Gastric cancer (GC) has continued to be a threat to human life. Diagnosis of GC at advanced stage is considered as a major reason for lower overall five-year survival rate in developing countries. A complex set of molecular irregularities occurs at cellular level during early stage of GC and its further progression will disturb normal cell functioning. These abnormalities include genetic and epigenetic modifications leading to differential expression of many genes in normal and affected cells. Many efforts are made to spot these molecular aberrations to understand the underlying mechanism which governs abnormal cell behavior. Current review summarizes recent works addressing GC etiology, epidemiology, pathology and therapy treatment.