Yes, if someone has a life insurance policy and later passes away from cancer, the life insurance policy will pay the death benefit. The only exception would be if the applicant knew they had cancer but did not disclose it at the time the application was filled out, and if death occurred within the first two years. If the policy was guaranteed issue and the application did not ask about cancer, then not disclosing it will not matter.
If someone is diagnosed with cancer and then applies for life insurance, the type of policy that can be obtained will be dependent on the type, stage and treatment of the cancer, and when the cancer was diagnosed and last treated. Life insurance almost never carries exclusions for cancer, but a graded policy can exclude paying the full death benefit for all but accidental death during the first 1-3 years of the policy.
If someone is diagnosed with cancer and then applies for life insurance, the type of policy that can be obtained will be dependent on the type, stage and treatment of the cancer, and when the cancer was diagnosed and last treated. Life insurance almost never carries exclusions for cancer, but a graded policy can exclude paying the full death benefit for all but accidental death during the first 1-3 years of the policy.