Table 1.

Demographic, tumor, and clinical characteristics of the AA and non-AA breast cancer cases evaluated for DNA methylation

AANon-AA
Characteristicn (%)n (%)Pa
Cases with tumors
 Total216301
 Age, y
  50+ y97 (44.9)102 (33.9)0.01
  <50 y119 (55.1)199 (66.1)
 Menopausal status
  Postmenopausal113 (52.3)129 (42.9)0.03
  Premenopausal103 (47.7)172 (57.1)
 Stageb
  I69 (34.5)109 (38.8)0.64
  II104 (52.0)141 (50.2)
  III22 (11.0)23 (8.2)
  IV5 (2.5)8 (2.8)
 Primary tumor size, cm
  ≤298 (47.1)152 (52.6)0.23
  >2110 (52.9)137 (47.4)
 Lymph node status
  Negative115 (55.6)176 (60.5)0.27
  Positive92 (44.4)115 (39.5)
 HR expression
  ER+/PR+88 (42.5)162 (55.3)0.01
  ER+/PR20 (9.7)28 (9.5)
  ER/PR+15 (7.2)24 (8.2)
  ER/PR84 (40.6)79 (27.0)
 Intrinsic subtypec
  Luminal A81 (47.9)131 (53.7)0.04
  Luminal B22 (13.0)43 (17.6)
  HER2+/HR13 (7.7)13 (5.3)
  Basal-like46 (27.2)40 (16.4)
  Unclassified7 (4.1)17 (7.0)
Cases with PBLs
 Total N2940
 Age, y
  50+9 (31.0)16 (40.0)0.44
  <5020 (69.0)24 (60.0)
 Menopausal status
  Postmenopausal9 (31.0)20 (50.0)0.12
  Premenopausal20 (69.0)20 (50.0)
  • aChi-square P values.

  • bAccording to the AJCC breast tumor staging guidelines.

  • cIntrinsic subtypes determined by a panel of immunohistochemical markers included luminal A (ER+ and/or PR+, HER2), luminal B (ER+ and/or PR+, HER2+), basal-like (ER, PR, HER2, cytokeratins CK5+ and/or CK6+, or epidermal growth factor receptor–positive), HER2+ (ER, PR, HER2+), and unclassified (all markers negative).