Methods of computed tomography screening and management of lung cancer in Tianjin: design of a population-based cohort study

Objective: European lung cancer screening studies using computed tomography(CT) have shown that a management protocol based on measuring lung nodule volume and volume doubling time(VDT) is more specific for early lung cancer detection than a diameter-based protocol. However, whether this also applies to a Chinese population is unclear. The aim of this study is to compare the diagnostic performance of a volume-based protocol with a diameter-based protocol for lung cancer detection and optimize the nodule management criteria for a Chinese population.Methods: This study has a population-based, prospective cohort design and includes 4000 participants from the Hexi district of Tianjin, China. Participants will undergo low-dose chest CT at baseline and after 1 year. Initially, detected lung nodules will be evaluated for diameter and managed according to a routine diameter-based protocol(Clinical Practice Guideline in Oncology for Lung Cancer Screening, Version 2.2018). Subsequently, lung nodules will be evaluated for volume and management will be simulated according to a volume-based protocol and VDT(a European lung nodule management protocol). Participants will be followed up for 4 years to evaluate lung cancer incidence and mortality. The primary outcome is the diagnostic performance of the European volume-based protocol compared to diameter-based management regarding lung nodules detected using low-dose CT.Results: The diagnostic performance of volume-and diameter-based management for lung nodules in a Chinese population will be estimated and compared.Conclusions: Through the study, we expect to improve the management of lung nodules and early detection of lung cancer in Chinese populations.

Clinical characteristics and work-up of small to intermediate-sized pulmonary nodules in a Chinese dedicated cancer hospital

Objectives:To evaluate the characteristics and work-up of small to intermediate-sized pulmonary nodules in a Chinese dedicated cancer hospital.Methods:Patients with pulmonary nodules 4–25 mm in diameter detected via computed tomography(CT)in 2013 were consecutively included.The analysis was restricted to patients with a histological nodule diagnosis or a 2-year follow-up period without nodule growth confirming benign disease.Patient information was collected from hospital records.Results:Among the 314 nodules examined in 299 patients,212(67.5%)nodules in 206(68.9%)patients were malignant.Compared to benign nodules,malignant nodules were larger(18.0 mm vs.12.5 mm,P<0.001),more often partly solid(16.0%vs.4.7%,P<0.001)and more often spiculated(72.2%vs.41.2%,P<0.001),with higher density in contrast-enhanced CT(67.0 HU vs.57.5 HU,P=0.015).Final diagnosis was based on surgery in 232 out of 314(73.9%)nodules,166 of which were identified as malignant[30(18.1%)stage III or IV]and 66 as benign.In 36 nodules(11.5%),diagnosis was confirmed by biopsy and the remainder verified based on stability of nodule size at follow-up imaging(n=46,14.6%).Among 65 nodules subjected to gene(EGFR)mutation analyses,28(43.1%)cases(EGFR19 n=13;EGFR21 n=15)were identified as EGFR mutant and 37(56.9%)as EGFR wild-type.Prior to surgery,the majority of patients[n=194(83.6%)]received a contrast-enhanced CT scan for staging of both malignant[n=140(84.3%)]and benign[n=54(81.8%)]nodules.Usage of positron emission tomography(PET)-CT was relatively uncommon[n=38(16.4%)].Conclusions:CT-derived nodule assessment assists in diagnosis of small to intermediate-sized malignant pulmonary nodules.Currently,contrast-enhanced CT is commonly used as the sole diagnostic confirmation technique for pre-surgical staging,often resulting in surgery for late-stage disease and unnecessary surgery in cases of benign nodules.