[Serum B-protein in patients with nasopharyngeal carcinoma].
B-protein is an acidic glycoprotein that appears in the serum of cancer patients, although it is not produced by cancer cells. It is not a cell surface antigen but can serve as a biological marker for detecting malignancies and monitoring cancer therapy. From January to August 1987, serum samples were collected from 133 patients with nasopharyngeal carcinoma (NPC) and 19 patients without cancer as the control group. The positive rates of B-protein in NPC patients without distant metastasis (107) and with distant metastasis (26) were 78.5% and 84.6% respectively. The overall positive rate of B-protein in NPC patients was 79.7%, which did not correlate with tumor stage and sex. The positive rate of B-protein in the control group was 5.3%. The difference in positive rates between NPC and the control group was significant (p less than 0.001). The quantitative changes of B-protein did not correlate with the tumor burden of NPC patients. Therefore, B-protein assay is not recommended in monitoring the treatment of NPC.