A US government review of scientific studies has shown no proof that exposure to the dust and rubble from the World Trade Center after the attacks of September 11, 2001 caused cancer. The review of peer-reviewed medical and scientific literature sparked anger among some firefighters, police and other first responders who said they have seen too many colleagues suffer from cancer to believe that there was no link. \"Insufficient evidence exists at this time to propose a rule to add cancer, or a certain type of cancer, to the list of WTC-related health conditions,\" said the review released Tuesday by John Howard, a doctor who heads the US government\'s World Trade Center Health Program. Howard said his 93-page review was only preliminary and that more information would follow in early to mid 2012 to include the latest data. \"It is important to point out that the current absence of published scientific and medical findings demonstrating a causal association between the exposures resulting from the September 11, 2001, terrorist attacks and the occurrence of cancer in responders and survivors does not indicate evidence of the absence of a causal association,\" he wrote. The next review should \"capture any emerging findings about exposures and cancer in responders and survivors affected by the September 11, 2001, terrorist attacks.\" His findings mean that cancer treatment will not be covered by health care legislation signed this year to help thousands of first responders struggling to pay for medical care due to illnesses they believe are linked to WTC cleanup. \"The collapse of the Trade Center towers released a cloud of poisons, including carcinogens, throughout lower Manhattan and we fully expect that cancers will be covered under our legislation,\" said a statement by US lawmakers Carolyn Maloney, Jerrold Nadler, and Peter King. The trio authored the James Zadroga 9/11 Health and Compensation Act, named for a NYC police officer who died of lung disease at age 34 after helping in the recovery effort. \"This is disappointing news for 9/11 responders and survivors who tragically have been diagnosed with cancer since the attacks and are suffering day-to-day and awaiting help,\" their statement said. \"Thankfully, we know that today\'s announcement is not the last word on the inclusion of cancers in the program.\" John Feal, a construction worker who was among thousands who helped at the massive rubble pile at Ground Zero and who has since become a leading advocate for those who have fallen ill, contended that there is no doubt about a link. \"As we have seen countless of our brethren fall to a form of this horrible disease time and again following 9/11, we know in our hearts, having breathed in those noxious fumes and having spent hour after hour in that undeniably toxic air, that many forms of cancer are due to our exposure at the site,\" he said in a statement.