific scanning methods it was confirmed that HPV 18 was found in the nuclei of cells of many breast cancer tissue samples except for one sample with HPV 16. In the past 15 out of 17 studies detected HPV in breast cancer world wide with incidence ranging from 4 % all the way up to 86%. It is possible that the two studies that did not identify HPV may have used inferior techniques for detection. Additionally in this new study the risk of contamination was nil. The study is published in the British Journal of Cancer.