Association of Telomere Length with Breast Cancer Prognostic Factors

INTRODUCTION: Telomere length, a marker of cell aging, seems to be affected by the same factors thought to be associated with breast cancer prognosis. OBJECTIVE: To examine associations of peripheral blood cell-measured telomere length with traditional and potential prognostic factors in breast cancer patients. METHODS: We conducted a cross-sectional analysis of data collected before surgery from 162 breast cancer patients recruited consecutively between 01/2011 and 05/2012, at a breast cancer reference center. Data on the main lifestyle factors (smoking, alcohol consumption, physical activity) were collected using standardized questionnaires. Anthropometric factors were measured. Tumor biological characteristics were extracted from pathology reports. Telomere length was measured using a highly reproducible quantitative PCR method in peripheral white blood cells. Spearman partial rank-order correlations and multivariate general linear models were used to evaluate relationships between telomere length and prognostic factors. RESULTS: Telomere length was positively associated with total physical activity (r(s) = 0.17, P = 0.033; P(trend) = 0.069), occupational physical activity (r(s) = 0.15, P = 0.054; P(trend) = 0.054) and transportation-related physical activity (r(s) = 0.19, P = 0.019; P = 0.005). Among post-menopausal women, telomere length remained positively associated with total physical activity (r(s) = 0.27, P = 0.016; P(trend) = 0.054) and occupational physical activity (r(s) = 0.26, P = 0.021; P(trend) = 0.056) and was only associated with transportation-related physical activity among pre-menopausal women (r(s) = 0.27, P = 0.015; P = 0.004). No association was observed between telomere length and recreational or household activities, other lifestyle factors or traditional prognostic factors. CONCLUSIONS: Telomeres are longer in more active breast cancer patients. Since white blood cells are involved in anticancer immune responses, these findings suggest that even regular low-intensity physical activity, such as that related to transportation or occupation, could be recommended to breast cancer patients.