The role of radiologic screening in lung cancer.

The present available data do not support the routine utilization of chest radiography or sputum cytology for the early detection of lung cancer. While on an individual basis, as part of a general health maintenance consideration, some high risk individuals may benefit from radiologic or cytologic screening, there has been no overall decrease in cancer mortality associated with these screening procedures. The early cases picked up by screening while asymptomatic and often detected by sputum cytology have lead-time bias to account for prolonged survival. Furthermore, many of these asymptomatic lesions are so indolent that they may never come to the patient's attention during his or her lifetime and the patient may die of other causes. There are other cancers, which may be of the same histology, that develop in the interval between even closely applied screening examinations. Patients with these cancers are often symptomatic and the biologic behavior of these lung cancers is so aggressive that, regardless of intervention, the prognosis is miserable. The cooperative studies also show a fairly high miss rate for the diagnosis of lung cancer even in patients who are being heavily screened. The miss rate for the early detection of lung cancer with chest radiography is probably on the order of 30% or more. That is, in at least 30% of cases, the tumor can be identified retrospectively on earlier examination. Nevertheless, in spite of the significant miss rate, those tumors with an indolent biologic behavior can be present for 2, 3, or more years and still remain localized, have a high resectability rate, and carry a prolonged survival prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)