Marciniak W, Derkacz R, Muszyńska M, et al. - In a cohort of 1,702 healthy women in northern Poland aged 40 and above, researchers assessed blood arsenic level as a predictor of the risk of breast and other cancers. By inductively coupled plasma mass spectrometry, they measured blood arsenic level. Participants were observed for an average of 4.5 years. A very significant 13-fold increase in the risk of developing breast cancer was observed in women in the highest quartile of arsenic vs those in the lowest quartile. They found comparable results for arsenic and all incident cancers. If corroborated, findings are indicative of possible utility of the blood arsenic level as a predictive marker of cancer risk in women.