DNA ploidy measurement in oral leukoplakia: Different results between flow and image cytometry

SummaryThe estimated prevalence of oral leukoplakia is worldwide approximately 2%, with an annual malignant transformation rate of approximately 1%. The aim of the present study was to evaluate the possible contribution of ploidy measurement to the prediction of the clinical course, in a well defined cohort of patients with oral leukoplakia. Ploidy was measured by both flow cytometry (FCM-DNA) and image cytometry (ICM-DNA) and we focussed on the comparison of the two different techniques to determine ploidy. A total of 41 patients have been included, with a mean age of 59years (range 36–78years). With FCM-DNA, three lesions were aneuploid, with ICM-DNA, 19 lesions were aneuploid. DNA ploidy was compared with clinicopathological and patients parameters. There were no statistically significant differences between DNA ploidy and any patient factor with both FCM-DNA and ICM-DNA. Using FCM-DNA, DNA aneuploid lesions showed statistically significant more dysplasia (p=0.04) than diploid lesions. Furthermore, DNA aneuploid lesions were more frequently encountered at high-risk locations (p=0.03) as being determined with FCM-DNA. These relations were not found when DNA ploidy was determined with ICM-DNA

Prognostic value of DNA ploidy status in patients with oral leukoplakia

Oral leukoplakia is a potentially malignant disorder that will develop into oral cancer at an estimated rate of 1-2% per year. Aim of the present study is to assess the possible predictive value of DNA ploidy for malignant progression of oral leukoplakia. A cohort of 62 leukoplakia patients was studied and their biopsy was examined with standard histopathology and DNA image cytometry. Cox regression analysis was performed to establish the relationship between progression-free survival and the DNA ploidy status. During the follow-up time (median of 69 months) 13 patients developed an oral squamous cell carcinoma (OSCC). DNA aneuploidy was observed in 27 (44%) patients and was significantly associated with a shorter progression-free survival [Hazard ratio of 3.7, 95% confidence intervals (CI) of 1.1 and 13.0 and a p-value of 0.04]. Sensitivity and specificity scores were 54% and 60%, respectively. Aneuploidy was not correlated with dysplasia grading (chi-square analysis). DNA aneuploidy in oral leukoplakia is associated with an increased risk of progression to OSCC. However, for the individual leukoplakia patient, DNA ploidy status as single biomarker has limited value to predict progression to cancer

White blood cell and cell-free DNA analyses for detection of residual disease in gastric cancer

Liquid biopsies are providing new opportunities for detection of residual disease in cell-free DNA (cfDNA) after surgery but may be confounded through identification of alterations arising from clonal hematopoiesis. Here, we identify circulating tumor-derived DNA (ctDNA) alterations through ultrasensitive targeted sequencing analyses of matched cfDNA and white blood cells from the same patient. We apply this approach to analyze samples from patients in the CRITICS trial, a phase III randomized controlled study of perioperative treatment in patients with operable gastric cancer. After filtering alterations from matched white blood cells, the presence of ctDNA predicts recurrence when analyzed within nine weeks after preoperative treatment and after surgery in patients eligible for multimodal treatment. These analyses provide a facile method for distinguishing ctDNA from other cfDNA alterations and highlight the utility of ctDNA as a predictive biomarker of patient outcome to perioperative cancer therapy and surgical resection in patients with gastric cancer.Experimentele farmacotherapi