Lifetime risk refers to the probability that an individual, over the course of their lifetime, will develop cancer or die from it. Currently in the US, men have a one in two lifetime risk of developing cancer, and for women the risk is one in three. During the early 1980's, the lifetime cancer risk for both men and women was one in three. This means men are slightly more at risk for cancer now, than they were then. There are some viruses that increase a person's risk of getting cancer, but cancer itself is not viral and not contagious.
Cancer is a group of diseases characterized by uncontrolled growth and spread of abnormal cells.
There is no way of knowing where this Internet information comes from. However, there are a variety of websites offering health and beauty products that are SLS-free. As a matter of fact, the majority of URLs returned in a standard Web search on the keywords 'sodium laureth sulfate' all point to versions of the same propaganda. It is best to be cautious when obtaining information, especially health-related information, from the Web. Check to see who owns the site, make sure reliable sources are used and if ever in doubt, check it out.