Invasive colorectal cancer within 5 years of negative colonoscopy in a Japanese population

Colorectal Dis. 2012 Sep;14(9):1090-4. doi: 10.1111/j.1463-1318.2011.02892.x.


Aim: Colonoscopy provides imperfect protection against colorectal cancer (CRC). In an attempt to improve cancer detection we evaluated the clinical features of invasive CRC detected within 5 years of a negative colonoscopy.

Method: The details of colonoscopies performed in a rural hospital in Japan were prospectively recorded at the time of the examination. The patients were followed over 5 years for the subsequent occurrence of cancer.

Results: In a 5-year period, 10148 patients underwent colonoscopy and 202 without previous colonoscopy were diagnosed with invasive CRC. Of 3212 patients with a colonoscopy negative for cancer, nine developed invasive cancer within 5 years. The ratios for invasive CRC detected without/with previous colonoscopy were 60:1 in the rectum, 54:1 in the sigmoid colon, 15:1 in the descending colon, 28:0 in the transverse colon, 31:5 in the ascending colon and 14:1 in the caecum (P=0.041). The ratio between left- and right-sided colonic cancer was also significantly different (129:3 and 45:6, P=0.0078). Six (67%) of the invasive CRCs were in the ascending colon or caecum. Five of six patients with invasive CRC in the ascending colon and caecum had right-sided small adenomas at prior colonoscopy.

Conclusion: The majority of early/missed CRCs were right-sided and associated with prior right-sided colonic adenomas. Repeated colonoscopy of patients with right-sided adenomas at a shorter surveillance interval deserves consideration.

MeSH terms

  • Adenoma
  • Adult
  • Aged
  • Aged, 80 and over
  • Carcinoma / diagnosis
  • Carcinoma / pathology*
  • Cecum / pathology
  • Colon, Ascending / pathology
  • Colon, Descending / pathology
  • Colon, Sigmoid / pathology
  • Colon, Transverse / pathology
  • Colonic Polyps / diagnosis
  • Colonic Polyps / pathology*
  • Colonoscopy
  • Colorectal Neoplasms / diagnosis
  • Colorectal Neoplasms / pathology*
  • Diagnostic Errors
  • Female
  • Humans
  • Japan
  • Male
  • Middle Aged
  • Rectum / pathology
  • Time Factors