e17617 Background: Abnormal uterine bleeding (AUB) is a cardinal symptom of endometrial cancer (EC). However, 90-95% of those with AUB will undergo invasive endometrial sampling with the finding of benign etiology. Our group has identified EC-related methylated DNA markers (MDMs) detectable in vaginal fluid obtained via self-collected tampon with high sensitivity to detect EC. To provide alternative vaginal fluid collection options, we compared total DNA recovery and detection of EC MDMs between tampon and swab collection methods. Methods: Patients ≥45 yrs with AUB or undergoing routine gynecologic care, and patients ≥18 yrs with biopsy-confirmed EC or atypical endometrial hyperplasia (AEH) were prospectively enrolled for paired vaginal fluid biospecimens collection. Participants self-collected vaginal fluid via tampon before provider-collected vaginal fluid sampling via swab immediately prior to clinically indicated endometrial sampling or hysterectomy. Cases (EC/AEH) and benign controls were determined by expert review. DNA was extracted from vaginal fluid. Bisulfite converted DNA was then used in long-probe quantitative amplified signal (LQAS) assays for 10 MDMs and 2 reference markers (RMs). Total DNA recovery using the RMs and detection of EC-specific MDMs were compared across sampling techniques. MDMs were standardized using the log of the ratio of the MDM and RM1. Standardized MDMs were compared between swabs and tampons using median and interquartile range (IQR). Results: A total of 40 eligible participants were evaluated in this study, 20 cases and 20 controls. Median time between tampon and swab collection was 27 hours (range 1-53). DNA quantity as measured using both RM1 and RM2 were comparable between swab and tampon in both cases and controls; MDM detection was also comparable between swab and tampon in both cases and controls (Table 1; 8 representative MDMs shown). Though not powered for sensitivity and specificity estimation, EC-related MDMs appear higher in EC cases vs controls, using either sample type. Conclusions: Sampling vaginal fluid with provider-collected swabs or self-collected tampons are both effective for detection of validated EC MDMs. Studies are ongoing to optimize an MDM panel to detect EC in vaginal fluid. Control Tampon Control Swab Case Tampon Case Swab RM1 3.5 [3.3-3.8] 4.2 [3.8-4.2] 3.6 [3.2-3.9] 4.2 [3.8-4.5] MDM1 0.5 [0.4-0.7] 0.4 [0.2-0.6] 1.3 [0.8-1.8] 1.1 [0.6-1.7] MDM2 1.5 [1.2-1.9] 0.9 [0.7-1.2] 3.2 [2.2-4.7] 2.9 [1.7-4.5] MDM3 0.5 [0.4-0.6] 0.4 [0.3-0.5] 1.5 [0.9-2.3] 1.0 [0.8-2.3] MDM4 0.9 [0.6-1.3] 0.5 [0.4-0.7] 2.3 [1.3-3.7] 1.9 [1.0-3.6] MDM5 1.3 [0.6-1.4] 0.8 [0.6-1.0] 3.3 [2.5-4.1] 3.1 [2.4-3.9] MDM6 1.6 [1.3-2.1] 1.2 [0.8-1.7] 3.3 [2.6-4.3] 3.1 [2.3-4.1] MDM7 1.5 [1.1-1.7] 1.0 [0.4-1.4] 3.5 [2.6-4.1] 3.3 [2.1-3.8] MDM8 0.5 [0.3-0.6] 0.5 [0.4-0.7] 1.8 [1.0-2.7] 1.7 [1.0-2.5] Median (IQR) for RM1 and 8 MDMs by case/control and sampling technique.
