Lung Cancer Screening 2004:

Experience gathered over the past thirty years indicates that we have had little impact on reducing the death toll of lung cancer by relying upon improvements in treatment. It is now clear that in the absence of a major breakthrough in the treatment of lung cancer, future progress in reducing deaths will depend upon prevention of lung cancer by tobacco control and smoking cessation, and upon early detection of lung cancer.

There is now good information from a number of different studies from the U.S., Europe and Japan, that the low-dose, non-contrast spiral computerized tomogram (CT or CAT scan) is highly effective in detecting lung cancer in an early stage in high risk persons.

CT scan detects 80% of lung cancers in Stage I; most in stage IA. This is about three times as sensitive as the chest x-ray. Most lung cancer is detected in the United States in advanced stages. Only about 7% of cases present in stage IA. The reason that it is important to detect lung cancer early is that most cases of Stage I lung cancer can be cured by surgical resection alone.

This physician thinks that it is perfectly reasonable to anticipate that persons whose lung cancers are detected by screening LDNCSCT, in stage I will have a much higher chance of long-term cure than will those who are unscreened and who will consequently have at least a 50% chance that their cancers will not be found until they reach stage IIIB or IV, in which there is a very small chance of long-term survival.

Others, typically epidemiologists with little actual experience in the treatment of lung cancer, believe that this is an improper assumption and that screening for lung cancer with CT scans is inappropriate outside of a randomized, controlled study. In such a randomized trial, study subjects would agree to randomization to one of two study arms. In this type of research project, one half of study subjects would have LDNCSCT and the other half would represent a control group who would have either no screening or a chest x-ray done annually.

There are currently large research projects designed to prove or disprove the value of CT scan in reducing the number of lung cancer deaths in our society (154,900 lung cancer deaths anticipated in 2002).

1. The International Early Lung Cancer Action Project (I-ELCAP)

is a non-randomized prospective, single-arm study based upon the results of the Cornell University ELCAP study

in which study subjects who are at high risk for lung cancer (i.e. adult smokers and ex-smokers) will have annual LDNCSCT at one of the more than 30 participating centers in the U.S., Europe and Asia.

All study subjects who are found to have a pulmonary nodule have management based upon a strict protocol. This is a very important feature of any screening test, because many people who have LDNCSCT will have nodules detected that are NOT lung cancer. It is important that further diagnostic and treatment steps following the detection of such a nodule does not expose the study subject to risk from inappropriate testing or surgery. The I-ELCAP protocol has been very successful in preventing unnecessary procedures.

Anyone wishing to participate in this lung cancer screening research trial can contact one of the ELCAP sites near them through the links provided at the individual center web sites, for further information about eligibility, costs and registration. A major advantage to screening at one of the I-ELCAP centers is that there is a management protocol, central data and image file management and quality control of radiologic interpretation, pathologic diagnosis and treatment.

There is also a new trial sponsored by the National Cancer Institute (NCI)

3. A third alternative is to participate in one of the many non-research based community radiographic screening programs that have opened throughout the country in the past few years. To date, there has been no publication of results of screening in these centers. There are two main types of programs. One is like the I-ELCAP and ACRIN trials and does only LDNCSCT to screen for lung cancer. The other type of program used a different technology called electron beam CT to test for both coronary artery disease as well as tumors in the chest and other parts of the body. Until there is publication of data reporting the results of management of pulmonary nodules in these programs, this author recommends participation in a research-based screening program.

If there is no availability of such screening at a reasonable distance from your home, I believe that participation in a non-research community screening program is preferable to no screening in individuals who are at high risk for lung cancer i.e. current smokers and ex-smokers who are at least 40 years of age and who have smoked a minimum of ten-pack years of cigarettes i.e. one pack per day for ten years or two packs per day for five years.