There are 141 different types of cancer.  The most common are :  

                 Bladder Cancer
                 Breast Cancer
                 Colon Cancer
                 Endometrial Cancer
                 Head and Neck Cancer
                 Leukemia
                 Lung Cancer
                 Lymphoma
                 Melanoma
                 Ovarian Cancer
                 Prostate Cancer
                 Rectal Cancer

 For these types of cancer as well as pediatric cancers and to identify cancers by body/system location,  more detailed information can be obtained at:  

http://www.cancer.gov/clinical_trials/cancer_type/