Abstract 2445: Peripheral blood immune phenotypes in pancreatic ductal adenocarcinoma
Abstract Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a major cancer killer with a low 5-year survival rate of 12%. Diagnosing PDAC at an early stage is one of the strongest predictors of long-term survival. Therefore, novel methods for early detection of PDAC must be explored. In this pilot study we aimed to compare the peripheral blood immune cell phenotypes in PDAC cases and cancer-free controls. Method: CyTOF (cytometry by time-of-flight) was used to evaluate peripheral blood mononuclear cells (PBMC) from newly diagnosed treatment naïve patients with PDAC and sex and age matched cancer-free controls using a 29-marker immune phenotyping panel. Multiple analysis approaches including dimensionality reduction using tSNE and clustering using Phenograph were used to evaluate the results. Immune subsets having differential abundance differences were verified by manual gating. Results: Twenty patients were included in this pilot study (15 PDAC cases; 5 Cancer-free controls). Among the 15 PDAC cases, 5 were early stage (Stage 1-2). Thirty-two unique immune cell clusters were identified using the Phenograph algorithm: 10 unique clusters with properties consistent with monocytes/macrophages, 9 CD4 T cell clusters, 6 CD8 T cell clusters and 4 NK cells clusters. When comparing the case and control groups we noted lower percentages of CD8+CD27+ T-cells in cases. This was further verified by manual gating that confirmed the distribution of CD8+CD27+ T-cells relative to all T-cells were decreased in PDAC patients. In addition, a 57% increase in naïve CD4 T cells was found in case samples compared to controls. A principal component analysis of the clustering results identified two unique clusters of immune profiles that emerged providing a potential peripheral blood immune cell signature that could stratify and differentiate PDAC cases from controls. A CD14+CD16+CD4LoCD38+CD45RO+ population of monocytes was the primary cell population driving this difference. Conclusion: This study provides early evidence to indicate that a distinct PBMC immune phenotype may differentiate PDAC patients from control subjects. Further analysis in larger sample sets is warranted for in-depth characterization and identification of unique immune based biomarkers for PDAC detection. Citation Format: Kevin D. Pavelko, Jose C. Villasboas, William R. Taylor, Karen A. Doering, John B. Kisiel, Shounak Majumder. Peripheral blood immune phenotypes in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2445.
Abstract 3784: Methylated DNA markers for detection of peritoneal metastasis in pancreatic cancer
Abstract Introduction: Laparoscopy with peritoneal lavage enhances staging accuracy in patients with pancreatic ductal adenocarcinoma (PDAC). Occult intra-abdominal metastases are identified by staging laparoscopy in approximately 20% of patients with radiologically localized PDAC. Peritoneal fluid cytology has limited sensitivity in detecting occult intra-abdominal metastasis. Methylated DNA markers (MDMs) can accurately detect PDAC from tumor tissue, blood, and pancreatic secretions. This study aims to assess the feasibility of assaying MDMs in peritoneal lavage fluid obtained at the time of staging laparoscopy for patients with PDAC. Methods: Peritoneal lavage fluid (25-60 mL) obtained from patients with PDAC at the time of staging laparoscopy was centrifuged for 10 minutes at 1200 × g. The pellet was resuspended and aliquoted into 200µL tubes and frozen at -80°C. DNA extracted from one aliquot was assayed for mutant KRAS (G12A and G13D) and then bisulfite converted to measure 13 MDMs (GRIN2D, CD1D, ZNF781, FER1L4, RYR2, CLEC11A, AK055957, LRRC4, MAX.CHR5.4295, HOXA1, PRKCB, SHISA9, NTRK3) and a normalizing reference gene (B3GALT6) using quantitative methylation specific PCR. The association of KRAS and the average signal from the 13 MDMs (MDMscore) with intra-abdominal metastasis (Y/N) was assessed with the area under the receiver operator characteristic curve (AUC). Results: Among 48 PDAC patients, staging laparoscopy revealed intra-abdominal metastasis in 15 (31%). Of the 15 intra-abdominal metastases, 6 were found to have biopsy-confirmed intra-abdominal metastasis and positive peritoneal cytology, 4 were positive on peritoneal cytology alone, and 5 had biopsy-confirmed intra-abdominal metastasis alone. The sensitivity of the MDMscore for intra-abdominal metastasis was 87% (CI: 60-98%) at 90% (CI: 76-98%) specificity whereas the sensitivity for KRAS was 40% (CI: 16-68%) at 85% (CI: 68-95) specificity. The AUC for the MDMscore was 0.98 (CI: 0.94-1.00) compared to 0.62 (CI: 0.48-0.77) for that of KRAS (p<0.0001). Conclusion: MDMs assayed from peritoneal lavage fluid collected during staging laparoscopy is a novel tool for accurate molecular staging of PDAC. These early results warrant further study in a larger cohort to assess impact on peritoneal staging and its clinical utility in the neoadjuvant treatment paradigm of PDAC. Citation Format: Kalika Maheshwari, Calise K. Berger, William R. Taylor, Douglas W. Mahoney, Kelli N. Burger, Adriana M. Delgado, Karen A. Doering, Heather M. Streich, Patrick H. Foote, Sean P. Cleary, Travis E. Grotz, Micheal L. Kendrick, Rory L. Smoot, Patrick P. Starlinger, Cornelius A. Thiels, Mark J. Truty, Susanne G. Warner, John B. Kisiel, Shounak Majumder. Methylated DNA markers for detection of peritoneal metastasis in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3784.
