9/11 cancer study is inconclusive

CHICAGO — The most comprehensive study of potential World Trade Center-related cancers raises more questions than it answers and will not end a debate over whether the attacks were really a cause.

The study suggests possible links with prostate, thyroid, and a type of blood cancer among rescue and recovery workers exposed to toxic debris from the terrorist attacks. But there were few total cancers and even the study leaders say the results ‘‘should be interpreted with caution.’’

The study involved nearly 56,000 people enrolled in a registry set up to monitor health effects from those exposed to the aftermath of the trade center attacks. Most participants volunteered for enrollment, which could skew the results if people who already had symptoms were more likely to enroll than healthier people.