Weakness and fatigue after 9/11 - "I couldn't pull my kids in a wagon to the beach" - led doctors to discover a large mass in his abdomen.
The disabled vice cop, bald from the treatment and on many medications, is so vulnerable to deadly infection he can't eat out or play with his two sons.
He couldn't root for them at the recent Boy Scout Pinewood Derby because of the crowd.
"It breaks my heart," Vallebuona said. "I'm just holed up in the house. I feel like such a lump."
Fellow detective Rich Volpe, 38, "spit up blood and black stuff from my lungs for months" during 12-hour shifts at Ground Zero and the Fresh Kills landfill.
Volpe was diagnosed with kidney disease in 2002, and has lost 50 percent of function in both kidneys.
He will eventually need a transplant to survive. Doctors have told the bachelor he may never have kids.
Speaking between loud gasps and coughs, ironworker John Sferazo, 50, recalled inhaling "green gases" bubbling up from Ground Zero for 30 days after the terror attacks.
"There were times I couldn't wear any type of respiratory protection because the air was so bad you had to inhale whatever you could to try and pull some oxygen out of it," he said
Sferazo, a father of three, has lost a third of his lung capacity. Last week he attended the funeral of a fellow Local 361 worker and Ground Zero partner, Michael Kendrick, who died of lung cancer.
"I saw his daughter kiss his corpse goodbye. It was tragic," he said.
While "cancer is a continuing concern," among firefighters, cancer and heart attacks have not risen above normal since the terror attacks, said Dr. Kerry Kelly, the FDNY's chief medical officer. She did not give numbers.
But more than 2,000 Bravest have suffered pulmonary problems, including 500 forced to retire on disability, she said.
WHAT OFFICIALS HAVE BEEN SAYING:
Sept. 13, 2001 - EPA spokeswoman Tina Kreisher: "The good news for the residents of New York is that the air, while smoky, is not dangerous . . . it is not something we would classify as toxic."
Sept. 17, 2001 - EPA Administrator Christie Whitman: "I am glad to reassure the people of New York and Washington, D.C., that their air is safe to breathe and their water is safe to drink."
Sept. 28, 2001 - Rudy Giuliani: "The air quality is safe and acceptable. I know there are people concerned and worried about it, but that's just the reality."
Oct. 25, 2001 - EPA spokeswoman Mary Mears: "Yes, [toxic levels] are high. But you get a little distance from the plume and they go dramatically down."
Nov. 29, 2003 - Former EPA Deputy Administrator Linda Fisher: "In hindsight, we should have qualified the [safe to breathe] statements by saying that this was our best judgment given the data that we had."
Feb 2. 2006 - Manhattan federal Judge Deborah Batts: "No reasonable person would have thought that telling thousands of people that it was safe to return to lower Manhattan."
Name: Tim Keller
Job: Fire Dept. EMT
Residence: Levittown, L.I.
Time at Ground Zero: Two days from the morning of Sept. 11.
Symptoms: Coughing over the first year, then severe breathing difficulty, inability to walk several steps without stopping for air.
Diagnosis: Severe hypertension, chronic asthma, bronchitis and pulmonary emphysema.
Prognosis: Granted a three-quarters-pay disability pension in January 2005. The father of four died of a heart attack on June 23, and had yet to receive a full pension check.
Name: Rich Volpe
Job: NYPD detective
Residence: Mount Kisco
Time at Ground Zero: 18 hours on 9/11, then six months sifting debris at Fresh Kills landfill, up to 12 hours a day. Symptoms: Spit up blood and black gunk. Chest pains, shortness of breath, collapsed walking up stairs, coughing attacks.
Diagnosis: Function in both kidneys dropped 50%; high blood pressure; high cholesterol.
Prognosis: Taking 7-8 medications. On disability. Will need kidney dialysis and transplant. May not be able to have children.
Name: John Walcott