If genetic damage is minimal, the available evidence suggests that there will be no cancer.
Here follows  practical recommendations to minimize genetic damage.

Adopt a varied and balanced diet of unprocessed food.
Avoid deep-fried food and minimize consumption of over cooked and browned food.
Eat no more  than required.
Avoid toxic synthetic chemicals as far as possible.

Regarding eating, the Natural Health standpoint would be to adopt the wisdom of Hippocrates  : “Let food be your medicine and medicine be your food -”

A balanced diet of natural, unprocessed foods – in accordance with Natural Health Dietary
Guidelines – is along the following lines:

Low fat, with the source of fat being plant foods. Avoid animal fats and hydrogenated
oils, including margarine. Include fresh flaxceed oil (or fish oil) for omega-3 fats.
Eat an abundance of fresh  fruit and vegetables (green, yellow, and red ) at the level of
approximately three quarters of total food intake by weight.
Regularly incude cruciferous vegetables (Cabbage family), carrots, tomatoes and other   particularly protective vegetables, and also garlic.
Eat adequate protein and no more. Have the protein all or mostly  from plant foods.
Ensure adequate fiber. Sources are: vegetables, fruits, whole grains, nuts, legumes,
seeds and ‘fiber’ foods such as psyllium husks, oat brain and rice bran.
Increase natural mineral and vitamin intake with the juices of  green, red and yellow
vegetables.

Consider topping up antioxidant vitamins and minerals with naturally deprived
supplements, particulary carotenoids, vitamin C, vitamin E, zinc and selinium.
Also consider extra B vitamins, especially folic acid (Vitamin B9)
Obtain organically grown foods where possible.
Keep calorie/kilojoule intake low overall.
Consume only two meals daily, the third meal being fruit only ( if this is suitable
for the individual.
Avoid or minimize intake of caffeine, alcohol, white sugar, white flour, table salt
(if necessary, use unrefined sea salt), cured meats and smoked foods.

And regarding other aspects of lifestyle:
Minimize exposure to synthetic chemicals, particularly pesticides, other very
toxic chemicals and the chlorine in town water supplies
Also keep well clear of radiation.
Have regular, moderate physical activity in order to keep fit and trrim.
Brisk walking for half an hour daily, which need not be all in one session,
can make the necessary difference to an otherwise sedentary lifestyle.
Develop ways of coping with stress more safely, such as meditation, visualisation,
affirmations, and, most importantly, social support.