Human papillomavirus in tonsillar and nasopharyngeal carcinoma: Isolation of HPV subtype 31.

Abstract

We retrospectively studied biopsy specimens obtained from 16 patients who had carcinoma of the tonsil or nasopharynx. Polymerase chain reaction testing detected the presence of human papillomavirus (HPV) in 13 samples (81.3 %)--six tonsillar and seven nasopharyngeal. Eleven of the 13 positive samples (84.6%) contained HPV subtype 31. We believe that this is the first report of the presence of HPV subtype 31 in these carcinomas. In addition to the significant association between tonsillar and nasopharyngeal cancer and HPV, our analysis of descriptive variables confirmed the association between the incidence of these neoplasms and poor oral hygiene and low socioeconomic status in older adults.

Introductiojn

Patients who develop carcinoma of the tonsil and nasopharynx in western Mexico are usually not identified until the disease has progressed to a late stage. The reasons for this delay might be attributable to the asymptomatic nature of early disease or to socioeconomic factors specific to this population. It is not unusual for these patients to also have a concomitant neck mass. Most of these patients are referred by their primary care physician, dentist, or local otolaryngologist to the Centro Medico Nacional de Occidente, a tertiary care academic facility in the city of Guadalajara, state of Jalisco, in western Mexico. Macroscopically, the lesion typically appears as an exophytic tumor with a raised erythematous mucosa and ill-defined margins surrounding a necrotic ulcer.

Previous reports in the literature have established an association between carcinomas of the tonsil and human papillomavirus (HPV). [1-3] The aim of our study was to retrospectively document the presence of HPV and its subtypes in specimens preserved at the Centro Nacional.

Patients and methods

We retrospectively analyzed biopsy samples obtained from 16 patients--nine women and seven men, aged 45 to 70 years (mean: 63)--with tonsillar or nasopharyngeal cancer who were treated at the Hospital de Especialidades in Jalisco. One biopsied specimen from each patient was preserved at the Centro Nacional in Guadalajara and studied retrospectively. All tissue specimens were fixed in paraffin blocks and analyzed by DNA electrophoresis and spectrophotometry. Polymerase chain reaction testing (PCR) was performed to detect the presence of HPV and, if found, to identify its subtype (figure). [4-6] Descriptive variables included age, sex, education level, socioeconomic level, and geographic region.

Results

We detected HPV in 13 of the 16 specimens (81.3%)--six from the tonsil and seven from the nasopharynx. Eleven of the 13 positive samples (84.6%) contained HPV subtype 31, a virus primarily associated with cervical uterine cancer. [7-11] Subtypes 16, 18, and 35 were also isolated in various specimens, and one specimen (tonsillar) contained all four subtypes (16, 18, 31, and 35).

Discussion

The presence of HPV 31 in this population is significant because this subtype has not heretofore been reported in association with carcinoma of the tonsil or nasopharynx. The association between HPV and tonsillar carcinoma found in previous investigations is intriguing, even though these studies were far from conclusive. In 1989, Brandsma and Abramson detected HPV 16 by hybridization in two patients with tonsillar carcinoma and in one with pharyngeal carcinoma.[12] Kashima et al found two cases of HPV in tonsillar carcinoma, including subtype 13 in one, via the reverse blot method.[13] Niedobitek et al analyzed 28 cases of tonsillar carcinoma by hybridization in situ and detected HPV 16 in six of them.[14] They did not identify the presence of subtypes 6 or 11, Epstein-Barr virus, or cytomegalovirus in any of the 28 specimens.

PCR was first used in Amsterdam in 1992 by Snijders et al in an attempt to identify HPV subtypes 16, 18,31, and 33 in tonsillar carcinoma.[15] Of the 10 specimens these investigators analyzed, four had HPV 33 only and one was positive for two subtypes: 16 and 33. PCR detected HPV in two other specimens, but the genotype could not be identified. False negatives in this study were excluded by subsequent analysis with the Southern blot technique. A further application of hybridization in situ analysis in the study by Snijders et al identified HPV oncogenic proteins E6 (specific for subtype 16) and E7. The fact that the E7 protein was detected exclusively in carcinoma cells and was not detected in adjacent stroma or tissue strongly supports the hypothesis that HPV is associated with tonsillar carcinoma,[16,17]

In conclusion, the findings of our study are in agreement with others published in the literature that associate tonsillar and nasopharyngeal cancers with poor oral hygiene and low socioeconomic status in older adults. Our analysis also suggests that in western Mexico, there is a significant association between these cancers and HPV, particularly HPV subtype 31 (p[less than] 0.05). We believe that our study represents the first reported association of HPV subtype 31 with cancer of the tonsil and nasopharynx.

