Background The study aim was to investigate the association between knowledge of breast cancer and practice of breast self-examination (BSE) and having clinical breast examination (CBE) in a cross-sectional sample of 700 Malaysian secondary school teachers.

Methods A two-stage sampling frame was used; a simple random sample of 10 out of 24 schools was selected and all teachers within those schools were invited to participate. The following data were collected using a self-administered questionnaire (i) socio-demographic data, (ii) five knowledge categories: general knowledge of breast cancer, signs and symptoms, risk factors, mammography, recommended frequency of BSE and CBE, and (iii) practice of BSE and CBE. Separate knowledge scores were computed for each knowledge category and an overall summative score. Backwards stepwise (Wald) logistic regression models were developed (SPSS V20) with BSE and CBE practice as dependent outcome measures. Independent variables were: socio-demographic, lifestyle factors, total score or knowledge score for each of the five categories.

Results The response rate was 74% (518/700). Level of exercise was associated with BSE (p = 0.02) and CBE (p = 0.01), with exercise twice a week showing the strongest association compared to never exercising, OR=2.71 (95% CI 1.38–5.33, p = 0.004) for BSE, OR=2.40 (95% CI 1.27–4.55, p = 0.007) for CBE. Self-report of having an annual medical checkup was associated with BSE, OR=2.13, (95% CI 1.29–3.52, p < 001) and CBE, OR=2.41, (95% CI 1.57–3.70, p < 001). Likelihood of practicing BSE improved with increasing total knowledge score (quartiles) in a dose dependent manner, Q2, OR=1.78 (95% CI 0.97–3.27), Q3 OR=1.89 (95% CI 1.06–3.36), Q4 OR=2.2 (95% CI 1.15–3.91, p = 0.02) compared to the lowest quartile Q1 when adjusted for exercise and annual checkup. Knowledge of symptoms and signs was associated with BSE practice, OR =1.25 (95% CI 1.06–1.48, p = 0.009) and CBE, OR=1.3 (95% CI 1.08–1.57, p = 0.005) having adjusted for exercise and annual checkup (BSE and CBE) and age and marital status (CBE). General knowledge was also positively associated with BSE, OR=1.39 (95% CI 1.07–1.81, p = 0.01) after adjustment though not with CBE (p = 0.41). Knowledge of mammography was inversely associated with BSE however the association was not statistically significant OR=0.77 (95% CI 0.56–1.05, p = 0.10).

Conclusion Correct knowledge of symptoms and signs of breast cancer is the most important factor associated with BSE and CBE in Malaysian women after adjustment for other positive health behaviours. Knowledge of risk factors, mammography and recommended frequency of BSE and CBE were not associated with practice of BSE and CBE.