Table 5.

Ongoing clinical trials of extended aromatase inhibitor therapy

Study	Number	Population (treatment received pre-enrollment)	Arms at random assignment	Study number
MA.17R	1,918	Prior 4.5-6 years of AI, with or without prior Ta	L (5 years) versus placebo (5 years)	NCT00754845
		Completed AI ≤2 years prior random assignment
SALSA	3,486	Any endocrine therapy (5 years)	A (5 years) versus A (2 years)	NCT00295620
LEAD	4,050	T (4-6 years)	L (5 years) versus L (2-3 years)	NCT01064635
DATA	1,900	T (2-3 years)	A (6 years) versus A (3 years)	NCT00301457
NSABP-B42	3,966	AI or T→AIb (to 5 years)	L (5 years) versus placebo (5 years)	NCT00382070
SOLE	4,800	Any endocrine therapyc (5 years)	L (5 years) versus intermittentd L (5 years)	NCT00553410

^aIncluding as part of MA.17. ^bTamoxifen must have been up to 3 years and may not have been given during years 4 and 5 of the 5 years of adjuvant hormonal therapy. ^cMust have completed 4 to 6 years of prior selective estrogen receptor modulators or aromatase inhibitors (AIs), or a sequential combination of both. When calculating 4 to 6 years, neoadjuvant endocrine therapy should not be included. ^dIntermittent: 48 months over 5 years: 4 × 9 months (9 months followed by 3-month treatment-free interval in years 1 to 4, at least 36 months) plus 1 × 12 months in years 5 at least 48 months. →, switch to; A, anastrozole; DATA, Different Durations of Anastrozole after Tamoxifen trial; L, letrozole; LEAD, Letrozole Adjuvant Therapy Duration trial; NSABP, National Surgical Adjuvant Breast and Bowel Project; SALSA, Secondary Adjuvant Long-term Study with Arimidex trial; SOLE, Study of Letrozole Extension trial; T, tamoxifen.