From the Universidad de Guadalajara School of Medicine (Dr. Lopez-Lizarraga), Centro de Investigacion Biomedica de Occidente (Dr. Sanchez-Corona, Dr. Montoyn-Fuentes, and Dr. Bravo-Cuellar), Hospital Civil de Guadalajara (Dr. Campollo-Rivas and Dr. Lopez-Demerutis), Centro Medico Nacional de Occidente (Dr. Morgan-Villela), Unidad Medica del Campo Militar No. 1 (Dr. Arcaute-Velazquez), Unidad de Otorrinolaringologia, Guadalajara (Dr. Monreal-Martinez), and Centro Universitario Ciencias de la Salud (Mr. Troyo), Mexico.

Reprint requests: Eduardo Lopez-Lizarraga, MD, Av. Ninos Heroes #1921, Guadalajara, Jal., Mexico CP44100.

References

(1.) zurHausen H. Viruses in human cancers. Sciencel99l;254:1167-73.

(2.) Lancaster WD, Jenson AB. Human papillomavirus infection and neoplasia. Speculations for the future. Dermatol Clin 1991;9:371-6.

(3.) Thawley SE, O'Leary M. Malignant neoplasms of the oropharynx. In: Cummings CW, ed. Otolaryngology-Head and Neck Surgery. St. Louis: Mosby, 1992:1310-1.

(4.) Tham KM, Chow VT, Singh P, et al. Diagnostic sensitivity of polymerase chain reaction and Southern blot hybridization for the detection of human papillomavirus DNA in biopsy specimens from cervical lesions. Am J Clin Pathol 199l;95:638-46.

(5.) Gustincich S, Manfioletti G, Del Sal G, et al. A fast method for high-quality genomic DNA extraction from whole human blood. Biotechniques 1991;11:298-300, 302.

(6.) Watanabe S, Ogura H, Fukushima K, Yabe Y. Comparison of Virapap filter hybridization with polymerase chain reaction and Southern blot hybridization methods for detection of human papillomavirus in tonsillar and pharyngeal cancers. Eur Arch Otorhinolaryngol 1993;250:l15-9.

(7.) Cole ST, Streeck RE. Genome organization and nucleotide sequence of human papillomavirus type 33, which is associated with cervical cancer. J Virol 1986;55:991-5.

(8.) Lancaster WD, Jenson AB. Human papillomavirus infection and anogenital neoplasia: Speculations for the future. Obstet Gynecol Clin North Am 1957;14:601-9.

(9.) Pao CC, Lin SS, Lin CY, et al. Identification of human papillomavirus DNA sequences in peripheral blood mononuclear cells. Am J Clin Pathol 199l;95:540-6.

(10.) Melchers WJ, Clans HC, Quint WG, Use of the polymerase chain reaction to study the relationship between human papillomavirus infections and cervical cancer. Eur J Clin Microbiol Infect Dis 1991; 10:7 14-27.

(11.) Vandenvelde C, Scheen R, Van Pachterbeke C, et al. Prevalence of high risk genital papillomaviruses in the Belgian female population determined by fast multiplex polymerase chain reaction. J Med Virol 1992;36:279-82.

(12.) Brandsma JL, Abramson AL. Association of papillomavirus with cancers of the head and neck. Arch Otolaryngol Head Neck Surg 1989;115:621-5.

(13.) Kashima HK, Kutcher M, Kessis T, et al. Human papillomavirus in squamous cell carcinoma, leukoplakia, lichen planus, and clinically normal epithelium of the oral cavity. Ann Otol Rhinol Laryngol 1990;99:55-61.

(14.) Niedobitek U, Pitteroff 5, Herbst H, et al. Detection of human papillomavirus type 16 DNA in carcinomas of the palatine tonsils. J Clin Pathol 1990;43:918-21.

(15.) Snijders PJ, Cromme FV, van den Brule AJ, et al. Prevalence and expression of human papillomavirus in tonsillar carcinomas, indicating a possible viral etiology. Int J Cancer 1 992;5 1:845-50.

(16.) Vousden K. Interactions of human papillomavirus transforming proteins with the products of tumor suppressor genes. FASEB J 1993;7:872-9.

(17.) Cole ST, Danos 0. Nucleotide sequence and comparative analysis of the human papillomavirus type 18 genome. Phylogeny of papillomaviruses and repeated structure of the E6 and E7 gene products. J Mol Biol 1987;193:599-608.