By the time doctors detect pancreatic cancer, it's almost always too late. Hidden from the sight of most screening techniques and asymptomatic until the late stages, the disease is rarely diagnosed early enough for any intervention to save a person's life.
That stark fact explains why pancreatic cancer is the fourth-deadliest type of cancer in the US, despite not even appearing in the top 10 most common cancers.
"It's more aggressive in terms of mortality than any of the solid tumours," said Dr Michelle Anderson, a gastroenterologist at the University of Michigan. "Everybody dies from it, even people caught at an early stage."
But a team of researchers at Northwestern University and NorthShore University HealthSystem in the Chicago area may have found a way to spot cancer in the pancreas before it even begins.
Vadim Backman, a biomedical engineer at NU, and his colleagues developed a method of peering into a cell's inner architecture on a nano-scopic level, observing cellular "disorder" building in cells before they become cancerous.
"When we look in a microscope, we see the house of a cell, its roof and walls," Backman said. "When we look with (the new method), we see the individual bricks, and we might find some cracks that tells us the house is going to collapse at some point later."
Currently, a patient's best chance of surviving pancreatic cancer is if doctors find a tumour by accident. In the recent case of US supreme court justice Ruth Bader Ginsburg, a follow-up scan based on her history of colon cancer found a one-centimetre pancreatic tumour, for which she underwent surgery earlier this month.
Doctors occasionally can spot early signs of cancer in cells taken from the pancreas in a biopsy, but limitations of microscopes mean that even this method, known as histology, may not see the cancer forming until too late.
The technique developed by Backman and his team over the past three years, called partial wave spectroscopy or PWS, focuses one-dimensional light inside the cell. The light waves bounce off intracellular structures and generate a signal researchers can record, allowing the study of cellular structures 10 to 20 times smaller than can be observed with normal microscopes.
When applied to pancreatic cell samples taken from patients previously diagnosed as healthy or cancerous, the method revealed a clear increase in the "architectural disorder" of cells from people who developed cancer. Even more promising, the method detected elevated disorder in cells from six patients who were misdiagnosed as normal but later developed cancer, suggesting that PWS can identify cancer cells earlier and more accurately than the standard method.
"Our thinking right now is that this could be useful in [screening] high-risk patients," such as those with a family history of pancreatic cancer, smokers and heavy drinkers, said Dr Hemant Roy, director of gastroenterology research at NorthShore and part of the research team.
The technique also has potential to be applied to the detection of other cancers, the researchers and outside observers said. Research published in December by the same team used PWS to detect early colon cancer in animals.
Doctors uninvolved in the newest study expressed enthusiasm about the preliminary results, saying the method could lead to a screening test for pancreatic cancer that is more effective and less expensive than the current best technique, called endoscopic ultrasound.
"If this indeed pans out, with very minimally invasive technology you could be able to detect a pancreatic cancer even at an earlier stage," said Dr Irving Waxman, director of the Centre for Endoscopic Research and Therapeutics at the University of Chicago medical centre. "It would definitely add a significant technology where right now we don't have a very good solution to screening."
