Table 4.
Hazard Ratio of Invasive Breast Cancer according to Randomized Folic Acid/Vitamin B6/Vitamin B12 Treatment, by Tumor Characteristics at Diagnosis
| Variable | Active Group (N = 2,721) | Placebo Group (N = 2,721) | Hazard Ratio (95% Confidence Interval) | P Value |
|---|---|---|---|---|
| Invasive breast cancer — no. of cases | 70 | 84 | 0.83 (0.60–1.14) | .24 |
| Hormone receptor status | ||||
| ER+/PR+ | 48 | 52 | 0.92 (0.62–1.36) | .66 |
| ER+/PR− | 6 | 15 | 0.40 (0.15–1.02) | .06 |
| ER−/PR+ | 0 | 1 | -- | |
| ER−/PR− | 7 | 8 | 0.87 (0.32–2.40) | .79 |
| Tumor size | ||||
| ≤ 2 cm | 55 | 62 | 0.88 (0.61–1.27) | .49 |
| >2 cm | 8 | 16 | 0.50 (0.21–1.16) | .11 |
| Missing | 7 | 6 | 1.15 (0.39–3.43) | .80 |
| Lymph nodes | ||||
| No metastasis | 46 | 53 | 0.86 (0.58–1.28) | .46 |
| Metastasis to lymph nodes | 14 | 17 | 0.82 (0.40–1.66) | .57 |
| Missing | 10 | 14 | 0.70 (0.31–1.58) | .39 |
| Histology | ||||
| Ductal carcinoma | 52 | 57 | 0.91 (0.62–1.32) | .60 |
| Lobular carcinoma | 6 | 10 | 0.60 (0.22–1.65) | .32 |
| Duct and lobular carcinoma | 3 | 8 | 0.38 (0.10–1.41) | .15 |
| Adenocarcinoma | 2 | 0 | -- | |
| Tubular adenocarcinoma | 3 | 1 | 2.99 (0.31–28.7) | .34 |
| Mucinous adenocarcinoma | 2 | 3 | 0.66 (0.11–3.94) | .65 |
| Other | 2 | 5 | 0.40 (0.08–2.04) | .27 |
| Histologic grading and differentiation | ||||
| Well differentiated | 19 | 23 | 0.82 (0.45–1.51) | .52 |
| Moderately differentiated | 26 | 34 | 0.76 (0.46–1.27) | .29 |
| Poorly differentiated/anaplastic | 16 | 15 | 1.06 (0.52–2.14) | .87 |
| Missing | 9 | 12 | 0.74 (0.31–1.76) | .50 |
Abbreviations: ER: estrogen receptor; PR, progesterone receptor