The James Zadroga 9/11 Health and Compensation Act of 2010, Public Law 111-347, Title XXXIII of the Public Health Service Act, 124 Stat. 3623 (codified at 42 U.S.C. sec. 300mm-300mm-61), requires the Administrator of the World Trade Center (WTC) Health Program to "periodically conduct a review of all available scientific and medical evidence, including findings and recommendations of Clinical Centers of Excellence, published in peer-reviewed journals to determine if, based on such evidence, cancer or a certain type of cancer should be added to the applicable list of WTC-related health conditions." 42 U.S.C. sec. 300mm-22(a)(5)(A). This first periodic review of cancer for the WTC Health Program is based on three information sources. First, a systematic search was conducted for peer-reviewed findings on exposure and cancer resulting from the September 11, 2001, terrorist attacks that have been published in the scientific and medical literature between September 11, 2001, and July 1, 2011. Second, findings and recommendations related to cancer were solicited from the WTC Clinical Centers of Excellence and Data Centers, the WTC Health Registry at the New York City Department of Health and Mental Hygiene, and the New York State Department of Health. Third, information from the public about cancer was solicited through a Request for Information published in the Federal Register on March 8, 2011, and March 29, 2011. Overall, this inaugural review of cancer presents findings from the peer-reviewed scientific and medical literature about exposures and cancer resulting from the September 11, 2001, terrorist attacks. In addition, the review provides the status of planned and ongoing research efforts to address questions about cancer related to the exposures resulting from the terrorist attacks.