To print: Select File and then Print from your browser's menu --------------------------------------------------------------------------------------- Title: DG DISPATCH - BREAST CANCER: PCBs Linked To Breast Cancer Risk, Study Shows URL: http://www.pslgroup.com/dg/11BADA.htm Doctor's Guide July 29, 1999
By Louise Gagnon Special to DG News OTTAWA, ON -- July 29, 1999 -- A study presented at the World Conference on Breast Cancer in Ottawa shows a link between increased exposure to PCBs (polychlorinated biphenyls) and elevated breast cancer risk. The study, the largest conducted to date on the association between breast cancer risk and organochlorine concentrations in breast tissue, was a hospital-based case control study carried out between 1995 and 1997 in Kingston and Toronto. A total of 824 women scheduled for an excision biopsy were eligible to take part in the study. A total of 663 did, resulting in an 80 percent response rate. The study included 217 cases of invasive and in situ breast cancer as well as 213 controls of a similar age. Controls had benign breast disease. Researchers examined breast adipose tissue concentrations of 14 kinds of polychlorinated biphenyls (PCBs), congeners, total PCBs and 10 other organochlorines to evaluate their association with breast cancer risk. To establish the link between exposure to organochlorines and breast cancer risk, researchers calculated statistical relationships between the two variables. They determined a statistically-significant relationship existed between exposure to three PCB congeners, namely 105, 118, and 156, and breast cancer risk. The relative risk was greater than two -- meaning a two-fold increased risk of breast cancer -- when patients were exposed to the highest levels of two PCBs, 105 and 118. "The higher the levels were of exposure to three specific PCBs, the higher was the risk of breast cancer," explained Dr. Kristan Aronson, principal author of the study and a member of the department of community health and epidemiology at Queens' University in Kingston, Ontario. Menopausal status increased the relative risk in some instances. Post-menopausal women had increased risk when exposed to PCB 170 and PCB 180 while pre-menopausal women had increased risk when exposed to PCB 105 and PCB 118. Dr. Aronson added that more studies need to be conducted to establish if organochlorines contribute to the etiology of breast cancer. --------------------------------------------------------------------------------------------- Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content. --------------------------------------------------------------------------------------------- This news story was printed from *Doctor's Guide to the Internet* located at http://www.docguide.com --------------------------------------------------------------------------------------- Return to News Story Page This site is maintained by webmaster@pslgroup.com Please contact us with any comments, problems or bugs. All contents Copyright (c) 1998 P\S\L Consulting Group Inc. All rights reserved.