Having cancer should not usually make any difference to your car insurance.
Insurers are allowed to put up the price of premiums, or increase the excess you would have to pay in the case of a claim, if you are getting used to a new disability, or new medical condition, which puts you at increased risk of making a claim.
They are also able to charge more if your vehicle has to be specially modified because of your medical condition. This is to cover the extra cost of any repairs that may be necessary if you had an accident.
Most people who get cancer will not be affected by these problems.
However, if you develop a new medical condition, like cancer, it's best to let your insurance company know. If you don't it might make it more difficult for you to make a claim if you need to.

