Table 1. Patient, Tumor, and Treatment Characteristics by Locoregional Treatment.
| Characteristic | No. (%) | P value | |||
|---|---|---|---|---|---|
| BCS+RT (n = 29 367) | Mx-RT (n = 12 413) | Mx+RT (n = 7206) | Total (n = 48 986) | ||
| Follow-up time from surgery, median (range), y | 6.35 (0.02-11.70) | 6.20 (0.01-11.69) | 6.02 (0.12-11.66) | 6.28 (0.01-11.70) | <.001 |
| No. of deaths | |||||
| OS | 2272 (7.7) | 2912 (23.5) | 1389 (19.3) | 6573 (13.4) | <.001 |
| BCSS | 727 (2.5) | 771 (6.2) | 815 (11.3) | 2313 (4.7) | <.001 |
| Age at diagnosis, y | |||||
| <40 | 736 (2.5) | 451 (3.6) | 643 (8.9) | 1830 (3.7) | <.001 |
| 40-49 | 4170 (14.2) | 1457 (11.7) | 1503 (20.9) | 7130 (14.6) | |
| 50-64 | 12 424 (42.3) | 3212 (25.9) | 2366 (32.8) | 18 002 (36.7) | |
| 65-74 | 10 134 (34.5) | 3383 (27.3) | 1629 (22.6) | 15 146 (30.9) | |
| ≥75 | 1903 (6.5) | 3910 (31.5) | 1065 (14.8) | 6878 (14.0) | |
| Mean (SD) | 60.8 (10.5) | 66.3 (14.2) | 58.7 (13.9) | 61.9 (12.4) | <.001 |
| Median (range) | 62 (22-94) | 68 (21-97) | 59 (19-95) | 63 (19-97) | <.001 |
| Year of surgery | |||||
| 2008-2009 | 5044 (17.2) | 2665 (21.5) | 1404 (19.5) | 9113 (18.6) | <.001 |
| 2010-2011 | 6076 (20.7) | 2934 (23.6) | 1636 (22.7) | 10 646 (21.7) | |
| 2012-2013 | 6759 (23.0) | 2782 (22.4) | 1571 (21.8) | 11 112 (22.7) | |
| 2014-2015 | 7437 (25.3) | 2683 (21.6) | 1691 (23.5) | 11 811 (24.1) | |
| 2016-2017 | 4051 (13.8) | 1349 (10.9) | 904 (12.5) | 6304 (12.9) | |
| T stagea | |||||
| T1 | 23 266 (79.2) | 7114 (57.3) | 2643 (36.7) | 33 023 (67.4) | <.001 |
| T2 | 6101 (20.8) | 5299 (42.7) | 4563 (63.3) | 15 963 (32.6) | |
| T stageb | |||||
| T1mi | 177 (0.6) | 116 (0.9) | 43 (0.6) | 336 (0.7) | <.001 |
| T1a | 1146 (3.9) | 435 (3.5) | 97 (1.3) | 1678 (3.4) | |
| T1b | 7082 (24.1) | 1479 (11.9) | 379 (5.3) | 8940 (18.3) | |
| T1c | 14 737 (50.2) | 5035 (40.6) | 1935 (26.9) | 21 707 (44.3) | |
| T1 | 124 (0.4) | 49 (0.4) | 189 (2.6) | 362 (0.7) | |
| T2 | 6101 (20.8) | 5299 (42.7) | 4563 (63.3) | 15 963 (32.6) | |
| Lymph node status | |||||
| N0 | 22 933 (78.1) | 9871 (79.5) | 1701 (23.6) | 34 505 (70.4) | <.001 |
| N1 | 5666 (19.3) | 2268 (18.3) | 3989 (55.4) | 11 923 (24.3) | |
| N2 | 768 (2.6) | 274 (2.2) | 1516 (21.0) | 2558 (5.2) | |
| Prognostic groups | |||||
| T1N0 | 19 147 (65.2) | 6021 (48.5) | 805 (11.2) | 25 973 (53.0) | <.001 |
| T1N1 | 3732 (12.7) | 1036 (8.3) | 1420 (19.7) | 6188 (12.6) | |
| T1N2 | 387 (1.3) | 57 (0.5) | 418 (5.8) | 862 (1.8) | |
| T2N0 | 3786 (12.9) | 3850 (31.0) | 896 (12.4) | 8532 (17.4) | |
