Forty-Year Analysis of Colonoscopic Surveillance Program for Neoplasia in Ulcerative Colitis: An Updated Overview

Abstract

Objectives: This study provides an overview of the largest and longest-running colonoscopic surveillance program for colorectal cancer (CRC) in patients with long-standing ulcerative colitis (UC).

Methods: Data were obtained from medical records, endoscopy, and histology reports. Primary end points were defined as death, colectomy, withdrawal from surveillance, or censor date (1 January 2013).

Results: A total of 1,375 UC patients were followed up for 15,234 patient-years (median, 11 years per patient). CRC was detected in 72 patients (incidence rate (IR), 4.7 per 1,000 patient-years). Time-trend analysis revealed that although there was significant decrease in incidence of colectomy performed for dysplasia (linear regression, R=-0.43; P=0.007), IR of advanced CRC and interval CRC have steadily decreased over past four decades (Pearson's correlation, -0.99; P=0.01 for both trends). The IR of early CRC has increased 2.5-fold in the current decade compared with past decade (χ(2), P=0.045); however, its 10-year survival rate was high (79.6%). The IR of dysplasia has similarly increased (χ(2), P=0.01), potentially attributable to the recent use of chromoendoscopy that was twice more effective at detecting dysplasia compared with white-light endoscopy (χ(2), P<0.001). CRCs were frequently accompanied by synchronous CRC or spatially distinct dysplasia (37.5%). Finally, the risk of CRC was not significantly different between "indefinite" or low-grade dysplasia (log-rank, P=0.78).

Conclusions: Colonoscopic surveillance may have a significant role in reducing the risk of advanced and interval CRC while allowing more patients to retain their colon for longer. Given the ongoing risk of early CRC, patients with any grade of dysplasia who are managed endoscopically should be monitored closely with advanced techniques.

Figure 1

A linear regression plot showing the proportion of surveillance colonoscopies performed with chromoendoscopy (number of chromoendoscopy / total number of colonoscopy) from 2003 to 2012.

Figure 2

Kaplan Meier plots and life tables showing cumulative risk of colorectal cancer (CRC) development. (a) Cumulative risk of CRC by duration of ulcerative colitis (UC). (b) Cumulative risk of CRC by age of patients.

Figure 3

Histograms showing per-decade incidence rate of colorectal cancer (CRC) over past 40 years. (a) Incidence rate of all CRC combined. (b) Incidence rate of CRC by tumor stage: Early (Dukes' A or B; denoted in dotted green bars) and advanced CRC (Dukes' C or D; denoted in red plain bars).

Figure 4

Histograms showing declining risk of interval colorectal cancer (CRC) over last 40 years. (a) Per-decade incidence rate of interval CRC. (b) Proportion of surveillance detected CRC (denoted by dotted green bars) or interval CRC (denoted by plain red bars) out of all per-protocol surveillance (PPS) CRCs.

Figure 5

Kaplan-Meier plots showing overall survival rates following colorectal cancer (CRC) diagnosis. (a) Overall survival rates by Dukes' stage of tumor. (b) Overall survival rates by mode of CRC detection. PPS CRC: surveillance = cancers detected in scheduled surveillance procedure or colectomy performed for dysplasia, PPS CRC: interval = cancers detected in between scheduled surveillance procedures, NPPS CRC = cancers detected at least 6 months after the date of originally planned surveillance procedures.

Figure 6

Linear regression plot showing a decrease in annual incidence of colectomy performed for dysplasia over past 40 years.

Figure 7

Risk of developing neoplasia over time. (a) Kaplan–Meier plot and a life table showing the risk of developing any neoplasia (i.e. adenoma, dysplasia, or colorectal cancer (CRC)) by duration of UC. (b) Kaplan–Meier plot and a life table showing cumulative incidence of CRC for each type of neoplasia grade. HGD, high-grade dysplasia; LGD, low-grade dysplasia.