Prognostic significance of high podoplanin expression after chemoradiotherapy in esophageal squamous cell carcinoma patients

Background The correlation between high tumor podoplanin (PP) immunoreactivity and poor outcome in patients with non-chemoradiotherapy(CRT) pretreated upper aerodigestive tract squamous cell carcinoma (SCC) has been reported recently. Little is known about the implication of PP expression after CRT. Therefore, we conducted this study. Methods We evaluated the PP immunoreactivity in ypT3N0 esophageal SCC patients by using immunohistochemistry. The impact of PP expression intensity in tumors on patient survival was judged in combination with clinical and pathological descriptors. Results Our study included 109 males and 4 females (mean age, 57.6 years; range, 38-79 years). PP immunoreactivity was expressed in tumors in 95% of patients and 38% of patients had high PP expression. High PP expression tumors had positive association with lymphovascular invasion (LVI). Multivariate analyses revealed tumor PP immunoreactivity and circumferential resection margin (CRM) status as independent prognostic factors. Patients with positive CRM and high PP expression had shortest survival followed by those with either positive CRM or high PP expression, and then by patients with neither positive CRM nor high PP expression (5-year disease-specific survival: 5%, 20%, 40%, P < 0.001). Conclusion Tumor PP immunoreactivity in conjunction with CRM status are useful markers to identify aggressive post-CRT treated ypT3N0 stage esophageal SCC.