Researchers reported that results of a simple blood test measuring VEGF-A and TGF-β1 can be used as predictive markers for response to treatment in patients with squamous cell esophageal cancer undergoing concurrent chemotherapy and radiation therapy (CCRT) followed by esophagectomy, or removal of part of the esophagus.
“The blood levels of these two proteins can be used as biomarkers to predict tumor response to therapy. This simple test can help tailor treatment decisions in patients with esophageal cancer,” stated lead author Yun Chiang, MD, National Taiwan University Hospital, Taipei.
From 2004 to 2013, blood samples were collected from 103 patients with esophageal squamous cell carcinoma before and after CCRT. Serum samples were measured for 15 potential markers to correlate the levels of these markers with pathologic response and survival. The assay used to screen tiny blood samples was developed at Stanford University and is called proximity ligation assay (PLA), said Chiang.
The biomarkers significantly associated with pathologic response and survival rates were further analyzed by enzyme-linked immunoabsorbent assay (ELISA) to confirm findings using PLA.
Only 2 of the markers were significantly associated with disease-free survival (DFS; P = .009) and these were of borderline significance for overall survival (OS; P = .07). Patients with low levels of VEGF-A pre-CCRT were more likely to achieve a pathologic complete response to CCRT than those with higher levels: 57.1% versus 26.5%, respectively (P = .002).
Patients with high pre-CCRT serum VEGF-A/TGF-β1 levels had significantly worse median DFS versus those with lower levels, and worse median OS (19.2 months vs 46.2 months, respectively; P = .07).
“Low serum levels of VEGF-A increased the chance of pathological complete tumor regression, and high serum levels of VEGF-A and TGF-β1 were associated with significantly worse disease control and borderline worse survival,” Chiang told listeners.
The clinical implication of high serum levels of both proteins suggests that more intensive therapy is needed, he said.
Chiang Y, Cheng J, Graber M, et al. Serum vascular endothelial growth factor-A and transforming growth factor-β1 can predict pathological response and disease-free survival of esophageal cancer patients treated with neoadjuvant chemoradiotherapy followed by esophagectomy. Int J Radiat Oncol Biol Phys. 2014;90(1)(suppl):S9-S10. Presented at: 56th Annual Meeting of the American Society for Radiation Oncology; September 14-17, 2014; San Francisco, CA. Abstract 10.