PCT within 0.05 and 2ng / ml in the lung cancer group and the pneumonia group was 0.81 ± 0.97ng / ml and 0.88 ± 0.84ng / ml, respectively; but PCT > 10ng / ml in the pneumonia group was higher than that in the lung cancer group, which was 13.13 ± 2.49ng / ml and 12.05 ± 1.64ng/ml.