Background
Methods
Hospital selection, case sampling, and data collection
Area-based socioeconomic indicators
Data Analysis
Results
SEIs, individual demographic and pathologic characteristics by area
Variable by level | Total (Range) | Beijing (North) | Liaoning (Northeast) | Hunan (Central) | Guangdong (South) | Zhejiang (East) | Shannxi (Northwest) | Sichuan (Southwest) |
F(P-value) | SNK* (No. of subgroups) |
---|---|---|---|---|---|---|---|---|---|---|
SEI | ||||||||||
GDP per capita(1)
| 13048 ± 5567 (8050-36146) | 36146 ± 17217a
| 17200 ± 6762b
| 9223 ± 4019c
| 21292 ± 9165b
| 23832 ± 10331b
| 8840 ± 4615c
| 8050 ± 3599c
| 12.69 (< 0.001) | 3 |
HSE percentage(2)
| 4.47 ± 0.43 (3.18-6.51) | 6.51 ± 0.51a
| 3.18 ± 0.41c
| 3.41 ± 0.74c
| 4.27 ± 0.45b
| 5.71 ± 0.71a
| 3.87 ± 0.75c
| 4.56 ± 0.66b
| 38.69 (< 0.001) | 3 |
PU/PR ratio(3)
| 0.80 ± 0.04 (0.54-5.39) | 5.39 ± 0.22a
| 1.45 ± 0.03c
| 0.66 ± 0.06d
| 1.67 ± 0.09b
| 1.32 ± 0.04c
| 0.66 ± 0.06d
| 0.54 ± 0.05d
| 1210 (< 0.001) | 4 |
FPI percentage(4)
| 15.17 ± 2.98 (7.20-17.74) | 7.21 ± 1.63a
| 7.20 ± 1.60a
| 11.31 ± 2.60b
| 9.89 ± 2.57b
| 17.30 ± 3.07c
| 15.86 ± 4.30c
| 17.74 ± 3.31c
| 23.02 (< 0.001) | 3 |
Total | Beijing (North) | Liaoning (Northeast) | Hunan (Central) | Guangdong (South) | Zhejiang (East) | Shannxi (Northwest) | Sichuan (Southwest) | Statistical value |
P-value | |
---|---|---|---|---|---|---|---|---|---|---|
Demographic Characteristic | Total N = 4211 | Total N = 641 | Total N = 832 | Total N = 546 | Total N = 604 | Total N = 606 | Total N = 483 | Total N = 499 | ||
N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |||
Age at diagnosis (years)
| ||||||||||
Mean ± SD | 48.68 ± 10.47 | 50.45 ± 10.92 | 48.88 ± 9.95 | 48.25 ± 10.34 | 47.82 ± 10.94 | 47.35 ± 9.58 | 50.10 ± 11.01 | 47.86 ± 10.32 | 7.63* | < 0.001 |
≤ 40 | 919 (21.8) | 113 (17.6) | 161 (19.4) | 133 (24.4) | 155 (25.7) | 147 (24.3) | 89 (18.4) | 121 (24.2) | ||
40-69 | 3126 (74.2) | 489 (76.3) | 645 (77.5) | 387 (70.9) | 429 (71.0) | 443 (73.1) | 369 (76.4) | 364 (72.9) | ||
≥ 70 | 166 (3.9) | 39 (6.1) | 26 (3.1) | 26 (4.8) | 20 (3.3) | 16 (2.6) | 25 (5.2) | 14 (2.8) | ||
Body Mass Index (kg/m
2
)
(1)
| ||||||||||
Mean ± SD | 23.35 ± 2.89 | 24.65 ± 3.46 | 24.01 ± 3.08 | 21.72 ± 1.85 | 23.25 ± 3.47 | 22.28 ± 2.86 | 23.25 ± 1.29 | 23.25 ± 1.82 | 67.42* | < 0.001 |
