Table 2.
Description of variables in the dataset.
| Variable | Levels | Total (n=3580) |
Status | P-value | |
|---|---|---|---|---|---|
| Censored (n=3146) |
Deceased (n=434) |
||||
| Age at diagnosis (years) | Mean ± SD | 48.83 ± 11.59 | 48.59 ± 11.30 | 50.51 ± 13.38 | 0.005 |
| Education | Higher education | 1293 (36.12%) | 1188 (37.76%) | 105 (24.19%) | <0.001 |
| Highschool diploma | 1327 (37.07%) | 1188 (37.76%) | 139 (32.03%) | ||
| Middle school | 402 (11.23%) | 333 (10.58%) | 69 (15.90%) | ||
| Elementary school | 353 (9.86%) | 288 (9.15%) | 65 (14.98%) | ||
| Illiterate | 205 (5.73%) | 149 (4.74%) | 56 (12.90%) | ||
| Marital status | Not married | 539 (15.06%) | 471 (14.97%) | 68 (15.67%) | 0.704 |
| Married | 3041 (84.94%) | 2675 (85.03%) | 366 (84.33%) | ||
| Gravidity | 0 | 426 (11.90%) | 384 (12.21%) | 42 (9.68%) | <0.001 |
| 1-2 | 1320 (36.87%) | 1182 (37.57%) | 138 (31.80%) | ||
| 3-4 | 1260 (35.20%) | 1103 (35.06%) | 157 (36.18%) | ||
| More than 4 | 574 (16.03%) | 477 (15.16%) | 97 (22.35%) | ||
| Abortion | No | 2466 (68.88%) | 2163 (68.75%) | 303 (69.82%) | 0.654 |
| Yes | 1114 (31.12%) | 983 (31.25%) | 131 (30.18%) | ||
| Breastfeeding duration | 0 | 585 (16.34%) | 529 (16.82%) | 56 (12.90%) | 0.001 |
| Less than 2 years | 1308 (36.54%) | 1130 (35.92%) | 178 (41.01%) | ||
| 2-4 years | 1396 (38.99%) | 1246 (39.61%) | 150 (34.56%) | ||
| 4-6 years | 291 (8.13%) | 241 (7.66%) | 50 (11.52%) | ||
| More than 6 years | 0 (0.00%) | 0 (0.00%) | 0 (0.00%) | ||
| Family history | None | 2601 (72.65%) | 2283 (72.57%) | 318 (73.27%) | 0.382 |
| 1st degree | 514 (14.36%) | 460 (14.62%) | 54 (12.44%) | ||
| 2nd degree | 465 (12.99%) | 403 (12.81%) | 62 (14.29%) | ||
| Tumor size | T1 | 1077 (30.08%) | 1006 (31.98%) | 71 (16.36%) | <0.001 |
| T2 | 1640 (45.81%) | 1447 (45.99%) | 193 (44.47%) | ||
| T3 | 863 (24.11%) | 693 (22.03%) | 170 (39.17%) | ||
| Lymph node status | N0 | 1803 (50.36%) | 1678 (53.34%) | 125 (28.80%) | <0.001 |
| N1 | 1006 (28.10%) | 901 (28.64%) | 105 (24.19%) | ||
| N2 | 528 (14.75%) | 406 (12.91%) | 122 (28.11%) | ||
| N3 | 243 (6.79%) | 161 (5.12%) | 82 (18.89%) | ||
| Tumor stage | I | 725 (20.25%) | 700 (22.25%) | 25 (5.76%) | <0.001 |
| II | 1528 (42.68%) | 1416 (45.01%) | 112 (25.81%) | ||
| III | 1160 (32.40%) | 944 (30.01%) | 216 (49.77%) | ||
| IV | 167 (4.66%) | 86 (2.73%) | 81 (18.66%) | ||
| Tumor grade | Low | 362 (10.11%) | 333 (10.58%) | 29 (6.68%) | 0.016 |
| Intermediate | 2044 (57.09%) | 1799 (57.18%) | 245 (56.45%) | ||
| High | 1174 (32.79%) | 1014 (32.23%) | 160 (36.87%) | ||
| Molecular Subtypes | Subgroup 1: ER + or PR +/HER2 + | 503 (14.05%) | 443 (14.08%) | 60 (13.82%) | <0.001 |
| Subgroup 2: ER + or PR +/HER2 - | 2175 (60.75%) | 1961 (62.33%) | 214 (49.31%) | ||
| Subgroup 3: ER - and PR -/HER2 + | 270 (7.54%) | 226 (7.18%) | 44 (10.14%) | ||
| Subgroup 4: ER – and PR -/HER2 – | 632 (17.65%) | 516 (16.40%) | 116 (26.73%) | ||
| Pathology | Invasive ductal carcinoma | 3358 (93.80%) | 2943 (93.55%) | 415 (95.62%) | 0.093 |
| Invasive lobular carcinoma | 222 (6.20%) | 203 (6.45%) | 19 (4.38%) | ||
| Lymph vascular invasion | No | 2426 (67.77%) | 2186 (69.49%) | 240 (55.30%) | <0.001 |
| Yes | 1154 (32.23%) | 960 (30.51%) | 194 (44.70%) | ||
| Type of surgery | Breast conserving surgery | 2548 (71.17%) | 2358 (74.95%) | 190 (43.78%) | <0.001 |
| Modified radical mastectomy | 1032 (28.83%) | 788 (25.05%) | 244 (56.22%) | ||
| Chemotherapy | None | 472 (13.18%) | 452 (14.37%) | 20 (4.61%) | <0.001 |
| Adjuvant | 2586 (72.23%) | 2247 (71.42%) | 339 (78.11%) | ||
| nonadjuvanted | 522 (14.58%) | 447 (14.21%) | 75 (17.28%) | ||
| Radiotherapy | None | 137 (3.83%) | 115 (3.66%) | 22 (5.07%) | <0.001 |
| External | 2937 (82.04%) | 2533 (80.51%) | 404 (93.09%) | ||
| Intraoperative | 506 (14.13%) | 498 (15.83%) | 8 (1.84%) | ||
| Hormonotherapy | No | 714 (19.94%) | 600 (19.07%) | 114 (26.27%) | <0.001 |
| Yes | 2866 (80.06%) | 2546 (80.93%) | 320 (73.73%) | ||
The frequency (percentage) was used to describe the categorical data. Numeric variables were presented using mean ± SD. The association between status (censored and deceased) and categorical variables was evaluated using Pearson Chi-Square test. The independent test was used to compare the mean of age between groups.