Sadly enough, it often seems to take a celebrity patient to get the rest of us to sit up and take notice of certain diseases, especially diseases in which the patient’s own behavior contributes to the risk.
This time, the celebrity is an active, young mother, Kara Kennedy , 42, the daughter of Sen. Edward M. Kennedy (D-Mass.). And the disease is lung cancer – the biggest cancer killer in the country, whose primary cause is smoking – an addiction, to be sure, but a potentially modifiable behavior as well.Kara Kennedy, a smoker, had a cancerous portion of her right lung removed 12 days ago at Brigham and Women’s Hospital in Boston and was recuperating last week before starting chemotherapy.
Though she may receive lots of emotional support, the societal prejudice against many lung cancer patients runs deep.
But this longstanding attitude is beginning to lift, thanks in part to a massive new study launched last fall by the National Cancer Institute. The $200 million, 8-year study is called the National Lung Screening Trial (NLST). It will involve 50,000 healthy smokers and former smokers at 30 medical centers across the country. So far, almost 10,000 have signed up. (For more information, visit http://cancer.gov/nlst or call, 1 800 422 6237 begin_of_the_skype_highlighting 1 800 422 6237 end_of_the_skype_highlighting.)
The trial is designed to determine which screening test, chest X-rays or a relatively new technology called spiral CT scanning, is more effective at reducing deaths by catching cancers at an earlier stage. (Currently, neither test is recommended for routine screening.) Researchers will also collect and store blood, urine and sputum samples to see which participants might be at higher genetic risk of lung cancer.
This year, 171,900 Americans will be told they have lung cancer and most will have spreading disease at the time of diagnosis. (Breast cancer, by contrast, will strike more people (212,600), but most cases will be caught before the cancer has spread.)
In a sense, there might appear to be no need for the big lung cancer trial. Everybody already knows that smoking causes lung cancer, or to be more precise, that it causes 80 to 85 percent of cases. (It’s not clear why nonsmokers also get lung cancer, why lung cancer is rising among nonsmokers, or why female nonsmokers are more likely than male nonsmokers to get the disease.)
So, if all smokers just quit, much of the lung cancer problem could disappear, which would free researchers (and funds) for cancers with less obvious causes.
But in reality, there’s an enormous need for this trial, says Dr. Denise Aberle, chief of radiology at the David Geffen School of Medicine at UCLA and one of the two co-principal investigators in the study.
Historically, lung cancer has gotten less funding than other cancers, even though it is responsible for more cancer deaths per year than cancer of the colon, breast, prostate and pancreas combined.
In 2001, the latest year for which figures are available, the National Cancer Institute spent a relatively paltry $206.5 million on lung cancer, compared to $475.2 million on breast cancer. Yet lung cancer is projected to kill 157,200 people this year, according to the American Cancer Society – nearly four times the deaths expected from breast cancer.
And the “reservoir” of people at risk is huge – 45 million current smokers and 45 million former smokers. Moreover, if the $200 million trial, as hoped, shows that early detection translates into lives saved, it could make a sizeable dent in the nearly $5 billion the country now spends annually to treat lung cancer patients, Aberle notes.
“This is an incredibly important trial,” agrees Dr. Phillip Boiselle, director of thoracic imaging at Beth Israel Deaconess Medical Center in Boston, one of the Massachusetts sites for the study. (The other is at Brigham and Women’s Hospital). “Even if widespread efforts at smoking cessation are successful, lung cancer will continue to be a major problem because the risk among former smokers, though less than for smokers, is still high.”
Not only does the trial address “the most lethal cancer that we face,” adds Dr. Andrew C. von Eschenbach, director of the National Cancer Institute, it should point the way to better detection at a stage of disease when therapy can do the most good. “We need a proven effective way to detect lung cancer when it is still curable.”
In recent years, studies of smokers and former smokers (including one in Japan in 1996 and one in New York in 1999) have convinced researchers of the need for a truly definitive trial.
These studies showed that spiral CT scans (an improved version of the standard computed tomography X-rays) are good at catching cancers while they are small) and in fact, are better than chest X-rays. But because these studies were small and did not randomize participants to get CT scans or chest X-rays, they could not show whether earlier detection saves lives, says Robert Smith, director of cancer screening at the American Cancer Society.
Another study, by the Mayo Clinic in 2002, also showed that spiral CT scans are better than chest X-rays at finding small tumors, but it highlighted a problem that the earlier studies also suggested: spiral CT scans are so sensitive that they often pick up tiny abnormalities that turn out not to be cancer.
Indeed, most of the abnormal nodules detected in the Mayo study turned out to be false alarms, often just tiny patches of scar tissue from bronchitis or pneumonia. But finding any suspicious nodule often sets a patient on a path of follow-up and further testing, sometimes including surgery.
The high rate of false positives “is a big drawback” to CT scans, says Aberle of UCLA. “You convert healthy participants into patients and expose them to additional tests or additional anxiety.”
Despite the risk of false positives, some worried smokers and former smokers already get spiral CT scans on their own. (The test costs $300 to $400 and is often not covered by insurance unless a doctor suspects lung cancer and orders it.)
Though it might seem obvious that CT scans constitute a better detection method, there are actually significant pros and cons to both the scans and chest X-rays.
The advantage of a spiral CT scan is that it can pick up abnormalities smaller than a dime, while chest X-rays find nodules only if they are the size of a quarter.
CT scans also give doctors a 3-D image, while chest X-rays provide only a 2-D image. On the other hand, while chest X-rays can miss up to 30 percent of suspicious nodules, they also are far less likely to yield false positives. Then again, chest X-rays expose a person to low dose radiation, while the exposure from spiral CT scans is roughly 15 times higher. (Even so, the CT scan is a lower dose of radiation than a person gets from environment radiation every year.)
The bottom line, of course, is that no knows yet which method is better. But the strong hope is that whichever one is, that earlier detection will indeed save lives.