Prospective Markers for Early Diagnosis and Prognosis of Sporadic Pancreatic Ductal Adenocarcinoma
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- Tobi, M., Kim, M., Weinstein, D.H. et al. Dig Dis Sci (2013) 58: 744. doi:10.1007/s10620-012-2387-x
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Background and Aim
Sporadic pancreatic ductal adenocarcinoma (PDA) is a highly lethal cancer. No proven screening strategies are available and frequent cross-sectional imaging studies (CT/MRI) are impractical even in patients thought to be at higher risk than the general population. Few PDA biomarkers have been studied prospectively for screening. Here, we prospectively evaluated the Adnab-9 monoclonal antibody in stool, pancreaticobiliary secretions, and tissue for screening and prognostic value in sporadic PDA. We also evaluated the prognostic value of characterized early biomarkers in pancreaticobiliary secretions.
Adnab-9 diagnostic ability was tested in stool in 249 and 1,132 patients from China and the US, respectively. Immunohistochemistry was performed in 22 tissue samples with Adnab-9 antibody and anti-Defensin 5, a constituent of Paneth cells. Pancreatobiliary secretions were collected from 12 PDA patients and 9 controls. The enriched PCR method was performed to detect K-ras mutations. ELISA was performed with Adnab-9, anti-Her-2/neu, and monoclonal antibody D4 (anti-Reg I).
Adnab-9 alone was diagnostic and prognostic when measured in pancreatic secretions, feces, and tissues of PDA patients compared to controls (p < 0.05). Significantly, Adnab-9 fecal binding can precede the clinical diagnosis by 2.3 years, potentially allowing earlier clinical intervention. In pancreatic secretions, a combination of K-ras and Her-2/neu when appropriately standardized can be diagnostic in 75 % of PDA.
Our study suggests that Adnab-9 may be an effective marker for diagnosis and prognosis of PDA. Adnab-9 may be reflective of the presence of Paneth cells confirmed by Defensin-5 staining. These cells may modulate the biological activity of the cancer and confer a better prognosis.