http://www.cancer.org
http://www.cancer.gov
http://www.cancerresearchuk.org/aboutcancer/specificcancers/9543
http://cis.nci.nih.gov/fact/7_8.htm
http://cis.nci.nih.gov/fact/7_34.htm
http://www.nccc-online.org/research.asp
http://www.nccc-online.org/research_012.asp
http://news.bbc.co.uk/1/hi/health/2643223.stm
