Background: Undifferentiated carcinoma of the salivary glands is a rare disease, the incidence of which is highest among the Inuit of Greenland and North America. It was demonstrated to be closely related to Epstein- Barr virus (EBV) infection. However, the relation of EBV to this tumor has not been studied to any great extent here in Taiwan because of the small number of cases.
Methods: Twelve cases of undifferentiated carcinoma of the salivary glands from the period 1977-1996 were retrieved from the cancer registry at National Taiwan University Hospital. The clinical data were analyzed retrospectively based on the medical records. Eleven formalin fixed, paraffin embedded tissue sections were used for in situ hybridization with an antisense probe complementary to EBV-encoded RNA 1 (EBER1).
Results: Ten of 12 tumors originated from the parotid gland and 2 from the submandibular gland. The patients' ages ranged from 22 to 63 years, with an average of 38.1 years. One patient was lost to follow-up, 2 patients died of metastatic disease, and the remaining 9 patients were all alive and disease free at last follow-up. The actuarial 5-year survival rate was 79.8%. In situ hybridization demonstrated EBER1 in 9 of the undifferentiated carcinomas with lymphoid stroma, but EBER1 was not demonstrated in the other 2 tumors without lymphoid stroma.
Conclusions: Undifferentiated carcinoma with lymphoid stroma of the major salivary glands is closely associated with EBV. The mainstay of treatment is surgery and postoperative radiotherapy. The outcomes in this series were good except for two elderly patients who died of rapid and progressive distant metastases.