The association between smoking and breast cancer characteristics and outcome

BMC Cancer

Table 4 Five-year disease free survival, breast cancer specific survival and overall survival

Population (num)^a	DFS			BCSS			OS
Population (num)^a	5-y DFS	HR 95% CI	p	5-y BCSS	HR 95% CI	p	5-y OS	HR 95% CI	p
All (662)	95.7%	-	-	95.8%	-	-	98.5%	-	-
Hx smoking^b
Yes (173)	96.4%	0.73	0.456	99.2%	0.53	0.404	98.8%	0.80	0.74
No (439)	95.1%	(0.32–1.68)		98.4%	(0.12–2.38)		98.6%	(0.22–2.92)
Current Smokering^b
Yes (101)	98.2%	0.36	0.155	NA	NA	NA	NA	NA	NA
No (508)	95.1%	(0.09–1.48)
Number of pack years (PY)
PY² 0–29 (518)	95.2%	0.85	0.794	98.5%	0.73		98.6%	1.50	0.596
PY > =30 (66)	96.1%	(0.26–2.80)		99.1%	(0.09–5.70)	0.764	98.5%	(0.33–6.78)

^aSample size: DFS: Smoking history n = 599, smoking status n = 596, pack years n = 575, BCSS: Smoking history n = 607, smoking status n = 604, pack years n = 580, OS: Smoking history n = 610, smoking status n = 607, pack years n = 582
^bData regarding smoking was retrieved during the first visit at the oncologist clinic. Current smokers were defined as patients who actively smoked at the time of breast cancer diagnosis. Patients with history of smoking were defined as ever smoker
- Abbreviations: BCSS breast cancer specific survival, DFS disease free survival, NA not applicable, OS overall survival
- Cohort included patients with ER positive, HER2 negative disease

ISSN: 1471-2407