Anatomic Site Based Ploidy Analysis of Oral Premalignant Lesions

Abstract

The location of oral leukoplakia correlates strongly with the probability of finding dysplastic or malignant alterations at biopsy. It is well established that early detection can dramatically improve the 5-year survival rates for oral squamous cell carcinomas. Since aneuploidy is predictive of future conversion to malignancy, we hypothesized that dysplastic lesions from highrisk sites (floor of mouth, tongue and lips) would exhibit greater aneuploidy than low-risk sites (palate, gingiva and buccal mucosa). Epithelial sections from 60 archival samples diagnosed as mild dysplasia (36 females, 20 males) from various high/low risk locations were stained with Blue Feulgen Stain for DNA Ploidy Analysis (Clarient, Aliso Viejo, CA) and ploidy was analyzed using a ChromaVision ACIS II (Clarient, ALiso Viejo, CA) Image cytometry system. A DNA histogram was generated using an image analyzing software that evaluated the amount of Feulgen stain which is proportional to the amount of nuclear DNA. An ANOVA analysis followed by the Student's't' test revealed significant differences between means (P B 0.05). Lesions originating from lateral/ventral tongue (85%), floor of mouth (50%) and soft palate (44%) exhibited a higher frequency of aneuploidy than lesions from gingiva (22%) and lower lip (25%). This pilot study demonstrates that dysplastic lesions from highrisk sites such as the floor of the mouth and lateral/ventral tongue have higher frequency of aneuploidy.

Urban legends series: oral leukoplakia

“…Different intraoral sites, particularly floor of mouth, ventrolateral tongue and soft palate complex, have been proposed as a high risk of OL malignant transformation (van der Waal, ). These sites exhibited a high frequency of aneuploidy and loss of heterozygosity (LOH) (Zhang et al , ; Islam et al , ; Castagnola et al , ). However, not always just OLs have been included in these studies, and prospective clinical studies are needed to confirm these findings.…”

Excisional biopsy for management of lateral tongue leukoplakia

“…According to previous papers, the lateral tongue is reported to harbor many dysplasias or malignancies (5, 6). In a recent study, 85% of leukoplakia in the lateral/ventral tongue is reported to exhibit aneuploidy, which is recognized as one of the risk factors of malignant transformation: 50% occurring on the floor of the mouth, 44% in the soft palate, and 22% in the gingival (7).…”

Genetics/epigenetics of oral premalignancy: current status and future research*

“…Aneuploidy was found to be significantly and positively associated with the histologic grade of dysplasias (Saito et al , 1995; Pentenero et al , 2009; Donadini et al , 2010). Even mild dysplasias may show aneuploidy particularly if these are located on the tongue or floor of mouth (Islam et al , 2010). One study showed that aneuploid dysplasias were more likely to progress than diploid lesions (33% vs 11%, P = 0.01) and that aneuploid lesions transformed to OSCC within 5 years in 53% of cases vs 25% of diploid cases (Torres‐Rendon et al , 2009b).…”