Smoking and survival after breast cancer diagnosis in Japanese women: A prospective cohort study

Abstract

The results of previous studies investigating whether there is an association between active smoking and risk of death among breast cancer patients have been inconsistent. We investigated the association between active and passive smoking and risk of all-cause and breast cancer-specific death among female breast cancer patients in relation to menopausal and tumor estrogen/progesterone receptor (ER/PR) status. The present study included 848 patients admitted to a single hospital in Japan from 1997 to 2007. Active or passive smoking status was assessed using a self-administered questionnaire. The patients were followed until 31 December 2010. We used a Cox proportional-hazard model to estimate hazard ratios (HR). During a median follow-up period of 6.7 years, 170 all-cause and 132 breast cancer-specific deaths were observed. Among premenopausal patients, current smokers showed a non-significant higher risk of all-cause and breast cancer-specific death. A duration of smoking >21.5 years was positively associated with all-cause (HR = 3.09, 95% confidence interval [CI], 1.17–8.20) and breast cancer-specific death (HR = 3.35, 95% CI: 1.22–9.23, Ptrend = 0.035) among premenopausal patients. In premenopausal patients with ER+ or PR+ tumors, there was some suggestion that a longer duration of smoking was associated with higher risk of all-cause and breast cancer-specific death. Passive smoking demonstrated no significant risk. Our results suggest that a longer duration of active smoking is associated with an increased risk of all-cause and breast cancer-specific death among premenopausal patients, possibly with hormonal receptor-positive tumors. Breast cancer patients should be informed about the importance of smoking cessation.

Postdiagnosis Changes in Cigarette Smoking and Survival Following Breast Cancer

“…Our findings of an association between at-diagnosis smoking and all-cause, but not breast cancer–specific, mortality are inconsistent with most studies conducted to date, which report approximately a 30% increased risk ( 6 ); however, the confidence interval, which ranged from 0.77 to 1.51, suggests that these data may in fact be consistent. Among former smokers, we observed a suggestive inverse association with breast cancer mortality, which is consistent with at least two prior studies ( 36 , 37 ). One possible explanation for this finding is that successful quitters may also adopt healthier lifestyle behaviors, including an increase in the use of routine clinical preventive services such as mammographic screening ( 38 ).…”

Active smoking and survival following breast cancer among African American and non-African American women in the Carolina Breast Cancer Study

“…Our finding of no association between smoking and 5-year breast cancer survival is in agreement with prior studies with short duration of follow-up [15, 25–27]. One possible explanation for this is that short-term survival is more likely to be determined by tumor characteristics and treatment, than by behavioral factors [23].…”

Associations of cigarette smoking and alcohol drinking with stomach cancer survival: A prospective patient cohort study in Japan

“…The positive association between pretreatment smoking and the risk of stomach cancer death in the curative group may be mainly explained by the biologic effects of smoking. Tobacco smoke contains carcinogenic substances, some of which may be involved in tumor promotion and recurrence, and so hypothetically, smoking‐related tumors might be of high grade and rapidly progressive . Additionally, smoking might cause immunological deterioration .…”