Article Abstract

Gastric squamous cell carcinoma and gastric adenosquamous carcinoma, clinical features and outcomes of rare clinical entities: a National Cancer Database (NCDB) analysis

Authors: Mehmet Akce, Renjian Jiang, Olatunji B. Alese, Walid L. Shaib, Christina Wu, Madhusmita Behera, Bassel F. El-Rayes


Background: Gastric squamous cell carcinoma (GSCC) and gastric adenosquamous carcinoma (GASC) comprise less than 2% of gastric cancers. The current knowledge about clinical presentation, treatment modalities and outcomes of GSCC and GASC is limited. The aim of this study is to characterize the clinicopathological features, treatment modalities, and outcomes of GSCC and GASC in comparison to gastric adenocarcinoma (GAC) in National Cancer Database (NCDB).
Methods: Patients with GSCC, GASC and GAC between 2004 and 2013 were identified using ICD-O-3 histology and topography codes 8070/3, 8560/3, 8140/3 and C16.0-9. Univariate, and multivariate analysis were performed, and Kaplan-Meier curves was used to compare survival based on histological subtype.
Results: A total of 61,215 patients were identified, 836 (1.4%) GSCC, 327 (0.5%) GASC, 60,052 (98.1%) GAC between 2004 and 2013, in which 77.4% was Caucasian and 68.7% was male, 46.6% of tumors were in gastric cardia and 13.7% in gastric antrum. Neoadjuvant and adjuvant chemotherapy was administered in 11.2%, 14.1%, 8.9% vs. 2.9%, 11.9%, 9.5% for GSCC, GASC, GAC. Surgery was performed in 26.0%, 54.4%, 45.2% of GSCC, GASC, GAC. Radiotherapy was administered in 48.1%, 37.6%, 31.6% of GSCC, GASC, GAC. Median overall survival was 8.9, 9.9 and 13.2 months for GSCC, GASC, GAC. On multivariate analysis squamous cell (HR =1.14; 95% CI, 1.06–1.24, P=0.001) and adenosquamous cell histology (HR =1.52; 95% CI, 1.35–1.73, P<0.001) was associated with worse survival compared to adenocarcinoma.
Conclusions: GSCC and GASC have poorer survival outcomes compared to GAC. Less patients with GSCC received surgery and adjuvant chemotherapy, more patients with GSCC received radiation therapy.