Why pancreatic cancer is usually found late, and why that matters so much
Pancreatic cancer tends to stay silent until it has spread. Jaundice, often the first sign people notice, appears only when a tumour grows big enough to squeeze the bile duct. Globally just 9% of people with the commonest form are alive five years after diagnosis, a figure that roughly doubles when it is caught early.
The pancreas is a gland tucked behind the stomach, and most of it makes digestive enzymes. About 95% of its cancers start in that enzyme-producing, or exocrine, part. The dominant type is ductal adenocarcinoma, which begins in the tiny tubes that carry enzymes and bicarbonate out of the organ. Oddly, those duct linings make up under 10% of the pancreas by cell volume, yet they give rise to the great majority of its tumours, and about 60 to 70% of adenocarcinomas sit in the head of the gland.
A much smaller family, the neuroendocrine tumours, grows from hormone-making cells and is generally less aggressive. Some of these pour out insulin, gastrin or glucagon, which can cause striking symptoms such as low blood sugar and so, paradoxically, lead to earlier discovery. Others release too little hormone to be noticed and tend to be found only after spreading. They were once called islet cell cancers, a label now known to be mistaken. Five years after diagnosis, around 65% of people with neuroendocrine cancers are alive, though this varies widely by type.
The disease rarely appears before 40, and more than half of adenocarcinoma cases involve people over 70, though diagnoses under 50 are rising, especially among younger women. Smoking accounts for about a quarter of cases; current smokers face roughly double the risk of people who never smoked, and the excess fades over 10 to 20 years after quitting. Obesity, diabetes and inherited genes, linked to 5 to 10% of cases, also raise risk. Studies tying red meat to the disease are mixed, with meta-analyses generally finding no clear link.
Diagnosis relies on imaging such as ultrasound or CT, blood tests and biopsy, and screening the general population has not proved effective. Surgery is the only treatment that can cure adenocarcinoma. In 2021 pancreatic cancers caused 508,532 deaths worldwide, up from 411,600 in 2013, making them the third most common cause of cancer death in the United States.
Source: Pancreatic cancer
