Early detection of lung cancer

Abstract

Most patients with lung cancer are diagnosed when they present with symptoms, they have advanced stage disease, and curative treatment is no longer an option. An effective screening test has long been desired for early detection with the goal of reducing mortality from lung cancer. Sputum cytology, chest radiography, and computed tomography (CT) scan have been studied as potential screening tests. The National Lung Screening Trial (NLST) demonstrated a 20% reduction in mortality with low-dose CT (LDCT) screening, and guidelines now endorse annual LDCT for those at high risk. Implementation of screening is underway with the desire that the benefits be seen in clinical practice outside of a research study format. Concerns include management of false positives, cost, incidental findings, radiation exposure, and overdiagnosis. Studies continue to evaluate LDCT screening and use of biomarkers in risk assessment and diagnosis in attempt to further improve outcomes for patients with lung cancer.

Keywords: lung Screening; lung cancer; lung cancer screening.

Figure 1.

A 62-year-old woman, former smoker with a 40-pack year history, had a low-dose computed tomography (CT) screen showing a 3 mm nodule ( A) in the left lung (lingula). At 1-year follow-up, the nodule had grown ( B) and at surgical resection was a 6 mm adenocarcinoma. She remains without evidence of disease 9 years after removal.

Figure 2.. A 67-year-old woman, former smoker with a 9 mm ground glass opacity (GGO) in the lingula.

The nodule has changed minimally over 3 years and is currently being followed with annual computed tomography (CT). If this is a cancer, it is likely to be an adenocarcinoma in situ and may represent an overdiagnosis cancer.