After four years, doctors told Jerry Sanford in January that his lung cancer had returned.
Even now, Sanford, a former New York City firefighter and current spokesman for the North Naples fire department, can't say for sure what caused it. But like other first responders to the attacks on the World Trade Center, his suspicions date back to Sept. 11, 2001.
"I stopped smoking in 1970. Almost 40 years later, I come down with lung cancer," he said. "I just think everything points to the fact that breathing in (toxic dust), there's a good chance that caused it."
Sanford, who was back visiting New York City on Sept. 11 and helping in the press office during the weeks after the attacks, first was diagnosed with cancer in August 2007. About three years later, Congress set up a compensation program for anyone with health problems due to exposure to the rubble at ground zero.
The decision could help hundreds of people get payouts from a multibillion-dollar World Trade Center health fund to repay those ailing after they breathed in toxic dust created by the collapsing twin towers. But several experts now say there's no hard evidence to support the federal government's declaration this month that 50 kinds of cancer could be caused by exposure to World Trade Center dust.
And many acknowledge the payouts to cancer patients could take money away from those suffering from illnesses more definitively linked to Sept. 11, like asthma and some types of lung disease.
"To imagine that there is strong evidence about any cancer resulting from 9/11 is naive in the extreme," said Donald Berry, a biostatistics professor at the University of Texas MD Anderson Cancer Center in Houston.
Yet this month, Dr. John Howard, who heads the federal agency that researches workplace illnesses, added scores of common and rare cancers to a list that had previously included just 12 ailments caused by dust exposure. Lung, skin, breast and thyroid cancer were among those added; of the most common types of cancer, only prostate cancer was excluded.
Several factors about the decision by the National Institute for Occupational Safety and Health raised eyebrows in the scientific community:
Only a few of the 17 people on the advisory panel are experts at tracking cancer and weighing causal risks; they were outnumbered by occupational physicians and advocates for Sept. 11 rescue and cleanup workers.
Exposure to a cancer-causing agent doesn't necessarily mean someone will develop cancer. And if they do, conventional medical wisdom says it generally takes decades. But the panel agreed to cover those diagnosed with cancer within just a few years of the disaster.
The panel members favored adding cancers if there was any argument to include them. They added thyroid cancer because a study found a higher-than-expected number of cases in firefighters who responded to 9/11, even though thyroid cancer is generally linked to genetics or high doses of radiation. The same study found a lower-than-expected number of lung cancers, but it was added because it was considered a plausible consequence of inhaling toxins at the site.
Even lawyers for the first responders were stunned: They had expected to see only certain blood and respiratory cancers put on the list.
"I understand the urge to want to compensate and reward the heroes and victims of that tragedy," said Dr. Alfred Neugut, a Columbia University oncologist and epidemiologist. But "if we're using medical compensation as the means to that, then we should be scientifically rigorous about it."
In late 2010, Congress set up two programs for anyone exposed to the rubble, smoke and dust at ground zero: rescue and cleanup workers and others who worked or lived in the area. Cancer was initially excluded, but Congress ordered periodic reviews based on the latest scientific evidence.
One $1.55 billion program is for treatment for any illness determined to be related to ground zero. The second $2.78 billion fund is to compensate people who suffered economic losses or a diminished quality of life because of their illness. Both programs expire in 2016, but could be extended.
Registration for the compensation program only began in October. Applicants could qualify for treatments and payments as long as they and their doctors make a plausible case that their disease was connected to the caustic dust.
Sanford, with the North Naples fire department, said he has received paperwork about the compensation fund but is unsure if he will apply.
"What's the money going to do, you know?" he said. "Is it going to bring back the portions of my lungs that I lost or eliminate the chemo I go through?"
The Associated Press contributed to this report.