miRNA Test Raises Pancreatic Cancer Diagnostic Hopes

MicroRNA testing may boost the ability to detect pancreatic cancer at an early stage of the disease

medwireNews: Micro (mi)RNA testing, used alone or in combination with the serum biomarker cancer Antigen 19-9 (CA19-9), can differentiate between patients with and without pancreatic cancer, research suggests.

The preliminary study, published in JAMA, identified 38 dysregulated miRNAs expressed in the blood of 143 patients with pancreatic cancer at significantly higher levels than found in the blood of 18 patients with pancreatitis and 69 healthy controls.

Results from a training cohort of 180 pancreatic cancer patients and 200 controls allowed the researchers to create two diagnostic panels, one consisting of four miRNAs and the second of 10 miRNAs, explain Julia Johansen, from Herlev Hospital in Denmark, and co-authors.

The first panel was 85% sensitive and 64% specific for the presence of pancreatic cancer, with an area under the curve (AUC) value of 0.86. The second panel’s values were 85%, 85% and 0.93, respectively.

By comparison, CA19-9 was 86% sensitive and 99% specific, with an AUC of 0.90, reports the team.

Moreover, in a validation cohort of 86 pancreatic patients and 51 controls, combining the first miRNA panel with CA19-9 significantly improved performance compared with CA19-9 testing alone, giving an AUC of 0.94.  Adding CA19-9 testing to the second panel also improved discrimination, although the difference did not reach significance.

Finally, combining the first panel with CA19-9 allowed researchers to discriminate patients with stage IA–IIB pancreatic cancer from controls with an AUC of 0.83 and with 74% sensitivity and 96% specificity.

While acknowledging that their results are preliminary, Julia Johansen and team say further research should be performed to determine the potential of miRNA testing for pancreatic cancer screening.

“Although there is a risk of generating false-positive test results using our panels of microRNAs in combination with serum CA19-9, the test could refer more individuals with characteristic or uncharacteristic symptoms to CT [computed tomography], magnetic resonance, or ultrasound imaging,”

“The test could thereby diagnose more patients with pancreatic cancer, some of them at an early stage, and thus have a potential to increase the number of patients that can be operated on and possibly cured of pancreatic cancer.”

In an accompanying editorial, Donald Buchsbaum, from the University of Alabama in Birmingham, USA, and Carlo Croce, from Ohio State University in Columbus, USA, say that combining CA19-9 with miRNA testing gave “modest improvements” in AUC over CA19-9 alone but did not demonstrate clinically significant information.

“Given the dismal prognosis for patients with pancreatic cancer, it is important that new diagnostic approaches, such as the one used in this study, are sought,” they write.

“However, additional rigorous investigation will be necessary to support and extend these interesting findings.”

Reference

Schultz N, Dehlendorff C, Jensen B, et al. MicroRNA Biomarkers in Whole Blood for Detection of Pancreatic Cancer. JAMA 2014; 311: 363–365 392–404.

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