According to the review published in Lancet, a US based health magazine, 1.9 million of those cancers are caused by four deadly infectious viruses.
The four viruses, human papilloma virus, Helicobacter pylori, hepatitis B and C viruses, are reason behind almost 95% of cervical, gut and liver cancers. While women are mostly affected by cervical cancer, almost all of the men are affected by liver and gastric cancers.
As per the review, cancer causing infectious agents, classified as carcinogenic to humans by the International Agency for Research on Cancer based in France, which is a part of the World Health Organization, are more prevalent in developing nations than developed nations where free and effective public health system is unavailable.
So by applying existing public health care methods such as vaccinations, safer injection practices and antimicrobial treatments in developing and under developed nations, 16·1% out of 12·7 million cancers around the globe can be prevented.
It is better to be safe than sorry!