Abstract P6-07-08: Associations between lifestyle parameters and prognostic factors used for stratifying for adjuvant treatment in breast cancer

Abstract

Abstract Background: At present, tumour related factors and age at time of diagnosis are used to determine type of adjuvant treatment for women diagnosed with early stage breast cancer (ESBC). Aim: To investigate associations between lifestyle parameters and prognostic factors used for stratifying for adjuvant treatment, by correlating known clinical prognostic factors to comorbidity, body mass index (BMI), and physical activity. Method: 4917 women who had been treated for ESBC in Denmark in 2001–2004 were identified. Disease-and treatment data were obtained from The Danish Breast Cancer Cooperative Group. Data concerning comorbidity was collected at the surgical departments. Health related behaviours were assessed by questionnaires three months after surgery, using the Physical Activity Scale for the Elderly to assess level of physical activity. Results: All lifestyle parameters were significantly associated with one or more tumour related prognostic factors at time of surgery: Increasing BMI was associated with unfavourable nodal status (OR: 1.026; 95%CI:1.009–1.043), with not having grade I malignancy (OR:1.028; 95%CI:1.008–1.048) and with tumour size >20mm (OR:1.083; 95%CI: 1.065–1.102) but not with oestrogen receptor (ER) status (OR:1.002; 95%CI:0.981–1.023). Similarly, decreasing levels of physical activity was associated with nodal status (OR: 1.001; 95%CI: 1.001–1.003), with tumour size (OR: 1.002; 95%CI: 1.001–1.003) and with higher grade of malignancy (OR: 1.001; 95%CI: 1.000–1.003; p = 0.014), but not with ER status (OR: 1.000; 95%CI:0.999–1.002). Comorbidity was significantly associated with tumour size>20mm (OR: 1.137; 95%CI: 1.002–1.275), but not with nodal status (OR: 0.989; 95%CI: 0.878–1.115), higher grade of malignancy (OR: 0.918; 95%CI: 0.803–1.050) or ER status (OR: 1.176; 95%CI: 0.992–1.393). Some of the significant associations between lifestyle parameters and tumour related prognostic factors only pertained to premenopausal women. This pattern was observed in the associations between BMI and nodal status (Premenopausal: χ2: 14.55; p = 0.002. Postmenopausal: χ2:2.39; p = 0.495), and physical activity and tumour size (Premenopausal: χ2:13.72; p = 0.008. Postmenopausal: χ2: 7.10; p = 0.130). No such differences were found for comorbidity. Conclusion: Higher levels of BMI and comorbidity were found to be associated with poorer prognostic factors at time of surgery in women suffering from ESBC. Furthermore, inactivity and higher BMI was associated with significantly poorer prognostic factors in the premenopausal population than it was in the postmenopausal population. Physically inactive women had poorer prognostic factors at time of surgery; however, caution is needed due to possible confounding by treatment parameters. Future data on the relapse-pattern in this cohort will shed further light on whether specific lifestyle patterns can predict disease outcome and the potential relevance of stratifying women suffering from ESBC to relevant adjuvant treatment according to lifestyle parameters at time of diagnosis, especially in the younger premenopausal population. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-08.