Table 2.

Association Between Cigarette Smoking Status Before Diagnosis and Death As a Result of Breast Cancer and All Causes

Cigarette Smoking Status Before Diagnosis	No. (%) of Patients (N = 20,691)	Cause of Death
		Breast Cancer		All Causes
		No. of Deaths (n = 2,894)	HR* (95% CI)	No. of Deaths (n = 6,778)	HR* (95% CI)
Never smoker	10,399 (50)	1,448	1 (Reference)	3,234	1 (Reference)
Former smoker	6,233 (30)	755	0.93 (0.85 to 1.02)	1,910	1.11 (1.05 to 1.17)
Recent smoker	4,059 (20)	691	1.25 (1.13 to 1.37)	1,634	1.67 (1.57 to 1.79)

Abbreviation: HR, hazard ratio.

^*HR stratified by age at diagnosis, study phase, state of residence, and stage at diagnosis and adjusted for education, body mass index, parous status, age at first birth, menopausal status, use of postmenopausal hormone therapy, mammography history, alcohol consumption, and first-degree family history of breast cancer.