Population-Based Analysis of Sex-Dependent Risk Factors for Mortality in Thoracic Surgery for Lung Cancer

Abstract

Objective: Sex is an important predictor for lung cancer survival and a favorable prognostic indicator for women compared to men. Specific surgery-related sex differences of patients with lung cancer remain unclear. The aim of this study is to analyze sex-specific differences after lung cancer resections to identify factors for an unfavorable prognosis. Methods: This is a retrospective analysis of a German nationwide discharge register of every adult inpatient undergoing pulmonary resection for lung cancer from 2014 until 2017. DRG data and OPS procedures were analyzed with the help of the Federal Statistical Office using remote controlled data. A multivariable regression model was established in a stepwise process to evaluate the effect of sex on inpatient mortality. Results: A total of 38,806 patients underwent surgical resection for lung cancer between January 2014 and December 2017 in Germany. Women were significantly younger at admission than men (mean 64.7 years [SD 10.1] vs. 66.6 years [SD 9.5]; p < 0.0001). They had fewer unreferred admissions (risk ratio 0.83 [0.77, 0.90], p < 0.0001) and were significantly less likely to have recorded comorbidities. Raw in-hospital mortality was 1.8% for women and 4.1% for men. In the multivariable analysis of in-hospital mortality, the likelihood of death for women compared to men was 21% reduced (OR 0.79 [CI: 0.66, 0.93, p = 0.005]). The risk of postoperative complications such as ventilation >48 h, ARDS, tracheotomy, or pneumonia was significantly lower for women. Conclusions: Women undergoing lung cancer surgery were younger and had less comorbidities than men in Germany. Female sex was associated with lower mortality and less postoperative complications.