Hi, Tatianne- You are right to be concerned. If you can purchase group life insurance through your employer, you may be able to get around any questions regarding current health- those plans often insure everyone in the group with no questions asked. Some other insurers who will write everyone regardless of health advertise on TV for folks in certain age groups.
If, however, you are talking about a standard life insurance policy through an agent, questions are asked about your health (my current insurer keeps trying to get me to up my insurance but also wants to know about conditions affecting brain, CNS, etc). Unfortunately, writing a policy for someone with a brain tumor is considered "adverse selection" (makes it more likely they'll have to pay out sooner). Your best bet, though, it to check with a Life Insurance agent that you know and trust for information in your state. Hopefully, you'll have more options than we do in New York. Good luck!