Patient's characteristics
| Gender (male/female) | 28/15 |
| Age (median) | 53 (28–74) |
| Age at diagnosis of UC (median) | 33 (15–72) |
| Disease duration (year) (median) | 13.0 (0–40) |
| The number of patients who had disease duration of more than 10 years | 29 (67.4%) |
| Time to previous colonoscopy (months) (median) | 14.0 (1–72) |
| Extent of disease (%) | |
| Extensive colitis | 34 (79.1) |
| Left-sided colitis | 8 (18.6) |
| Unclear | 1 (2.3) |
| Family history of UC (%) | |
| Yes | 5 (11.6) |
| None | 36 (83.7) |
| Unknown | 2 (4.7) |
| Family history of CRC | |
| Yes | 3 (7.0) |
| None | 37 (86.0) |
| Unknown | 3 (7.0) |
| Tobacco | |
| Current smoker | 3 (7.0) |
| Past smoker | 12 (27.9) |
| Never smoker | 22 (51.2) |
| Unknown | 6 (14.0) |
| Concomitant PSC (%) | 2 (4.7) |
| Duration of treatment with 5-ASA (%) | |
| Naïve | 3 (7.0) |
| Within 1 year | 2 (4.7) |
| From 1 to 5 years | 5 (11.6) |
| From 6 to 10 years | 6 (14.0) |
| Over 10 years | 24 (55.8) |
| Unknown | 3 (7.0) |
| Duration of treatment with CS (%) | |
| None | 11 (25.6) |
| Within 1 year | 8 (18.6) |
| Over 1 year | 18 (41.9) |
| Unknown | 6 (14.0) |
| Dose of CS (g) (median) | 6.4 (0–30) |
| The number of patients treated with more than 10 g CS (%) | 4 (9.3) |
| Duration of treatment with immunomodulator (%) | |
| None | 18 (41.9) |
| From 1 to 2 years | 2 (4.7) |
| From 2 to 4 years | 3 (7.0) |
| Over 4 years | 5 (11.6) |
| Unknown | 15 (34.9) |
| Duration of treatment with an anti TNF-α agent (%) | |
| None | 27 (62.8) |
| From 1 to 2 years | 3 (7.0) |
| Over 2 years | 1 (2.3) |
| Unknown | 12 (27.9) |
| The number of patients treated with NSAIDs (%) | |
| None | 37 (86.0) |
| Yes | 4 (9.3) |
| Unclear | 2 (4.7) |
5-ASA, 5-aminosalicylic acid; CRC, colorectal cancer; CS, corticosteroid; NSAIDs, non-steroidal anti-inflammatory drugs; PSC, primary sclerosing cholangitis; TNF-α, tumour necrosis factor-α; UC, ulcerative colitis.