Malignant neoplasms of the nasal cavity and paranasal sinuses: A series of256 patients in Mexico City and Monterrey. Is air pollution the missing link?

Air pollution is a serious health problem in major cities in Mexico. The co ncentrations of monitored criteria pollutants have been above the US Nation al Ambient Air Quality Standards for the last decade. To determine whether the number of primary malignant nasal and paranasal neoplasms has increased , we surveyed 256 such cases admitted to a major adult oncology hospital lo cated in metropolitan Mexico City (MMC) for the period from 1976-1997 and t o a tertiary hospital in Monterrey, an industrial city, for the period from 1993-1998. The clinical histories and histopathologic material were review ed, and a brief clinical summary was written for each case. In the MMC hosp ital the number of newly diagnosed nasal and paranasal neoplasms per year f or the period from 1976-1986 averaged 5.1, whereas for the next 11 years it increased to 12.5. The maximal increase was observed in 1995-1997, with an average of 20.3 new cases per year (P = 0.0006). The predominant neoplasms in these series were non-Hodgkin's lymphoma, squamous cell carcinoma, mela noma, adenocarcinoma, Schneiderian carcinoma, and nasopharyngeal carcinoma. In the Monterrey hospital a 2-fold increase in the numbers of newly diagno sed nasal and paranasal neoplasms was recorded between 1993 and 1998. The p redominant MMC neoplasm in this series, namely nasal T-cell/natural killer cell non-Hodgkin's lymphoma, is potentially Epstein-Barr virus related. Nas al and paranasal malignant neoplasms are generally rare. Environmental caus ative factors include exposure in industries such as nickel refining, leath er, and wood furniture manufacturing. Although epidemiologic studies have n ot addressed the relationship between outdoor air pollution and sinonasal m alignant neoplasms, there is strong evidence for the nasal and paranasal ca rcinogenic effect of occupational aerosol complex chemical mixtures. Genera l practitioners and ear, nose, and throat physicians working in highly poll uted cities should be aware of the clinical presentations of these patients . Identification of this apparent increase in sinonasal malignant neoplasms in two urban Mexican polluted cities warrants further mechanistic and epid emiologic studies.