Most Dutch gastroenterologists perform endoscopic surveillance without following international recommended guidelines. Although, surveillance guidelines are widely used, there is no agreement on surveillance guidelines or a national surveillance protocol in Netherlands. We studied the surveillance practice of Dutch GEs using a postal questionnaire. Overall, 153 out of 244 questionnaires were returned, a response rate which was comparable to most questionnaire-based studies directed at physicians[11
]. We, therefore, assume that this study gives a representative overview of the use, feasibility, and ability to follow surveillance guidelines in Netherlands and that the results reflect the practice of a representative number of Dutch GEs. It is possible that the GEs who answered this questionnaire were more in favour of surveillance than GEs that did not fill out the questionnaire, which might have led to information bias. All GEs who provided surveillance agreed that screening patients with UC is necessary. It appears from the literature that not only UC, but also Crohn’s colitis is associated with an increased risk of colorectal cancer and, therefore, most experts recommend the use of the same guidelines for both UC and Crohn’s colitis[4,6
]. However, only 65% of Dutch GEs provide surveillance for patients with Crohn’s colitis.
We compared our results with the guidelines set by the AGA. Firstly, we observed a large discrepancy between answers from GEs regarding the principle of surveillance in general, and the responses they provided related to their exact employment of surveillance in daily practice. Furthermore, although both pancolitis and left-sided colitis are associated with an increased risk of CRC[3
], a quarter of the GEs do not provide surveillance for patients with left-sided colitis. On the other hand, a small group of GEs considered disease activity limited to the rectum an indication for screening, although there are no data to support the concept that proctitis increases the risk of CRC. All these inconsistencies could result in inefficient surveillance and missed dysplasia or even cancer.
The time between onset of symptoms and confirmed diagnosis of IBD can also differ substantially. Although there is no consensus on this subject, this difference in opinion might potentially lead to a delay in screening of months or even years.
Another important aspect of surveillance for CRC in IBD is adherence to the biopsy protocol. The median number of biopsies taken amongst Dutch GEs was 24 (range 10-40), while only 27% of the GEs approached the recommended number of 33 random biopsies. This number of biopsies was estimated to be necessary to detect possible dysplasia with a sensitivity of 90%[10
]. A similar questionnaire-based study in New Zealand showed a median number of 17 biopsies[12
]. This again, will inevitably lead to a pronounced decrease in sensitivity, rendering the surveillance tool ineffective.
If dysplasia is detected histopathologically, there seems to be uncertainty as to how to proceed with clinical decision-making. In the case of unifocal LGD, most of the Dutch GEs would have the histopathology revised, and would shorten the time interval to the next colonoscopy. If multifocal LGD is detected, Dutch GEs hesitate to recommend immediate colectomy, but prefer to revise the histopathology by consulting another pathologist or order a new colonoscopy with biopsies. Another suggested option was to shorten the time interval between screenings. Although controversy exists regarding the treatment policy which should be adopted after diagnosing dysplasia in patients with colitis, most experts agree that in all cases of confirmed dysplasia a colectomy should be recommended. Even the presence of LGD, which is associated with CRC in 21.4%-54%, can be considered an indication for surgery[4,6
]. There is a disconcertingly low referral rate for colectomy amongst Dutch GEs, and even more so when findings are compared with 3 similar questionnaire-based studies in New Zealand, United Kingdom and Canada[12–14
]. It is remarkable that the referral rate is higher for LGD and much lower for HGD and DALM compared with the other studies. The difficulty in confirming dysplasia, the lack of consensus for management of LGD, and the underestimation of the potential risk of LGD and HGD may contribute to the cautious management of LGD and HDG in Dutch GEs. Another reason could be that in the UK and the USA, the guidelines have already been implemented, which would explain the higher referral rate of cases with HGD in these countries.
In conclusion, 95% of Dutch GEs offer some form of surveillance, but most do not adhere to international guidelines. This leads to a decreased sensitivity for dysplasia, rendering this surveillance practice less effective. Furthermore, the management of dysplasia, even in cases of DALM, is inconsistent and will potentially lead to delays in the diagnosis of carcinomas. We suspect that this deviation from the guidelines is a general phenomenon in clinical practice, and is not only restricted to the Netherlands. Implementation of national guidelines and education of GEs concerning all aspects of colonoscopic surveillance is of great importance and will lead to a more consistent and efficient surveillance practice.