P779 Intestinal cancer associated with Crohn’s disease: difference between those with short duration and those with long duration

M. Shinozaki, R. Takahashi

The University of Tokyo, Department of Surgery- The Institute of Medical Science- Department of Medical Science Hospital, Tokyo, Japan

Background

Patients with Crohn’s disease (CD) have increased risk of developing intestinal cancer (IC). In patients with ulcerative colitis, cancer risk is thought to increase around 10 years after the onset of colitis. However, in patients with CD, significant proportion of those was with shorter CD duration, and little has been known about the clinical management. The aim of this study was to clarify the clinicopathological characteristics of IC associated with Crohn’s disease with short duration.

Methods

We searched for IC cases associated with CD from a Japanese medical database (Ichushi). We picked up 272 cases, where we selected the two groups: those with short duration (5 years or less; S-group; n = 51) and those with long duration (15 years or more; L-group; n = 135). The median durations of the two groups were 0 year and 20 years, respectively.

Results

The age at cancer diagnosis was 51 years (interquartile (40–62)) and 45 (39–56) in S-group and L-group, respectively (p = 0.028). Patients in S-group were significantly older at the time of cancer diagnosis (p < 0.0001). The age at CD diagnosis was older in S-group than that in L-group (51 (38.5–62) years vs. 22 (9–68) years) with statistically significance (p < 0.0001). Relating to disease location of CD according to the Montreal classification, the proportion of L1 and L2 were significantly more in S-group than L-group (31% vs. 18%, and 49% vs. 10%, respectively; p < 0.0001). Penetrating type were significantly less in S group than that in L-group (28% vs. 59%; p = 0.003) in terms of disease behaviour according to the Montreal classification. In Japan, we found that majority of the colorectal cancer associated with CD is located at anorectum. However, in S-group, the proportion of anorectal cancer was only 26%, whereas that in L-group was 69%, and the difference reached statistical significance (p < 0.0001). Well to moderately differentiated adenocarcinoma accounts for 81% in S-group, while the ratio was 44% in L-group, and the difference was significant (p < 0.0001). Mucinous carcinoma was predominant in L-group (39%), and the proportion was significantly lower in S-group (12%; p = 0.0022). Clinical stage was similar in both groups, and the median was stage 2 (interquartile 1–3; p = 0.071). Median survivals were 21 and 26 months, and overall survival was also similar between the two groups (p = 0.51).

Conclusion

Some features were different between S-group and L-group, while the prognosis was not satisfactory in both groups despite relatively early clinical cancer stage. Older patients with short CD duration should be included as candidates of surveillance for neoplasia.