Primary esophageal adenosquamous carcinoma: a retrospective analysis of 24 cases

Abstract

Primary adenosquamous carcinoma (ASC) of the esophagus is a rare kind of malignancy characterized by mixed glandular and squamous differentiation as well as a propensity for aggressive clinical behavior. Data on the evaluation of the clinicopathological features and the prognosis of patients suffering from this malignancy are few because of the rarity of this disease. We conducted a retrospective review of 24 patients with primary esophageal ASC among 6546 esophageal cancer patients who underwent transthoracic esophagectomy in our hospital. The clinicopathological presentation, diagnosis, treatment, and prognostic factors of the patients were respectively investigated. The Kaplan-Meier method and the log rank test were used to calculate and compare overall survival (OS). The Cox proportional hazards model was employed to identify independent prognostic factors. There were 18 males and 6 females with a median age of 60 years (range: 40-78 years). The clinical symptoms, macroscopic type, as well as the radiological and endoscopic features of esophageal ASC were similar to those of esophageal squamous cell carcinoma. Sixteen (88.9%) of the 18 cases who underwent preoperative esophagoscopic biopsy were misdiagnosed as adenocarcinoma or squamous cell carcinoma. The overall median follow-up period was 36 months, and the median survival time was 32 months. The 1, 3, 5-year OS rates were 75.0%, 48.5%, and 19.4%, respectively. Univariate analysis showed that gender (P=0.047), lymph node metastasis (P=0.007), and TNM stage (P=0.037) were important factors associated with OS of the 22 patients who underwent radical resection. Multivariate analysis showed that the pathological N stage was the only independent prognostic factor (P=0.031, hazard ratio [HR], 5.369, 95% confidence interval [CI], 1.167-24.700). These results suggest that esophageal ASC is an uncommon disease prone to be misdiagnosed by endoscopic biopsy. Surgical resection is the primary treatment, but the prognosis of ASC is usually poorer than conventional squamous cell carcinoma. Lymph node metastasis is an independent prognostic factor after radical resection.