Plasma Assay of Cell-Free Methylated DNA Markers of Colorectal Cancer: A Tumor-Agnostic Approach to Monitor Recurrence and Response to Anticancer Therapies
Background: Radiographic surveillance of colorectal cancer (CRC) after curative-intent therapy is costly and unreliable. Methylated DNA markers (MDMs) detected primary CRC and metastatic recurrence with high sensitivity and specificity in cross-sectional studies. This study evaluated using serial MDMs to detect recurrence and monitor the treatment response to anti-cancer therapies. Methods: A nested case-control study was drawn from a prospective cohort of patients with CRC who completed curative-intent therapy for CRC of all stages. Plasma MDMs were assayed vis target enrichment long-probe quantitative-amplified signal assays, normalized to B3GALT6, and analyzed in combination with serum carcinoembryonic antigen to yield an MDM score. Clinical information, including treatment and radiographic measurements of the tumor burden, were longitudinally collected. Results: Of the 35 patients, 18 had recurrence and 17 had no evidence of disease during the study period. The MDM score was positive in 16 out of 18 patients who recurred and only 2 of the 17 patients without recurrence. The MDM score detected recurrence in 12 patients preceding clinical or radiographic detection of recurrent CRC by a median of 106 days (range 90–232 days). Conclusions: Plasma MDMs can detect recurrent CRC prior to radiographic detection; this tumor-agnostic liquid biopsy approach may assist cancer surveillance and monitoring.
Plasma Methylated DNA Markers for Melanoma Surveillance
Plasma-based MDMs may offer a cost-effective alternative to imaging for melanoma detection. Early results show 80% sensitivity and 100% specificity against cancer-free controls. Further study needed. #MelanomaResearch #EarlyDetection
Abstract PO-039: Discovery and validation of methylated DNA markers of human papillomavirus associated oropharyngeal squamous cell carcinoma
Abstract Background: Reliable non-invasive biomarkers for human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPX) are lacking. We performed a discovery and validation study of methylated DNA markers (MDMs) for detection of OPX. In addition, we sought to evaluate the MDM profiles in saliva gargle samples from normal controls (nSAL). Methods: Formalin fixed paraffin embedded OPX and gender-balanced normal oropharyngeal tissue (NOP) were pathologically reviewed and punched for DNA extraction and sequenced using reduced representation bisulfite sequencing (RRBS). A tiling algorithm was used to define candidate MDMs. Highest ranked (e.g., area under the receiver operating characteristic curve (AUC), fold-change, p-value) candidate MDMs were validated by qMSP in independent OPX and NOP samples. nSAL DNA was used to assess MDM background signal. Discrimination between OPX tissue, NOP, and nSAL was assessed using AUC with corresponding 95% confidence intervals. HPV was confirmed with p16 staining or DNA in situ hybridization. Results: RRBS discovery assessed 18 OPX, 18 NOP, and 18 normal WBC samples. 234 MDM candidates from approximately 3 × 106 CpGs at >10X coverage were identified. 36 MDMs were selected for validation in independent patient samples which included 32 OPX, 36 NOP, and 35 nSAL specimens. OPX patients were older (median 51; IQR 45-54 years) than NOP patients (median 29; IQR 24-42). 69 and 61% of OPX and NOP patients were female, respectively. The majority of OPX patients were Stage I (n=27, 84%). We observed excellent discrimination between OPX and NOP in the validation set; the median AUC across 36 MDMs was 0.90 (IQR 0.87-0.95). The 10 highest performing markers (PARP15, EPDR1, SHROOM1, EMBP1.rs, IFFO1, MAX.chr19.118, ZNF763, ITGB4, FAM19A2, and MT1IP) exhibited AUCs ranging from 0.95-0.99. Strong discrimination was also observed between OPX and nSAL (Median AUC=0.97; IQR=0.93-0.99). All 10 of the highest-performing markers in tissue exhibited AUCs of at least 0.97 for discriminating OPX versus nSAL. Median fold change between NOP and nSAL across all MDMs was 1.9 (IQR 1.4-3.8), demonstrating low background signal in nSAL. Conclusions: We found strong discrimination in a panel of 36 MDMs between OPX case and control tissue as well as between OPX case tissue and normal saliva. The low background signal observed in normal saliva makes this media a strong candidate for non-invasive detection of OPX. Further studies are in development to assess the utility of measuring these MDMs in both case and control saliva and blood for detecting OPX non-invasively. Citation Format: Benjamin R. Gochanour, David M. Routman, Kathleen R. Bartemes, William R. Taylor, Douglas W. Mahoney, Rondell P. Graham, Xiaoming Cao, Calise K. Berger, Sara S. Then, Karen A. Doering, Kelli N. Burger, Patrick H. Foote, John B. Kisiel, Kathryn M. Van Abel. Discovery and validation of methylated DNA markers of human papillomavirus associated oropharyngeal squamous cell carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Innovating through Basic, Clinical, and Translational Research; 2023 Jul 7-8; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2023;29(18_Suppl):Abstract nr PO-039.
