After my operation, when I was waiting to do chemo therapy. I had to have blood tests every week for about 5 weeks. During that period, when I was visiting the oncologist, they told me that there was a slight chance that another tumour was growing. I tell you what, it will cause anyone sleepless nights when they are already dealing with just being diagnosed.
http://www.thecancerstory.com/2011/09/part-10-game-of-time.html