Histopathology of nasopharyngeal carcinoma.Correlations with epidemiology, survival rates and other biological characteristics

Abstract

A total of 363 cases of nasopharyngeal carcinoma (NPC) in Singapore were classified into squamous cell carcinoma (SCC; 73 cases), non-keratinizing carcinoma (NKC; 178 cases) and undifferentiated carcinoma (UC; 172 cases). Possible biological differences between these histologic types and between tumors with and without lymphocytic infiltration were investigated by correlations with survival rates and with selected epidemiologic, immunovirologic, and immunogenetic data on the disease. The 5-year survival rates following radiotherapy were 25.3% for all cases and 58.8% for tumors restricted to the nasopharynx. The 5-year survival rate for SCC was poorer than for the combined NKC and UC groups (p < 0.05). The 3-year survival rate was better for tumors with lymphocytic infiltration (p < 0.05), but there were no differences in the 5-year survivals. The survival rates were better in females (p < 0.01) and in the younger age groups (p < 0.01). There were no significant correlations between histopathology of NPC and the distributions of cases by age, sex, HLA antigen profiles, or cell-mediated immune status. Spuamous cell carcinoma was associated with lower levels of antibodies to the Epstein-Barr nuclear antigen (p < 0.05), but there were no differences with respect to antibodies against other EBV related antigens. These findings support the view that SCC, NKC, and UC of the nasopharynx, as defined in the WHO classification, are variants of a fairly homogeneous group of neoplasms in the Singapore population.

Avaliação dos fatores clínicos e do tratamento em pacientes com carcinoma indiferenciado da nasofaringe

“…Race was a second variation compared to the literature; most of the patients were Caucasian, and there were no patients of Asian origin. 12,13 These findings coincide with those of the National Cancer Institute (USA), showing a higher incidence of nasopharyngeal carcinomas in young adult Caucasians and Afro-Americans compared to Asian patients. 14 Tobacco and alcohol are relevant etiological factors in upper digestive airways.…”

Nonkeratinizing Undifferentiated Nasopharyngeal Carcinoma

“…The subtypes may overlap, with approximately a quarter of cases demonstrating features of more than one subtype [6]. The histologic features of keratinizing NPC are similar to those of conventional squamous cell carcinomas arising elsewhere in the aerodigestive tract.…”

Constitutive activation of STAT3 and STAT5 is present in the majority of nasopharyngeal carcinoma and correlates with better prognosis

“…Most studies demonstrating constitutive activation of STATs in solid human malignancies have used either Western blot analysis and/or electrophoretic mobility shift assay (EMSA) as the main methodology. However, considering the 'lymphoepithelioma-like' nature of NPC (Shanmugaratnam et al, 1979), applicability of these methods might be confounded by the infiltrating lymphocytes in this tumour and is not suitable under such conditions. Therefore, we decided to use immunohistochemical methods to study the expression patterns of STATs in NPC.…”

“…All of the 61 patients, including 49 males and 12 females, were histologically confirmed to have WHO type II (nonkeratinising) or WHO type III (undifferentiated) NPC (Shanmugaratnam et al, 1979). The clinical status of these patients was determined using the 1997 UICC/AJCC staging system (Sobin and Wittekind, 1997) after reviewing their clinical records and image studies which included chest X-ray, abdominal sonography, bone scan and CT scan.…”