Urinary titanium and vanadium and breast cancer: a case-control study.

Titanium and vanadium are essential trace elements. This study examined the associations of urinary titanium and vanadium with breast cancer risk in a hospital-based case-control study comprising 240 women with incident breast cancer, and 246 cancer-free and age-matched controls who attended health screening assessments in 2 affiliated hospitals of Sun Yat-sen University in Guangzhou between October 2009 and July 2010. Survey data and urine specimens were collected before treatment for the patients and after interview for the controls. The urinary concentrations of titanium and vanadium were measured by inductively coupled plasma mass spectrometry. Women in the second and the highest tertile of vanadium showed 64% and 40% decreased risk of breast cancer, respectively, when compared with those in the lowest tertile after adjustment for established risk factors of breast cancer (ORs [95%CI]: 0.36 [0.21-0.60] and 0.60 [0.37-0.97], respectively). In contrast, urinary titanium was not significantly related to a decreased risk of breast cancer. These results have potentially significant implications on nutritional chemoprevention of breast cancer and the development of new anticancer drugs. Further replications of the study are recommended, and the biological mechanisms warrant clarification.