There are many arguments on either side of this question; with some showing little if any signs of cancer in ancient humans leading to a link between cancer and modern human industrialized society, while others argue that ancient humans rarely lived beyond their 30's which explains the low almost zero rate of cancer within their society.
Michael Zimmerman, a researcher from the University of Villanova, argues this theory saying that "Cancer nowadays is largely caused by man-made environmental factors such as pollution and diet." He goes on to say, "In industrialized societies, cancer is second only to cardiovascular disease as a cause of death, but in ancient times, it was extremely rare".
He follows this up by saying, "There is nothing in the natural environment that can cause cancer."
I must say it was nice to see someone within the research community voice such conclusions publicly, and I just can't fathom why the majority of researchers within the medical community can't grasp this notion. It is an indisputable documented fact that prior to being "infected" by the cancer causing ways of the modern western world, societies of humans existed living well into their hundreds; I'm talking 120's and 130's... to us that's unheard of! But to people from Vilcabamba Valley high within the Andes Mountains (just as one example) this was the norm.
This to me rebuts the theory that we suffer from cancer more than our ancient ancestors did simply because we live longer. As man evolved some stayed within small remote communities out of sight from the rest of the world, and some became the industrial society we live in today where man-made pollution and toxins are the norm; and it's this branch that lives with cancer as an epidemic.
The best we can do is to live the healthiest life we can; that means fresh organic fruits and vegetables, natural organic whole grains and legumes, and grass fed meats and free-range eggs. It means limit your exposure to anything toxic; household chemicals and cleaners, cosmetics, soaps, toothpastes, etc.
It's your life; choose to live a long one!
If you would like to read more about Michael Zimmerman's findings, click on "Cancer is a man-made disease, controversial study claims".