Overexpression of p53 and neoplastic cell proliferation in undifferentiated nasopharyngeal carcinoma.

Abstract. The author investigated the p53 status in correlation with cellular proliferation in the undifferentiated subgroup, which is infrequently found in caucasians. The author evaluated formalin-fixed, paraffin embedded tissue blocks from sixty cases with undifferentiated carcinoma of the nasopharynx by p53 and Ki67 immunostaining. All samples were retrieved from the surgical pathology file at King Chulalongkorn Memorial Hospital from 2001-2005. The patients had a mean age of 47 years. Stage IV was the most common stage, found in 21 cases (35%). Forty-four tumors (73%) overexpressed p53 protein, which was significantly associated with high rate of tumor cell proliferation (r = 0.477, p < 0.001). The higher the amount of p53 stained, the higher the rate of tumor cell proliferation. However, there was no statistically significant association between p53 protein overexpression and clinical status, including tumor volume, nodal status, and metastatic condition. This observation may explain why some tumors are resistant to radiation and are poorly controlled when they recur in distant organs.

Prevalence of IgA specific antibodies to Epstein-Barr virus capsid and early antigens in nasopharyngeal carcinoma.

Ninety-one patients with nasopharyngeal carcinoma (NPC), and 164 age-matched healthy controls were tested for presence of IgA antibodies to Epstein-Barr virus capsid antigen (VCA) and early antigen (EA) in their sera by indirect ELISA using "EBViral DETECT" commercial test kit. IgA anti-VCA was found in 76 (83.5%) of NPC patients and 16 (9.8%) of the controls. Meanwhile, IgA anti-EA was found in 72 (79.1%) of NPC patients and 21 (12.8%) of the controls. In a parallel study by indirect immunofluorescence test (IIF), IgA anti-VCA was found in 77 of 91 (84.6%) NPC patients and 22 of 142 (15.5%) controls. The prevalence rates of anti-VCA as screened by ELISA and IIF were very similar suggesting that neither one of the two tests can be used alternatively depending on the purpose and facilities in each individual laboratory. IgA antibodies to VCA and EA were more prevalence in NPC patients than those in the controls, the finding which again supported the association between EBV and NPC as was suggested in many other reports.

Malaria antibody levels in patients with nasopharyngeal carcinoma.

The antibody titres to P. falciparum and Epstein-Barr Virus-associated antigens were assayed in 22 patients with NPC and 43 controls. All, but one patient had antimalarial titres; 14 had titres greater than 80 and 4 patients greater than 640. Compared to controls the mean anti-malarial titre for most age groups were higher in the patients. Those patients with high anti-malarial titres also had high IgA anti-VCA titre, an antibody which has been demonstrated to be diagnostic for NPC. The peak anti-VCA (IgG) and anti-EA (IgG) antibody titres were associated with anti-falciparum titres of 320-640 and 80-160, respectively. The results are discussed in relation to the possible association between malarial infection and etiology of NPC.