While your insurance company will probably pay for your lung cancer treatment, don't expect them to come onboard a lawsuit against a tobacco company. They may, however, demand you repay them whatever sum they've spent on you if win your lawsuit
You should be thorough when searching for a lawyer to help you with your lung cancer case, no matter what the cause. Interview at least three, and don't be afraid to ask them questions about their background, credentials, and win rate. You need the best possible mix of cost, ability, and experience that you can afford.