Oesophageal basaloid squamous cell carcinoma: a unique clinicopathologicalentity with telomerase activity as a prognostic indicator

Oesophageal basaloid squamous cell carcinoma (BSCC) is uncommon and has bee n reported to have a worse prognosis than squamous cell carcinomas (SCCs), but this tumour has not been fully characterized. The aim of the present st udy was to analyse the clinicopathological features of a large cohort of pa tients with oesophageal BSCC treated at a single institution. The pathology of 756 primary oesophageal cancers treated between January 1989 and Decemb er 1998 was reviewed. Tumours that fulfilled the diagnostic criteria of BSC C were identified and were compared with SCC. Their expression of MIB-1, DN A ploidy, and telomerase activity were also studied. Thirty Chinese patient s (25 men and five women) with BSCC were found, comprising 4% of patients w ith oesophageal cancer treated by surgical resection in the study period. T heir median age was 67 years (range 40-78 years). Dysphagia was usually the main presenting symptom. Other concomitant malignant tumours were seen in three patients and paraneoplastic glomerulopathy in one. Five tumours were located in the upper third, 19 in the middle third, and six in the lower th ird. The median length was 5.8 cm (range 2-12 cm). The median MIB-1 score o f BSCC was 750 (range 400-858) and was higher than that of SCC (p = 0.003). The primary tumour and metastatic BSCC were aneuploid,: as detected by flo w cytometric analysis in nine patients. Telomerase activity was positive in 95%, (19 out of 20) of the cases analysed. The 5-year survival of patients with BSCC was 12%. Distant metastases were seen in 53% (n = 16); lung and liver were the most common sites. The median survival of patients with tumo urs which had a high level of telomerase activity was significantly shorter than those with low levels of telomerase activity (1 vs. 27 months) (p = 0 .001). The median survival of patients with BSCC and SCC was 26 and 16 mont hs, respectively (p = 0.3). In conclusion, BSCC has distinctive clinicopath ological features and its long-term prognosis is no worse than SCC. The lev el of telomerase activity may have a prognostic role. Copyright (C) 2001 Jo hn Wiley & Sons, Ltd.