lung cancer metastisis

I hope someone can answer this question..how long, if left untreated, does it take for lung cancer to metastsise to lymph nodes, brain, and spine? I have read that it takes quite awhile for it to spread, but my husband has been having MRI's of a spot in his lung, and the results kept coming back no growth of spot. Now all of a sudden they say it has spread to lymph nodes, 2 brain tumors, and spinal tumors. Also possible liver cancer. He was fine for 8 months, then got up one morning looking like he had had a stroke. Also sever back pain, , headaches, etc. Any help appreciated.