BACKGROUND:

The development of nasopharyngeal carcinoma reflects interactions of genetics, diet, and viral agents. It is more common in Asians than non-Asians, with different characteristic histologic types. This study examined nasopharyngeal carcinoma in the U.S. as a function of patient origin and histology.

METHODS:

The data were from the National Cancer Data Base (NCDB). The 5069 nasopharyngeal carcinoma cases were grouped by histologic type: keratinizing squamous cell, nonkeratinizing, and undifferentiated carcinoma. Patient origin was derived from race, Hispanic ethnicity, and place of birth.

RESULTS:

World Health Organization (WHO) type 1 keratinizing squamous cell carcinomas comprised 75% of the U.S. nasopharyngeal carcinoma cases and were found most often in U.S.-born, non-Hispanic whites. WHO-2 nonkeratinizing and WHO-3 undifferentiated carcinomas of the nasopharnyx comprised the remaining 25% of nasopharyngeal carcinomas and were more common in Asians. Histologic composition varied for each of the 12 patient origin groups in the study and correlated with survival after treatment with ionizing radiation. Asians had the highest proportion of radioresponsive WHO-2 nonkeratinizing and WHO-3 undifferentiated carcinomas of the nasopharynx and better survival than African-Americans and Hispanic and non-Hispanic whites, who had the greatest number of the less radioresponsive keratinizing squamous cell carcinomas of the nasopharynx. The 5-year relative survival was 65% for the nonkeratinizing and undifferentiated carcinomas of the nasopharynx and 37% for the keratinizing variety.

CONCLUSIONS:

The survival rate of the patient origin groups correlated with the histologic composition of their nasopharyngeal carcinomas. Those with the highest proportion of radioresponsive nonkeratinizing and undifferentiated carcinomas had the best survival.