Characteristics according to the amount of Fusobacterium nucleatum DNA in colorectal cancer tissue
| The amount of F. nucleatum DNA in colorectal cancer tissue | |||||
|---|---|---|---|---|---|
| Characteristic* | All patients (n=1069) | Negative (n=935) | Low (n=67) | High (n=67) | p Value† |
| Mean age±SD (year) | 69.3±8.8 | 69.2±8.8 | 71.1±9.0 | 68.8±8.3 | 0.21 |
| Sex | 0.36 | ||||
| Men | 449 (42%) | 400 (43%) | 26 (39%) | 23 (34%) | |
| Women | 620 (58%) | 535 (57%) | 41 (61%) | 44 (66%) | |
| Year of diagnosis | 0.016 | ||||
| Prior to 1995 | 351 (33%) | 322 (34%) | 12 (18%) | 17 (25%) | |
| 1996 to 2000 | 298 (28%) | 260 (28%) | 18 (27%) | 20 (30%) | |
| 2001 to 2008 | 420 (39%) | 353 (38%) | 37 (55%) | 30 (45%) | |
| Family history of colorectal carcinoma in a first-degree relative | 0.27 | ||||
| Absent | 857 (80%) | 745 (80%) | 59 (88%) | 53 (80%) | |
| Present | 208 (20%) | 187 (20%) | 8 (12%) | 13 (20%) | |
| Tumour location | 0.001 | ||||
| Caecum | 178 (17%) | 145 (15%) | 13 (20%) | 20 (30%) | |
| Ascending to transverse colon | 346 (32%) | 296 (32%) | 23 (34%) | 27 (41%) | |
| Splenic flexure to sigmoid | 311 (29%) | 287 (31%) | 12 (18%) | 12 (18%) | |
| Rectosigmoid and rectum | 231 (22%) | 205 (22%) | 19 (28%) | 7 (11%) | |
| pT stage (depth of tumour invasion) | 0.0008 | ||||
| pT1 (submucosa) | 99 (10%) | 93 (11%) | 1 (1.6%) | 5 (8.2%) | |
| pT2 (muscularis propria) | 205 (21%) | 189 (22%) | 12 (19%) | 4 (6.6%) | |
| pT3 (subserosa) | 620 (63%) | 532 (62%) | 41 (66%) | 47 (77%) | |
| pT4 (serosa or other organs) | 57 (5.8%) | 44 (5.1%) | 8 (13%) | 5 (8.2%) | |
| pN stage (number of positive lymph nodes) | 0.84 | ||||
| pN0 (0) | 602 (63%) | 531 (64%) | 35 (58%) | 36 (61%) | |
| pN1 (1–3) | 211 (22%) | 182 (22%) | 16 (27%) | 13 (22%) | |
| pN2 (≥4) | 138 (15%) | 119 (14%) | 9 (15%) | 10 (17%) | |
| AJCC disease stage | 0.003 | ||||
| I | 241 (25%) | 225 (26%) | 9 (15%) | 7 (11%) | |
| II | 325 (33%) | 274 (32%) | 23 (37%) | 28 (45%) | |
| III | 278 (28%) | 239 (28%) | 25 (40%) | 14 (23%) | |
| IV | 133 (14%) | 115 (14%) | 5 (8.1%) | 13 (21%) | |
| Tumour differentiation | <0.0001 | ||||
| Well to moderate | 965 (90%) | 862 (92%) | 55 (83%) | 48 (72%) | |
| Poor | 102 (9.6%) | 72 (7.7%) | 11 (17%) | 19 (28%) | |
| MSI status | <0.0001 | ||||
| MSI-low/MSS | 858 (84%) | 780 (87%) | 42 (66%) | 36 (55%) | |
| MSI-high | 165 (16%) | 114 (13%) | 22 (34%) | 29 (45%) | |
| MLH1 hypermethylation | <0.0001 | ||||
| Absent | 844 (86%) | 759 (89%) | 48 (79%) | 37 (60%) | |
| Present | 134 (14%) | 96 (11%) | 13 (21%) | 25 (40%) | |
| CIMP status | <0.0001 | ||||
| Low/negative | 800 (82%) | 716 (84%) | 48 (79%) | 36 (58%) | |
| High | 178 (18%) | 139 (16%) | 13 (21%) | 26 (42%) | |
| BRAF mutation | 0.0009 | ||||
| Wild type | 866 (84%) | 771 (86%) | 50 (78%) | 45 (68%) | |
| Mutant | 165 (16%) | 130 (14%) | 14 (22%) | 21 (32%) | |
| KRAS mutation | 0.44 | ||||
| Wild type | 566 (57%) | 499 (57%) | 29 (50%) | 38 (61%) | |
| Mutant | 423 (43%) | 370 (43%) | 29 (50%) | 24 (39%) | |
| PIK3CA mutation | 0.88 | ||||
| Wild type | 813 (84%) | 713 (84%) | 48 (83%) | 52 (83%) | |
| Mutant | 157 (16%) | 136 (16%) | 10 (17%) | 11 (17%) | |
| Mean LINE-1 methylation level (%)±SD | 63.3±10.0 | 63.1±10.0 | 64.8±10.7 | 65.2±8.9 | 0.11 |
*Percentage indicates the proportion of cases with a specific clinical, pathological or tumour molecular feature according to the amount of F. nucleatum DNA in colorectal cancer tissue. There were cases which had missing values for any of the characteristics except for age, sex and year of diagnosis.
†To assess associations between the ordinal categories (negative, low and high) of the amount of F. nucleatum DNA in colorectal cancer tissue and categorical variables, Fisher's exact test was performed. To compare mean age and mean LINE-1 methylation levels, an analysis of variance was performed. We adjusted two-sided α level to 0.003 (=0.05/16) by simple Bonferroni correction for multiple hypothesis testing.
AJCC, American Joint Committee on Cancer; CIMP, CpG island methylator phenotype; LINE-1, long interspersed nucleotide element-1; MSI, microsatellite instability; MSS, microsatellite stable.