My Dad was diagnosed with Lung Cancer in 1983 shortly after my wife and I had learned that his first grandchild was on the way. Dad did not smoke. Sadly the race was on and I went from the funeral of my Dad to less than a month later the birth of my son. Not a good time.
I believe treatment is better now and Chemo isn't as difficult, but as most have said, anytime Cancer is involved it's not a good thing. I wish all the best to you and your family with this.