Background: Although considerable evidence has demonstrated that physical activity is associated with breast cancer prevention, few studies have assessed the level of awareness of this association. Awareness is a key first step to successful of behavior change. Increasing awareness may contribute to promote physical activity and prevent breast cancer at the population level. The present study examined the prevalence and correlates of awareness about the role of physical activity in breast cancer prevention among Japanese women.

Methods: 1,000 Japanese women aged 20–69 years (mean age: 44.3 ± 13.4 years) who responded to an internet-based cross-sectional survey. Awareness of the role of physical activity in breast cancer prevention, knowledge of breast cancer (symptom, risk factor, screening), exposure to information about physical activity and cancer, a self-reported physical activity, and sociodemographic variables (age, marital status, having a child, education level, employment status, and household income) were obtained. Force-entry logistic regression analysis was used.

Results: The prevalence of awareness was 31.5% (95% CI: 28.6-34.4). Factors significantly associated with awareness included sociodemographic variables, exposure to information, and knowledge of breast cancer. Being married (AOR, 95% CI: 1.75, 1.05–2.92) was positively related to awareness, while having children (0.65, 0.36–0.86) was negatively related. College graduates or those with higher levels of education (1.50, 1.01–2.22) were significantly more likely to be aware than those who had not graduated high school. Moreover, exposure to information (2.11, 1.51–2.95), and high knowledge of symptoms (2.43, 1.75–3.36) were positively associated with awareness. Finally, low knowledge of risk factors (0.30, 0.22–0.40) was negatively associated with awareness.

Conclusions: Japanese women through internet-based study were poorly aware of the role of physical activity in breast cancer prevention. Awareness was especially low among individuals with children and higher knowledge of risk factors whereas high in married women, those with higher educational level, exposure to information, and greater knowledge of symptoms. The findings suggest that strategies to increase the awareness about the preventive role of physical activity are needed for breast cancer prevention in consideration of subgroups with low awareness.