initial diagnosis of stage 4

I am so sorry to read of your diagnosis. I can relate. I have just been diagnosed with stage 3. After an agonising 3 day wait, I found out on Monday, that my bone & CT scans were clear. During that 3 day period I was doing all the reading I could on Stage 4. Like you, I was wondering how on earth it could have got to this stage without my knowing. My surgeon said that my cancer is very large (8cm across) & has probably been growing for the past 8 or more months. Goodness knows how I could possibly have missed that! Wishing you all the best with your treatment. As my surgeon said "there is nothing to be gained by looking back, concentrate on what you need to be doing now", or words to that effect.