Table 1. Main characteristics of included studies.
| Study | Location | Data source | No. of patients | Age/years | Stage | Chemotherapy regimen a | Delay cutoff |
|---|---|---|---|---|---|---|---|
| Hershman, 2006 7 | United States | SEER | 5007 | >65 | Ⅰ, Ⅱ | N/S | 3 months |
| Lohrisch, 2006 5 | Canada | Breast Cancer Outcomes Unit Database of the British Columbia Cancer Agency | 2594 | 47(median) | Ⅰ, Ⅱ | AC, CEF, FAC/CAF, CMF | 12weeks |
| Jara Sanchez, 2007 10 | United States | El A´ lamo | 2782 | 21–93 | Ⅰ, Ⅱ, Ⅲ | CMF, A-based, T-based, TA | 9 weeks |
| Alderman, 2010 11 | United States | N/S | 3643 | N/S | Ⅰ, Ⅱ, Ⅲ | N/S | 8weeks |
| Fedewa, 2010 12 | United States | National Cancer Data Base | 107587 | 18–99 | Ⅰ, Ⅱ, Ⅲ | N/S | 90 days |
| Balasubramanian, 2012 13 | United States | New Jersey State Medicaid Files | 365 | 20–64 | Ⅰ, Ⅱ, ⅢA | CAF-based | 3 months |
| Simon, 2012 14 | United States | Henry Ford Health System | 2234 | 61.2 (average) | Ⅰ, Ⅱ, Ⅲ | N/S | 60 days |
| Freedman, 2013 15 | United States | SEER | 54592 | ≥66 | Ⅰ, Ⅱ, Ⅲ | N/S | 90 days |
| Sheppard, 2013 16 | United States | N/S | 359 | 25–89 | N/S | N/S | 90 days |
| Barry, 2014 17 | United States | N/S | 70 | 30–65 | Ⅰ, Ⅱ | N/S | 45 days |
| Gagliato Dde, 2014 6 | United States | Breast Medical Oncology Institutional Database | 6827 | 19–85 | Ⅰ, Ⅱ, Ⅲ | A-based, TA-based, or other type. | 60 days |
| Seneviratne, 2014 18 | New Zealand | Waikato breast cancer register | 922 | N/S | Ⅰ, Ⅱ, Ⅲ | N/S | 60 days |
Abbreviation: SEER: Surveillance, Epidemiology, and End Results Program; N/S: not stated.
a AC = doxorubicin + cyclophosphamide; CEF = cyclophosphamide + epirubicin + fluorouracil; FAC/CAF = fluorouracil + doxorubicin + cyclophosphamide; CMF = cyclophosphamide + methotrexate + fluorouracil; A-based = anthracycline-based; T-based = taxane-based; TA = anthracycline + taxane; CAF-based = cyclophosphamide, doxorubicin/ epirubicin, 5-fluorouracil, or a combination of these agents.