"Has your tumour shrunk at all?"
How was I supposed to know? The doctor's were the ones with the fancy measuring tapes. The best I have is a straight edge, not the best tool for measuring a 3 cm tumour. Anyway, this chemo stuff isn't actually supposed to work, is it? Well, guess what. Three weeks after starting chemo, the oncologist measured my tumour and found it had shrunk 0.5 cms in one dimension and 1 cm in another (the 3rd dimension being unmeasurable by hand). That was enough to inspire me to figure out a way that I could easily measure my tumour to monitor how much it was shrinking.
Here's my handy method that requires no tools (provided that you can feel your tumour).
With one hand, place your thumb and forefinger on the outer edges of the tumour. Then with the other hand place as many fingers as will fit between the two fingers of the first hand. Make a note of the number of fingers (and which ones) -- this is your measurement.