From: Association of early-onset breast cancer with body mass index, menarche, and menopause in Taiwan
Characteristics, n (%) | Early-onset (≤ 40 years old) (n = 131) | Late-onset (> 40 years old) (n = 644) | P-valuesa | P-values after Bonferroni correction |
---|---|---|---|---|
Age at diagnosis (year), mean ± SD | 35.87 ± 4.13 | 54.24 ± 8.68 |  < 0.001 |  < 0.001 |
BMI (kg/m2) |  |  |  < 0.001 |  < 0.001 |
  BMI < 24 | 100 (76.3) | 361 (56.1) |  |  |
  BMI ≥ 24 | 31 (23.7) | 282 (43.9) |  |  |
Education |  |  |  < 0.001 |  < 0.001 |
  < college | 43 (32.8) | 438 (68.0) |  |  |
  ≥ college | 88 (67.2) | 206 (32.0) |  |  |
Marriage |  |  |  < 0.001 |  < 0.001 |
  Unmarried/Divorce/Widowed | 49 (37.4) | 125 (19.4) |  |  |
  Married | 82 (62.6) | 519 (80.6) |  |  |
Smoking state | Â | Â | 0.677 | 1.000 |
  Never | 124 (94.7) | 615 (95.5) |  |  |
  Ever | 7 (5.3) | 29 (4.5) |  |  |
Alcohol intake | Â | Â | 1.000 | 1.000 |
  Never | 128 (97.7) | 627 (97.4) |  |  |
  Ever | 3 (2.3) | 17 (2.6) |  |  |
Physical activity | Â | Â | 0.035 | 0.875 |
  None | 67 (51.1) | 265 (41.1) |  |  |
  Yes | 64 (48.9) | 379 (58.9) |  |  |
Menopausal status |  |  |  < 0.001 |  < 0.001 |
  Premenopause | 79 (60.3) | 108 (16.8) |  |  |
  Peri-/Postmenopause | 52 (39.7) | 536 (83.2) |  |  |
BMI < 24 |  |  |  < 0.001 |  < 0.001 |
  Premenopause | 67 (67.0) | 65 (18) |  |  |
  Peri-/Postmenopause | 33 (33.0) | 296 (82) |  |  |
BMI ≥ 24 |  |  | 0.001 | 0.025 |
  Premenopause | 12 (38.7) | 43 (15.2) |  |  |
  Peri-/Postmenopause | 19 (61.3) | 239 (84.8) |  |  |
Oral contraceptive use | Â | Â | 0.149 | 1.000 |
 Never | 119 (90.8) | 555 (86.2) |  |  |
  Ever | 12 (9.2) | 89 (13.8) |  |  |
Parity |  |  |  < 0.001 |  < 0.001 |
  Nulliparous | 52 (39.7) | 79 (12.3) |  |  |
  Parous | 79 (60.3) | 565 (87.7) |  |  |
Number of births | Â | Â | 0.001 | 0.025 |
  One | 21 (26.6) | 72 (12.7) |  |  |
  More than one | 58 (73.4) | 493 (87.3) |  |  |
Age at first birth |  |  |  < 0.001 | 0.001 |
  < 27 years | 23 (29.1) | 303 (53.7) |  |  |
  ≥ 27 years | 56 (70.9) | 261 (46.3) |  |  |
Lactation history | Â | Â | 0.003 | 0.075 |
  Never | 21 (26.6) | 251 (44.4) |  |  |
  Ever | 58 (73.4) | 314 (55.6) |  |  |
Fried food |  |  |  < 0.001 |  < 0.001 |
  1 ~ 2 times a week | 113 (86.3) | 619 (96.1) |  |  |
  3 ~ 6 times a week | 18 (13.7) | 25 (3.9) |  |  |
Benign breast disease | Â | Â | 0.559 | 1.000 |
  Never | 98 (74.8) | 497 (77.2) |  |  |
  Ever | 33 (25.2) | 147 (22.8) |  |  |
Family history of BC | Â | Â | 0.073 | 1.000 |
  None | 96 (73.3) | 517 (80.3) |  |  |
  Yes | 35 (26.7) | 127 (19.7) |  |  |