The Laryngoscope Lippincott Williams & Wilkins, Inc. © 2004 The American Laryngological, Rhinological and Otological Society, Inc. Microsatellite Alterations in African Americans with Head and Neck Cancer George H. Yoo, MD; Nghia X. Nguyen, MD; Wei Du, PhD; Ann G. Schwartz, PhD; Susan Land, PhD; Ho-Sheng Lin, MD; Danny Kewson, MD; Leslie L. Murphy; Dave Cilluffo; John F. Ensley, MD; Michael A. Tainsky, PhD Objective: To determine the genetic differences between African Americans (AA) and Non-African Americans (NAA) with head and neck squamous cell carcinoma (HNSCC). Methods: DNA was obtained from tumor tissues and peripheral blood from 18 AA and 19 NAA patients with HNSCC. Microsatellite analysis using a fluorescent technique was performed on chromosomal arms 1p, 3p, 4q, 9p, 13q, and 17p. Statistical analyses were performed on the molecular and clinical outcome data. Results: Based on the Sur- veillance, Epidemiologic, and End Result (SEER) data from southeast Michigan, the incidence rate of HNSCC in AA has been higher than for NAA, and the overall 5-year relative survival rate is lower for AA than NAA (36.2% vs. 47.6%). In this study, we found that the rate of loss of heterozygosity of chromosomal arms 1p, 3p, 4q, 9p, 13q, and 17p ranged from 68.8% to 83.3% for HNSCC in AA and from 66.7% to 90.0% in NAA. The difference in the rates of microsatellite alterations in chromosomal arms 3p, 4q, and 9p between AA and NAA were between 12.5% and 20% and were not statistically significant. Conclusion: The incidence and clinical outcomes for AA with HNSCC are different from that of NAA in south- east Michigan. In our group of patients with HNSCC, differences in rates of microsatellite al- terations and survival were found between AA and NAA; however, these differences were not sta- tistically significant. We conclude that genetic difference, as determined by the rates of micro- satellite alterations, is not predictive of outcome difference between AA and NAA HNSCC patients. Key Words: Microsatellite analysis, head and neck cancer, loss of heterozygosity. Laryngoscope, 114:1619 –1624, 2004 INTRODUCTION African Americans (AA) have previously been shown to have a higher incidence of head and neck squamous cell carcinoma (HNSCC) than that of non-African Americans (NAA) and lower survival rates. 1–3 This discrepancy may be partially attributed to socioeconomic factors, such as delay in diagnosis, poor compliance or follow-up, and other epidemiologic factors such as higher level of tobacco or alcohol exposure; 4 however, genetic factors may also con- tribute to the discrepancy. 5–7 Racial differences in genetic alterations in AA as opposed to NAA have been docu- mented for oral and breast cancer. For example, novel p53 mutations in oral and breast cancer in the AA population have been reported. 5,6 In addition, genetic alterations, such as p53 mutations, in AA with breast cancer have been associated with a significantly worse prognosis. 7 Genetic alterations in various chromosomal arms, such as loss of heterozygosity (LOH) at 3p, 8p, 11q, 14q, 17p, and 18q 8–12 and p53 mutations 10 have been shown to predict poor survival and recurrence in HNSCC. Mutagen sensitive individuals, as determined by the bleomycin- induced chromatid breaks assay, have been shown to have more advanced disease and a higher likelihood of chromo- somal loss associated with alcohol and tobacco use. 13 Moreover, risk estimates for mutagen sensitivity and lung cancer have been reported to be higher in AA than in the white population. 14 These data suggest that there are genetic differences in different subsets of patients with HNSCC, as well as other cancers, which are associated with more advanced disease and poor prognosis. Therefore, it is be important to determine whether there are genetic differ- ences in AA with HNSCC as compared with NAA that might account for the racial disparity in survival. Microsatellite markers are short tandem repeats that are dispersed throughout the genome. 15 Microsatellite al- terations are thought to be an integral part of neoplastic progression and have been found in a variety of cancers including lung, colorectal, cervical, brain, breast, and HNSCC. 16 –21 The use of fluorescent microsatellite analy- From the Department of Otolaryngology—Head and Neck Surgery (G.H.Y., N.X.N., H.S.L., D.K., J.F.E.), Wayne State University, Detroit, MI; the Department of Medicine, Division of Hematology/Oncology (A.S., W.D., J.F.E.), Wayne State University and Karmanos Cancer Institute, Detroit, MI; the Molecular Biology and Human Genetics Program (S.L.)., Wayne State University, Applied Genomic Technology Center, Michigan Center for Genomic Technology, and Karmanos Cancer Institute, Detroit, MI; Compuware Corporation (L.L.M., D.C.), Detroit, MI; and the Molecular Bi- ology and Human Genetics Program (M.A.T.), Wayne State University and Karmanos Cancer Institute, Detroit, MI, U.S.A. Editor’s Note: This Manuscript was accepted for publication Febru- ary 6, 2004. Send Correspondence to Dr. George H. Yoo, Department of Otolar- yngology—Head and Neck Surgery, Wayne State University, 5E Univer- sity Health Center, 540 E. Canfield Avenue, Detroit, MI 48201, U.S.A. E-mail: gyoo@med.wayne.edu Laryngoscope 114: September 2004 Yoo et al.: Gene Alterations in Head and Neck Cancer 1619