Physical Activity Levels of Breast Cancer Patients Before Diagnosis Compared to a Reference Population: A Cross-Sectional Comparative Study

Sufficient physical activity before breast cancer surgery is associated with a wide range of health benefits during and after cancer treatment. Therefore, we compared physical activity levels of breast cancer patients (before surgery) with a female reference population without breast cancer. Results indicate that patients show lower total physical activity levels compared to the reference population. Purpose: We hypothesize that prediagnosis physical activity (PA) levels of breast cancer patients are below those of a reference population without breast cancer. Therefore, the aim of the present study was to compare prediagnosis PA levels (including total-, occupational-, sport-and household activity levels) of breast cancer patients with activity levels of a reference population. Methods: Female patients with primary breast cancer (n = 265) filled in the Flemish Physical Activity Computerized Questionnaire (FPACQ) the day before surgery recalling the year before diagnosis. PA levels were expressed as Metabolic Equivalent Task (MET) values. Smooth reference curves of PA levels were estimated in a representative sample of 3466 women without breast cancer with the LMS method, which allowed comparison of prediagnosis PA data of the breast cancer sample with this reference. Results: Compared to women without breast cancer, total PA levels were significantly lower in the year prior to breast cancer diagnosis over all age groups (Mean & PLUSMN; SD z-scores (95% CI) =-1.51 & PLUSMN; 1.86 (-1.74 to-1.29)). More specifically, household PA levels of breast cancer patients were significantly lower between ages 40-60, while occupational PA levels were significantly higher in this age group. No differences were found bet ween spor ts PA levels. Conclusions: Patients with breast cancer show significantly lower total PA levels during the year prior to surgery compared to a reference population. Especially household activity levels are lower in patients between ages 40 and 60. Given this, a return to prediagnosis PA levels may not be sufficient for protection from disease in the future.