Safety analysis of chemotherapy for colitis-associated colorectal cancer in Japan

Aim/Background: Inflammatory bowel diseases (IBD) often cause colorectal cancer. Efficacy and safety profile of chemotherapy (CT) for colitis-associated colorectal cancer (CAC) has not been well examined. Methods: Patients with a CAC who were treated with CT between 2000 and 2014 were retrospectively examined. Results: Twenty-nine patients (median age, 48 years; 23 males) were assessed. Palliative and adjuvant CT were performed in 13 and 16 patients, respectively. Eighteen patients had ulcerative colitis (UC), and 11 had Crohn's disease (CD). Three UC and 7 CD patients were in the active disease phase. Sixteen UC patients (89%) underwent proctocolectomy. Primary tumors were located in the rectum/anus (n = 16), the left colon (n = 9), or the right colon (n = 4). First-line palliative CT regimens were as follows: FOLFOX (fluorouracil (5-FU), leucovorin (LV), and oxaliplatin) (n = 6), FOLFOX + bevacizumab (BV) (n = 3), FOLFOX + cetuximab, FOLFIRI (5-FU, LV, and irinotecan) + BV and others (n = 2). Adjuvant CT regimens were S-1 (n = 7), UFT/LV (n = 3), FOLFOX (n = 2), XELOX (capecitabine and oxaliplatin) (n = 2) and others (n = 2). In palliative CT, the objective response rate was 15%, and median progression free survival and overall survival were 182 and 315 days, respectively. In adjuvant CT, 5-year relapse-free survival rate was 78%. Grade 3/4 adverse events (AE) were observed in 16 patients (55%). While 43% of active CD patients suffered G3/4 AE, no inactive CD patients had G3/4 AE. Dose-reduction was required in 11 patients (38%), 8 of which were due to hematological AE. CT was terminated because of AE in 7 cases, whereas only in 1 case caused by IBD. Conclusions: While equivalent efficacy to the common colorectal cancer was achieved in adjuvant setting, modest efficacy in palliative setting was shown. CT was safely performed in CAC, however, consideration of the disease activity especially in CD is required. Disclosure: All authors have declared no conflicts of interest.