| T2N1 | 1934 (6.6) | 1232 (9.9) | 2569 (35.7) | 5735 (11.7) | |
| T2N2 | 381 (1.3) | 217 (1.7) | 1098 (15.2) | 1696 (3.5) | |
| Primary treatment | |||||
| Surgery | 28 859 (98.3) | 12 149 (97.9) | 6038 (83.8) | 47 046 (96.0) | <.001 |
| Neoadjuvant systemic treatment | 508 (1.7) | 264 (2.1) | 1168 (16.2) | 1940 (4.0) | |
| Bilateral breast cancer | |||||
| No | 28 761 (97.9) | 11 965 (96.4) | 7034 (97.6) | 47 760 (97.5) | <.001 |
| Yes | 606 (2.1) | 448 (3.6) | 172 (2.4) | 1226 (2.5) | |
| Histological invasive subtype | |||||
| Ductal | 23 607 (80.4) | 9367 (75.5) | 4920 (68.3) | 37 894 (77.4) | <.001 |
| Lobular | 3052 (10.4) | 1906 (15.4) | 935 (13.0) | 5893 (12.0) | |
| Other | 2114 (7.2) | 848 (6.8) | 208 (2.9) | 3170 (6.5) | |
| Missing | 594 (2.0) | 292 (2.4) | 1143 (15.9) | 2029 (4.1) | |
| Nottingham grade | |||||
| 1 | 7388 (25.2) | 2086 (16.8) | 514 (7.1) | 9988 (20.4) | <.001 |
| 2 | 14 346 (48.9) | 6296 (50.7) | 2878 (39.9) | 23 520 (48.0) | |
| 3 | 6873 (23.4) | 3602 (29.0) | 2596 (36.0) | 13071 (26.7) | |
| Missing | 760 (2.6) | 429 (3.5) | 1218 (16.9) | 2407 (4.9) | |
| ERBB2 amplification | |||||
| Yes | 2932 (10.0) | 1619 (13.0) | 1425 (19.8) | 5976 (12.2) | <.001 |
| No | 25 304 (86.2) | 9979 (80.4) | 5454 (75.7) | 40 737 (83.2) | |
| Missing | 1131 (3.9) | 815 (6.6) | 327 (4.5) | 2273 (4.6) | |
| ER status | |||||
| Positive | 23 512 (80.1) | 9091 (73.2) | 5066 (70.3) | 37 669 (76.9) | <.001 |
| Negative | 2197 (7.5) | 1091 (8.8) | 933 (12.9) | 4221 (8.6) | |
| Missing | 3658 (12.5) | 2231 (18.0) | 1207 (16.7) | 7096 (14.5) | |
| PR status | |||||
| Positive | 19 541 (66.5) | 7185 (57.9) | 3982 (55.3) | 30 708 (62.7) | <.001 |
| Negative | 5529 (18.8) | 2622 (21.1) | 1849 (25.7) | 10 000 (20.4) | |
| Missing | 4297 (14.6) | 2606 (21.0) | 1375 (19.1) | 8278 (16.9) | |
| Subtype | |||||
| HR+ERBB2- | 21 177 (72.1) | 7852 (63.3) | 4193 (58.2) | 33 222 (67.8) | <.001 |
| HR+ERBB2+ | 1960 (6.7) | 919 (7.4) | 786 (10.9) | 3665 (7.5) | |
| HR-ERBB2+ | 519 (1.8) | 346 (2.8) | 356 (4.9) | 1221 (2.5) | |
| HR-ERBB2- | 1536 (5.2) | 678 (5.5) | 519 (7.2) | 2733 (5.6) | |
| Missing | 4175 (14.2) | 2618 (21.1) | 1352 (18.8) | 8145 (16.6) | |
| Chemotherapy | |||||
| Yes | 8168 (27.8) | 2727 (22.0) | 4377 (60.7) | 15 272 (31.2) | <.001 |
| No | 21 199 (72.2) | 9686 (78.0) | 2829 (39.3) | 33 714 (68.8) | |
| Endocrine treatment | |||||
| Yes | 18 932 (64.5) | 8004 (64.5) | 4794 (66.5) | 31 730 (64.8) | .003 |
| No | 10 435 (35.5) | 4409 (35.5) | 2412 (33.5) | 17 256 (35.2) | |
