Thursday, August 22, 2002

The case for lung cancer screening


Patients push for widespread testing, but doctors question benefits, reliability

By Peggy O'Farrell, pofarrell@enquirer.com
The Cincinnati Enquirer

        Julia Neal got a lung scan only because her daughter, a nurse, nagged her into it.

        The Fairfield woman was lucky: The little-used scan caught her cancer soon enough that a surgeon could simply cut it out. She didn't require chemotherapy or radiation to kill the malignancy.

[photo] Jean Wagner's friends and family are supporting her by decorating a wall of her Loveland home with encouraging messages and pictures.
(Ernest Coleman photo)
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        Her mother had been 54 when she died of lung cancer that had spread to her lymph nodes and throughout her body. “The only thing they didn't do for my mother was give her a scan,” Ms. Neal, who's 55, says.

        Fifteen percent of patients who are diagnosed with lung cancer on any given day will still be alive five years later. There are no recommended routine screenings for lung cancer, unlike cancers of the breast, cervix, colon or prostate.

        Now doctors want to know if routine CT (computerized tomography) scans or other screening measures, including a potential blood test to detect protein markers produced by cancer cells, can accurately identify lung cancer while there's still time to treat it.

        The American Cancer Society estimates that 169,400 American men and women will be diagnosed with lung cancer this year, and about 154,900 people will die of the disease — more than breast, colon and prostate cancers combined.

        Lung cancer is the deadliest form of cancer in the U.S. “in part because most patients are diagnosed at advanced stages and there hasn't been any widely accepted screening methods available for it,” says Dr. Michael Cross, a radiation oncologist in Crestview Hills.

        Risk factors include exposure to tobacco smoke, either first or secondhand, asbestos and radon.

[photo] Julia Neal, with her Irish wolfhound, Carbo, believes better screening could save lives.
(Brandi Stafford photo)
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        Most people with lung cancer are asymptomatic until the cancer is in its advanced stages. Ms. Neal felt fine, but her cancer was small and hadn't spread to surrounding tissues or her lymph nodes.

        Jean Wagner, 54, was riding her bicycle along the Loveland trail last year when she suffered a seizure. A brain scan revealed a lesion, but doctors could tell it had originated elsewhere in her body. Further tests showed a large lesion on her lung.

        Last month, she finished a six-week course of chemotherapy for the lung cancer. She's had two courses of radiation therapy for the brain lesion.

        Her cancer is in stage IV, the most severe. It's not spreading, but it's not going anywhere.

        “They'll keep shooting bullets at it. It's stable. It doesn't get much bigger,” the Loveland woman says. “I have one lesion in my lung and a larger lesion in my brain and several small ones around in my brain, also. The ones in my brain seem to be a little more active.”

        Mrs. Wagner and Ms. Neal both want to see doctors put more emphasis on screening lung cancer. Efforts now focus on prevention — think of all those “don't smoke” messages — and finding better treatments.

        But doctors aren't sure how effective early screening for lung cancer can be.

        “No one's found the equivalent of a PSA (prostate-specific antigen) for lung cancer,” says Dr. John Howington, a thoracic surgeon at the University of Cincinnati. Dr. Howington is working with a lung cancer screening study at UC's Barrett Cancer Center to determine how effective spiral CT scans can be in screening for lung cancer in the Ohio Valley region. Ms. Neal got her lung scan through the study.

        In the 1970s, several centers, including the Mayo Clinic and Johns Hopkins, participated in a national study to determine if a combination of chest X-rays and chest sputum samples could be used to screen early for lung cancer and improve survival rates.

        The answer was no.

        Theoretically, catching cancer earlier should improve survival rates. But some experts have expressed doubt about how effective routine mammography is for improving breast cancer survival. And the few studies that have been done on lung cancer screening are contradictory.

