My dad had advanced bowel cancer in October 2014 and had part of his bowel removed and 6 months of chemo

He now has liver cancer. He went in for a liver resection op yesterday which when they went in found it was not in part of his liver they thought it wwas the right side but also has a few tumors on his left lobe which the pep scan did not pick up therefore they did not remove any of the rumour and said they will now give him chemo erc to try and shrink them and then do the op again as he need more than 55% of his liver to be ok and if they did it yesterday he would have 45%. He's now in intensive care and been cut open for nothing! I'm devastated. And wonder why the pep scan never picked up on the ones in the left side of his liver before? He was scanned in November last year. Can cancer spread that much and quickly? Now I'm worried it's going to carry on spreading before they give him chemo, anyone had a similar situation ? Anybody know anything and the chances this might still be able to be cut out