Pancreatic cancer is terrifyingly deadly and there are almost no symptoms until it’s too late. But, analysing the dozens of patients I’ve treated, there ARE warning signs… including this specific back pain: DR PHILIPPA KAYE

As a GP at a busy London surgery, I see thousands of patients every year. Sometimes, even often, you won’t remember every consultation without your notes – but there are some patients, and some diagnoses, that stay with you for years.

Take Alan – not his real name – who I’d seen regularly at my surgery for more than a decade. Over that time, as his GP, I’d got to know him and his health well.

So it came as a shock when a letter arrived from the hospital informing me that, at 77, he had been diagnosed with stage four pancreatic cancer.

He was extremely unwell by then and, sadly, died within a few months.

I immediately went back through his notes. Had we missed something?

Had he come to the surgery months earlier with indigestion, unexplained weight loss, nausea or fatigue – vague complaints which, with hindsight, might have been the first signs of his cancer?

I could find nothing.

Alan’s case illustrates the terrifying truth about pancreatic cancer. It can strike almost without warning, causing few obvious symptoms until it has already spread and become far harder to treat.

But then I think of another patient, Leroy – also not his real name.

He was a sprightly, generally healthy man in his late 60s, who would come in every year for his flu jab. He wasn’t overweight, didn’t smoke and ate pretty healthily. Aside from high blood pressure, there was little remarkable about his medical history.

Then a routine blood tests showed something unexpected: he had developed diabetes.

That in itself wasn’t extraordinary. Type 2 diabetes is extremely common. But Leroy didn’t look like the typical patient I would expect to develop it. He wasn’t overweight, had no family history of the condition and, when we spoke, mentioned something else: over the previous few weeks, he had actually been losing weight.

That combination bothered me.

Further investigations eventually revealed the cause. Leroy had pancreatic cancer.

His tumour could not be surgically removed, but as we caught it relatively early, he was able to receive other treatment and enjoyed several more years with his family.

These two men illustrate something important about one of the most brutal cancers I encounter as a doctor.

Pancreatic cancer kills around three-quarters of patients within a year of diagnosis, and its reputation as a ‘silent killer’ is not entirely undeserved. Its early symptoms can be absent or so vague that neither patient nor doctor has any obvious reason to suspect cancer.

But I worry that we have allowed that message to become too simplistic.

Because pancreatic cancer can give us clues. And sometimes, as with Leroy, the important warning isn’t a dramatic symptom at all. It is simply that something about a patient’s health suddenly doesn’t make sense.

As a GP, those are the changes I pay attention to.

In Leroy’s case, it was the sudden development of diabetes that first raised the alarm.

And his experience is not unusual. Research shows that about one in every 100 people with new-onset diabetes is diagnosed with pancreatic cancer within three years.

I don’t want people with newly diagnosed diabetes to panic. Type 2 diabetes is common and in the vast majority of cases, the cause won’t be a tumour.

But if someone develops diabetes in later life without the risk factors we usually expect to see – particularly without being overweight or with a family history – then I want to know why.

If they are losing weight unexpectedly, as Leroy was, it would make me more suspicious still.

There is a biological reason for this. The pancreas is a gland that produces insulin – the hormone that helps regulate blood sugar.

A tumour can interfere with this process, causing blood sugar levels to rise and, in some cases, triggering diabetes before the more recognisable symptoms of pancreatic cancer appear.

Ordinary type 2 diabetes tends to develop gradually, often over several years. Many people have no obvious symptoms at all and are diagnosed only after a routine blood test.

But diabetes linked to pancreatic cancer can behave differently. Blood sugar may rise rapidly, over a matter of weeks or months, and can prove unexpectedly difficult to control.

In some patients, levels continue to climb despite treatment – meaning they need increasingly powerful medication.

It’s also important to know that while pancreatic cancer can trigger diabetes, having longstanding type 2 diabetes is itself associated with an increased risk of developing pancreatic cancer.

Studies suggest that people who have had type 2 diabetes for more than five years have almost twice the risk of pancreatic cancer compared with those without diabetes.

Again, that needs perspective: Pancreatic cancer remains rare, so the overwhelming majority of people with diabetes will never develop it.

What would concern me more as a GP is a sudden, unexplained change. If someone’s diabetes has been well controlled for years but their blood sugar suddenly starts climbing despite treatment, requiring stronger medication or increasing doses of insulin, I would want to understand why.

Blood sugar changes aren’t the only easily missed early warning sign, however. Some of the most useful clues may be visible when you go to the loo.

Patients are understandably not always keen to discuss their bowel movements with their GP. But a persistent change in what is normal for you – particularly one lasting several weeks – is a symptom I want to know about.

The pancreas produces enzymes that help us digest food, particularly fats. If a tumour disrupts this process, stools can become unusually greasy or oily, pale, foul-smelling and prone to floating in the toilet.

There is another change to look out for. A tumour can block the flow of bile into the intestine. Without the pigments in bile that normally give stools their brown colour, they can become unusually pale or even clay-coloured.

At the same time, urine can become noticeably darker. Research examining symptoms recorded in primary care has suggested that dark urine can appear months before pancreatic cancer is diagnosed.

Finally, many patients with pancreatic cancer describe a particular type of back pain as one of the early symptoms they initially dismissed.

Of course, back pain is extraordinarily common and, as with diabetes and changes in bowel habits, in the vast majority of cases it will have nothing to do with pancreatic cancer.

But there is a particular pattern patients should be aware of.

The pain can begin in the upper abdomen and seem to bore or radiate straight through to the back. Some patients find it becomes worse after eating or when lying flat, while sitting forward or leaning over can bring relief.

This can happen because a growing tumour presses on nerves and other structures around the pancreas, with eating or changes in posture altering that pressure.

None of the symptoms I have described automatically means pancreatic cancer. But we do need to stop describing pancreatic cancer simply as a disease with no early warning signs.

Yes, it can be frighteningly difficult to detect early. But difficult is not the same as impossible. If something about your health changes unexpectedly, persists or simply doesn’t make sense, don’t dismiss it.

Tell your GP, as this can lead to a swift diagnosis and a much better outcome.