Loss of heterozygosity at 10q in tumors of the upper respiratory tract is associated with poor prognosis

Frequent loss of a specific chromosomic region in cancers is often associat ed with inactivation of a tumor-suppressor gene. The long arm of chromosome 10 is deleted in several types of tumor, among them squamous-cell carcinom as of the head and neck (HNSCC). To determine the role of 10q deletions in the tumorigenesis of the upper respiratory tract, 47 HNSCCs were examined f or loss of heterozygosity (LOH) at 10q: 43% of the cases analyzed showed LO H at 10q, and 2 distinct hot spots of deletion were identified, at 10q22-23 and 10q25-26. The possible involvement of pTEN/MMACI, a tumor-suppressor g ene mapped at 10q23, was also evaluated. No mutation, homozygous deletion o r loss of expression of pTEN/MMACI was detected, indicating that inactivati on of this gene plays a minor role in HNSCC development. Interestingly, the frequency of deletion at 10q was greater in invasive carcinoma than in adj acent carcinoma in site, and a significant association between LOH and poor prognosis was observed. Taken together, our results suggest the presence i n the long arm of chromosome 10 of (a) tumor-suppressor gene(s) other than pTEN/MMACI and presumably involved in the malignant progression of tumors o f the upper respiratory tract. Int. J. Cancer (Pred. Oncol.) 84:432-436, 19 99. (C) 1999 Wiley-Liss, Inc.