≤ 24.99 | 3287 (78.1) | 371 (57.9) | 559 (67.2) | 520 (95.2) | 422 (70.2) | 492 (81.2) | 464 (96.1) | 460 (92.2) | ||
≥ 25.00 | 921 (21.9) | 270 (42.1) | 273 (32.8) | 26 (4.8) | 180 (29.8) | 114 (18.8) | 19 (3.9) | 39 (7.8) | ||
Occupation
| ||||||||||
Homemaker | 173 (4.0) | 17 (2.7) | 2 (0.2) | 72 (13.2) | 39 (6.5) | 11 (1.8) | 14 (2.9) | 18 (3.6) | 6.52** | < 0.001 |
Manual worker | 1893 (45.0) | 230 (35.9) | 258 (31.1) | 185 (33.9) | 159 (26.3) | 487 (80.4) | 261 (54.0) | 313 (62.7) | ||
White-collar worker | 1028 (24.4) | 203 (31.7) | 174 (20.9) | 168 (30.8) | 167 (27.6) | 61 (10.1) | 153 (31.7) | 102 (20.4) | ||
Other | 529 (12.6) | 70 (10.9) | 99 (11.9) | 114 (20.9) | 162 (26.8) | 40 (6.6) | 19 (3.9) | 25 (5.0) | ||
Unknown | 588 (14.0) | 121 (18.9) | 299 (35.9) | 7 (1.2) | 77 (12.8) | 7 (1.1) | 36 (7.5) | 41 (8.2) | ||
Education
| ||||||||||
None | 186 (4.4) | 5 (0.8) | 1 (0.1) | 0 (0.0) | 41 (6.8) | 124 (20.5) | 14 (2.9) | 1 (0.2) | 4.63*** | < 0.001 |
Primary school | 462 (11.0) | 3 (0.5) | 0 (0.0) | 125 (22.9) | 116 (19.2) | 173 (28.5) | 39 (8.1) | 6 (1.2) | ||
Middle school | 606 (14.4) | 0 (0.00) | 0 (0.0) | 147 (26.9) | 172 (28.5) | 165 (27.2) | 115 (23.8) | 7 (1.4) | ||
High school | 441 (10.5) | 0 (0.00) | 2 (0.2) | 122 (22.3) | 143 (23.7) | 56 (9.2) | 116 (24.0) | 2 (0.4) | ||
University and above | 396 (9.4) | 4 (0.6) | 23 (2.8) | 150 (27.5) | 112 (18.5) | 29 (4.8) | 76 (15.7) | 2 (0.4) | ||
Unknown | 2120 (50.3) | 629 (98.1) | 806 (96.9) | 2 (0.4) | 20 (3.3) | 59 (9.8) | 123 (25.5) | 481 (96.4) | ||
Marital Status
| ||||||||||
Single | 51 (1.2) | 6 (0.9) | 9 (1.1) | 4 (0.7) | 17 (2.8) | 5 (0.8) | 3 (0.6) | 7 (1.4) | 56.43** | < 0.001 |
Married | 4090 (97.1) | 620 (96.7) | 821 (98.7) | 525 (96.2) | 586 (97.0) | 589 (97.2) | 474 (98.1) | 475 (95.2) | ||
Widowed/Divorced | 52 (1.2) | 12 (1.9) | 0 (0.0) | 17 (3.1) | 0 (0.0) | 7 (1.2) | 5 (1.0) | 11 (2.2) | ||
Unknown | 18 (0.5) | 3 (0.5) | 2 (0.2) | - | 1 (0.2) | 5 (0.8) | 1 (0.2) | 6 (1.2) |
Total | Beijing (North) | Liaoning (Northeast) | Hunan (Central) | Guangdong (South) | Zhejiang (East) | Shannxi (Northwest) | Sichuan (Southwest) |
χ2 |
P-value | |
---|---|---|---|---|---|---|---|---|---|---|
Pathological Characteristics | Total N = 4211 | Total N = 641 | Total N = 832 | Total N = 546 | Total N = 604 | Total N = 606 | Total N = 483 | Total N = 499 | ||
