Sanchez-Bayona R, Gardeazabal I, Romanos-Nanclares A, et al. - Researchers investigated a middle-aged cohort of university graduates to examine if and how higher sedentary behavior and leisure-time physical activity (LTPA), separately and in combination, were related to the risk of breast cancer (BC). This analysis involved 10,812 females, with 11.8 years of median follow-up. A significantly lower risk of BC was found in females in the highest category of LTPA (>16.5 MET-hours/week) vs those in the lowest category (≤6 MET/hours-week). A higher risk was observed in females watching >2 hours/day of TV vs those who watched TV <1 hours/day. Findings revealed no significant supra-multiplicative interaction between TV-watching and LTPA. A substantially elevated BC risk may be conferred by both low LTPA and TV-watching >2 hours/day, independently of each other.