Prostate cancer rate higher than expected in WTC workers

Incidence rates for prostate and other cancers are statistically higher than expected among World Trade Center rescue and recovery workers, according to a recent study.

The comprehensive analysis of health data collected through the World Trade Center Health Program at the Icahn School of Medicine at Mount Sinai in New York found elevations for cancers at all anatomic sites combined, as well as prostate, thyroid, hematopoietic and lymphoid cancer, and soft-tissue cancer. Cancer incidence rates were most highly elevated in very highly exposed responders who were trapped in the dust cloud or who worked a significant number of days at the WTC site.

The study was based on self-reported health information combined with follow-up medical testing data from 20,984 consented participants in the WTC Health Program. A total of 575 cancers were diagnosed in 552 individuals. The findings, published online in Environmental Health Perspectives (April 23), are concordant with previous research on firefighters conducted by the New York City Fire Department (FDNY) and with research on New York City residents conducted by the New York City Department of Health and Mental Hygiene’s WTC Health Registry.

"Previous studies have looked at cancer incidence rates after September 11, but did not report on associations according to levels of exposure. This study is significant because for the first time it examines associations between several types of cancers in a specific population-WTC rescue and recovery workers-and levels of exposure to the dust on the debris pile in lower Manhattan," said study co-author Philip Landrigan, MD, MSc.

Cancers among 20,984 consented participants in the WTC Health Program were identified through linkage to state tumor registries in New York, New Jersey, Connecticut, and Pennsylvania. Standardized incidence ratios (SIRs) were calculated to compare cancers diagnosed in responders to predicted numbers for the general population. Multivariate regression models were used to estimate associations with degree of exposure.

Through linkage with the four state cancer registries, researchers identified 575 tumor diagnoses between Sept. 11, 2011 and Dec. 31, 2008 in 552 individuals from a total of 20,984 consented responders. Researchers estimated a 15% increase in all cancer sites combined among all responders (SIR 1.15; 95% CI: 1.06, 1.25) based on 575 cases diagnosed versus 498.8 expected. Among other cancers, researchers estimated statistically significant increases over expected registrybased incidence rates for prostate cancer (SIR 1.21; 95% CI: 1.01, 1.44; 129 observed, 106.8 expected). In addition, a nonsignificant positive association was estimated for kidney cancer (SIR 1.39; 95% CI: 0.95, 1.98; 31 observed, 22.2 expected).

"The findings of this study, while significant, should be interpreted with caution given the short follow-up and long latency period for most cancers; the intensive medical surveillance of this cohort by Mount Sinai researchers and our partners; and the small numbers of cancers at specific sites," said Samara Solan, MD, a corresponding author of the study. "However, our findings strongly highlight the need for continued follow-up and medical surveillance of WTC responders."