        CT scans give more accurate images than X-rays. But a CT scan can't differentiate between a cancerous lesion and a non-cancerous nodule on the lung. A New York study found that scanning 1,000 patients identified 24 cancers. A five-year study at the Mayo Clinic found that two-thirds of the patients who received CT scans had at least one non-calcified nodule on the lung that required further testing, usually a biopsy.

        “There were a lot of false-positives. So a lot of people are going to have concerns because they've been smoking and they're getting older and they get a scan and it shows a nodule. Certainly that causes a lot of angst,” Dr. Howington says.

        In river regions like Cincinnati, there's a high incidence of histoplasmosis, a fungal infection of the lungs. A CT scan can't differentiate between histoplasmosis and lung cancer.

        Most spots turn out to be histoplasmosis or other non-malignant conditions, Dr. Howington says, but sometimes patients have to undergo surgical biopsies to find that out.

        CT scans aren't as reliable for lung cancer screenings as mammograms are for breast cancer, Dr. Howington says.

        “But we certainly can do better than we do now, which is where two-thirds of the (lung cancer) patients present in what's an incurable stage” when their cancer is diagnosed, he says.

        Dr. Ned Patz, a thoracic radiologist at Duke University Medical Center in Durham, N.C., is working on a blood test that could be used to help screen for lung cancer and other malignancies.

        Dr. Patz and his colleagues are developing a blood test to look for protein markers that are produced by cancer cells. Such a test could be used following a CT scan or other radiological test that spots a suspicious growth but can't tell whether it's cancerous or not. The blood test would be a non-invasive alternative to biopsy and a quick and efficient way to identify cancers, Dr. Patz says.

        He and is colleagues are a building a database of protein markers that could be used to identify cancers, he says.

        “As we continue to develop the platform and the more we learn about this, the more we're going to find different markers,” he says. But there's no way of predicting how fast this is going to be.”

        Doctors say more studies like the one under way at UC are needed to show whether CT scans or other methods work. “The bottom line is that nobody knows whether screening for lung cancer will actually save lives,” says Dr. James Roebker, a diagnostic radiologist at St. Elizabeth Medical Center.

        There are four criteria to determine whether a specific screening method is effective for catching a specific disease. CT scans and lung cancer meet three of those criteria: Lung cancer is widespread enough that an effective screening method would be worthwhile. It can be detected before it's malignant. A CT scan is an effective and efficient test.

        “The fourth one is the one where we're not sure,” Dr. Roebker says. “There must be an effective treatment that reduces mortality. We don't know that to be the case. There is no study that has proven that catching lung cancer early would save lives. It seems intuitive that it would, but, in fact, that's not necessarily the case.”

        The fact that no national organization endorses CT scans or any other method for lung cancer screening “is a pretty telling statement to me,” he says.

        There's no insurance reimbursement for CT scans when they're used to screen for lung cancer, so cost is a factor for most patients and providers. The technology itself is widely available.

        Ms. Neal doesn't share most doctors' questions about the scan. “The cool thing about this test is it caught it in time,” she says.

        Ms. Neal and Mrs. Wagner want to use their experience with lung cancer to raise awareness about the disease and the need for preventive screening.

        Now, national efforts to fight lung cancer focus on prevention, primarily targeting tobacco use. Exposure to tobacco smoke is the single greatest risk factor for developing lung cancer.

        Mrs. Wagner smoked for a few years while she was in her 20s — “maybe three or four cigarettes a day,” she says — but quit more than 30 years ago. Since she wasn't considered high risk for lung cancer, her routine physicals didn't include a chest X-ray.

        “Previous to this, I'd always had such a boring medical history,” she says.

        Ms. Neal, who started smoking when she was 11, quit three weeks before her surgery to remove the cancerous lesion from her lung. She used nicotine patches and the drug Wellbutrin to help combat the urge for a cigarette.

        She still misses her smokes. “I want one, but I will not have one. I have to look at this like I'm addicted to cocaine, and I cannot afford it anymore,” she says.

       



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