The quality of colonoscopy is key for ensuring protection against colorectal cancer.
Dr Silvia Sanduleanu and colleagues from the Netherlands elucidated the etiology of postcolonoscopy colorectal cancers, and especially to identify preventable factors.
The team conducted a population-based study of all patients diagnosed with colorectal cancer in South-Limburg from 2001 to 2010 using colonoscopy and histopathology records and data from the Netherlands Cancer Registry.
Postcolonoscopy colorectal cancers were defined as cancers diagnosed within 5 years after an index colonoscopy.
According to location, colorectal cancer were categorised into proximal or distal from the splenic flexure and, according to macroscopic aspect, into flat or protruded.
Etiological factors for postcolonoscopy colorectal cancers were subdivided into procedure-related, and biology-related.
|Of the postcolonoscopy colorectal cancers, 58% were attributed to missed lesions|
The researchers included a total of 5107 patients with of whom 147 had postcolonoscopy colorectal cancers diagnosed on average 26 months after an index colonoscopy.
The team showed that postcolonoscopy colorectal cancers were significantly more often proximally located, smaller in size, and more often flat than prevalent colorectal cancers.
Of the postcolonoscopy colorectal cancers, 58% were attributed to missed lesions, 20% to inadequate examination/surveillance, and 9% to incomplete resection, while 14% were newly developed cancers.
Dr Sanduleanu's team concludes, "In our experience, 86% of all postcolonoscopy colorectal cancers could be explained by procedural factors, especially missed lesions."
"Quality improvements in performance of colonoscopy, with special attention to the detection and resection of proximally located flat precursors, have the potential to prevent postcolonoscopy colorectal cancers."