APC and cervical small cell carcinoma: Identifying correlation between differentiation status and APC promoter methylation in conjunction with lower survival rate of patients with hypermethylated APC promoter implies the importance of epigenetic control of tumor suppressor genes in the tumorigenesis of SCCE, as well as the significant indicatory role of APC hypermetylation for evaluating tumor malignancy and predicting survival of SCCE patients subsequent to treatment.