| Targeted treatment | |||||
| Yes | 2174 (7.4) | 960 (7.7) | 1164 (16.2) | 4298 (8.8) | <.001 |
| No | 27 193 (92.6) | 11 453 (92.3) | 6042 (83.8) | 44 688 (91.2) | |
| Country of birth | |||||
| Sweden | 25 208 (85.8) | 10 797 (87.0) | 6051 (84.0) | 42 056 (85.9) | <.001 |
| Europe, not Sweden | 2791 (9.5) | 1206 (9.7) | 717 (10.0) | 4714 (9.6) | |
| Asia, Africa, North/South America, Australia, and Oceania | 1354 (4.6) | 401 (3.2) | 431 (6.0) | 2186 (4.5) | |
| Missing | 14 | 9 (0.1) | 7 (0.1) | 30 (0.1) | |
| Region of residence | |||||
| Stockholm/Gotland | 7377 (25.1) | 1997 (16.1) | 1770 (24.6) | 11 144 (22.7) | <.001 |
| Uppsala/Örebro | 6222 (21.2) | 2313 (18.6) | 1743 (24.2) | 10 278 (21.0) | |
| Southeast | 2631 (9.0) | 1437 (11.6) | 1006 (14.0) | 5074 (10.4) | |
| South | 5323 (18.1) | 2889 (23.3) | 1226 (17.0) | 9438 (19.3) | |
| West | 4978 (17.0) | 2769 (22.3) | 939 (13.0) | 8686 (17.7) | |
| North | 2836 (9.7) | 1008 (8.1) | 522 (7.2) | 4366 (8.9) | |
| Family income | |||||
| Low | 5527 (18.8) | 4282 (34.5) | 1609 (22.3) | 11 418 (23.3) | <.001 |
| Middle | 15 580 (53.1) | 5720 (46.1) | 3524 (48.9) | 24 824 (50.7) | |
| High | 8211 (28.0) | 2399 (19.3) | 2063 (28.6) | 12 673 (25.9) | |
| Missing | 49 (0.2) | 12 (0.1) | 10 (0.1) | 71 (0.1) | |
| Highest attained education | |||||
| ≤9 y (Primary) | 5596 (19.1) | 3748 (30.2) | 1447 (20.1) | 10 791 (22.0) | <.001 |
| 10-13 y (Secondary) | 12 867 (43.8) | 4819 (38.8) | 2962 (41.1) | 20 648 (42.2) | |
| >13 y (Tertiary) | 10 664 (36.3) | 3680 (29.6) | 2707 (37.6) | 17 051 (34.8) | |
| Missing | 240 (0.8) | 166 (1.3) | 90 (1.2) | 496 (1.0) | |
| Charlson comorbidity index within 1 y before treatment | |||||
| Mean (SD) | 0.268 (1.12) | 0.525 (1.53) | 1.05 (2.27) | 0.449 (1.47) | <.001 |
| Median (range) | 0 (0-12.0) | 0 (0-14.0) | 0 (0-10.0) | 0 (0-14.0) | <.001 |
| Charlson Comorbidity Index within 1 y before treatment | |||||
| 0 | 26 810 (91.3) | 10 209 (82.2) | 5664 (78.6) | 42 683 (87.1) | <.001 |
| ≥1 | 2557 (8.7) | 2204 (17.8) | 1542 (21.4) | 6303 (12.9) | |
Abbreviations: BCS, breast-conserving surgery; BCSS, breast cancer–specific survival; ERBB2, Erb-B2 receptor tyrosine kinase 2; ER, estrogen receptor; HR, hormone receptor status; Mx, mastectomy; OS, overall survival; PR, progesterone receptor; RT, radiotherapy.
a
Histopathologic tumor size for primarily operated patients but clinical T stage for patients receiving neoadjuvant treatment.
b
Histopathologic tumor size available only for primarily operated-on patients.