Performance Comparisons of Methylation and Structural Variants From Low-Input Whole-Genome Methylation Sequencing
Abstract Purpose: Many cancer deaths could be avoided, and survival could be improved with detection of cancer at an earlier stage. Screening programs for breast, colon, and cervical cancer as well as the NLST trial for lung cancer screening demonstrated significant improvement in survival rates with screening. However, for 2021, the American Cancer Society estimates these screened cancers represent less than ~40% of cancer incidence and deaths. The remainder of cancer deaths occur because of tumors in unscreened organs and, therefore, a multicancer test that detects cancer in these organs can increase survival rates. By focusing on detection of unscreened cancers, this type of multicancer test would be complementary to current screening procedures. Here we describe the validation of a combined panel of methylated DNA markers (MDMs) and proteins for multicancer detection through testing an independent set of case/control samples. Experimental Procedures: In this study, we further evaluate the performance of our previously identified panel of 15 MDMs and 5 proteins for multicancer detection (Allawi et al., 2021 AACR Annual Meeting) by testing 315 controls and 160 cases encompassing 6 cancer types (liver, esophageal, lung, ovarian, pancreatic, and stomach). All samples used in the study were case-control collections with smoking status, age, and gender matching between cases and asymptomatic controls. Testing was performed in blinded fashion using multiplex PCR followed by LQAS (Long probe Quantitative Amplified Signal) assay on bisulfite converted DNA extracted from 3 mL of plasma collected in LB Gard® blood tubes. Protein concentrations were determined from paired serum aliquots and combined with MDMs for a multi-analyte analysis. The subjects were divided into training and validation with equal representation of cancer type, staging, gender, and age. Two thirds of the cases and controls were used to train with a logistic prediction algorithm, and the remaining 1/3 were used to validate the model. Results: Using stepwise logistic regression, a training model of MDMs and protein markers resulted in an area under the receiver operating characteristics curve (AUC) of 0.97 and cancer sensitivity of 89% at 98% specificity. The same model predicted the validation set with an AUC of 0.96 and cancer sensitivity of 85% at a specificity of 95%. Applying the algorithm to the combined training and validation sets resulted in sensitivities and specificities of 88% and 97%, respectively. The sensitivities per cancer type ranged from 73% for pancreatic cancer to 97% for lung cancer. Conclusion and Next Steps: This study demonstrates the performance of our MDMs and protein markers and their importance as components in our multi-omics strategy for multicancer detection. The next steps would be to expand the testing to include additional cancer types and combine with NGS-based methods to improve performance and optimize workflow. Citation Format: Hatim T. Allawi, Slava Katerov, Abram Vaccaro, Harrison L. Fleming, Debra E. Rugowski, Brittany Otto, Justin Heilberger, Jillian Cassel, Jacquelyn Hennek, William Taylor, Graham Lidgard. Validation of a panel of methylated DNA and protein markers for multi-cancer detection in plasma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 631.
Methylated DNA markers in early detection of lymphoma: Discovery, validation, and clinical pilot.
