Characteristics of Singapore lung cancer patients who miss out on lung cancer screening recommendations

Abstract

Introduction: The National Lung Screening Trial (NLST) identified individuals at high risk for lung cancer and showed that serial low-dose helical computer tomographic scans (CT) were able to identify lung cancer at an earlier stage and also demonstrated mortality reduction. However, there has been little evidence regarding the effectiveness of the Lung Cancer Screening Criteria in the Asian population. Methods: To determine lung cancer patients who miss out on Lung Cancer screening criteria, we performed a retrospective audit from January to December 2018 in our hospital, and describe the characteristics of our patients diagnosed with lung cancer. Results: We found that only 38.1% of the patients in our cohort who were diagnosed with lung cancer in 2018 fitted into NLST Criteria strictly by age and smoking criteria. However, those who fitted the inclusion criteria of lung cancer screening would derive significant benefits, as 85.4% presented at advanced stage and 54.6% did not survive one year. We explored using the United States Preventive Services Task Force criteria, which increased sensitivity to 58.7% of identifying our patients with diagnosed lung cancer. 15.5% of females with lung cancer in our cohort fitted into NLST Criteria, but their low smoking quantity is a significant contributing factor for females being excluded. Conclusion: Majority of Singapore patients diagnosed with lung cancer would not have been picked up by NLST Criteria, especially female patients. However, those who fitted the inclusion criteria would derive significant benefit, while expanding to an older limit may yield benefits with improved sensitivity.

Low-dose computerised tomography screening for lung cancer in Singapore: Practical challenges of identifying participants

“…A recent retrospective audit in a single hospital of Singapore patients (N=126) showed that 85.4% of those presenting at an advanced stage would have benefited from an LDCT based on NLST criteria. 16 However, a trade-off needs to be acknowledged, in that this proposed targeted high-risk screening approach will probably not capture the subpopulation of East Asian non-smoking lung adenocarcinoma cancers. 16,17 Non-smokers represented a third of patients (33.3%) diagnosed with lung cancer in the hospital audit.…”

“…16 However, a trade-off needs to be acknowledged, in that this proposed targeted high-risk screening approach will probably not capture the subpopulation of East Asian non-smoking lung adenocarcinoma cancers. 16,17 Non-smokers represented a third of patients (33.3%) diagnosed with lung cancer in the hospital audit. 16 Apart from smoking, additional risk factors in Asian populations have been described, including a positive family history 18 and environmental carcinogen signatures, 19 which may need further research as a distinct cohort from the high-risk smoking population.…”

“…16,17 Non-smokers represented a third of patients (33.3%) diagnosed with lung cancer in the hospital audit. 16 Apart from smoking, additional risk factors in Asian populations have been described, including a positive family history 18 and environmental carcinogen signatures, 19 which may need further research as a distinct cohort from the high-risk smoking population. Furthermore, in clinical practice, the Lung Imaging Reporting and Data System (Lung-RADS) classification system of nodules is based on the NLST high-risk smoking population.…”

Letter from Singapore

“…7 A local lung cancer study demonstrated that many females and non-smokers diagnosed with lung cancer did not fit US National Lung Screening Trial criteria, a finding observed across other Asia Pacific countries. 8 The Lung Cancer Consortium Singapore (LCCS) SOLSTICE screening study is currently ongoing to assess the early detection of lung cancer (https://lccs.com.sg).…”