Table 4. Univariable analysis for overall survival.
AJCC, American Joint Committee on Cancer; MBC, metaplastic breast cancer; N, number of patients; HR, hazard ratio; CI, confidence interval; NA, not applicable; Ref, reference; ECOG, Eastern Cooperative Oncology Group; HER2, human epidermal growth factor receptor 2
^Four patients were excluded from survival analysis due to missing information such as the date of diagnosis, last follow-up, or date of death.
*Progression was treated as an event and death as a competing risk event.
#Other histology in our study includes ductal carcinoma in situ micropapillary pattern, heterologous type with matrix production, high-grade metaplastic carcinoma, large cells with intermingling mature plasma cells, matrix-producing carcinoma, and sarcomatoid features, and metaplastic carcinoma.
| Variable | Variable level | N^ | Number of events* | One-year rate (% (range)) | Two-year rate (% (range)) | Five-year rate (% (range)) | HR (95% CI) | p-value |
| Race | Black | 31 | 12 | 94% (77%-98%) | 81% (62%-91%) | 63% (43%-78%) | Ref | |
| White | 97 | 30 | 91% (83%-96%) | 78% (68%-85%) | 70% (60%-79%) | 0.88 (0.45-1.71) | 0.70 | |
| Lymphovascular invasion | No | 77 | 20 | 95% (86%-98%) | 86% (76%-92%) | 75% (63%-84%) | Ref | |
| Yes | 27 | 10 | 96% (76%-99%) | 72% (50%-86%) | 63% (40%-79%) | 1.47 (0.68-3.14) | 0.32 | |
| ECOG performance status | 0 | 74 | 13 | 99% (90%-100%) | 88% (78%-94%) | Ref | ||
| 1 | 37 | 12 | 95% (80%-99%) | 86% (71%-94%) | 1.90 (0.87-4.17) | 0.11 | ||
| 2 | 12 | 12 | 58% (27%-80%) | 25% (6%-50%) | 17.81 (7.55-41.98) | <0.001 | ||
| 3 | 9 | 6 | 78% (36%-94%) | 56% (20%-80%) | 9.31 (3.33-26.09) | <0.001 | ||
| p63 | Negative | 89 | 32 | 93% (85%-97%) | 77% (66%-84%) | 67% (55%-76%) | Ref | |
| Positive | 43 | 11 | 90% (76%-96%) | 85% (70%-93%) | 74% (57%-85%) | 0.80 (0.40-1.58) | 0.51 | |
| AJCC stage | I | 25 | 6 | 96% (75%-99%) | 88% (76%-100%) | 83% (69%-100%) | Ref | |
| II | 81 | 17 | 96% (88%-99%) | 88% (81%-96%) | 79% (71%-89%) | 0.96 (0.38-2.44) | 0.93 | |
| III | 19 | 13 | 94% (67%-99%) | 61% (42%-88%) | 30% (14%-64%) | 4.53 (1.71-12.01) | 0.002 | |
| IV | 7 | 7 | 29% (4%-61%) | 43.26 (12.34-151.64) | <0.001 | |||
| Hormonal therapy | No | 100 | 32 | 92% (84%-96%) | 78% (68%-85%) | 68% (57%-77%) | Ref | |
| Yes | 24 | 7 | 100% (NA) | 96% (73%-99%) | 77% (54%-90%) | 0.86 (0.38-1.96) | 0.72 | |
| Radiation therapy | No | 53 | 16 | 87% (74%-93%) | 77% (63%-86%) | 70% (55%-81%) | Ref | |
| Yes | 74 | 25 | 97% (89%-99%) | 81% (70%-89%) | 69% (56%-78%) | 1.01 (0.54-1.90) | 0.97 | |
| Chemotherapy type | Anthracycline | 68 | 18 | 97% (89%-99%) | 85% (74%-92%) | 77% (64%-85%) | Ref | |
| Non-anthracycline | 36 | 12 | 85% (67%-93%) | 79% (61%-89%) | 67% (46%-81%) | 1.52 (0.73-3.15) | 0.26 | |
| Surgery | Mastectomy | 74 | 24 | 94% (86%-98%) | 82% (71%-89%) | 69% (56%-79%) | Ref | |
| Lumpectomy | 48 | 11 | 98% (85%-100%) | 89% (75%-95%) | 79% (63%-89%) | 0.66 (0.32-1.34) | 0.25 | |
| Histologic subtypes | Spindle cell | 27 | 10 | 92% (73%-98%) | 77% (56%-89%) | 67% (44%-82%) | Ref | |
| Squamous | 40 | 15 | 90% (76%-96%) | 77% (61%-88%) | 64% (46%-77%) | 0.97 (0.43-2.15) | 0.94 | |
| Mixed MBC/mesenchymal | 54 | 15 | 94% (83%-98%) | 80% (66%-89%) | 73% (58%-83%) | 0.71 (0.32-1.58) | 0.40 | |
| #Others | 11 | 3 | 91% (51%-99%) | 91% (51%-99%) | 71% (34%-90%) | 0.56 (0.15-2.05) | 0.38 | |
| Estrogen receptor | No | 111 | 36 | 92% (84%-9%) | 77% (68%-84%) | 67% (57%-75%) | Ref | |
| Yes | 21 | 7 | 95% (71%-99%) | 90% (67%-98%) | 75% (51%-89%) | 0.95 (0.42-2.13) | 0.89 | |
| Progesterone receptor | No | 121 | 40 | 91% (85%-95%) | 78% (69%-84%) | 67% (57%-75%) | Ref | |
| Yes | 11 | 3 | 100% (NA) | 100% (NA) | 89% (43%-98%) | 0.70 (0.22-2.26) | 0.55 | |
| HER2-neu expression | No | 119 | 39 | 92% (85%-96%) | 80% (71%-86%) | 68% (59%-76%) | Ref | |
| Yes | 13 | 4 | 92% (57%-99%) | 77% (44%-92%) | 69% (37%-87%) | 0.87 (0.3-2.43) | 0.79 | |
| Metastasis to the lung | No | 102 | 18 | 96% (89%-98%) | 88% (79%-93%) | 81% (72%-88%) | Ref | |
| Yes | 30 | 25 | 80% (61%-90%) | 53% (34%-69%) | 27% (11%-44%) | 7.85 (4.18-14.72) | <0.001 | |
| Metastasis to the bone | No | 114 | 28 | 95% (88%-97%) | 82% (74%-88%) | 76% (67%-83%) | Ref | |
| Yes | 18 | 15 | 78% (51%-91%) | 61% (35%-79%) | 24% (7%-46%) | 4.90 (2.57-9.34) | <0.001 | |
| Metastasis to the brain | No | 123 | 34 | 92% (85%-95%) | 83% (75%-89%) | 72% (63%-80%) | Ref | |
| Yes | 9 | 9 | 100% (100%-100%) | 33% (8%-62%) | 22% (3%-51%) | 5.53 (2.61-11.72) | <0.001 | |
| Metastasis to the liver | No | 126 | 39 | 93% (86%-96%) | 81% (73%-87%) | Ref | ||
| Yes | 6 | 4 | 83% (27%-97%) | 50% (11%-80%) | 3.06 (1.08-8.67) | 0.036 |