This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, it’s important to understand some key concepts. Learn how to read a research table.
Introduction: Growing evidence suggests smoking lowers the chances of survival for women with breast cancer.
A pooled analysis of data from about 10,000 breast cancer survivors found smoking increased the risk of :
The more women smoked, the higher these risks .
Learn more about smoking and breast cancer survival.
Learn about smoking and breast cancer risk.
Learn about the strengths and weaknesses of different types of studies.
Study selection criteria: Prospective cohort studies with at least 900 participants, pooled analyses and meta-analyses.
All studies measured smoking after breast cancer diagnosis.
Table note: Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.
Study Population(number of participants)
Breast Cancer Mortality in Current Smokers Compared to Never Smokers,RR (95% CI)
Prospective cohort studies
Nurses' Health Study 
Collaborative Breast Cancer and Women’s Longevity Study 
Life After Cancer Epidemiology 
Parada et al. 
U.S. Health and Functioning in Women study 
Pooled and meta-analyses
California Breast Cancer Survivorship Consortium 
1 or fewer packs of cigarettes per day: 1.22(1.01-1.47)
More than 1 pack of cigarettes per day: 1.63(1.11-2.38)
After Breast Cancer Pooling Project [1,8]
Duan et al. 
*Among survivors who had estrogen receptor-positive breast cancers, current smokers did not have an increased risk of late recurrence (5 or more years after diagnosis) compared to never smokers, 1.30 (0.94-1.81).