Influence of the body mass index on postoperative outcome and long-term survival after pancreatic resections in patients with underlying malignancy

Pancreatic ductal adenocarcinoma (PDAC) is the 4th leading cause of cancer deaths and is projected to become the second by 2030 (1). Despite advances in the treatment and management of this malignancy, the overall five-year survival rate remains only 5–7% and one-year survival is achieved in less than 20% of patients (2). As patients who have early-stage disease are often those with the best outcomes (3) increased attention has been paid to known risk factors for this disease including family history, diabetes and obesity (4). Obesity is a known risk factor for the development of PDAC (5-7) while underweight has a negative impact on morbidity in patients with a known diagnosis of PDAC (8,9). Overweight and obesity are currently linked to more deaths worldwide than underweight and the prevalence of obesity is rising (10,11). The most commonly used indicator of weight in healthcare is the body mass index (BMI); the WHO defines obesity as a BMI ≥30 while a BMI <18.5 is defined as underweight. Many studies have observed the relationship between body mass and surgical morbidity and mortality; however, the data available remain controversial. Interestingly, in specific conditions a decrease in mortality has been reported in overweight patients: this is the case of patients with septic shock (12) and acute respiratory distress syndrome (13) and is referred to as the obesity paradox. While the long-term survival rate among patients with periampullary carcinomas remains low (14), it can be influenced by various factors. Some recent reports show that being overweight or obese correlates with a lower risk for hospital mortality and a lower risk of adverse postoperative outcomes (15). The purpose of this retrospective study was to quantify the effects of body mass on postoperative complications and patient survival after pancreatic resections for underlying malignancy over a 20-year observation period in a European high-volume cancer center