The effect of postoperative gemcitabine on overall survival in patients with resected pancreatic cancer: A nationwide population-based Danish register study.

Background: Adjuvant chemotherapy following curative resection is the standard treatment for pancreatic adenocarcinoma (PC). Randomized clinical trials using gemcitabine have shown a median overall survival (mOS) of 2 years and a 5-year survival rate of 15-20%. However, the effect of gemcitabine outside these trials is less clear. We examined the effect of postoperative gemcitabine on survival in an unselected cohort of patients receiving curative resection for PC in Denmark during a five-year period. Material and methods: From 1 May 2011 to 30 April 2016, 731 patients treated with curative resection were identified in the Danish Pancreatic Cancer Database (DPCD). Thirty patients died within 10 weeks postoperatively; 78 received other regimens or preoperative chemotherapy and were excluded. Of the remaining 623 patients, the chemotherapy (CT) group (n = 409, 66%) received gemcitabine within 10 weeks after resection, whereas the non-chemotherapy (NCT) group (n = 214, 34%) did not receive CT within 10 weeks. Results: CT patients were slightly younger than NCT patients but did not otherwise differ in baseline characteristics. The CT group showed a mOS of 24 months (95% CI; 21-27) and a 5-year survival rate of 22% (95% CI; 17-27); the NCT group had a mOS of 22 months (95% CI; 16-26, p = .27) and a 5-year survival rate of 26% (95% CI; 19-34, p = .66). Most patients (415/623) had lymph node metastases. Of these patients, those in the CT group (n = 280) had significantly longer mOS [20 months (95% CI; 18-24)] than those in the NCT group (n = 135) [14 months (95% CI; 11-17)]. Conclusions: In this national Danish cohort of PC patients undergoing resection between 2011 and 2016, the survival after postoperative gemcitabine was similar to that reported in previous clinical trials. However, the survival advantage of postoperative gemcitabine was limited to patients with lymph node metastases.

Measuring KRAS Mutations in Circulating Tumor DNA by Droplet Digital PCR and Next-Generation Sequencing.

Measuring total cell-free DNA (cfDNA) or cancer-specific mutations herein has presented as new tools in aiding the treatment of cancer patients. Studies show that total cfDNA bears prognostic value in metastatic colorectal cancer (mCRC) and that measuring cancer-specific mutations could supplement biopsies. However, limited information is available on the performance of different methods. Blood samples from 28 patients with mCRC and known KRAS mutation status were included. cfDNA was extracted and quantified with droplet digital polymerase chain reaction (ddPCR) measuring Beta-2 Microglobulin. KRAS mutation detection was performed using ddPCR (Bio-Rad) and next-generation sequencing (NGS, Ion Torrent PGM). Comparing KRAS mutation status in plasma and tissue revealed concordance rates of 79% and 89% for NGS and ddPCR. Strong correlation between the methods was observed. Most KRAS mutations were also detectable in 10-fold diluted samples using the ddPCR. We find that for detection of KRAS mutations in ctDNA ddPCR was superior to NGS both in analysis success rate and concordance to tissue. We further present results indicating that lower amount of plasma may be used for detection of KRAS mutations in mCRC.