Table 2. RPMM methylation calss membership by patient demographic and tumor characteristic covariates.
| Class 1 | Class 2 | Class 3 | Class 4 | Class 5 | Class 6 | Class 7 | Class 8 | Permutation | ||
| Covariate | n = 68 | n = 39 | n = 23 | n = 14 | n = 5 | n = 4 | n = 4 | n = 5 | test P * | |
| Age (years) | Mean (sd) | 60.8 (11.7) | 56.6 (10.4) | 61.3 (13.4) | 61.4 (10.2) | 61.0 (9.0) | 57.5 (15.5) | 53.8 (10.8) | 49.6 (8.0) | 0.23 |
| Race | Caucasian, n (%) | 53 (79.1) | 29 (74.4) | 17 (73.9) | 7 (50.0) | 3 (60.0) | 3 (75.0) | 2 (50.0) | 3 (60.0) | 0.015 |
| Hispanic | 6 (9.0) | 0 | 2 (7.4) | 0 | 0 | 1 (25.0) | 0 | 1 (20.0) | ||
| African American | 1 (1.5) | 7 (18.0) | 2 (7.4) | 2 (14.3) | 0 | 0 | 1 (25.0) | 0 | ||
| Asian | 3 (4.5) | 3 (7.7) | 0 | 4 (28.6) | 0 | 0 | 0 | 0 | ||
| Other | 4 (6.0) | 0 | 2 (7.4) | 1 (7.1) | 2 (40.0) | 1 (25.0) | 1 (25.0) | 1 (20.0) | ||
| Alcohol | Never drinker, n (%) | 16 (24.6) | 13 (36.1) | 6 (27.2) | 6 (42.9) | 0 (0) | 3 (75.0) | 0 (0) | 0 (0) | 0.07 |
| Ever drinker | 49 (75.4) | 23 (63.9) | 16 (72.7) | 8 (57.1) | 5 (100) | 1 (25.0) | 4 (100) | 5 (100) | ||
| Alcohol (g/day) | Mean (sd) | 10.2 (16.5) | 6.3 (10.0) | 11.4 (16.0) | 2.3 (4.5) | 6.8 (4.0) | 8.9 (17.8) | 9.1 (11.9) | 27.9 (37.9) | 0.27 |
| Folic acid (ìg/day) | Mean (sd) | 90.2 (68.8) | 118 (133) | 91.1 (60.2) | 55.6 (30.6) | 92.9 (37.5) | 159 (7.1) | 97.7 (52.8) | 100 (44.6) | 0.06 |
| Dietary folate (ìg/day) | Mean (sd) | 457 (209) | 497 (284) | 405 (145) | 378 (138) | 522 (114) | 648 (109) | 386 (145) | 538 (170) | 0.08 |
| Stage | Low (1 or 2), n (%) | 44 (65.7) | 16 (41.0) | 12 (52.1) | 10 (71.4) | 4 (80.0) | 2 (50.0) | 3 (75.0) | 4 (80.0) | 0.18 |
| High (3 or 4) | 23 (44.3) | 23 (59.0) | 11 (47.9) | 4 (28.6) | 1 (20.0) | 2 (50.0) | 1 (25.0) | 1 (20.0) | ||
| Lymph Node status | Negative | 48 (73.8) | 22 (57.9) | 12 (54.5) | 10 (76.9) | 5 (100) | 4 (100) | 3 (75) | 4 (80) | 0.19 |
| Positive | 17 (26.2) | 16 (42.1) | 10 (45.5) | 2 (23.1) | 0 | 0 | 1 (25) | 1 (20) | ||
| Tumor Size (mm) | Mean (sd) | 14.7 (8.9) | 24.2 (21.5) | 18.3 (12.7) | 18.0 (20.0) | 13.0 (12.6) | 15.3 (13.0) | 8.5 (4.9) | 9 (9.2) | 0.0006 |
| Estrogen receptor | Positive, n (%) | 60 (89.6) | 35 (89.7) | 19 (82.6) | 11 (78.6) | 4 (80.0) | 4 (100) | 3 (75.0) | 5 (100) | 0.75 |
| Negative | 7 (10.4) | 4 (10.3) | 4 (17.4) | 3 (21.4) | 1 (20.0) | 0 | 1 (25.0) | 0 | ||
| Parity | Nulliparous, n (%) | 13 (19.4) | 7 (17.9) | 3 (13.6) | 2 (14.3) | 1 (20.0) | 1 (25.0) | 1 (25.0) | 2 (40.0) | 0.95 |
| 1–2 children | 29 (43.3) | 20 (51.3) | 13 (59.1) | 5 (35.7) | 3 (60.0) | 1 (25.0) | 3 (75.0) | 3 (60.0) | ||
| 3–4 children | 22 (32.8) | 9 (23.1) | 5 (22.7) | 6 (42.9) | 1 (20.0) | 2 (50.0) | 0 | 0 | ||
| ≥5 children | 3 (4.5) | 3 (7.7) | 1 (4.5) | 1 (7.1) | 0 | 0 | 0 | 0 | ||
| Oral contraceptive | No, n (%) | 21 (31.3) | 5 (13.5) | 7 (31.8) | 6 (42.9) | 1 (20.0) | 1 (25.0) | 0 | 1 (20.0) | 0.35 |
| Yes | 46 (68.7) | 32 (86.5) | 15 (62.2) | 8 (57.1) | 4 (80.0) | 3 (75.0) | 4 (100) | 4 (80.0) |
*Running 10,000 permutations.
Tumor grade, histology, and menopausal status were not significantly associated with methylation class.