Predicting Progression of Low-Grade Oral Dysplasia Using Brushing-Based DNA Ploidy and Chromatin Organization Analysis

Abstract

Most oral cancers arise from oral potentially malignant lesions, which show varying grades of dysplasia. Risk of progression increases with increasing grade of dysplasia; however, risk prediction among oral low-grade dysplasia (LGD), that is, mild and moderate dysplasia can be challenging as only 5%–15% transform. Moreover, grading of dysplasia is subjective and varies with the area of the lesion being biopsied. To date, no biomarkers or tools are used clinically to triage oral LGDs. This study uses a combination of DNA ploidy and chromatin organization (CO) scores from cells obtained from lesion brushings to identify oral LGDs at high-risk of progression. A total of 130 lesion brushings from patients with oral LGDs were selected of which 16 (12.3%) lesions progressed to severe dysplasia or cancer. DNA ploidy and CO scores were analyzed from nuclear features measured by our in-house DNA image cytometry (DNA-ICM) system and used to classify brushings into low-risk and high-risk. A total of 57 samples were classified as high-risk of which 13 were progressors. High-risk DNA brushing was significant for progression (P = 0.001) and grade of dysplasia (P = 0.004). Multivariate analysis showed high-risk DNA brushing showed 5.1- to 8-fold increased risk of progression, a stronger predictor than dysplasia grading and lesion clinical features. DNA-ICM can serve as a non-invasive, high-throughput tool to identify high-risk lesions several years before transformation. This will help clinicians focus on such lesions whereas low-risk lesions may be spared from unnecessary biopsies. Prevention Relevance: DNA ploidy and chromatin organization of cells collected from oral potentially malignant lesions (OPMLs) can identify lesions at high-risk of progression several years prior. This non-invasive test would enable clinicians to triage high-risk (OPMLs) for closer follow-up while low-risk lesions can undergo less frequent biopsies reducing burden on healthcare resources.

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“…DNA aneuploidy has been known to be a marker of malignancy in a number of sites, including the oral cavity [ 47 ]. Indeed, DNA ploidy and chromatin organization of cells collected from OPMLs can identify lesions at high risk of progression several years prior [ 48 ]. This non-invasive test would enable clinicians to triage high-risk OPMLs for closer follow-up, while low-risk lesions can undergo less frequent biopsies, reducing the burden on healthcare resources [ 48 ].…”

“…Indeed, DNA ploidy and chromatin organization of cells collected from OPMLs can identify lesions at high risk of progression several years prior [ 48 ]. This non-invasive test would enable clinicians to triage high-risk OPMLs for closer follow-up, while low-risk lesions can undergo less frequent biopsies, reducing the burden on healthcare resources [ 48 ]. Quite interestingly, in a study on individuals with Fanconi anemia (people with a 500-fold to 700-fold elevated risk, much earlier onset, and limited therapeutic options for oral SCC compared with the general population), a careful inspection of the oral cavity associated with brush biopsy-based cytology could identify visible oral lesions, either malignant or potentially malignant, that warrant treatment [ 49 ].…”

Use of DNA image cytometry in conducting oral cancer screening in rural India

“…Previous studies by our group in specialist clinic settings have shown DNA‐ICM to be more effective in detecting high‐grade dysplasia, cancers, or LGD at a high‐risk of progression 28,29 . This may explain the low sensitivity of DNA‐ICM in detecting LGD in our study.…”

“…27 Previous studies by our group in specialist clinic settings have shown DNA-ICM to be more effective in detecting high-grade dysplasia, cancers, or LGD at a high-risk of progression. 28,29 This may explain the low sensitivity of DNA-ICM in detecting LGD in our study. Thus, DNA-ICM may be more useful for detecting high grade dysplasia and high-risk LGDs that should be followed-up or treated following screening.…”

Predictors of malignant transformation in oral leukoplakia and proliferative verrucous leukoplakia: An observational prospective study including the DNA ploidy status

“…Current data on the predictive role of the DNA ploidy status come from retrospective studies, 16–19 often only focusing on lesions characterized by the presence of OED 20–23 and with little data collected from patients with PVL 24–27 . All previous studies harbor potential biases due to the retrospective study design and none of them compared the predictive value of a DNA aneuploid status in OL and PVL.…”