No symptoms and felt fine til they told me i had stage iv primary lung cancer / 2nd kidney cancer. is it that unusual or rare for a person to live a long normal life without ever knowing they have it?

Lung cancer: About 35-40% patients when diagnosed with stage 4 nsclc do not have symptoms and signs of that and it is found as part of routine imaging or based on some very subtle and non specific signs and symptoms.

Yes: ..It is highly unusual not have had some earlier awareness of the challenges you now face. It would be pleased to hear that you are being supported by the best medical care available and are doing well!

Yes!: The lung has an enormous respiratory reserve. You have to lose a lot of your lung capacity before you have symptoms, especially if you are relatively sedentary. I hope you are being followed at a dedicated cancer center. Good luck.

Unlikely: It is extremely unlikely to have such advanced cancers without any physical indication (i.e. Weight loss, coughing up blood, blood in the urine, etc.). This sounds like a strange situation. How did they come to this conclusion?

Not really: U may have lived a long and normal life because u did not have cancer for most of it. U only got cancer recently. Cancer is when cells that have divided over and over again in a controlled manner (to replace injured or damaged cells in ur lungs or kidney) suddenly lose control and begin to divide out of control growing into tumors. U feel fine til the tumors take over. Then symptoms start.