The LCT 13910 C/T polymorphism as a risk factor for osteoporosis, has no impact on metastatic bone disease in breast cancer

To the editorThe most common skeletal complication of breast can-cer is bone metastasis, which occurs in 80% of patientswith advanced disease [1, 2].The maintenance of skeletal integrity in a healthyindividual requires a balanced bone remodeling. Osteo-clast-mediated bone resorption is a common factor in thepathogenesis of osteoporosis and metastatic bone disease[3, 4]. Evidence is given, that tumor mediated osteoclastactivation disrupts the normal equilibrium of boneremodeling, allowing tumor cells to survive and grow inthis microenvironment [4, 5].A functional dimorphism, 13910 C/T (LCT) which isassociated with adult lactose intolerance, has been sug-gested as a possible risk factor for osteoporosis and bonefractures, particularly in postmenopausal women [6].In the present study, we investigated the impact of the13910 C/T LCT polymorphism on the risk of bonemetastasis in 500 breast cancer patients. Patient charac-teristics have been described previously [7]. The study wasperformed according to the Austrian Gene Technology Actand had been approved by the local ethics committee.Written informed consent was obtained from all subjects.LCT -13910 genotypes were determined as describedpreviously [7]. SPSS 14.0 for Windows was used for sta-tistical analysis. Continuous values were analyzed byStudent’s t-test, and proportions of groups compared by the