Role of radiotherapy in oligometastatic breast cancer: Review of the literature

Table 1 Prospective randomized phase III trials investigating the role of locoregional treatment in de novo metastatic breast cancer

Ref.	n	Treatment	Patients	Median follow-up (mo)	Outcomes
Khan et al[21] (ECOG-ACRIN E2108)	256	Primary systemic therapy: LRT (n = 125); No LRT (n = 131)	NR	59	3-yr OS: 68.4% vs 67.9%, P = 0.63
					3-yr locoregional recurrence/progression: 10.2% vs 25.6%, P = 0.003
Fitzal et al[18] (ABCSG-28 POSYTIVE)	90	Arm A: Primary surgery + systemic therapy (n = 45)	Arm A: More cT3 and cN2 tumors	37.5	Stopped early
					Median OS (mo): 34.6 vs 54.8, P = 0.267
					Time to distant progression (mo): 13.9 vs 29.0, P = 0.0668
		Arm B: Primary systemic therapy (n = 45)
Soran et al[20] (MF07-01)	274	LRT + systemic therapy (n = 138)	LRT arm: More ER/PR (+), less triple negative tumors	54.5 vs 55	Median OS (mo): 46 vs 37, P = 0.005
		Systemic therapy (n = 136)			Unplanned subgroup analysis: Improvement in survival: ER/PR (+), HER2 (-), < 55 yr, solitary bone-only metastasis
Badwe et al[19] (NCT00193778)	350	Primary systemic therapy: LRT (n = 173); No LRT (n = 177)	Similar patient and tumor characteristics	23	Median OS (mo): 19.2 vs 20.5, P = 0.79
					Median LR-PFS (mo): not attained vs 18.2, P < 0.0001
					Median distant-PFS (mo): 11.3 vs 19.8, P = 0.012

NR: Not reported; LRT: Locoregional treatment; c: Clinic; T: Tumor; N: Node; ER: Estrogen receptor; PR: Progesterone receptor; OS: Overall survival; HER2: Human epidermal growth factor receptor 2; LR: Locoregional; PFS: Progression-free survival.