What questions should I ask?

koritzls Member Posts: 1
edited March 2014 in Lung Cancer #1
My dad was just told he has stage 4 nsclc. They analyzed the fluid around his right lung (positive, of course), and found a 2cm mass in the upper lobe. They CAT scanned him and found nothing else. He had a bone scan yesterday and they only found a possible Pancoast tumor.

What determines that it's stage 4? What's the difference between 3 and 4? Am I missing some key info here?

Thanks in advance!