Periostin, a matricellular protein, has been reported to be important in supporting tumor cell dissemination. However, the molecular mechanisms underlying periostin function within the tumor microenvironment are poorly understood. In this study, we observe that loss of periostin decreases esophageal squamous cell carcinoma (ESCC) tumor growth in vivo and demonstrate that periostin cooperates with a conformational missense p53 mutation to enhance invasion. Pathway analyses reveal that invasive esophageal cells expressing periostin and p53R175H mutation display activation of signal transducer and activator of transcription 1 (STAT1) target genes, suggesting that the induction of STAT1 and STAT1-related genes could foster a permissive microenvironment that facilitates invasion of esophageal epithelial cells into the extracellular matrix (ECM). Genetic knockdown of STAT1 in transformed esophageal epithelial cells underscores the importance of STAT1 in promoting invasion and potentiate tumor resistance to genotoxic stress. Furthermore, we find that STAT1 is activated in ESCC xenograft tumors but this activation is attenuated with inducible knockdown of periostin in ESCC tumors. Overall, these results highlight the molecular mechanisms supporting the capacity of periostin in mediating tumor invasion during ESCC development. Pre-clinical study hTERT: EPC cells immortalized by expression of hTERT hTERT_p53: EPC cells expressing hTERT and mutant P53 hTERT_p53_POSTN: EPC cells expressing hTERT, mutant P53, and POSTN.