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Background: In early-stage pancreatic cancer, there are currently no biomarkers to guide selection of therapeutic options. This prospective biomarker trial evaluated the feasibility and potential clinical utility of circulating tumor DNA (ctDNA) analysis to inform adjuvant therapy decision making. Material(s) and Method(s): Patients considered by the multidisciplinary team to have resectable pancreatic adenocarcinoma were enrolled. Pre- and post-operative samples for ctDNA analysis were collected. PCR-based-SafeSeqS assays were used to identify mutations at codon 12, 13 and 61 of KRAS in the primary pancreatic tumor and to detect ctDNA. Results of ctDNA analysis were correlated with CA19-9, recurrence-free and overall survival (OS). Patient management was per standard of care, blinded to ctDNA data. Result(s): Of 112 patients consented pre-operatively, 81 (72%) underwent resection. KRAS mutations were identified in 91% (38/42) of available tumor samples. Of available plasma samples (N = 42), KRAS mutated ctDNA was detected in 62% (23/37) pre-operative and 37% (13/35) post-operative cases. At a median follow-up of 38.4 months, ctDNA detection in the pre-operative setting was associated with inferior recurrence-free survival (RFS) [hazard ratio (HR) 4.1; P = 0.002)] and OS (HR 4.1; P = 0.015). Detectable ctDNA following curative intent resection was associated with inferior RFS (HR 5.4; P < 0.0001) and OS (HR 4.0; P = 0.003). Recurrence occurred in 13/13 (100%) patients with detectable ctDNA post-operatively, including in seven that received gemcitabine-based adjuvant chemotherapy. Conclusion(s): ctDNA studies in localized pancreatic cancer are challenging, with a substantial number of patients not able to undergo resection, not having sufficient tumor tissue for analysis or not completing per protocol sample collection. ctDNA analysis, pre- and/or post-surgery, is a promising prognostic marker. Studies of ctDNA guided therapy are justified, including of treatment int

Background: While adjuvant therapy provides a survival benefit for patients (pts) with early-stage pancreatic cancer there are currently no biomarkers that define pts that are more or less likely to benefit from such treatment. This prospective study investigated the use of circulating tumour DNA (ctDNA) as a marker of residual disease, where detection could predict recurrence. Method(s): Patients newly diagnosed with operable pancreatic adenocarcinoma were enrolled. PCR-based-SafeSeqS assays were used to identify mutations at codons 12, 13 and 61 of KRAS in the primary tumor and to detect ctDNA in plasma samples. Patient management was as per standard of care, blinded to ctDNA data. Result(s): From January 2015 to June 2017, 42 pts with matched plasma samples, collected pre- and post-operatively, and tumor tissue available were evaluated. The median time between surgery and post-op blood collection was 6.3 (range:4-8) weeks. RAS mutations were identified in 38 (90.5%) tumor samples. ctDNA was detected in 23/37 (62.2%) pre-op and 13/35 (37.1%) post-op plasma samples. In multivariate analysis including stage, and resection margin, ctDNA status was the only statistically significant variable. Pre-op ctDNA detection was associated with worse median recurrence free survival (RFS), 10.3 months versus not reached, (Hazard Ratio (HR),3.4; 95% confidence interval (CI), 1.5- 7.6; P = 0.005) and 5.4 months versus 17.1 months, (HR, 5.4; 95% CI, 4.7-37.3; P < 0.0001) post-operatively. Similarly, the presence of ctDNA was associated with worse median overall survival (OS), 13.8 months versus not reached pre-operatively, (HR,3.4; 95% CI 1.1 to 8.3; P = 0.04) and 10.6 months versus not reached (HR,4.5; 95% CI 2.4-28.6; P = 0.001) post-operatively. Notably, recurrence occurred in 13 of 13 pts with detectable post-op ctDNA, despite more than half receiving standard adjuvant chemotherapy. Conclusion(s): ctDNA analysis is a promising prognostic marker in early-stage pancreatic cancer

