Bacon, ham, tobacco, alcohol... are all part of the list release by the International Agency for Research on Cancer (IARC) of carcinogenic products. The IARC has divided said products, as well as certain activities, into three categories: "Exposure circumstances", "mixtures" and "agents".
We can see that the exposure circumstances which most contribute to the illness are tobacco and tanning salons, but also aluminium and non-filtered water (because it can contain arsenic). To escape cancers many sufferings, you should also not drink alcohol, breath in car exhaust fumes or use contraception... but then that doesn't really leave much you are allowed to do!
The full list of carcinogens can be found here.