Hale MJ, Howell A, Dowsett M, et al. - Findings from studies in the adjuvant setting indicate the predictive value of endocrine therapy related side effects for breast cancer recurrence risk. In this study, researchers examined how early reported side effects correlate with the incidence of breast cancer in women randomized to tamoxifen for cancer prevention in the International Breast Intervention Study (IBIS)-I trial. Observations revealed a non-statistically significant increase in breast cancer among women randomized to tamoxifen and reporting hot flushes at the 6-month follow-up visit vs those without hot flushes. Overall, there appeared no correlation between side effects reported at 6 months and subsequent breast cancer occurrence. In postmenopausal women, some side effects might be valuable markers for breast cancer occurrence.