Effectiveness of supervised vs brief counselling physical activity promotion interventions in breast cancer survivors on aromatase inhibitors: the PAC-WOMAN randomized controlled trial

Aromatase inhibitors (AI) are used to treat hormone-receptor-positive breast cancer, but have several side effects that often lead to premature discontinuation/switch. Physical activity (PA) can attenuate side effects and improve quality of life. However, most cancer survivors fail to meet PA guidelines. Theory-based PA interventions are effective in breast cancer survivors, but scarce. PAC-WOMAN tested the effects of two PA promotion interventions (supervised exercise vs brief counseling) on primary outcomes – PA, sedentary behavior, quality of life –, and secondary outcomes – body composition, fitness, physical function, sleep, body image, depression, psychological well-being, pain, and motivational variables – in women on AI. This pragmatic randomized controlled trial included 110 women with stage I-III hormone-receptor-positive breast cancer on AI (56.1 ± 7.6 yr; 28.1 ± 5.9 kg/m2; 23.4 ± 20.1 months on AI), randomized to: 1) brief PA counseling (PAC); 2) structured exercise (ExG); 3) waiting-list control. Primary and secondary outcomes were evaluated with validated instruments at the end of the intervention period. Repeated measures’ Anovas, adjusted for age, AI duration, body mass index and chronic diseases, were conducted. Bonferroni corrections were applied (significance level at p < 0.0083). Significant group-by-time interactions were observed for moderate-vigorous PA (MVPA), exercise motivations and affect, muscle strength and leg endurance (p ≤ 0.008). Objectively measured PA showed no significant effects in either intervention group, except for a near-significant MVPA increase of 107 min/week [95% CI: 4; 209] over time in ExG. Larger improvements were observed in all self-reported PA indicators in ExG, while PAC revealed gains only in light PA and active choices. ExG improved global health status, physical functioning and physiological indicators (e.g., fitness, body composition) over time; PAC enhanced future perspectives, body image functioning, breast symptoms, and other psychological outcomes, with changes in depressive symptoms (-1.4 [-2.4; -0.3]) and life satisfaction (0.8 [0.2; 1.5]) approaching significance. PAC-WOMAN showed that ExG and PAC yielded distinct benefits for breast cancer survivors on AI. ExG improved total PA, fitness, physical function, physical quality of life, and alleviated pain symptoms. PAC primarily enhanced light PA and psychological outcomes such as body image and life satisfaction. Together, these findings highlight the potential scalability of PAC alongside the robust physical benefits of ExG. April 2023 – NCT05860621; https://doi.org/10.17605/OSF.IO/ZAQ9N; UMIN000050945.