Table 2.

Risk of long-term breast cancer–specific death (25 years) by intratumor heterogeneity of ER in ER-positive breast cancer

			25-y breast cancer–specific survival
STO-3 trial	Intratumor heterogeneity of ER		25-y breast cancer–specific deaths	Crude estimates adjusted for age and period of diagnosis	Adjusted estimates for patient and tumor characteristics
Patients included	Category	No.	No.	HR (95% CI)	HR (95% CI)
All patients	High	196	44	1.64 (1.11 to 2.44)	1.98 (1.31 to 3.00)*
	Low	397	56	1.00 (ref.)	1.00 (ref.)
Tamoxifen-treated arm	High	102	17	1.94 (0.99 to 3.80)	2.15 (1.07 to 4.34)†
	Low	205	18	1.00 (ref.)	1.00 (ref.)
Untreated arm	High	94	27	1.52 (0.93 to 2.50)	1.91 (1.12 to 3.27)†
	Low	192	38	1.00 (ref.)	1.00 (ref.)
Luminal A tumor subtype	High	103	19	1.83 (0.99 to 3.39)	2.43 (1.18 to 4.99)†
	Low	233	22	1.00 (ref.)	1.00 (ref.)

^*Modeled by multivariable proportional hazard (Cox) analyses adjusted for treatment arm, age and calendar period of diagnosis, ER-positive stained cells, ER H-Score, progesterone receptor (PR) status, HER2 status, Ki-67 status, tumor grade, and tumor size. CI = confidence interval; ER = estrogen receptor; HER2 = human epidermal growth factor receptor 2; HR = hazard ratio; STO-3 = Stockholm Tamoxifen trial 3; ref. = referent.

^†Modeled by multivariable proportional hazard (Cox) analyses adjusted for age and calendar period of diagnosis, ER-positive stained cells, ER H-Score, progesterone receptor (PR) status, Ki-67 status, tumor grade, and tumor size. The luminal A analysis was additionally adjusted for treatment arm.