Cigarette Smoking Appears to Increase Potential for Metastasis of Pancreatic Cancer
Smoking has once again been implicated in
the development of advanced cancer. Exposure to nicotine by way of cigarette
smoking may increase the likelihood that pancreatic ductal adenocarcinoma will
become metastatic, according to researchers from the Kimmel Cancer Center at
Jefferson. Their study was published in the August edition of the journal
Surgery.
The culprit behind the increased
metastasis potential appears to be an isoform (variant type) of a protein called
osteopontin, according to Hwyda Arafat, M.D. Ph.D., associate professor of
Surgery at Jefferson Medical College of Thomas Jefferson University and a member
of the Jefferson Pancreatic, Biliary & Related Cancers Center.
Nicotine promotes the expression of
osteopontin, and high levels of osteopontin have been reported in pancreatic
ductal carcinoma (PDA). Dr. Arafat and her research team analyzed PDA samples
and confirmed that the isoform, called OPNc, was also expressed on invasive PDA
lesions. Previous studies have shown that OPNc is expressed in several invasive
cancers, and supports metastatic behavior.
The researchers correlated OPNc
expression with the patients’ smoking history. OPNc expression was found on 87
percent of the invasive PDA lesions analyzed, of which 73 percent were from
smokers. The OPNc expression also correlated with higher expression levels of
osteopontin. Premalignant lesions expressed no OPNc.
“This is the first time a relationship
between nicotine and OPNc expression has been identified,” Dr. Arafat said.
”These data are very exciting because now we can evaluate OPNc as a prognostic
and diagnostic marker of invasive PDA lesions. “Because of the lower expression
levels of OPNc in non-smokers, OPNc may be regulated by nicotine, which is
another novel finding of this study. The exact role of OPNc in PDA remains to be
defined, but it could provide a unique potential target to control pancreatic
cancer aggressiveness, especially in people who smoke cigarettes.”
Pancreatic cancer is the fourth-leading
cause of cancer death in the country, taking 34,000 lives a year. Only four
percent of individuals with pancreatic cancer live for five years after
diagnosis.
Media Only Contact:
Emily Shafer
Thomas Jefferson University Hospital
Phone: (215) 955-6300
Published: 7/27/2009