Cancer of the nasopharynx in British Columbia.

The Chinese population in British Columbia has been increasing in recent years due to the migration of the Chinese from Southern China, which has tripled during the last decade. From 1939 to 1980, 296 cases of nasopharyngeal carcinoma (NPC) were seen at the Cancer Control Agency of British Columbia (CCABC). Of these, 167 (56%) were Chinese and 119 (40%) were Caucasians. The incidence of cancer of the nasopharynx in the Chinese born in China was 115 times greater than Caucasians before 1970 and 107 times greater in the 1970s. The incidence of NPC in the Caucasian population remained unchanged as did that of the North American-born Chinese (six times greater than that of the Caucasians) for the last 2 decades. The overall survival for all cases was 39% at 5 years and 28% at 10 years. The survival of cases was better in patients treated after 1970 (48% at 5 years and 36% at 10 years) than in patients treated before 1970 (34% at 5 years and 20% at 10 years). The survival was 50% at 5 years for all N0 cases but it was only 27% in patients with nodal metastasis. The survival of NPC was related essentially to initial staging, type and dose of irradiation, and pre-irradiation biopsy of neck metastasis. The survival was not significantly related to birth place, race, or histological grade.