Propensity score analysis of lung cancer risk in a population with high prevalence of non-smoking related lung cancer

Abstract

Background: Lung cancer has been the leading cause of cancer-related mortality worldwide among both men and women in recent years. There is an increase in the incidence of nonsmoking-related lung cancer in recent years. The purpose of the present study was to investigate multiple potential risk factors for nonsmoking-related lung cancer among Asian Ethnic Groups.

Methods: We used a propensity score-mated cohort analysis for this study. We retrospectively review the medical record of 1975 asymptomatic healthy subjects (40 ~ 80 years old) who voluntarily underwent low-dose chest CT from August 2013 to October 2014. Clinical information and nodule characteristics were recorded.

Results: A propensity score-mated cohort analysis was applied to adjust for potential bias and to create two comparable groups according to family history of lung cancer. For our primary analysis, we matched 392 pairs of subjects with family history of lung cancer and subjects without history. Logistic regression showed that female gender and a family history of lung cancer were the two most important predictor of lung cancer in the endemic area with high prevalence of nonsmoking-related lung cancer (OR = 11.199, 95% CI = 1.444-86.862; OR = 2.831, 95% CI = 1.000136-8.015). In addition, the number of nodules was higher in subjects with family history of lung cancer in comparison with subjects without family history of lung cancer (OR = 1.309, 95% CI = 1.066-1.607).

Conclusions: In conclusion, risk-based prediction model based on the family history of lung cancer and female gender can potentially improve efficiency of lung cancer screening programs in Taiwan.

Keywords: Lung adenocarcinoma spectrum; Non-smoker lung cancer; Propensity score matching; Risk factor.

Fig. 1

Flowchart with a summary of patient enrollment and propensity score matching

Fig. 2

a-b Histograms of propensity score distribution before and after propensity score matching. Distribution of the propensity scores before and after matching for group of family history of lung cancer (+) and group of family history of lung cancer (−). a presents histograms of unbalanced propensity score distribution in both groups before propensity matching. b presents histograms of balanced propensity score distribution in both groups after propensity matching

Fig. 3

An example of multifocal GG/L lung cancer, a kind of lung adenocarcinoma subtype which often occurred in Asian women or non-smoker recently according to the IASLC Lung Cancer Staging Project in 2016. A 61-year-old woman had a 2.8 cm part-solid nodule in LUL, and another one pure GGN nodule 1.4 cm in RLL. The patient underwent sequentially video-thoracoscopic wedge resection of RLL and LUL. Further pathologic report demonstrated invasive adenocarcinoma in LUL, and adenocarcinoma in situ in RLL. Synchronous multiple primary lung cancer was diagnosed according to the diagnostic criteria proposed by Martini and Melamed. Abbreviations: RLL = right lower lobe; GGN = groundglass nodule; LUL = left upper lobe