Table 2 Comparison of baseline characteristics of breast cancer (BC) patients and secondary esophageal cancer (SEC) patients receiving radiotherapy (RT) or not.
From: Risk and prognosis of secondary esophagus cancer after radiotherapy for breast cancer
Characteristic | All BC patients | P-value | All SEC patients | P-value | ||
|---|---|---|---|---|---|---|
Surgery without RT (n = 268,367) | Surgery with RT (n = 255,135) | Surgery without RT (n = 226) | Surgery with RT (n = 207) | |||
Median age at BC diagnosis, (IQR), years | 62 (50–73) | 59 (49–68) | < 0.001a | 63 (55–71) | 62 (54–70) | 0.191a |
Age at BC diagnosis, No. (%), years | < 0.001b | 0.235b | ||||
20–49 | 63,763 (23.8) | 65,487 (25.7) | 23 (10.2) | 31 (15.0) | ||
50–69 | 117,872 (43.9) | 133,659 (52.4) | 133 (58.8) | 122 (58.9) | ||
≥ 70 | 86,732 (32.3) | 55,989 (21.9) | 70 (31.0) | 54 (26.1) | ||
Median year of BC diagnosis (IQR) | 1994 (1985–2005) | 2004 (1996–2011) | < 0.001a | 1989 (1982–1996) | 1995 (1988–2002) | < 0.001a |
Year of BC diagnosis, No. (%) | < 0.001b | < 0.001b | ||||
1975–1984 | 61,200 (22.8) | 15,526 (6.1) | 70 (31.0) | 33 (15.9) | ||
1985–1994 | 76,391 (28.5) | 37,005 (14.5) | 91 (40.3) | 66 (31.9) | ||
1995–2004 | 61,325 (22.9) | 77,106 (30.2) | 45 (19.9) | 69 (33.3) | ||
≥ 2005 | 69,451 (25.9) | 125,498 (49.2) | 20 (8.8) | 39 (18.8) | ||
Race, No. (%) | < 0.001b | 0.226b | ||||
White | 228,821 (85.3) | 209,179 (82.0) | 200 (88.5) | 176 (85.0) | ||
Black | 21,004 (7.8) | 23,375 (9.2) | 21 (9.3) | 20 (9.7) | ||
Other | 18,542 (6.9) | 22,581 (8.9) | 5 (2.2) | 11 (5.3) | ||
Tumor grade, No. (%) | < 0.001b | < 0.001b | ||||
Grade I/II | 104,186 (38.8) | 143,618 (56.3) | 72 (31.9) | 100 (48.3) | ||
Grade III/IV | 67,244 (25.1) | 74,509 (29.2) | 37 (16.4) | 48 (23.2) | ||
Unknown | 96,937 (36.1) | 37,008 (14.5) | 117 (51.8) | 59 (28.5) | ||
Tumor stage, No. (%) | < 0.001b | 0.630b | ||||
Localized | 88,926 (33.1) | 87,691 (34.4) | 148 (65.5) | 130 (62.8) | ||
Regional | 179,441 (66.9) | 167,444 (65.6) | 78 (34.5) | 77 (37.2) | ||
Tumor site, No. (%) | < 0.001b | 0.179b | ||||
UI | 24,596 (9.2) | 30,861 (12.1) | 23 (10.2) | 32 (15.5) | ||
LI | 12,709 (4.7) | 14,726 (5.8) | 15 (6.6) | 14 (6.8) | ||
UO | 90,797 (33.8) | 95,472 (37.4) | 81 (35.8) | 83 (40.1) | ||
LO | 18,445 (6.9) | 18,386 (7.2) | 15 (6.6) | 17 (8.2) | ||
CEN | 20,452 (7.6) | 13,418 (5.3) | 16 (7.1) | 8 (3.9) | ||
Other | 101,368 (37.8) | 82,272 (32.2) | 76 (33.6) | 53 (25.6) | ||
Histology, No. (%) | < 0.001b | 0.874b | ||||
Ductal | 198,944 (74.1) | 199,391 (78.2) | 168 (74.3) | 154 (74.4) | ||
Lobular | 21,897 (8.2) | 20,511 (8.0) | 19 (8.4) | 20 (9.7) | ||
Ductal and lobular | 13,135 (4.9) | 14,025 (5.5) | 5 (2.2) | 6 (2.9) | ||
Other | 34,391 (12.8) | 21,208 (8.3) | 34 (15.0) | 27 (13.0) | ||
Chemotherapy, No. (%) | < 0.001b | 0.019b | ||||
Yes | 204,518 (76.2) | 151,600 (59.4) | 39 (17.3) | 56 (27.1) | ||
No/Unknown | 63,849 (23.8) | 103,535 (40.6) | 187 (82.7) | 151 (72.9) | ||
