Secondhand Smoke and Breast Cancer Risk: A Community-Based Prospective Cohort Study

To test the hypothesis that secondhand smoke (SHS) is associated with breast cancer risk, we analyzed data from 72,259 female nonsmokers, re-cruited in 1997–2000, as part of the Shanghai Women’s Health Study. A total of 390 women were diagnosed with primary breast cancer during the follow-up period of 1997–2003. Data collected at baseline and the ﬁrst biennial follow-up were used to assess lifetime exposure to SHS. Cox pro-portional hazard models were used to estimate the hazard ratio (HR) and 95% conﬁdence interval (CI) of breast cancer. Overall, the HR of breast cancer increased with an increase in lifetime SHS. The HRs were 1.02 (0.73–1.43), 1.42 (0.93–2.16), and 1.72 (1.07–2.76), respectively, for aver-age exposures of < 2.0, 2.0– < 4.0, and –Y 4 hours per day, with a p for trend < 0.0001, compared to never exposed to SHS in lifetime. The HR for SHS was higher among pre-menopausal than post-menopausal women. The HR for SHS was synergistically increased by oral contraceptive (a p for interaction ¼ 0.04) and other female hormone use (a p for interaction ¼ 0.01). In conclusion, this study supports evidence that SHS is associated with breast cancer risk and suggests a synergistic interaction with oral contraceptive and other female hormone use among non-smoking women in Shanghai. for the years 1998–2002, was 69.1 per 100,000 constituting the highest rate of recorded breast cancer in Asia. Studies in different regions of Pakistan demonstrate a high proportion ( (cid:1) 50%) of late stage breast cancer presentation. A pragmatic solution to early detection lies in breast cancer education of women. In order to implement public educational programs, the health professionals should be adequately aware of the disease. Nurses constitute a special group having characteristics most suited for disseminating breast cancer information to the women. The objective of this study was to assess the level of knowledge of breast cancer risk factors among registered female nurses in teaching hospitals of Karachi and to identify factors associated with the level of knowledge. A cross-sectional survey was conducted in seven teaching hospitals of Karachi using stratiﬁed random sampling. A total of 609 registered female nurses were interviewed using a structured questionnaire adapted from the Stager’s Comprehensive Breast Cancer Knowledge Test. Knowledge of breast cancer risk factors was categorized into good, fair and poor categories. Thirty ﬁve percent of nurses had good knowledge of risk factors. Graduates from private nursing schools (aOR ¼ 4.23, 95% CI: 2.93, 6.10), nurses who had cared for breast cancer patients (aOR ¼ 1.87, 95% CI: 1.34, 2.61), those having received a breast examination themselve (aOR ¼ 1.56, 95% CI: 1.08, 2.26) or those who ever examined a patient’s breast (aOR ¼ 1.87, 95% CI: 1.34, 2.61) were more likely to scorewell on the knowledge scale. Since only a third of the nursing students had good knowledge about risk factors, there is a need to introduce breast cancer education in nursing schools particularly in the public sector. Continuing medical education at the workplace can be of additional beneﬁt. study with 1799 BCIS cases (83% of eligible), 6138 invasive breast cancer cases (80% of eligible), and 7276 controls (76% of eligible) aged 20–69 years in 1997–2001. Data on weight by decade of life and other factors were collected through structured interviews. Multivariable-adjusted odds ratios (OR) and 95% conﬁdence intervals (CI) were calculated for 5 kg increments of body weight and weight gain, and adjusted for age, height, and other factors. In premenopausal women, heavier weight 1 year prior to diagnosis (‘‘recent weight’’) was inversely associated with risk of both BCIS (OR 0.94, CI 0.91–0.97 per 5 kg) and invasive breast cancer (OR 0.98, CI 0.96– 1.0 per 5 kg). Weight gain since age 18 was not signiﬁcantly associated with risk of BCIS (P-value 0.2) or invasive breast cancer (P-value 0.5) among premenopausal women. In postmenopausal women, recent weight was pos- itively associated with invasive (P-value 0.008) but not in situ (P-value 0.13) breast cancer risk. However, weight gain since age 18 was associated with risk of both in situ (OR 1.05, CI 1.02–1.08 per 5 kg) and invasive (OR 1.04, CI 1.02–1.06 per 5 kg) postmenopausal breast cancer. Examination of associations with in situ and invasive postmenopausal breast cancer by decade of life indicated weight gain after age 40 was most strongly asso- ciated with elevated risk-up to 14% per 5 kg. Overall, these results suggest that, unlike recent body weight, adult weight gain increases risk of both invasive and in situ postmenopausal breast cancer. of of BD prior actual mammo- extrapolations on a modiﬁed logistic to model changes in BD over all using 4 mini- BD, BD, of BD point. cases BD 20 BD data different predictions of BD trends, at the extrapolated ages. a hypothesis-generating look age-related trends in BD between breast cancer cases and controls at ages where BD cannot be