Patterns and trends with cancer incidence and mortality rates reported by the China National Cancer Registry.

National cancer registration reports provide a huge potential for identifying patterns and trends of important policy, research, prevention and treatment significance. As summary reports written on an annual basis, the China Cancer Registry Annual Reports (CCRARs) fall short from fully addressing their potential. This paper attempts to explore part of the patterns and trends hidden behind published CCRARs. It extracted data for cancer incidence rates (IRs) and mortality rates (MRs) for 2004, 2006 and 2009 from relevant CCRARs and portrayed 4 kinds of indicators in line graphs. The study showed that: a) all of the line graphs of age-specific IRs and MRs characterized typical "growth curves or histogram"; b) graphs of IRs and MRs for males and urban areas had higher peaks than that for females and rural regions; c) most of the line graphs of IR/MR ratios comprised a starting peak, a secondary peak and a decreasing tail and the secondary peaks for females and urban areas were higher than those for males and rural areas; d) most of the urban versus rural IR ratios valued above one, but most the urban versus rural MR ratios, below one; e) the accumulative IRs and MRs showed a stable increasing trend from 2004 to 2009 for urban areas, but mixed for rural regions.