GSE59856
What We Learned
  • It is difficult to detect pancreatic cancer or biliary-tract cancer at an early stage using current diagnostic technology. Utilizing microRNA (miRNA) markers that are stably present in peripheral blood, this study aimed to identify pancreatic and biliary-tract cancers in patients.
  • 81 miRNAs for pancreatic cancer and 66 miRNAs for biliary-tract cancer showed statistically different expression compared with healthy controls. 
  • Among those markers, 55 miRNAs were common in both the pancreatic and biliary-tract cancer samples.
  • A combination of eight miRNAs (miR-6075, miR-4294, miR-6880-5p, miR-6799-5p, miR-125a-3p, miR-4530, miR-6836-3p, and miR-4476) achieved a sensitivity, specificity, accuracy and AUC of 80.3%, 97.6%, 91.6% and 0.953, respectively.
  • Most pancreatic cancers do not accompany any particular clinical symptoms in the early stage, permitting the cancers to progress undetected.
  • In addition, ambiguous radiological images of cancerous lesions and inflammatory conditions in the pancreas prevent pancreatic cancers from being correctly identified.
  • The five-year survival rate for patients with exocrine pancreatic cancer is estimated at 14% for stage IA, but it drops to 1% for stage IV.
  • Because the most promising treatment for pancreatic cancer is surgical resection, detecting pancreatic cancer at surgically resectable stages is crucial for improving the survival rate of patients with pancreatic cancer.
  • The most validated and clinically useful biomarker is carbohydrate antigen (CA) 19–9; however, CA19-9 is known to be up-regulated in other inflammatory conditions, and its low positive predictive value makes it a poor biomarker for screening, limiting its current use mostly to the post-surgical monitoring of progressed pancreatic cancers.
  • The discrepancies of previous studies could be attributed to:
  1. Various empirical factors that include the blood sample types (PBMC, plasma or serum)
  2. Different detection technologies (PCR, microarray or sequencer)
  3. Heterogeneity of the sample cohorts
  • The sufficient size and the diversity of the sample cohorts are critical in biomarker research not only for the targeted group but also for the control group.
  • This study examined the expression profiles of comprehensive serum miRNAs from the largest cohorts of patients:
    • pancreatic cancer 100
    • colon cancer 50
    • biliary tract cancer 98
    • esophagus cancer 50
    • liver cancer 52
    • healthy control 150
    • stomach cancer 50
    • benign pancreatic or biliary tract diseases 21
What We Did
  • A classification model has been built using Trainset. The selected probes were:
    1. hsa-mir-6849-5p
    2. hsa-mir-204-3p
    3. hsa-mir-663b
    4. hsa-mir-106a-5p
  • The model has been tested using Testset.