• advanced colorectal adenoma;
  • clinicopathological characteristic;
  • colonoscopy;
  • colorectal cancer;
  • detection rate

OBJECTIVE:  The best cure for colorectal cancer (CRC) lies on its early diagnosis and treatment. We aimed to provide the epidemiological features of advanced colorectal adenoma (A-CRA) and CRC in symptomatic patients and to determine whether the incidences of A-CRA and CRC increased simultaneously in China between 1990 and 2009.

METHODS:  A total of 157 943 patients who had undergone a colonoscopy from 1990 to 2009 were enrolled, of which 6 777 patients had A-CRA and 3 503 had CRC. They were compared with controls in a stratified analysis. The detection rates of A-CRA and CRC in the 1990s and 2000s were also compared.

RESULTS:  The detection rate of A-CRA increased 1.88-fold over the two decades, while that of CRC increased 0.66-fold. The percentages of patients with A-CRA and CRC who were elder than 50 years were significantly higher in the 2000s than those in the 1990s (P = 0.000). The changes of location of A-CRA and CRC during the two decades indicated a shift of lesions from the distal colon to proximal colon.

CONCLUSION:  There was a significant increase in detection rate of A-CRA in the 2000s, but CRC did not increase at a similar speed. Our results indicated that the early detection and removal of colorectal adenoma in symptomatic patients might decrease the incidence of CRC.