N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |||
Type of Postoperative Pathological Diagnosis
(1)
| ||||||||||
Carcinoma in Situ (CIS) | 143 (3.4) | 61 (9.5) | 22 (2.6) | 17 (3.1) | 19 (3.1) | 7 (1.2) | 5 (1.0) | 12 (2.4) | 169.1 | < 0.001 |
Invasive Ductal Carcinoma | 3471 (82.4) | 528 (82.4) | 583 (70.1) | 504 (92.4) | 528 (87.4) | 523 (86.3) | 406 (84.1) | 399 (80.0) | ||
Other Invasive Carcinoma | 385 (9.1) | 47 (7.3) | 87 (10.5) | 21 (3.8) | 29 (4.8) | 59 (9.7) | 70 (14.5) | 72 (14.4) | ||
Other | 15 (0.4) | 5 (0.8) | 0 (0.0) | 1 (0.2) | 4 (0.7) | 0 (0.0) | 2 (0.4) | 3 (0.6) | ||
Unavailable | 197 (4.7) | - | 140 (16.8) | 3 (0.5) | 24 (4.0) | 17 (2.8) | - | 13 (2.6)) | ||
Pathological stage
(2)
| ||||||||||
Stage 0 | 39 (0.9) | 7 (1.1) | 13 (1.6) | 6 (1.1) | 8 (1.3) | 4 (0.7) | 0 (0.0) | 1 (0.2) | 450.5 | < 0.001 |
Stage I | 663 (15.7) | 172 (26.8) | 131 (15.7) | 73 (13.4) | 98 (16.2) | 95 (15.7) | 77 (15.9) | 17 (3.4) | ||
Stage II | 1891 (44.9) | 280 (43.7) | 323 (38.8) | 400 (73.3) | 243 (40.2) | 239 (39.4) | 170 (35.2) | 236 (47.3) | ||
Stage III | 788 (18.7) | 93 (14.5) | 119 (14.3) | 53 (9.7) | 117 (19.4) | 152 (25.1) | 127 (26.3) | 127 (25.5) | ||
Stage IV | 113 (2.7) | 2 (0.3) | 4 (0.5) | 3 (0.5) | 20 (3.4) | 5 (0.8) | 56 (11.6) | 23 (4.6) | ||
Unavailable | 717 (17.1) | 87 (13.6) | 242 (29.1) | 11 (2.0) | 118 (19.5) | 111 (18.3) | 53 (11.0) | 95 (19.0) | ||
ER/PR test
| ||||||||||
Performed | 3555 (84.4) | 616 (96.1) | 711 (85.5) | 535 (98.0) | 511 (84.6) | 462 (76.2) | 282 (58.4) | 438 (87.8) | 483.2 | < 0.001 |
Not performed | 471 (11.2) | 24 (3.7) | 85 (10.2) | 8 (1.5) | 54 (8.9) | 67 (11.1) | 192 (39.8) | 41 (8.2) | ||
Unknown | 185 (4.4) | 1 (0.2) | 36 (4.3) | 3 (0.5) | 39 (6.5) | 77 (12.7) | 9 (1.8) | 20 (4.0) | ||
Her-2 test
| ||||||||||
Performed | 3251 (77.2) | 609 (95.0) | 693 (83.3) | 533 (97.6) | 469 (77.6) | 424 (70.0) | 241 (49.9) | 282 (56.5) | 640.2 | < 0.001 |
Not performed | 762 (18.1) | 31 (4.8) | 98 (11.8) | 8 (1.5) | 99 (16.4) | 98 (16.1) | 227 (47.0) | 201 (40.3) | ||
Unknown | 198 (4.7) | 1 (0.2) | 41 (4.9) | 5 (0.9) | 36 (6.0) | 84 (13.9) | 15 (3.1) | 16 (3.2) | ||
ER/PR status
(3)
| ||||||||||
ER+&PR+ | 1691 (47.6) | 373 (60.6) | 318 (44.7) | 244 (45.6) | 241 (47.2) | 221 (47.8) | 109 (38.7) | 185 (42.2) | 121.0 | < 0.001 |
