A new genomic analysis of over 450 pancreatic tumors reveals that the cancer may be more accurately classified as four different diseases, each with its own characteristics and survival rates.
This insight provides potential new avenues for treatment, as patients and doctors may one day be able to customize targeted treatments based on the type of pancreatic cancer they have.
Four distinct subcategories of the disease were identified by researchers from the Australian Pancreatic Cancer Genome Initiative and the Garvan Institute of Medical Research: squamous, pancreatic progenitor, immunogenic and aberrantly differentiated endocrine exocrine, or ADEX.
"We have previously shown that pancreatic cancer is not one disease but several -- but now we have identified distinct subgroups in detail, along with the genetic drivers that underpin them,” said researcher Amber Johns in a statement.
This University of Melbourne video has more information about how the research was conducted. The story continues below.
Pancreatic cancer is one of the most deadly cancers in the world. Because the pancreas is deep inside the abdomen behind the stomach, cancer is often not felt or caught until the late stages of the disease, when the tumors have spread to other organs. There's no screening test that has been proven to catch tumors early and increase survival rates of the disease. Its location also makes surgery difficult, as surgeons have to make a long incision in order to reach it.
Because of the difficulty detecting and treating pancreatic cancer, the approach to the disease hasn't really changed in about 40 years, notes the Hirshberg Foundation for Pancreatic Cancer Research. Around five percent of people diagnosed with the disease live for more than five years in Australia, while in the U.S., that number is eight percent. In contrast, the five-year survival rate for breast cancer in the U.S. is 89.4 percent.
William Phelps, a program director with the American Cancer Society who was not involved in the study, says that the finding, however small it may seem, is actually extremely significant for the estimated 49,000 people who'll be diagnosed with pancreatic cancer in the U.S. this year. In addition to opening up opportunities to customize different kinds of treatments to better suit each subcategory, the division of the cancer into four different groups is important simply for the fact that it might give doctors more accurate information about predicting how long a patient can expect to live after diagnosis, or how well a certain treatment might work for them.
"It may not make a lot of difference today, but hopefully, as you begin to try different therapies on different groups, you’re going to find that different collections of therapies will work better on one group or another,” he explained to HuffPost. "These are the molecular underpinnings for why that might be true."
Johns also added in an email to HuffPost that while her findings aimed to address the critically low number of effective drugs for pancreatic cancer, they could one day be significant for cancer research on a larger scale. APGI intends to use the findings, published in the journal Nature, to develop new protocols for treatment among real-life patients.
"The prognosis for people that are diagnosed with pancreatic cancer, by and large, is a year or less from point of diagnosis,” Phelps concluded. "When you’ve got a disease with such a miserable prognosis, even a seemingly small advance is really a big advance, because it’s a terrible disease."
UPDATE: This story was updated to include the most recent survival rates for pancreatic cancer in both the U.S. and Australia.