Table 1.
Baseline characteristics of study patients of highly methylated colorectal cancer (HMCC) and low methylated colorectal cancer (LMCC) subgroups in two independent cohorts
| Variable | First cohort | P‐value | Second cohort | P‐value | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| All samples | HMCC | LMCC | All samples | HMCC | LMCC | |||||||||
| n | % | n | % | n | % | n | % | n | % | n | % | |||
| Total | 45 | 100 | 17 | 37.8 | 28 | 62.2 | 52 | 100 | 17 | 43.8 | 35 | 56.3 | ||
| Gender | 0.79† | 0.29† | ||||||||||||
| Male | 28 | 66.2 | 11 | 64.7 | 17 | 60.7 | 38 | 73.1 | 14 | 82.4 | 24 | 68.6 | ||
| Female | 17 | 37.8 | 6 | 35.3 | 11 | 39.3 | 14 | 26.9 | 3 | 17.6 | 11 | 31.4 | ||
| Median age, years (range) | 0.70‡ | 0.15‡ | ||||||||||||
| 61 (32–77) | 61 (33–73) | 61.5 (32–77) | 61 (29–83) | 63 (39–83) | 60 (29–79) | |||||||||
| Primary site | 0.02† | 0.04† | ||||||||||||
| Proximal | 12 | 26.7 | 8 | 47.1 | 4 | 14.3 | 15 | 33.3 | 8 | 47.1 | 7 | 20.0 | ||
| Cecum | 2 | 4.4 | 1 | 5.9 | 1 | 3.6 | 2 | 4.4 | 1 | 5.9 | 1 | 2.9 | ||
| Ascending | 7 | 15.6 | 5 | 29.4 | 2 | 7.1 | 8 | 17.8 | 6 | 35.3 | 2 | 5.7 | ||
| Transverse | 3 | 6.7 | 2 | 11.8 | 1 | 3.6 | 5 | 11.1 | 1 | 5.9 | 4 | 11.4 | ||
| Distal | 33 | 73.3 | 9 | 52.9 | 24 | 85.7 | 37 | 82.2 | 9 | 52.9 | 28 | 80.0 | ||
| Descending | 1 | 2.2 | 0 | 0.0 | 1 | 3.6 | 1 | 2.2 | 1 | 5.9 | 0 | 0.0 | ||
| Sigmoid | 6 | 13.3 | 1 | 5.9 | 5 | 17.9 | 13 | 28.9 | 2 | 11.8 | 11 | 31.4 | ||
| Rectum | 26 | 57.8 | 8 | 47.1 | 18 | 64.3 | 23 | 51.1 | 6 | 35.3 | 17 | 48.6 | ||
| Stage at diagnosis | 0.68† | 0.94† | ||||||||||||
| I | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
| II | 2 | 4.4 | 1 | 5.9 | 1 | 3.6 | 3 | 6.7 | 1 | 5.9 | 2 | 5.7 | ||
| III | 13 | 28.9 | 6 | 35.3 | 7 | 25.0 | 17 | 37.8 | 5 | 29.4 | 12 | 34.3 | ||
| IV | 30 | 66.7 | 10 | 58.8 | 20 | 71.4 | 32 | 71.1 | 11 | 64.7 | 21 | 60 | ||
| Number of organs with metastasis | 0.53‡ | 0.84‡ | ||||||||||||
| 0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 2 | 4.4 | 0 | 0 | 2 | 5.7 | ||
| 1 | 22 | 48.9 | 9 | 20 | 13 | 28.9 | 22 | 48.9 | 8 | 47.1 | 14 | 40.0 | ||
| 2 | 21 | 46.7 | 8 | 17.8 | 13 | 28.9 | 23 | 51.1 | 7 | 41.2 | 16 | 45.7 | ||
| 3 | 2 | 4.4 | 0 | 0.0 | 2 | 4.4 | 5 | 11.1 | 2 | 11.8 | 3 | 8.6 | ||
| BRAF mutation | 0.38† | 0.17† | ||||||||||||
| + | 3 | 7.5 | 2 | 11.8 | 1 | 4.3 | 3 | 5.9 | 2 | 12.5 | 1 | 2.9 | ||
| − | 37 | 92.5 | 15 | 88.2 | 22 | 95.7 | 48 | 94.1 | 14 | 87.5 | 34 | 97.1 | ||
| NA | 5 | 0 | 5 | 1 | 1 | 0 | ||||||||
| No. of previous regimens | 0.33‡ | 0.57‡ | ||||||||||||
| 0 | 5 | 11.1 | 0 | 0.0 | 5 | 17.9 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | ||
| 1 | 4 | 8.9 | 2 | 11.8 | 2 | 7.1 | 5 | 8.2 | 2 | 11.8 | 3 | 8.6 | ||
| 2 | 33 | 73.3 | 14 | 82.4 | 19 | 67.9 | 33 | 65.3 | 11 | 64.7 | 22 | 62.9 | ||
| ≥3 | 3 | 6.7 | 1 | 5.9 | 2 | 7.1 | 14 | 26.5 | 4 | 23.5 | 10 | 28.6 | ||
| No. of following regimens | <0.01‡ | 0.57‡ | ||||||||||||
| 0 | 29 | 64.4 | 17 | 100.0 | 12 | 42.9 | 33 | 61.2 | 12 | 70.6 | 21 | 60 | ||
| 1 | 10 | 22.2 | 0 | 0.0 | 10 | 35.7 | 14 | 26.5 | 3 | 17.6 | 11 | 31.4 | ||
| ≥2 | 6 | 13.3 | 0 | 0.0 | 6 | 21.4 | 5 | 10.2 | 2 | 11.8 | 3 | 8.6 | ||
| Type of anti‐EGFR therapy | 0.02† | 0.70† | ||||||||||||
| Monotherapy | 12 | 26.7 | 8 | 47.1 | 4 | 14.3 | 14 | 26.5 | 4 | 23.5 | 10 | 28.6 | ||
| Combination with irinotecan | 33 | 73.3 | 9 | 52.9 | 24 | 85.7 | 38 | 73.5 | 13 | 76.5 | 25 | 71.4 | ||
†χ2‐test. ‡Wilcoxon test. NA, Not Available.