BACKGROUND: Lung cancer is the leading cause of cancer death in the United States in men and women, but it is also one of the most preventable. Four out of five cases are associated with cigarette smoking and the cause-effect relationship has been historically documented. In the 1920s, large numbers of men started smoking cigarettes. Twenty years later, the number of lung cancer patients in men increased extensively. In the 1940s, women began to smoke. Twenty years later, there was a similar increase in lung cancer in women. (Source: www.webmd.com)
CAUSES: Tumors in the lungs usually start in the spongy, pinkish gray walls of the bronchi airways. There are twenty types of cancerous tumors that start in the lung itself. Close to 85% of lung cancer is caused by smoking. People who smoke one pack of cigarettes a day are 20 times more likely than a nonsmoker to develop lung cancer. Secondhand smoke is also deadly. Approximately 3,000 people die each year from lung cancer associated with secondhand smoke. Other cancerous substances can cause lung cancer if inhaled over time. For example, workers exposed to uranium dust, asbestos, or radioactive gas radon are more likely to develop cancer. However, it can also depend on each person’s genetics. Lung cancer can run in some families, therefor, suggesting that it can be inherited. Certain genetic traits have been identified that make people more likely than others to cancerous substances like tobacco. (Source: www.webmd.com)
DIAGNOSIS: Once lung cancer begins to cause symptoms, it is usually visible through an X-ray. However, According to the American Cancer Society, saliva, music, and chest X-rays are not proved particularly effective in detecting small tumors. Annual chest X-rays are not recommended. On occasion mucus and lung fluid exams can reveal fully developed cancer cells; diagnosis is usually confirmed through a lung biopsy. If the biopsy confirms lung cancer, other tests will determine the type of cancer. If fluid is in the lining of the lung, then the doctor can remove the fluid through a needle (thoracentesis) and it could help to diagnose cancer. Sixty percent of the time the fluid tests negative, but if it is positive then a procedure called video-assisted thoracoscopic surgery may also be administered to examine the lung for tumors. Sometimes a CT scan of the chest can be performed for a more detailed exam. There have been clinical trials to study screening through a CT scan. In one study, over 31,000 people were screened with a CT scan and 1.5% (484 people) discovered they had lung cancer. CT scan screening does, however, increase the risk of radiation exposure and development of radiation related cancers. Also there is a high incidence of false positive results. (Source: www.webmd.com)
NEW TECHNOLOGY: CT scanning has been questionable for some researchers, but a low-dose CT scan has revamped the idea. Several observational studies have shown that low-dose CT scans of the lung detects more nodules and lung cancers, including early-stage cancers, than chest radiography does. The National Cancer Institute funded the National Lung Screening Trial to determine if low-dose CT screening compared to chest radiography would reduce mortality from lung cancer among people in a high risk category. In 2010, the study found that there was a significant reduction with low-dose CT screening in the rates of death from lung cancer and death from any cause. (Source: New England Journal of Medicine) Patients who benefitted had the following characteristics: they were between the ages of 55 and 74, current smokers or quit within the last 15 years, and they smoked 30 or more packs a year. There is a high likelihood that the screening exam will not be a covered benefit of insurance companies. The out-of-pocket cost for the CT screen is $300. (Source: www.seattlecca.org)
David Madtes, MD, Director of the Seattle Cancer Care Alliance Early Detection and Prevention Program, talks about low dose CT scanning that could catch lung cancer early.
Is there a way to say you’re in trouble, you could be heading down a bad path, and getting lung cancer?
Dr. Madtes: Unfortunately by the time patients have symptoms concerning or suggestive of lung cancer, such as coughing up of blood, chronic cough, or unexplained weight loss, by the time they get medical attention they usually have far advanced disease. Treatment for cure of far advanced lung cancer is very, very difficult. That’s why we advocate in high risk populations to have a screening CT scan to try and detect a lung cancer while it’s still small in size and well contained within one area of the chest.
So before a CT scan would put us at more risk of getting cancer?
Dr. Madtes: Right. There is a low radiation exposure dose from the CT scanner and because of that we caution individuals who are not high risk patients for the possibility of having lung cancer to not get scanned. Individuals who are high risk for developing lung cancer, are defined by their age, 55 to 75 years of age, tobacco history, thirty pack years or more smoking, which translates in to one pack a day for thirty years and are either current smokers or have quit in the last fifteen years. These are the high risk category in which we’ve been able to show and the National Cancer Institute has been able to show can dramatically reduce their risk for death from lung cancer by being screened by CT scan.
Now you are using a low dose CT scan, what’s the difference?
Dr. Madtes: Low dose CT scans are specially set so that the amount of radiation that they would expose the patient to is roughly in the ballpark of two millisieverts which is a unit of radiation exposure where as a routine diagnostic chest CT scan exposes a patient to five to eight millisieverts. So you can see that it’s considerably less. A low dose CT scan is the equivalent of about seventy five regular chest x-rays. It’s about the amount of exposure that we all have to atmospheric radiation over the course of one year. So that’s radon gas that comes up from the soil, cosmic radiation from the sun so it kind of puts it in terms people can better understand.
How small of a cancer can you detect?
Dr. Madtes: As small as one centimeter can be detected. That’s about a half an inch in size.
Is that a better screening than you’ve ever had before?
Dr. Madtes: Yes, absolutely. A number of decades ago studies where done to try and determine if chest x-rays were good ways to screen for lung cancer. Unequivocally those studies showed chest x-rays are not sufficient. CT scans provide us with the sensitivity and the detail to be able to pick up early lung cancers. By picking them up early when they’re small in size and haven’t spread to elsewhere in the chest, this is an opportunity for them to be surgically removed for a cure.
How small of a cancer would you be able to find with chest X-rays?
Dr. Madtes: The chest x-rays usually take something that’s more on the order of an inch or there about so it’s considerably larger.
That half inch could be the difference?
Dr. Madtes: Yes, it could be the difference
Tell me a little bit about Jack.
Dr. Madtes: Jack is a wonderful man. He is a retired Seattle City police officer. He became concerned about his possibility of lung cancer because he had been a smoker for a number of years and friends of his had been diagnosed with lung cancer. He saw what they were going through in terms of their treatment and so as Jack expressed to us he really wanted to find out if he had lung cancer. We provided him with that opportunity through our CT screening program.
What did he find out?