Oncologic outcomes of patients with resectable primary gastric squamous cell carcinoma: a systematic review.

Background: Primary gastric squamous cell carcinoma (PGSCC) is an uncommon type of gastric malignancy estimated to comprise around 0.04-0.5% of all gastric malignancies. PGSCC's long-term survival has been quoted to range from 17-50% depending on stage, with surgery arguably representing the most useful modality for prolonging oncologic survival. Nevertheless, reliable data on its effectiveness are still lacking in the literature. Method: A systematic literature search of the Medline, Cochrane library and Scopus databases was undertaken, to identify cases of surgically managed PGSCC reporting patient-related outcomes. Results: In total, 23 case reports and 1 case series incorporating 38 patients were identified. Mean patient age was 61.2 years and the male/female ratio was 18:1. Most tumors were high-stage at the time of diagnosis, with the T4 stage predominating in the patient pool (n=15, 50%) along with a high percentage of lymphatic spread (N positive tumors, n=15, 47%). All patients underwent curative-intent surgical resection and were subsequently followed for an average of 30.7±14 months. Extrapolated survival data revealed a projected 3- and 5-year overall survival of 62.2% and 51.9%, respectively, while the 3-year probability for being disease-free was calculated to be 30.8%. T4 stage and lymphatic spread were found to be predictors of poor survival in univariate but not in multivariate analysis. Conclusion: Notwithstanding the methodological limitations inherent to the present review, the obtained results, when superimposed on existing cross-sectional survival data, suggest significantly enhanced patient survival following surgery, solidifying its role in the management of patients with PGSCC.