What are symptoms of colon cancer

I have a dull pain in the upper right side of my abdomen .it's been there for two months and now my skin ,just under the right rib cage has started itching . I feel both most while I am relaxing . I have been told recently by my family that I am looking thin . I don't have any other symptoms at all. My B.M.I is 22.5 and I don't drink alcohol . I do smoke about 10 roll-up's a day. I don't eat spicy food but I do drink about 10 cups of instant coffee per day . Can you help me discover what this dull pain is please.