Cancer Progress: Much More Than You Wanted to Know

I've read an argument recently that the lion's share of the increase in longevity throughout the 20th century in America is almost entirely due to better hygiene at the personal and civil infrastructural levels, with a bit coming from antibiotics as well.

Doctors and the rest of modern medical care have provided some increases in the quality of life and certain treatments (i.e. orthopedics) are undeniably better but this doesn't do much to increase lifespans.

I believe this was from The Rise and Fall of American Growth: The U.S. Standard of Living Since the Civil War by Gordon.

Besides not smoking, what are scientifically justified steps one can take while young to reduce the risk of cancer?

So bad that the images do not load for me. Android, Chrome