The sensitivity and specificity of these four serum
tumor markers were different when separately conducted
in the diagnosis for lung cancer. Serum Hp showed a high
specificity (90.7%) but low sensitivity (43.5%). When
all of HP, CEA, NSE and CYFRA21-1 were used in
combination, the sensitivity in screening for lung cancer
was remarkably increased to 85.0% without compromising
the specificity (85.7%) (Table 2).