Determinants of changes in physical activity from pre-diagnosis to post-diagnosis in a cohort of prostate cancer survivors.

Abstract

Physical activity (PA) has been shown to improve quality of life and survival in cancer survivors; however, a cancer diagnosis may change PA patterns. We examine determinants of changes in meeting the PA guidelines (150min/week of moderate aerobic PA) before and after a prostate cancer diagnosis. Eight hundred and thirty prostate cancer survivors who participated in a population-based case-control study between 1997 and 2000 in Alberta, Canada, enrolled in a prospective cohort study. Past year activity levels were self-reported at diagnosis (pre-diagnosis measure) and again 2years post-diagnosis. Determinants were collected by questionnaires and medical chart abstractions. Four PA patterns were created: non-exercisers (fail to meet guidelines pre-diagnosis and post-diagnosis), adopters (fail to meet guidelines pre-diagnosis, meet guidelines post-diagnosis), maintainers (meet guidelines pre-diagnosis and post-diagnosis) and relapsers (meet guidelines pre-diagnosis, fail to meet guidelines post-diagnosis). Multinomial logistic regression analyses identified that being a non-exerciser compared to maintainer was associated with being employed, rural location, high PSA, smoking status, not attending support groups and less than average physical quality of life (QoL). Being a relapser compared to maintainer was associated with rural location and lack of friend support. Finally, being a non-exerciser compared to adopter was associated with urinary incontinence, smoking status and less than average physical and mental QoL. Demographic, health and lifestyle variables are associated with changes in meeting PA guidelines from pre-diagnosis to post-diagnosis in prostate cancer survivors. Programming should be aimed at offering interventions to help inactive survivors adopt PA and active survivors to maintain PA.