Tissue protein biomarker candidates to predict progression of esophageal squamous cell carcinoma and precancerous lesions.

Esophageal squamous cell carcinoma (ESCC) is one of the most predominant malignancies worldwide. The 5-year survival rate is still relatively low due to few symptoms presenting with the early disease, diagnosis at middle to late stage, and high risk of recurrence after therapy. Novel protein biomarkers for early detection and treatment of ESCC have the potential to reduce incidence and mortality rates, and significantly prolong the 5-year survival rate. To date, several ESCC biomarkers are being investigated for screening, diagnosis, and treatment to decrease the disease burden. This review summarizes recent developments in candidate protein biomarkers for early diagnosis, predictors for precancerous disease progression, and prognosis of ESCC. Protein biomarkers that enable identification of the different pathologic grades of ESCC will need to be identified. ESCC biomarkers have the potential to improve screening and treatment strategies; multicenter prospective studies with large sample sizes will be required to confirm the usefulness of these candidate biomarkers.