I Have Continuing Anemia And Blood In My Stool. My

I have continuing anemia and blood in my stool. My feces test showed blood in my stool. The endoscopy and Colonoscopy showed only that I have gastritis. I have lost 25 pounds in the last six months, have a loss of normal appetite, pain under my left breast and in my left shoulder. My grandfather had colon cancer and lung cancer, my mother had a cancerous mass under her heart, my brother died 3 yrs ago from lung cancer and my daughter has neuroendochrine cancer. I am a former smoker. Do I have to be concerned with cancer?