Background: In early-stage pancreatic cancer, there are currently no biomarkers to guide selection of therapeutic options. This prospective biomarker trial evaluated the feasibility and potential clinical utility of circulating tumor DNA (ctDNA) analysis to inform adjuvant therapy decision making. Material(s) and Method(s): Patients considered by the multidisciplinary team to have resectable pancreatic adenocarcinoma were enrolled. Pre- and post-operative samples for ctDNA analysis were collected. PCR-based-SafeSeqS assays were used to identify mutations at codon 12, 13 and 61 of KRAS in the primary pancreatic tumor and to detect ctDNA. Results of ctDNA analysis were correlated with CA19-9, recurrence-free and overall survival (OS). Patient management was per standard of care, blinded to ctDNA data. Result(s): Of 112 patients consented pre-operatively, 81 (72%) underwent resection. KRAS mutations were identified in 91% (38/42) of available tumor samples. Of available plasma samples (N = 42), KRAS mutated ctDNA was detected in 62% (23/37) pre-operative and 37% (13/35) post-operative cases. At a median follow-up of 38.4 months, ctDNA detection in the pre-operative setting was associated with inferior recurrence-free survival (RFS) [hazard ratio (HR) 4.1; P = 0.002)] and OS (HR 4.1; P = 0.015). Detectable ctDNA following curative intent resection was associated with inferior RFS (HR 5.4; P < 0.0001) and OS (HR 4.0; P = 0.003). Recurrence occurred in 13/13 (100%) patients with detectable ctDNA post-operatively, including in seven that received gemcitabine-based adjuvant chemotherapy. Conclusion(s): ctDNA studies in localized pancreatic cancer are challenging, with a substantial number of patients not able to undergo resection, not having sufficient tumor tissue for analysis or not completing per protocol sample collection. ctDNA analysis, pre- and/or post-surgery, is a promising prognostic marker. Studies of ctDNA guided therapy are justified, including of treatment int

Background: While adjuvant therapy provides a survival benefit for patients (pts) with early-stage pancreatic cancer there are currently no biomarkers that define pts that are more or less likely to benefit from such treatment. This prospective study investigated the use of circulating tumour DNA (ctDNA) as a marker of residual disease, where detection could predict recurrence. Method(s): Patients newly diagnosed with operable pancreatic adenocarcinoma were enrolled. PCR-based-SafeSeqS assays were used to identify mutations at codons 12, 13 and 61 of KRAS in the primary tumor and to detect ctDNA in plasma samples. Patient management was as per standard of care, blinded to ctDNA data. Result(s): From January 2015 to June 2017, 42 pts with matched plasma samples, collected pre- and post-operatively, and tumor tissue available were evaluated. The median time between surgery and post-op blood collection was 6.3 (range:4-8) weeks. RAS mutations were identified in 38 (90.5%) tumor samples. ctDNA was detected in 23/37 (62.2%) pre-op and 13/35 (37.1%) post-op plasma samples. In multivariate analysis including stage, and resection margin, ctDNA status was the only statistically significant variable. Pre-op ctDNA detection was associated with worse median recurrence free survival (RFS), 10.3 months versus not reached, (Hazard Ratio (HR),3.4; 95% confidence interval (CI), 1.5- 7.6; P = 0.005) and 5.4 months versus 17.1 months, (HR, 5.4; 95% CI, 4.7-37.3; P < 0.0001) post-operatively. Similarly, the presence of ctDNA was associated with worse median overall survival (OS), 13.8 months versus not reached pre-operatively, (HR,3.4; 95% CI 1.1 to 8.3; P = 0.04) and 10.6 months versus not reached (HR,4.5; 95% CI 2.4-28.6; P = 0.001) post-operatively. Notably, recurrence occurred in 13 of 13 pts with detectable post-op ctDNA, despite more than half receiving standard adjuvant chemotherapy. Conclusion(s): ctDNA analysis is a promising prognostic marker in early-stage pancreatic cancer