ER+&PR- | 337 (9.5) | 44 (7.1) | 79 (11.1) | 54 (10.1) | 37 (7.2) | 41 (8.9) | 31 (11.0) | 51 (11.6) | ||
ER-&PR+ | 367 (10.3) | 47 (7.6) | 108 (15.2) | 32 (6.0) | 75 (14.7) | 34 (7.4) | 37 (13.1) | 34 (7.8) | ||
ER-&PR- | 1139 (32.0) | 146 (23.7) | 206 (29.0) | 203 (37.9) | 152 (29.7) | 165 (35.7) | 101 (35.8) | 166 (37.9) | ||
Unavailable | 21 (0.6) | 6 (1.0) | - | 2 (0.4) | 6 (1.2) | 1 (0.2) | 4 (1.4) | 2 (0.5) | ||
Her-2 status
(4)
| ||||||||||
Her-2 + | 736 (22.6) | 286 (47.0) | 36 (5.2) | 156 (29.3) | 90 (19.2) | 68 (16.0) | 29 (12.0) | 71 (25.2) | 339.6 | < 0.001 |
Her-2 - | 2113 (65.0) | 299 (49.1) | 545 (78.6) | 314 (58.9) | 337 (71.9) | 317 (74.8) | 181 (75.1) | 120 (42.6) | ||
Uncertain/unavailable | 402 (12.4) | 24 (3.9) | 112 (16.2) | 63(11.8) | 42 (9.1) | 39 (9.2) | 31 (12.9) | 91 (32.2) |
SEIs, area-based SES, and breast cancer stage at diagnosis
Variable by level | Mean ± SD | Included Provinces | Total | Stage 0&I | Stage II | Stage III&IV | Unavailable | Chi-square for trend |
P-value |
---|---|---|---|---|---|---|---|---|---|
N (%) | N (%) | N (%) | N (%) | ||||||
GDP per capita
(1)
| |||||||||
Highest | 36146 ± 17217 | Beijing | 641 | 179 (27.9) | 280 (43.7) | 95 (14.8) | 87 (13.6) | 80.79 | < 0.001 |
High | 20774 ± 9006 | Liaoning, Guangdong, Zhejiang | 2024 | 349 (17.1) | 805 (39.4) | 417 (20.4) | 471 (23.1) | ||
Low | 8704 ± 3986 | Hunan, Shannxi, Sichuan | 1528 | 174 (11.4) | 806 (52.7) | 389 (25.5) | 159 (10.4) | ||
HSE percentage
(2)
| |||||||||
Highest | 6.11 ± 0.73 | Beijing, Zhejiang | 1247 | 278 (22.3) | 519 (41.6) | 252 (20.2) | 198 (15.9) | 3.307 | 0.081 |
High | 4.42 ± 0.57 | Guangdong, Sichuan | 1103 | 124 (11.2) | 479 (43.5) | 287 (26.0) | 213 (19.3) | ||
Low | 3.49 ± 0.70 | Liaoning, Hunan, Shannxi | 1861 | 300 (16.1) | 893 (48.0) | 362 (19.5) | 306 (16.4) | ||
PU/PR ratio
(3)
| |||||||||
Highest | 5.39 ± 0.22 | Beijing | 641 | 179 (27.9) | 280 (43.7) | 95 (14.8) | 87 (13.6) | 72.00 | < 0.001 |
Higher | 1.67 ± 0.09 | Guangdong | 604 | 106 (17.5) | 243 (40.2) | 137 (22.7) | 118 (19.6) | ||
High | 1.39 ± 0.08 | Liaoning, Zhejiang | 1438 | 243 (16.9) | 562 (39.1) | 280 (19.5) | 353 (24.5) | ||
Low | 0.62 ± 0.08 | Hunan, Shannxi, Sichuan | 1528 | 174 (11.4) | 806 (52.7) | 389 (25.5) | 159 (10.4) | ||
FPI percentage
(4)
| |||||||||
