Table 2.
Analysis of the variables of surgery, pathology, and adjuvant chemotherapy in the eligible UNITED cohort, stroma-low compared with the stroma-high patients
| Variables (unit) | Stroma-low (n = 960) | Stroma-high (n = 428) | P value |
|---|---|---|---|
| Sex | 0.385g | ||
| Female | 420 (44) | 198 (46) | |
| Male | 540 (56) | 230 (54) | |
| Age at surgery—older category | 0.185g | ||
| <75 years | 636 (66) | 299 (70) | |
| ≥75 years | 324 (34) | 129 (30) | |
| Biopsy taken | 0.530g | ||
| Yes | 843 (88) | 380 (89) | |
| Noa | 117 (12) | 47 (11) | |
| Surgery type | 0.309h | ||
| Hemicolectomy right | 435 (45) | 176 (41) | |
| Hemicolectomy left | 121 (13) | 59 (14) | |
| Sigmoidectomy | 277 (29) | 136 (32) | |
| Otherb | 127 (13) | 57 (13) | |
| Tumor-sidednessc | 0.049g | ||
| Right-sided tumor | 473 (49) | 186 (44) | |
| Left-sided tumor | 487 (51) | 241 (56) | |
| Missing | 0 (0) | 1 (0) | |
| Lymph nodes | 0.004g | ||
| <12 examined | 117 (12) | 30 (7) | |
| ≥12 examined | 843 (88) | 398 (93) | |
| Pathological tumor (pT) staged | <0.001g | ||
| pT1-3 | 810 (84) | 305 (71) | |
| pT1 | 10 (1) | 1 (0) | |
| pT2 | 61 (6) | 6 (1) | |
| pT3 | 739 (77) | 298 (70) | |
| pT4 | 150 (16) | 123 (29) | |
| Pathological nodal (pN) staged | <0.001g | ||
| pN0 | 541 (56) | 182 (43) | |
| pN1 | 292 (30) | 152 (36) | |
| pN2 | 127 (13) | 94 (22) | |
| Tumor morphology | 0.303g | ||
| Adenocarcinoma | 855 (89) | 390 (91) | |
| Mucinous carcinoma | 90 (9) | 33 (8) | |
| Other, including signet cell carcinoma | 15 (2) | 5 (1) | |
| Differentiation gradee | 0.062g | ||
| Well–moderate | 809 (84) | 378 (88) | |
| Poor–undifferentiated | 125 (13) | 41 (10) | |
| Grade cannot be assessed | 26 (3) | 9 (2) | |
| Pathology risk factorsf | <0.001g | ||
| No pathology risk factors present | 566 (59) | 197 (46) | |
| Presence of ≥1 pathology risk factor | 394 (41) | 231 (54) | |
| Extramural venous invasion (EMVI) | |||
| Not reported | 162 (17) | 55 (13) | |
| Reported, of which | 798 (83) | 373 (87) | <0.001g |
| Yes (EMVI+) | 86 (9) | 98 (23) | |
| No (EMVI−) | 712 (74) | 275 (64) | |
| Venous invasion | |||
| Not reported | 99 (10) | 56 (13) | |
| Reported, of which | 861 (90) | 372 (87) | <0.001g |
| Yes (V1) | 100 (12) | 69 (19) | |
| No (V0) | 761 (88) | 303 (81) | |
| Lymphatic invasion | |||
| Not reported | 28 (3) | 20 (5) | |
| Reported, of which | 932 (97) | 408 (95) | 0.193g |
| Yes (L1) | 304 (33) | 148 (36) | |
| No (L0) | 628 (67) | 260 (64) | |
| Perineural invasion | |||
| Not reported | 423 (44) | 186 (44) | |
| Reported, of which | 537 (56) | 242 (57) | <0.001g |
| Yes (Pn1) | 68 (13) | 58 (24) | |
| No (Pn0) | 469 (87) | 184 (43) | |
| Microsatellite instability/mismatch repair (MMR) status | |||
| Not determined | 439 (46) | 213 (50) | |
| Determined, of which | 521 (54) | 215 (50) | 0.012g |
| Microsatellite stable (MSS)/MMR proficient (pMMR) | 403 (77) | 184 (86) | |
| Microsatellite instable (MSI)/MMR deficient (dMMR) | 118 (23) | 31 (14) | |
| Pathological TNM stage | <0.001g | ||
| Stage II | 541 (56) | 182 (43) | |
| Stage III | 419 (44) | 246 (57) | |
| Adjuvant chemotherapy—received | <0.001g | ||
| No | 539 (56) | 174 (41) | |
| Yes | 421 (44) | 254 (59) | |
| Adjuvant chemotherapy—per pathological TNM stage | <0.001g | ||
| Stage II + no adjuvant therapy | 434 (45) | 125 (29) | |
| Stage II + adjuvant therapy | 107 (11) | 57 (13) | |
| Stage III + adjuvant therapy | 314 (33) | 197 (46) | |
| Stage III + no adjuvant therapy | 105 (11) | 49 (11) |
All variables are given as absolute numbers with associated percentages or medians with interquartile ranges. Sum of percentages can be less or more than 100 due to rounding. Bold indicates significance, when P < 0.05.
N/A, not applicable; TNM, tumor–node–metastasis.
Reasons why biopsy was not taken are, e.g. in emergency setting (obstructive ileus).
Other operation types include a (sub)total colectomy, high anterior resection, or transversectomy.
A right-sided tumor is defined as a colon carcinoma in the cecum, colon ascendens, flexura hepatica, or colon transversum.
Different versions of the Union for International Cancer Control (UICC) TNM classification were used. Here, all variables are converted to the UICC TNM version 5 (1997).
Differentiation grade is variously registered as separate or combined subgroups; this is then categorized into combined grades, i.e. well–moderate or poor–undifferentiated.
Pathology risk factors are stated in Table 2. Presence of a risk factor is defined as at least one of registered risk factors. Absence is the absence of registered risk factors, as not all risk factors are registered.
Calculated using the chi-square test.
Calculated using the chi-square test for the three most common and here presented operation types: hemicolectomy right, hemicolectomy left, and sigmoidectomy.