It really depends on your age, the type of cancer you have, when you were diagnosed, your prognosis, your current health and treatment, if your cancer is in remission, and the insurance company guidelines for acceptance.
There are insurance companies that insure people with cancer for life insurance.
However, you'll want to consider contacting a life insurance broker with expertise in placing life insurance with high risk insurance carriers that accept people with cancer.
In addition, there are Guaranteed Issue life insurance policies that offer a limited amount of life insurance, regardless of your health.
To learn more, find out if you can get life insurance if you have had cancer.