Help with graph

#1
Hi guys. I am new to this forum and really just starting to learn statistics as I have to use them in my medical research.

I would appreciate your help in the following query.
I have a data set of three different groups of cancer patients and I need to show the difference in the size of the cancer in the three groups in a single graph. What type of graph would best serve this purpose?
 
#2
Well, maybe a histogram of the tumor size? If it's skewed, you can use median and IQR to describe it. Sometimes you don't need to waste ink with elaborate visualization.