Lung cancer screening: Should we be excluding people with previous malignancy?

Abstract

The National Lung Screening Trial (NLST) was a large, randomized, controlled study showing a 20% reduction of lung cancer mortality and 7% reduction of all cause mortality using annual low dose computed tomography (LDCT) in a high risk population. NLST excluded people with a previous history of cancer treatment within the past 5 years and all people with a history lung cancer. The aim of this work is to review how lung cancer screening trials addressed the confounding effect of previous malignancy. We also review the subsequent recommendations by the United States Preventative Task Force Services, multiple professional societies and the Center for Medicaid and Medicare Services which defer either to NLST criteria or, clinician judgment or refrain from asserting any recommendation on the topic, respectively. Implications of lung cancer screening in the setting of previous malignancies, specifically lung, head and neck, esophageal, gastric, breast, colorectal cancer and lymphoma are also discussed. With lung cancer screening, an antecedent malignancy introduces the possibility of discovering metastasis as well as lung cancer. In some circumstances diagnosis and treatment of oligometastatic disease may confer a survival benefit. The survival benefit of treating either lung cancer or oligometastatic disease as result of lung cancer screening has yet to be determined. Further studies are needed to determine the role of lung cancer screening in the setting of previous malignancy.

Keywords: Lung cancer screening, Criteria, Previous malignancy, Antecedent malignancy, Lung metastasis, Guidelines, Head and neck cancer, Lung cancer, Low dose computed tomography, Gastric cancer, Breast cancer, Colorectal cancer, Lymphoma, Esophageal cancer

Core tip: Most lung cancer screening trials, including the National Lung Screening Trial, exclude those with a history of a previous malignancy as it may introduce confounding factors that influence survival. However, people with previous malignancy may benefit from the discovery of treatable lung cancer as well as treatable metastasis. In this review, we summarize the consideration that studies and national guidelines give in regards to lung cancer screening in patients with previous malignancy. Furthermore, we address the implications of lung cancer screening in the setting of specific malignancies, namely lung, head and neck, esophageal, gastric, breast, colorectal cancer and lymphoma.