MONDAY, Aug. 10 (HealthDay News) -- Preliminary findings suggest that responders to the attacks on the Twin Towers on 9/11 may be at higher risk for multiple myeloma, a cancer of the blood.
Notably, half of the cases identified among law enforcement officers were under the age of 45. Multiple myeloma is usually a disease of the elderly.
"This is very preliminary," cautioned Dr. Mitchell Smith, director of the Lymphoma Service at Fox Chase Cancer Center in Philadelphia. "It could turn out to be a statistical fluke and means nothing or it could be the tip of the iceberg and we'll see an increase in the next 10 years," he said.
"The concerning thing," he added, "is it makes biological sense. There is certain data that multiple myeloma is associated with an increased exposure to certain chemicals. It has never been shown with inhaled chemicals but this amount of exposure probably did get into the blood." Smith was not involved in the study.
"Practitioners should be on the lookout for unusual disease patterns," added Dr. Jacqueline Moline, lead author of the report, which appears in the August issue of the Journal of Occupational and Environmental Medicine. "Multiple myeloma is usually a disease that occurs in the seventh or eighth decade of life. A person is 10 times more likely to get myeloma when they're 70 than when they're 45 or 48. Clinicians should be sensitized to patients coming in with unusual symptoms. They should think broadly."
And that includes being on the alert for other types of cancers as well, added Moline, who is director of the World Trade Center Medical Monitoring and Treatment Program at Mount Sinai School of Medicine in New York City. "Time is really going to give us the answer in terms of other exposures," she said.
Rescue workers were heavily exposed to a toxic chemical soup released from the fires that raged at the World Trade Center site for three months after 9/11. The chemicals included several known carcinogens, some of which have been linked to a heightened risk of multiple myeloma.
Other health issues arising from the disaster that have already documented include a persistent "World Trade Center cough" in firefighters, along with increased levels of post-traumatic stress disorder (PTSD) and asthma.
According to a study released last week, new symptoms of PTSD have been reported as long as five and six years after the incident, although new cases of asthma have nearly returned to baseline levels.
However, there has been little information so far on cancer cases tied to the attack.
Of 28,252 responders being followed as part of the World Trade Center Medical Monitoring and Treatment Program, eight cases of multiple myeloma were diagnosed between Sept. 11, 2001 and Sept. 10, 2007.
Slightly more than six cases would be expected in the general population during a similar time frame, the researchers noted.
Even more intriguing, four of the cases were in men under the age of 45 when they were diagnosed. This compared to the 1.2 such cases that would be expected in the general population. There are actually slightly fewer cases than expected among responders 45 and over, the researchers noted.
All four cases were male law enforcement officers. None reported any other occupational exposure that might have raised their risk for this malignancy.
Three were present at the site on the day of the attack, when the dust cloud was heaviest. One of these spent 18 to 19 hours a day at Ground Zero, eating his meals there.
The other man worked near the site for almost two weeks following 9/11.
Their ages at time of diagnosis were 34, 37, 40 and 43 years, respectively.
"In all fairness, it is unusual for this patient population to have multiple myeloma but it's not unheard of," said Dr. Denise Pereira, assistant professor of clinical medicine at the University of Miami Miller School of Medicine. "But a lot of the things they were exposed to, such as benzene, have in the past possibly been implicated with an increased incidence in the cancer. It does make theoretical sense."
According to the Leukemia & Lymphoma Society, more than 15,000 Americans are diagnosed each year with multiple myeloma. The disease affects blood cells called B-lymphocytes. While some myelomas are slow-moving and pose little immediate threat, others can be very aggressive.
There's more on health effects associated with 9/11 at the World Trade Center Registry.