Profile of patients with pancreatic cancer and diabetes mellitus at the University Hospital of Brazzaville

Introduction: pancreatic cancer a poor prognosis disease for 
which there is no screening. Its association with diabetes is not uncommon and 
may influence the evolutionary profile. The aim of this study was to describe 
the profile of diabetic patients who could benefit from pancreatic cancer 
screening. Methods: we conducted a retrospective cross-sectional study 
in the gastroenterology department of the University Hospital of Brazzaville, 
from January 2010 to December 2019. Epidemiological variables (age, sex, 
alcoholism, smoking), tumor variables (symptoms, site, size, density, 
extension) and time of occurrence of both entities were analyzed using Epi info 
software. Results: A total of 35 patients were hospitalized for 
pancreatic cancer, of whom 17 were men and 15 women, for a sex ratio of 1.21. 
The mean age of the patients was 60.3 ± 13 years. Fifteen patients (43.75%) 
were diabetic, all classified as type 2. Among them, the diagnosis of diabetes 
of 10 patients (66.7%) preceded pancreatic cancer diagnosis and delay between 
the two pathologies was on average 3.4 years ± 5.3 months. Diabetes was 
observed in 11 patients older than 60 years. The difference was significant (OR 
= 4.8; 95% CI [1.1 - 22.8]; p = 0.0226). The other epidemiological variables 
studied were not related to the two pathologies. Conclusion: we propose 
a screening for pancreatic cancer when diabetes is discovered to patients from 
60 years old, whatever their sex, especially during the first 3 years after the 
discovery of diabetes.


Introduction
Pancreatic cancer is the third leading cause of cancer death worldwide [1]. Despite its seriousness, there is no existing screening programme for this cancer which generally has a poor prognosis. Diabetes mellitus, a major health problem affecting more than 7% of the world's population, is a risk factor for certain cancers, including pancreatic and liver cancer [2]- [7]. The lack of an early detection programme for pancreatic cancer probably explains its high mortality rate [8] [9] [10] [11] as its management is difficult [2] [3] [5]. Some authors have clearly shown an increase in the prevalence of cancers such as pancreatic cancer with diabetes [12] [13] [14]. The research hypothesis was that diabetes could be predictive of existing of pancreatic cancer. To help improve the early detection of pancreatic cancer, we analysed the characteristics of pancreatic cancer associated with diabetes mellitus. The objectives of this study were to determine the prevalence of diabetes in pancreatic cancer, to determine the risk factors associated with diabetes in pancreatic cancer and to analyse the characteristics of diabetics with pancreatic cancer.

Patients and Methods
We conducted a retrospective cross-sectional analytical study in the hepato-gastroenterology department of the CHUB from January 2010 to December 2019, a period of 10 years. We included all cases of pancreatic cancer regardless of age and gender. The diagnosis of pancreatic cancer was evoked clinically and confirmed by abdominal ultrasound or CT or MRI scan showing a solid tumour of the pancreas enhancing after contrast injection on CT or MRI. Histological evidence was not required for a diagnosis of pancreatic cancer. Non-solid tumours (cysts and pseudocysts) of the pancreas were excluded from this study.
The diagnosis of diabetes mellitus was made on the basis of blood glucose and glycated haemoglobin values. Diabetes was confirmed when the blood glucose level was above 1.26 g/l and/or the glycated haemoglobin level was above 6.5%.
We performed a non-probability sampling by systematically recruiting all cases meeting the inclusion criteria. The variables studied were epidemiological such as age, sex, alcohol and tobacco consumption; diabetes characteristics such as family history of diabetes, type, duration of diabetes, antidiabetic treatment administered and tumour characteristics such as symptoms, tumour site, size, tumour density on imaging, presence of metastases. The endpoints were the association between pancreatic cancer and diabetes mellitus, the diagnostic chronology of the two diseases and the diagnostic delay between diabetes and pancreatic cancer. Data were processed using Epi Info 7.2 software. The significance level for statistical tests was set at 0.05. Based on these criteria, 35 patients were included in the study.

Results
During our period study, we collected 958 cases of cancer diagnosed in the department, including 35 cases of pancreatic cancer, representing 3.6% of cancer hospitalizations.
Among the 35 cases of pancreatic cancer, there were 19 (54.3%) men and 16 (43.7%) women, a sex ratio of 1.2. The mean age was 60.3 ± 13 years, the young age were 23 years and the old one were 90 years. Figure 1 showed the distribution of patients in age groups. Alcohol and tobacco intake were observed in 21 (88.6%) and 8 (22.9%) cases. Jaundice was the main reason for hospitalization.

Discussion
Diagnosis of pancreatic cancer is often late sometimes difficult due to limited investigation exams in our country. That may explain the low of our sample size.
In addition, the retrospective nature of our study may be a source of selection  [9] reported alcohol and tobacco consumption of 20.6% and 32.5% and 46.8% and 59.4% respectively in male patients. However, tobacco consumption is more a risk factor for pancreatic cancer, alcohol consumption is a risk factor for chronic pancreatitis [1]. We did not find an association between these two risk factors and diabetes during pancreatic cancers. The pancreatic cancers localisations are cephalic extremity in more 80% of cases [8] [9], explaining the symptoms found in our study, dominated by jaundice. Jaundice is a symptom that most often motivates an immediate hospital consultation but it also reflects an already advanced form of pancreatic cancer, corroborating that pancreatic cancer is often of late diagnosis [9] [10] [12]. Therefore, the search for jaundice should not be an early diagnostic feature of pancreatic cancers. The frequency of metastasis at the time of diagnosis is variable according to some authors, 26.2% in Algeria [7] and 90.6% in Burundi [11], proof that it is a cancer with a poor prognosis. In the literature, the association between diabetes mellitus and pan-  [17]. For Prizment et al. [3], the duration of diabetes does not seem to increase the risk of pancreatic cancer, although this risk persists. In all cases, a risk of an association between diabetes mellitus and pancreatic cancer is described. In our study we cannot compare the duration of diabetes and the occurrence of pancreatic cancer with a control group, hence the interest in conducting a comparative prospective study at a later date in which the same epidemiological variables will be studied.

Conclusion
Our study confirms the association between pancreatic cancer and diabetes mellitus. The discovery of diabetes in patients aged 60 years and older was statistically related to the presence of pancreatic cancer, the mean time to diagnosis of pancreatic cancer was 3 years. Screening for pancreatic cancer can therefore be proposed by cross-sectional imaging combining abdominal ultrasound and injected abdominal CT when diabetes mellitus is discovered from 60 years old. The pace of screening will be able to specify by a prospective follow-up of diabetic patients which will be carried out in the near future to better evaluate the association between diabetes and pancreatic cancer.