Good questions - I can only tell you what has worked for me with my husband's treatment. Unlike your parents, my husband wants to know what is going on -- however sometimes he doesn't know what questions to ask or remembers what to ask. I'm there to get more information -- even when it isn't always pleasant. One of the hard things to accept there isn't any easy answers. I had to learn that they aren't being evasive, each person with cancer is different. If you want to be able to ask questions without your parents present, then make sure to find out what the docs and hospital require for authorization. Once we got that form signed, I am able to log on to his healthcare web site, call to ask questions.
As far as survival statistics and such, it depends on the type of lung cancer, the stage of the lung cancer, genetic markers of the individual, and other factors. (Most of the test reports will say the type of stage of lung cancer of the patient). For example, my husband as Non Small Cell Lung Cancer, Stage IV. When he was diagnosed it had metastasized to his brain, liver, lymph nodes and spine, -- his lungs were filled with lesions, he had a 6 cm tumor in one lung, and fluid around his heart. He had no symptoms, and rode 30-40 miles a day on his bike (he still does). His internist told him he had months to live. However, he referred us to a cancer research hospital where they did genetic testing of his tumor and he came back with a specific genetic marker that was treatable using targeted therapy using a pill. The tumors shrank but after a few months some tumors showed up in his brain and liver. Further tests showed that the genetics of the cancer had changed so he was enrolled in a clinical trial. After some months that targeted therapy also stopped working so they switched him to another targeted therapy which is working. However, it will stop working at some point and we'll have to see what to do next. It isn't a cure and there is plenty of uncertainty. Each day is a gift. Hope you can find some answers.