Pancreatic cancer is a rare but fatal disease. More than half of all patients with pancreatic cancer die within the first year after diagnosis. It is difficult to diagnose pancreatic cancer at a time, when the disease can still be treated successfully, because pancreatic tumours cause symptoms only when they have spread to other organs. A simple test that detects the disease before patients have symptoms is not available.
However, it has been observed that blood sugar levels continuously deteriorate in the years before a pancreatic cancer diagnosis in patients with type 2 diabetes, a disease where there is too much sugar in the blood. Examining all patients with worsening diabetes for pancreatic cancer in clinical practice is not justified, because 4.7 million patients in the United Kingdom have diabetes, but only few of them will have pancreatic cancer. Identification of the characteristics of diabetes deterioration in patients with pancreatic cancer may help selecting subgroups of diabetic patients for further medical examination.
The aim of our study is to characterize the worsening of diabetes before a pancreatic cancer diagnosis. Specifically, we will explore intensification of diabetes treatment and changes in blood sugar and body weight.
In this descriptive study, we aim to identify characteristics of the deterioration of glycaemic control in the years preceding a pancreatic cancer diagnosis in patients with pre-existing type 2 diabetes. We will select patients aged >50 to 90 years with a first-time Read code for pancreatic cancer between 2004 and 2017 (index date) and a type 2 diabetes diagnosis > 3.5 years before the index date. Patients with type 2 diabetes, but without a pancreatic cancer diagnosis, will be used as comparison group.
We will assess intensification of antidiabetic treatment, changes in glycated haemoglobin levels, and changes in body weight before the index date in diabetic pancreatic cancer patients compared with diabetic non-cancer patients.
More specifically, we will evaluate the total number of antidiabetic treatment intensifications (defined as increase in the number of drug classes prescribed or start of insulin treatment) in the time period from 3 years until 6 months before the index date. We will determine time intervals between successive intensifications and types of intensification, and we will assess changes in glycated haemoglobin levels preceding treatment intensification. Other than treatment intensification, we will assess the temporal changes in glycated haemoglobin and body weight in the 3 years before the index date. Baseline will be the last glycated haemoglobin level or body weight recorded > 3 years before the index date but after onset of diabetes. We will stratify our analyses by diabetes duration, as well as by antidiabetic treatment intensification and body mass index, where applicable or appropriate.
Health Outcomes to be Measured:
We will study type 2 diabetes patients with or without pancreatic cancer. In these patients, we will describe the following key variables before the cancer diagnosis (or the matched date): Number of antidiabetic treatment intensifications (defined as increase in the number of drug classes prescribed or start of insulin treatment); Timing of antidiabetic treatment intensification; Type of antidiabetic treatment intensification; Glycated haemoglobin levels; Changes in glycated haemoglobin levels; Body weight; Changes in body weight.