The following consensus statement was developed by over 30 researchers meeting in Varese, Italy, in December 1998.
We are in the midst of a global and growing lung cancer epidemic. On a worldwide basis, lung cancer is the most deadly malignancy; it will cause more that one million deaths this year. Because cigarette smoking is the vastly predominant cause, lung cancer is almost entirely preventable. Other sources of risk include environmental exposures and inherited risk.
Accordingly, the only currently effective means of prevention is to refrain from smoking. For children and adolescents, the focus should be on not starting smoking. For adults, smoking cessation is an effective method of reducing lung cancer risk, but this is often difficult to implement and achieve. It is important to recognize their continuing risk: even after quitting, long-term smokers remain at high risk for prolonged periods. There is a pressing need for effective secondary prevention (screening) measures.
The conference reviewed available evidence relative to early diagnosis of lung cancer. The pioneering studies have not shown mortality reductions, and have led many organizations to recommend against lung cancer screening. However, there are a number of limitations to these studies, leaving us with an imperfect basis for health policy. Paradoxically, case-finding studies show favorable outcomes when lung cancer is detected early. Furthermore, over the last 20 years, the pattern of disease has changed: conventional diagnostic techniques have improved, and new early detection techniques have emerged.
An important aspect of the conference was a review of new technology that holds the promise of substantial mortality reduction from lung cancer. These new technologies include low- dose spiral CT scan, autofluorescent bronchoscopy, and molecular markers in sputum cytology. Rigorous and rapid evaluation of these new technologies is essential in order to ensure confidence in their efficacy and timely application of their findings.
At this time, only one large trial with chest x-ray screening is ongoing, although newer modalities are being investigated in other studies around the world. The conference concluded that additional studies are needed. It is especially important that investigation of new early detection technologies receive high scientific and public health priority.
For those who develop lung cancer, the outcome is dramatically better when the disease is detected at an early stage and surgically treated. Unfortunately, at this time, the majority of lung cancers are diagnosed when the disease is overtly symptomatic, and in an advanced stage when prognosis is extremely poor. Available clinical data demonstrate that the vast majority of curable lung cancers are currently detected by chest x-rays and CT scan although there is no proven strategy to assure early detection.
The conference encourages national governments and public health organizations involved in cancer prevention and control to more aggressively address tobacco control and to urgently consider the issues surrounding the early detection of lung cancer. The conference recognizes that current and former smokers must be advised of their continuing risk of lung cancer. In order to address these issues, organizations must support research on new diagnostic techniques and chemoprevention. They must also develop recommendations regarding how health care providers and high-risk patients can make informed decisions about monitoring for the occurrence of lung cancer.