logo ecco
Portal

ECCO'24 Abstracts

ECCO'24 Abstracts on the JCC Website

ECCO'24 Abstract Book PDF Version

ECCO'24 Abstracts COI Disclosure

Oral presentations: Scientific Session 4: IBD out of the gut (2020)

OP14 Risk of colorectal cancer diagnosis and colorectal cancer mortality in Crohn’s disease: A Scandinavian population-based cohort study

O. Olen1, R. Erichsen2, M.C. Sachs1, L. Pedersen2, J. Halfvarson3, J. Askling1, A. Ekbom1, H.T. Sørensen2, J.F. Ludvigsson4

1Department of Medicine Solna, Clinical Epidemiology Division, Karolinska Institutet, Stockholm, Sweden, 2Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark, 3Department of Gastroenterology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden, 4Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden

Background

Crohn’s disease (CD) is a risk factor for colorectal cancer (CRC). Earlier studies reflect older treatment and surveillance strategies, and most have studied incident CRC without addressing potential lead-time and surveillance biases. Such bias can be reduced by examining tumour stage-adjusted CRC incidence and CRC mortality. We aimed to assess risks of CRC mortality and incident CRC among patients with CD compared with the general population.

Methods

Nationwide register-based cohort study during 1969–2017 of 47,035 patients with CD in Denmark (n = 13,056) and Sweden (n = 33,979), compared with 463,187 general population reference individuals, matched for sex, age, calendar year, and place of residence. We used Cox regression to estimate hazard ratios (HRs) for incident CRC and CRC mortality. In a multistate model, assessing competing events during follow-up (CRC diagnosis, CRC death, other death), we also took a tumour stage into account.

Results

During 1969–2017, 499 patients with CD developed CRC, corresponding to an adjusted HR of 1.40 [95% confidence interval (CI) 1.27–1.53]. We observed 296 (0.47/1000 person-years) deaths from CRC in patients with CD compared with 1968 (0.31/1000) in reference individuals [HR 1.74 (95% CI 1.54–1.96)]. CD patients diagnosed with CRC were at increased risk of CRC mortality compared with reference individuals also diagnosed with CRC [HR = 1.30 (95% CI 1.06–1.59)] and tumour stage at CRC diagnosis did not differ between groups (p = 0.27). CD patients who had 8 or more years of follow-up or who were diagnosed with primary sclerosing cholangitis (PSC) and hence were potentially eligible for CRC surveillance had an increased overall risk of CRC death [HR 1.41 (95% CI 1.18–1.69)] or CRC diagnosis [HR = 1.12 (95% CI = 0.98–1.28)]. However, in patients potentially eligible for CRC surveillance, we only found significantly increased risks in patients with CD onset <40 years, disease activity in the colon only, or with PSC (Figure 1).

Conclusion

CD patients are at increased risk of a CRC diagnosis and CRC death. Despite repeated colonoscopies during follow-up, CD patients are not diagnosed earlier (less severe tumour stage) with CRC than reference individuals. Nevertheless, CD patients with CRC have higher mortality than non-CD patients also diagnosed with CRC. CRC surveillance could likely be improved and should be focussed on CD patients <40 years at CD onset, patients with colon inflammation, and patients who have PSC.