Table 1.
Characteristics of Carolina Breast Cancer Study breast cancer cases or tumors evaluated or not evaluated for DNA methylation profile
| Characteristic | Cases evaluated for methylation | Cases not evaluated | Pvalue | |||
|---|---|---|---|---|---|---|
| (n =517) | (n =163) | |||||
| N | (%) | N | (%) | |||
| Age | Mean ± SD, years | 49.7 ± 11.9 | 52.2 ± 11.9 | |||
| <50 years | 318 | (62) | 84 | (52) | 0.02 | |
| 50+ years | 199 | (38) | 78 | (48) | ||
| Race | ||||||
| White/Othera | 301 | (58) | 106 | (65) | 0.12 | |
| African-American | 216 | (42) | 57 | (35) | ||
| Menopausal status | ||||||
| Premenopausal | 275 | (53) | 76 | (47) | 0.14 | |
| Postmenopausal | 242 | (47) | 87 | (53) | ||
| Stageb | ||||||
| I | 178 | (37) | 68 | (45) | 0.37 | |
| II | 245 | (51) | 67 | (44) | ||
| III | 45 | (9) | 12 | (8) | ||
| IV | 13 | (3) | 4 | (3) | ||
| Primary tumor size | ||||||
| ≤2 cm | 250 | (50) | 87 | (57) | 0.28 | |
| >2-5 cm | 205 | (41) | 52 | (34) | ||
| >5 cm | 42 | (9) | 13 | (9) | ||
| Lymph node status | ||||||
| Negative | 291 | (58) | 101 | (66) | 0.11 | |
| Positive | 207 | (42) | 53 | (34) | ||
| Hormone receptor expression | ||||||
| ER+/PR+ | 250 | (50) | 62 | (42) | 0.38 | |
| ER+/PR- | 48 | (10) | 17 | (12) | ||
| ER-/PR+ | 39 | (8) | 15 | (10) | ||
| ER-/PR- | 163 | (33) | 53 | (36) | ||
| Combined tumor gradec | ||||||
| I | 126 | (25) | 47 | (29) | 0.48 | |
| II | 156 | (30) | 49 | (30) | ||
| II | 228 | (45) | 65 | (40) | ||
| Histologic type | ||||||
| Ductald | 388 | (75) | 122 | (75) | 0.23 | |
| Ductal variantse | 13 | (3) | 9 | (5) | ||
| Poorly differentiatedf | 22 | (4) | 3 | (2) | ||
| Lobularg | 46 | (9) | 13 | (8) | ||
| Mixed lobular/Ductal | 48 | (9) | 16 | (10) | ||
| IHC intrinsic subtypeh | ||||||
| Luminal A | 212 | (51) | 42 | (51) | 0.76 | |
| Luminal B | 65 | (16) | 12 | (15) | ||
| Basal-like | 86 | (21) | 14 | (17) | ||
| HER2+/HR- | 26 | (6) | 7 | (8) | ||
| Unclassified | 24 | (6) | 7 | (8) | ||
| p53 mutation status | ||||||
| Positive | 218 | (42) | 47 | (34) | 0.08 | |
| Negative | 297 | (58) | 91 | (66) | ||
aThe white/other cases evaluated included 291 Caucasians, 3 American Indians, 6 Asians, and 1 other. bAccording to the American Joint Committee on Cancer breast tumor staging guidelines. cNottingham grade based on mitotic index, histologic grade, and nuclear grade. dDuctal not otherwise specified (n = 372), medullary (n = 3), neuroendocrine (n =2), apocrine (n = 2), and other mixed (n = 9). eDuctal variants include mucinous (n =8), papillary (n = 1), and cribriform (n = 4). fPoorly differentiated include metaplastic carcinoma (n = 6), anaplastic carcinoma (n =3), and undifferentiated high grade carcinoma (n = 13). gLobular, classic, and/or variant (n = 46). hIntrinsic subtype was determined by estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status determined by medical records or immunohistochemistry (IHC), and IHC staining for CK5, CK6, and epidermal growth factor receptor. HR, hormone receptor; SD, standard deviation.