Anti-p16 autoantibodies may be a useful biomarker for early diagnosis of esophageal cancer.

AIM: Our recent work suggested that circulating IgG antibodies to a linear
peptide derived from p16 protein were significantly increased in patients with
lung cancer. The present study was then designed to test whether such
autoantibodies were also altered in esophageal cancer.
METHODS: An enzyme-linked immunosorbent assay was developed in-house to determine
circulating IgA and IgG antibodies against p16 protein-derived antigens in 97
patients with esophageal squamous cell carcinoma (ESCC) and 226 healthy subjects.
RESULTS: The levels of anti-p16 IgG but not IgA antibodies were significantly
higher in the patient group than the control group (t = 2.81, P = 0.0052);
circulating anti-p16 IgG levels were inversely correlated with stages of ESCC
(r = -0.30, df = 81, P = 0.0058) and patients with stage I of ESCC had the
highest IgG level among all four stages (t = 5.25, P ≤ 0.0001, compared with
control subjects). There was no correlation between the levels of IgA and IgG
either in the patient group (r = -0.05, df = 86, P = 0.627) or in the control
group (r = -0.1, df = 205, P = 0.146).
CONCLUSION: Circulating IgG autoantibody to p16 protein may be a potential
biomarker for early diagnosis of esophageal cancer.