The overarching objective of the project is to define whether World Trade Center (WTC) responders included in the WTC Health Program experienced an increased risk of cancer and whether or not such increase can be associated with WTC-related exposures. The specific aims of the project are to: 1) identify and confirm all cases of cancer occurring among WTC responders included in WTC Health Program, using multiple sources of information and developing algorithms for confirmation of cancer diagnosis; 2) develop and apply an exposure assessment procedure to estimate Exposure Ranking Indices (ERIs) for selected known and suspected carcinogens for all WTC Health Program responders, and to conduct a systematic analysis of exposure-cancer associations, based on ERIs; and 3) conduct in-depth analyses of exposure-cancer associations.
World Trade Center (WTC) rescue and recovery workers enrolled in the WTC Health Program (WTCHP) were exposed to a complex mix of pollutants and carcinogens. Data on WTC responders were linked the tumor registries of New York, New Jersey, Connecticut, and Pennsylvania. Standardized incidence ratios (SIRs) were calculated to compare cancer by site in responders with that predicted for the general population adjusted for age, sex, and ethnicity/race. A preliminary Exposure Index was developed, integrating number of days on site, specific occupation, and work on debris pile. An enhanced Cancer Exposure Reconstruction Index (C-ERI) has also been developed, which addressed exposure to known and suspected carcinogens, based on date/time, location, job/activity and use of personal protection equipment. In addition, estimate of the Occupational Cancer Risk Indices, specific for 17 occupation-related cancers and based on employment in occupation associated with cancer risk in jobs held before and after the WTC experience, were developed for about 50% of cohort members. A total of 575 cancers were diagnosed up to 12/31/2008 among 20,984 consented responders. After excluding the first six month after enrollment, the standardized incidence ratio (SIR) for all cancers combined was 1.06 (95% confidence interval [CI] 0.94-1.18), that for thyroid cancer was 3.12 (95% CI 2.04-4.57) and that of lung cancer was 0.62 (95% CI 0.37-0.98). Analyses according to C-ERI and OCRI are on-going. These preliminary findings highlight the need for continued follow-up and surveillance of WTC responders.
The results will help to clarify whether WTC responders have an increased risk of cancer, and specifically (i) to identify cancers (if any) at increased risk, (ii) to quantify the magnitude of the associations, and (iii) to identify characteristics of WTC exposure which are more strongly associated with cancer risk. This information will be important to establish preventive actions such as enhanced medical surveillance and targeted screening. Although the study is conducted in occupationally exposed responders, the results will be relevant to other individuals exposed to the WTC attacks.
Solan S, Wallenstein S, Shapiro M, et al. 2013. Cancer incidence in World Trade Center rescue and recovery workers, 2001–2008. Environmental Health Perspectives. 121(6):699–704.
Boffetta, P, Zeig-Owens R, Wallenstein S, et al. 2016. Cancer in World Trade Center responders: Findings from multiple cohorts and options for future study. Am J Ind Med 59(2):96–105.
