CT screening can reduce death from lung cancer. We sought to improve the diagnostic accuracy of lung cancer screening using ultrasensitive methods and a lung cancer-specific gene panel to detect DNA methylation in sputum and plasma. This is a case-control study of subjects with suspicious nodules on CT imaging. Plasma and sputum were obtained preoperatively. Cases ( = 150) had pathologic confirmation of node-negative (stages I and IIA) non-small cell lung cancer. Controls ( = 60) had non-cancer diagnoses. We detected promoter methylation using quantitative methylation-specific real-time PCR and methylation-on-beads for cancer-specific genes (, and ). DNA methylation was detected in plasma and sputum more frequently in people with cancer compared with controls ( < 0.001) for five of six genes. The sensitivity and specificity for lung cancer diagnosis using the best individual genes was 63% to 86% and 75% to 92% in sputum, respectively, and 65% to 76% and 74% to 84% in plasma, respectively. A three-gene combination of the best individual genes has sensitivity and specificity of 98% and 71% using sputum and 93% and 62% using plasma. Area under the receiver operating curve for this panel was 0.89 [95% confidence interval (CI), 0.80-0.98] in sputum and 0.77 (95% CI, 0.68-0.86) in plasma. Independent blinded random forest prediction models combining gene methylation with clinical information correctly predicted lung cancer in 91% of subjects using sputum detection and 85% of subjects using plasma detection. High diagnostic accuracy for early-stage lung cancer can be obtained using methylated promoter detection in sputum or plasma. .
Purpose Pancreatic cancer is the fourth leading cause of cancer deaths and there currently is no reliable modality for the early detection of this disease. Here we identify cancer-specific promoter DNA methylation of BNC1 and ADAMTS1 as a promising biomarker detection strategy meriting investigation in pancreatic cancer. Experimental Design We used a genome-wide pharmacologic transcriptome approach to identify novel cancer-specific DNA methylation alterations in pancreatic cancer cell lines. Of 8 promising genes, we focused our studies on BNC1 and ADAMTS1 for further downstream analysis including methylation and expression. We used a nanoparticle-enabled MOB (Methylation On Beads) technology to detect early stage pancreatic cancers by analyzing DNA methylation in patient serum. Results We identified 2 novel genes, BNC1 (92%) and ADAMTS1, (68%) that showed a high frequency of methylation in pancreas cancers (n=143), up to 100% in PanIN-3 and 97% in Stage I invasive cancers. Using the nanoparticle-enabled MOB technology, these alterations could be detected in serum samples (n=42) from pancreas cancer patients, with a sensitivity for BNC1 of 79% (95%CI:66-91%) and for ADAMTS1 of 48% (95%CI:33-63%), while specificity was 89% for BNC1 (95%CI:76-100%) and 92% for ADAMTS1 (95%CI:82-100%). Overall sensitivity using both markers is 81% (95%CI:69-93%) and specificity is 85% (95%CI:71-99%). Conclusions Promoter DNA methylation of BNC1 and ADAMTS1 are potential biomarkers to detect early stage pancreatic cancers. Assaying the promoter methylation status of these genes in circulating DNA from serum is a promising strategy for early detection of pancreatic cancer and has the potential to improve mortality from this disease.
The use of methylated tumor-specific circulating DNA has shown great promise as a potential cancer biomarker. Nonetheless, the relative scarcity of tumor-specific circulating DNA presents a challenge for traditional DNA extraction and processing techniques. Here we demonstrate a single tube extraction and processing technique dubbed “methylation on beads” that allows for DNA extraction and bisulfite conversion for up to 2 ml of plasma or serum. In comparison to traditional techniques including phenol chloroform and alcohol extraction, methylation on beads yields a 1.5 to 5-fold improvement in extraction efficiency. The technique results in far less carryover of PCR inhibitors yielding analytical sensitivity improvements of over 25-fold. The combination of improved recovery and sensitivity make possible the detection of rare epigenetic events and the development of high sensitivity epigenetic diagnostic assays.
Purpose: Barrett's esophagus is the only known precursor of esophageal adenocarcinoma (EAC). Although endoscopy and biopsy are standard methods for Barrett's esophagus diagnosis, their high cost and risk limit their use as a screening modality. Here, we sought to develop a Barrett's esophagus detection method based on methylation status in cytology samples captured by EsophaCap using a streamlined sensitive technique, methylation on beads (MOB).Experimental Design: We conducted a prospective cohort study on 80 patients (52 in the training set; 28 in the test set). We used MOB to extract and bisulfite-convert DNA, followed by quantitative methylation-specific PCR to assess methylation levels of 8 previously selected candidate markers. Lasso regression was applied to establish a prediction model in the training set, which was then tested on the independent test set.Results: In the training set, five of eight candidate methylation biomarkers (p16, HPP1, NELL1, TAC1, and AKAP12) were significantly higher in Barrett's esophagus patients than in controls. We built a four-biomarker-plus-age lasso regression model for Barrett's esophagus diagnosis. The AUC was 0.894, with sensitivity 94.4% [95% confidence interval (CI), 71%-99%] and specificity 62.2% (95% CI, 44.6%-77.3%) in the training set. This model also performed with high accuracy for Barrett's esophagus diagnosis in an independent test set: AUC ¼ 0.929 (P < 0.001; 95% CI, 0.810%-1%), with sensitivity¼78.6% (95% CI, 48.8%-94.3%) and specificity ¼ 92.8% (95% CI, 64.1%-99.6%).Conclusions: EsophaCap, in combination with an epigenetic biomarker panel and the MOB method, is a promising, well-tolerated, low-cost esophageal sampling strategy for Barrett's esophagus diagnosis. This approach merits further prospective studies in larger populations.
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