7562 Background: Lymphoma is the 6th most common cancer and a top 10 cause of cancer deaths. To date, there are no blood test approaches to population screening, and accurate surveillance markers are limited. Methylated DNA markers (MDMs) are broadly informative for early detection of cancer but have not been extensively studied for lymphomas. We sought to discover and validate MDMs in DNA extracted from lymphoma tissue, then test these MDMs in archival blood plasma specimens. Methods: Reduced representation bisulfite sequencing (RRBS) was performed on DNA extracted from a discovery set of frozen tissues of classic Hodgkin lymphoma (CHL, n=24), non-Hodgkin lymphoma (NHL, n=78: T-cell-TCL (8); diffuse large B-cell-DLBCL (18); follicular-FL (12); mantle cell-MCL (20); marginal zone-MZL (15)), and lymphoma cell line samples (27); controls included benign lymph node (n=11) and healthy donor buffy coat (n=30). 30 MDMs were ranked by fold-change and AUC and used to design methylation-specific PCR assays for biological validation on independent DNA samples extracted from FFPE tissue from 13 normal lymph node and 63 lymphoma samples and 36 buffy coats from healthy patients. Target enrichment long-probe quantitative-amplified signal assays were developed for 16 MDMs and then assayed in plasma-extracted, bisulfite-converted DNA samples from 390 independent treatment-naïve lymphoma patients (100 CHL and 290 NHL:100 DLBCL, 73 FL, 41 MCL, 41 MZL, 35 TCL), and 210 controls without cancer. Lymphoma plasma samples and 159 controls were provided by the Lymphoma SPORE (CA97274); 51 controls came from a 7-county population archive. Classification of lymphoma cases vs controls was modeled with random forest method and cross-validated across 500 bootstrap samples of each dataset. Results: For MDMs tested in DNA from independent biological validation samples, cross-validated random forest models identified 60/63 cases (95% sensitivity) and 12/13 normal controls (92% specificity). In plasmas, a panel of 16 MDMs ( ZNF503, VWA5B1, HOXA9_5195, GABRG3, ITGA5, MAX_chr17_793, BNC1_2407, CDK20, MAX_chr4_184, TPBG, DNAH14, SYT2, CACNG8, FAM110B, and NRN1) detected 78% (95% CI, 74-82%) of lymphoma cases at 90% specificity. Excluding MZL and TCL, sensitivity increased to 84% (80-88%) including 26/49 (53% (38-67%)) of stage I and 59/71 (83% (71-90%)) of stage II cases. Conclusions: MDMs show promise to detect lymphoma. These markers could be evaluated as part of multicancer early detection testing and could also be evaluated as response markers to treatment and subsequent surveillance.[Table: see text]
Plasma methylated DNA markers detect recurrence and response to therapy in colorectal cancer.
e15567 Background: Radiographic surveillance of colorectal cancer (CRC) after therapy is costly and insensitive. We have reported high cross-sectional performance of methylated DNA markers (MDMs) for detection of primary CRC and metastatic recurrence. This study evaluated MDMs to detect recurrence and measure response to anti-cancer therapy in a longitudinal cohort. Methods: This was a nested case-control study drawn from a prospective cohort of adult patients with CRC who completed definitive treatment and followed forward from the start of surveillance by cross-sectional imaging (CT or MRI) and carcinoembryonic antigen (CEA), collected every 3-6 months under routine care. Blood was collected in LBgard® tubes (Biomatrica, San Diego CA). Cases had recurrent CRC (defined by RECIST v1.1 or radiographic findings that justify re-initiation of anti-cancer therapy as determined by treating clinicians). Controls remained NED (no radiographic recurrence and off therapy for ≥4 surveillance visits). From 6mL of plasma, MDMs ( CNNM1, ANKRD13B, FER1L4, ZNF568, CHST2, ZNF671, VAV3, QKI, GRIN2D, DTX1, PDGFD, SFMBT2, JAM3) were measured by target enrichment long-probe quantitative-amplified signal assays, normalized to B3GALT6, in blinded fashion. Previously published random forest models of MDMs +/- CEA, developed on independent patients with intact primary tumors, were used to develop a summary score. Results: With a median follow-up of 276 days (IQR 187-343) and 3 visits per patient (54 visits total), 18 patients had recurrence after start of surveillance. Another 18 patients remained NED after median 555 days (IRQ 469-662) and 4 surveillance visits per patient (76 visits total). Using a 90th %-ile cut-off summary score from 60 NED patients in a prior cross-sectional measurement, the MDM panel was positive in 15 of 18 patients who recurred and only 2 of the 18 NED patients (Table). Of the 76 patient visits for NED patients, 67 (88%) were below the threshold. The MDM panel score crossed the positivity threshold by a median of 127 days (IRQ 0-233) preceding clinical or radiographic documentation of recurrence. A random forest model with CEA was more sensitive but less specific (Table). In patients who resumed therapy, the MDM panel scores correlated closely with subsequent RECIST scores (not shown). Conclusions: Plasma MDMs rise in anticipation of recurrent CRC prior to radiographic detection and remain low in patients without radiographic disease over serial measurements, warranting further development of this tumor-agnostic liquid biopsy approach as a cost-effective tool to assist cancer surveillance.[Table: see text]