Developing type 2 diabetes in middle age may be a sign of pancreatic cancer, according to research.
Having diabetes is known to approximately double the risk of pancreatic cancer, but the new study suggests if you are diagnosed with type 2 after the age of 50, it may be a sign you already have the deadly disease.
More than half – 52.3 per cent – of pancreatic cancer cases among diabetics are in those who have been diagnosed less than three years before their cancer diagnosis.
The University of Southern California team did not speculate as to why the condition could be a sign of pancreatic cancer – and said their study just delved into the link between the two.
Around 3.6 million people in the UK have diabetes, and 90 per cent of cases are type 2, which is often linked to being overweight or inactive.
Pancreatic cancer affects around 9,600 people a year and fewer than one in ten people survive for five years after their diagnosis.
Almost half of all new pancreatic cancer cases are diagnosed in people over 75, and it is uncommon in people under 40.
Yet in the past decade pancreatic cancer rates have increased and it has a poor survival rate as around 80 per cent of cases are diagnosed at a late stage.
In their study on African-American and Latino adults, researchers found the number of cases of the cancer among diabetics diagnosed in middle age is more than double the number of those diagnosed in earlier life.
Recently diagnosed diabetes three times as common in pancreatic patients than among other cancers
The scientists found 16.4 per cent of people diagnosed with pancreatic cancer have diabetes that was diagnosed within the last three years.
This is striking when compared with other cancers – recently-diagnosed diabetes is only found in 6.7 per cent of bowel cancer patients, 5.3 per cent of those with breast cancer, and 5.5 per cent of prostate cancer patients.
Previous studies found there was a twofold higher risk of developing pancreatic cancer among diabetes patients.
Those with an African or South American heritage have a 2.3 times higher risk.
“This striking relationship [with] recent-onset diabetes is unique to pancreatic cancer, and is not seen in breast, prostate and colorectal cancer,” said one of the paper’s authors, Dr Wendy Setiawan.
“Our findings strongly support the hypothesis that recent-onset diabetes is a consequence of pancreatic cancer and that long-standing diabetes is a risk factor for this cancer.”
Findings could lead to earlier diagnosis of killer disease
The scientists suggest those patients with both conditions could be studied more closely to find other early warning signs for the deadly cancer, which often goes unnoticed until it is too late for lifesaving treatment.
They may also be targeted for development of the tests that are needed for earlier diagnosis.
Dr Setiawan said: ‘Because most people with pancreatic cancer are diagnosed at a late stage, the five-year survival rate is low – about 8 per cent.
“Identifying people who are at high risk early on could potentially save their lives.
“Importantly, here we show that the association of recent-onset diabetes with pancreatic cancer is observed in African Americans and Latinos, two understudied minority populations.”
How the research was carried out
The study looked at recent-onset diabetes and pancreatic cancer in African Americans and Latinos, two minority populations with high diabetes risk.
A total of 15,833 people – 32.3 per cent of the participants – developed diabetes between 1993 and 2013. Some 408 people developed pancreatic cancer.
During an average follow-up of 14 years, 128 of the people diagnosed with diabetes developed pancreatic cancer.
Among participants without diabetes, 280 people developed pancreatic cancer.
More than half – 52.3 per cent – of people who had both pancreatic cancer and diabetes were diagnosed with diabetes less than three years before they were diagnosed with cancer.
The study was published in the Journal of the National Cancer Institute, published by Oxford University Press.