Cancer is Contagious

That is the opposite of what I was told most of my life.

One in six cancers worldwide are caused by infection

One in six cancers - two million a year globally - are caused by largely treatable or preventable infections, new estimates suggest.

The Lancet Infectious Diseases review, which looked at incidence rates for 27 cancers in 184 countries, found four main infections are responsible.
These four - human papillomaviruses, Helicobacter pylori and hepatitis B and C viruses - account for 1.9m cases of cervical, gut and liver cancers.

This data is quite compelling.
And yet, there are even more infections which cause cancer.   They didn't screen for those, though.