Highest | 16.97 ± 3.55 | Zhejiang, Shannxi, Sichuan | 1588 | 194 (12.2) | 645 (40.6) | 490 (30.9) | 259 (16.3) | 135.83 | < 0.001 |
High | 10.60 ± 2.62 | Hunan, Guangdong | 1150 | 185 (16.1) | 643 (55.9) | 193 (16.8) | 129 (11.2) | ||
Low | 7.21 ± 1.57 | Beijing, Liaoning, | 1473 | 323 (21.9) | 603 (40.9) | 218 (14.8) | 329 (22.4) | ||
Area-based SES
(5)
| |||||||||
Highest | - | Beijing | 641 | 179 (27.9) | 280 (43.7) | 95 (14.8) | 87 (13.6) | 80.79 | < 0.001 |
High | - | Liaoning, Guangdong, Zhejiang | 2024 | 349 (17.1) | 805 (39.4) | 417 (20.4) | 471 (23.1) | ||
Low | - | Hunan, Shannxi, Sichuan | 1528 | 174 (11.4) | 806 (52.7) | 389 (25.5) | 159 (10.4) |
Association between individual demographic characteristics and breast cancer stage at diagnosis stratified by area-based SES
Variable | High SES areas | Low SES areas | ||
---|---|---|---|---|
OR (95%CI) | Wald (P) | OR (95%CI) | Wald (P) | |
Age at Diagnosis (Years)
| ||||
≤ 40 | 1.00 | 1.00 | ||
40-69 | 0.94 (0.29-3.09) | 0.01 (0.92) | 1.18 (0.43-3.23) | 0.10 (0.75) |
≥ 70 | 1.02 (0.70-1.51) | 0.02 (0.90) | 1.40 (0.85-2.29) | 1.75 (0.19) |
Body Mass Index (kg/m
2
)
| ||||
≤ 24.99 | 1.00 | 1.00 | ||
≥ 25.00 | 1.37 (0.92-2.06) | 2.39 (0.12) | 1.09 (0.40-12.97) | 0.03 (0.86) |
Occupation
| ||||
Homemaker | 1.00 | 1.00 | ||
Manual worker | 0.81 (0.33-2.02) | 0.20 (0.65) | 0.18 (0.05-0.64) |
6.99 (0.01)
|
White-collar worker | 0.77 (0.33-1.80) | 0.37 (0.54) | 0.26 (0.08-0.88) |
4.66 (0.03)
|
Other | 1.21 (0.45-3.25) | 0.14 (0.70) | 0.18 (0.05-0.65) |
6.85 (0.01)
|
Education
| ||||
University and above | 1.00 | 1.00 | ||
High school | 2.89 (1.30-6.44) |
6.76 (0.01)
| 0.42 (0.07-2.36) | 0.97 (0.32) |
Middle school | 2.77 (132-5.79) |
7.27 (0.01)
| 0.97 (0.42-2.21) | 0.01 (0.94) |
Primary school | 1.87 (0.99-3.64) | 3.43 (0.06) | 0.98 (0.47-2.05) | 0.01 (0.96) |
None | 1.64 (0.87-3.08) | 2.34 (0.13) | 0.74 (0.40-1.36) | 0.93 (0.34) |
Marital Status
| ||||
Married | 1.00 | 1.00 | ||
Single | 6.27 (0.81-48.76) | 3.08 (0.08) | 1.01 (0.11-9.51) | 0.001 (0.99) |
Widowed/Divorced | 1.18 (0.14-10.06) | 0.02 (0.88) | 0.49 (0.15-1.62) | 1.38 (0.24) |
ER/PR status
| ||||
ER+&PR+ | 1.00 | 1.00 | ||
ER+&PR- | 0.97 (0.50-1.90) | 0.01 (0.93) | 1.10 (0.54-2.23) | 0.07 (0.79) |
ER-&PR+ | 1.57 (0.83-2.95) | 1.96 (0.16) | 0.73 (0.36-1.51) | 0.70 (0.40) |
ER-&PR- | 1.04 (0.69-1.56) | 0.04 (0.85) | 1.31 (0.81-2.11) | 1.19 (0.28) |