Metachronous colorectal cancer: A competing risks analysis with consideration for a stratified approach to surveillance colonoscopy

Abstract

A patient aged under 65 at the time of the primary curative resection carries a 2% 5-year risk of metachronous cancer, implying that 3 year surveillance colonoscopy is justified. Whereas patients aged over 75 carry less than a 2% 10-year risk, implying that it is seldom warranted to repeat the colonoscopy more frequently than every 5 years. A stratified approach to the frequency of surveillance colonoscopy requires further consideration.

Metachronous colorectal cancers result from missed lesions and non-compliance with surveillance

“…Several studies evaluated the frequency of surveillance in patients at risk for recurrent CRC or mCRC, supporting the need for follow-up examination at 2 to 3 years after surgical resection. [41][42][43] However, most of these studies ignored the importance of the quality of examination. Recent data challenged the quality of colonoscopy by non-gastroenterologists.…”

Findings at surveillance colonoscopy following surgery for colorectal cancer

“…In addition to having further adenomas, patients with a personal history of colorectal cancer are at risk of developing metachronous cancers, which are usually asymptomatic but tend to be of early stage and potentially curable if detected by surveillance colonoscopy . A second colonoscopy performed at 3 years following an initial surveillance colonoscopy at 1 year after surgery may be the most appropriate interval to detect lesions at an early stage as a high proportion of these occur within 4 or 5 years of resection of the index cancer .…”

“…In addition to having further adenomas, patients with a personal history of colorectal cancer are at risk of developing metachronous cancers, which are usually asymptomatic but tend to be of early stage and potentially curable if detected by surveillance colonoscopy. 9,17,18 A second colonoscopy performed at 3 years following an initial surveillance colonoscopy at 1 year after surgery may be the most appropriate interval to detect lesions at an early stage as a high proportion of these occur within 4 or 5 years of resection of the index cancer. 3,8,9,19,20 Although only one cancer was detected in this cohort over the duration of the study, the detection rate for all colorectal cancer patients within this surveillance programme has previously been shown to be 2.5%, with around 40% being detected early.…”

Practice Guideline for the Surveillance of Patients After Curative Treatment of Colon and Rectal Cancer

“…Patients older than 75 to 80 years and those with comorbidities suggesting a shortened life expectancy are unlikely to benefit from scheduled endoscopy in the absence of symptoms. 64 Patients at higher risk, such as those with a genetic or clinical diagnosis of hereditary colorectal cancer syndrome, should follow more intensive endoscopic surveillance (eg, annual colonoscopy) as delineated elsewhere. 65 7.…”