Table 4.

Published medical literature evaluating times to radiotherapy in patients having radiotherapy without chemotherapy, and outcomes for breast cancer

Study	n	Cohort	Inclusion	Delay Groups (weeks unless specified)	Interval without decline (weeks)	Findings
Nixon, Int J Rad Oncol Biol Phys 1994	653	Single institution	Stage I, II	<4; 5–8; 9–12	< 8	No difference <8 weeks definitive No difference 9–12 weeks uncertain
Froud, Int J Rad Oncol Biol Phys 2000	1,962	British Columbia Cancer Agency Outcomes Unit Database	T1-3, N0	0–5; 6–8; 9–12; 13+	≤20	No difference <20 weeks (>20 unknown-sample too small)
Hershman, Int J Rad Oncol Biol Phys 2006	13,907	SEER-Medicare, 1991–1999	Stage I, II	<1; ≥1–<2; ≥2–<3; ≥3 months	<12	No difference <3 months; DSS HR 3.81; OS HR 1.91 >3 months
Vujovic, Int J Rad Oncol Biol Phys 2006	568	Single institution	T1-2, N0	0–8; >8–12; >12–16; >16	<16	No difference <16 weeks definitive No difference >16 weeks uncertain
Olivotto, J Clin Oncol 2009	6,428	British Columbia Cancer Agency Outcomes Unit Database	T1-2, N0-1	0–4, >4–8;>8–12;>12–16; >16–20;>20–42	≤20	No difference in LRFS, DRFS, BCSS ≤20 weeks; HRs >20 weeks: LRFS NS; DRFS 1.86; BCSS 2.15
Punglia, BMJ 2010	18,050	SEER-Medicare 1991–2002	Stage 0-II	Continuous modeling	<6	Time to XRT >6 weeks: HR 1.19 HR 1.005 for LR per day
Karlsson, Int J Rad Oncol Biol Phys 2011	964	Data from 3 IBCSG Trials (Trials VII, VIII, IX)	Any T, N±	≤48, 49–77; 78–112; ≥113 days	≤20	No difference <20 weeks

IBCSG = International Breast Cancer Study Group; d = days; LRFS = local recurrence-free survival; DRFS = distant recurrence-free survival; BCSS = breast cancer-specific survival; HR = hazard ratio; NS = nonsignificant; LR = local recurrence