Promise Seen in Pancreatic Cancer through Immunotherapy
/Pancreatic cancer advances have been making recent news, largely through the revolution that is personalized medicine, specifically immunotherapy. The statistics on pancreatic cancer are grim. Almost 50,000 people will be diagnosed in the US this year, with more than 40,000 dying from the disease. There exists no effective screening method. The disease is asymptomatic early on and spreads rapidly to other organs.
What is immunotherapy?
June is immunotherapy month. Immunotherapy is one of the hottest topics in cancer care. Traditional ways of treating cancer such as chemotherapy and radiation work through their direct killing effects on tumor cells. Immunotherapy works through an entirely different mechanism by leveraging the power of the immune system to attack the tumor.
One such important therapy to come out of this is that of the PD-1 pathway. This is a cascade of cellular reactions which “releases the brake” on the immune system, allowing it to be activated against the tumor, so-called “checkpoint inhibitors”.
Other forms of immunotherapy include cancer vaccines and antibodies that can be made to target tumor cells. Also, cytokines that activate the immune system and other drugs designed to boost the immune system are forms of immunotherapy.
Initial results suggest that immunotherapy can be effective in advanced cancer, even those with metastatic disease. Perhaps most promising is the finding that immunotherapy can be combined with traditional chemotherapy and radiation for an even more effective result. Currently immunotherapy is generally only available at larger academic medical centers as part of research studies. More resources on immunotherapy are available from the American Association for Cancer Research. Public awareness and education will help make this a reality for all those in need.
New screening possibilities
Exosomes are small particle released from tumor cells that contain DNA, RNA and proteins. These are different than circulating tumor cells that can sometimes be found in the blood. Recently researchers have demonstrated the presence of one of these proteins, glypican-1, in the blood of pancreatic cancer patients. This gives promise as a possible screening tool to detect the deadly cancer early when it is potentially curable.
Researchers have discovered genetic mutations that appear to confer an increased risk of pancreatic cancer. Though the results are preliminary, it gives hope for yet another powerful tool for identifying those at risk and instituting close surveillance.
Treatment advances in pancreatic cancer
There have been many recent advances in pancreatic cancer research. It is known that the SMAD4 gene plays a role. Expression is associated with a better prognosis, raising the hopes for its role in novel treatment strategies. Many other genes have been found to be involved in pancreatic cancer. There are even vaccines in development that show promise (GVAX and CRS-207).
We now understand that supporting tissues play a role and combination chemotherapy protocols targeting these cells show promise. New hope also comes from an experimental compound (MM41) which targets faulty DNA. All of these advances are examples of personalized medicine.
Value in cancer care
With the rapidly escalating costs of healthcare, and in particular that of cancer care, there has been much emphasis on value. What is value and how does one measure it? Recently the American Society of Clinical Oncology issued a tool that calculates a score based on benefit, costs and side effects of a particular cancer treatment in the hopes that both physicians and patients can make a more informed shared decision. Such novel therapies like immunotherapy are a perfect example.
What is the benefit and costs of personalized medicine? These are just a few of the questions raised in a recent Journal of the American Medical Association study. Time will tell just how this revolution of personalized medicine will play out. Pathologists have been integral to these developments through the diagnosis, testing, matching the right drug to the right patient and delivering value to the heath care team.
Cautiously optimistic is the way to describe the exciting new research into pancreatic cancer and the promise of immunotherapy. More research still needs to be done.
About Dr. Michael Misialek
Dr. Michael Misialek currently serves as Associate Chair of Pathology at Newton-Wellesley Hospital, Newton, MA. He is the Medical Director of the Vernon Cancer Center, Chemistry Laboratory and Point of Care Testing. He practices in all areas of pathology in a busy community hospital. Holding an academic appointment at Tufts University School of Medicine as a clinical assistant professor of pathology, he regularly instructs medical students and pathology residents. Dr. Misialek is a strong advocate for pathology and is very active in the College of American Pathologists (CAP), serving on the Personalized Healthcare Committee, the political action committee PathPAC, the CAP Foundation and as chair of the Massachusetts delegation in the CAP House of Delegates. He is an inspector with the CAP and has conducted several domestic and international hospital laboratory inspections.
He received his MD from the University of Massachusetts, did an internship in internal medicine at Boston Medical Center and completed his residency in anatomic and clinical pathology at the University of Massachusetts Medical Center. He did a fellowship in general surgical pathology at the University of Florida and is board certified in Anatomic and Clinical Pathology.