Pancreatic Adenocarcinoma Test – microRNA (miRNA) obtained from formalin-fixed paraffin-embedded
(FFPE) Tissues
Overview
Pancreatic cancer is the fourth leading cause of cancer-related deaths in the US,
with a 5-year survival rate lower than 5%. Pancreatic ductal adenocarcinoma accounts
for >90% cases of pancreatic cancer. Differentiation between a benign condition
of chronic pancreatitis and pancreatic carcinoma is often difficult, as both conditions
may present with the similar symptoms (abdominal pain, weight loss, jaundice) and
are not mutually exclusive. Additionally, chronic pancreatitis shares many of the
histopathological and imaging features of pancreatic carcinoma both microscopically
and during preoperative imaging studies. Inaccurate diagnosis can lead to major
surgery for benign disease or delay of surgery for a potentially curable lesion.
Because of these adverse clinical consequences, there is considerable subjectivity
in the final call which has been reported to have up to a 20% error rate [1,2].
Researchers in Asuragen's CLIA laboratory have developed a new miRNA-based laboratory-developed
test, to aid in the differential diagnosis and disease management of pancreatic
ductal adenocarcinoma. The test is based on the qRT-PCR analysis of the raw expression
difference (ΔCT) between 2 gene products, miR-196a and miR-217.
This miRNA signature is a balanced set wherein, one gene product is expected to
be up-regulated in pancreatic ductal adenocarcinoma (miR-196a), while the other
is expected to be down-regulated (miR-217), as compared to normal pancreas tissue
and chronic pancreatitis tissue [3].
The blinded validation study on FFPE samples using the threshold value of 0.5 ΔCT
resulted in assay sensitivity of 95.2% (95%CI: 77.3- 99.2) and
specificity of 94.9% (95%CI: 83.1- 98.6).
Physicians: How to order the new miRNA test from Asuragen
- Requisition form can be downloaded from the website
- Contact our CLIA Laboratory at 512-681-5200 or 1-877-777-1874
for shipping instructions
Specimen requirements
- At least three (3)10 µm FFPE tissue sections containing
≥60% abnormal area content. Include one (1) H&E stained slide.
- Five (5) to eight (8) unstained slides with 5 µm tissue sections
containing ≥60% abnormal area content. Include one (1) H&E stained slide.
- FFPE clinical blocks containing ≥60% abnormal area.
- For specimens with <60% abnormal area content, Asuragen’s in-house
pathologist will determine if the specimen abnormal area content can be enriched.
Billing
Asuragen bills third parties (private insurance or Medicare), patient, or hospital.
Note: Asuragen does not accept Medicaid. Asuragen cannot accept
samples from New York or California until Asuragen has received state licensure
in those states.
Turn Around Time
Within 10 business days.
Diagnosing Pancreatic Cancer
Early diagnosis of pancreatic tumors may permit a potentially curative surgical
intervention. But this diagnosis can be challenging, as symptoms of pancreatic cancer
are typically non-specific. Several medical tests are often required to establish
the diagnosis and to determine whether or not the cancer has spread beyond the pancreas.
Diagnostic tests for pancreatic cancer include:
Computer tomography (CT): The CT scan is the standard diagnostic
tool used to establish the stage of pancreatic cancer, which determines whether
a tumor can be surgically removed. Using a special X-ray machine, this test gives
detailed, three-dimensional pictures of the body and can help to determine if the
tumor has spread.
Ultrasound is a medical imaging procedure where a probe that produces
and senses high frequency sound waves is placed on the surface of the abdomen. Reflections
of these sound waves can be used to form an image of the inside of the body. Ultrasound
can help determine the size of the pancreas and possibly the presence of a pancreatic
tumor.
Endoscopic ultrasound (EUS) combines endoscopy and ultrasound in
order to obtain images and information about the digestive tract and the surrounding
tissue and organs. A small flexible endoscope is placed inside the body through
the mouth, down through esophagus and into the first portion of the small intestine.
Surgical instruments, called biopsy forceps, needles or brushes, may be inserted
through the endoscope to collect a tissue sample for further testing (biopsy).
Biopsy: Because the only definitive way to diagnose pancreatic
cancer is through positive identification of cancer cells under a microscope, a
biopsy may be performed when cancer is suspected. A biopsy is the process of removing
tissue samples, which are then examined under a microscope to determine the presence
of cancer cells. A biopsy can be performed in an outpatient setting or in the hospital.
It is generally not necessary to have a biopsy performed prior to surgery.
Fine-Needle Aspiration (FNA) Biopsy In a fine-needle aspiration
(FNA) biopsy procedure, CT or EUS imaging is used together with a long, thin needle
to obtain tissue specimens. The CT or EUS imaging method allows the doctor to position
the needle with respect to the suspected mass in the organ and ensure accurate sampling
of potentially diseased tissue. EUS also can be used to guide the specimen collection
needle directly through the wall of the duodenum or stomach and into the tumor for
collection of tissue specimens. General anesthesia is not required, but local anesthesia
may be provided.
1. Takahashi, K., et al., Differential diagnosis of pancreatic cancer and focal
pancreatitis by using EUS-guided FNA. Gastrointest Endosc, 2005: 61(1):
p. 76-9.
2. Taylor, B., et al. Carcinoma of the head of the pancreas versus chronic pancreatitis:
diagnostic dilemma with significant consequences. World J Surg, 2003: 27(11):
p. 1249-57.
3. Szafranska A.E., et al. MicroRNA expression alterations are linked to tumorigenesis
and non-neoplastic processes in pancreatic ductal adenocarcinoma. Oncogene.
2007: 26(30): p. 4442-52.