Survival in overweight patients with advanced pancreatic carcinoma: a multicentre cohort study.

Background: Obesity is a risk factor for developing pancreatic cancer. We investigated the impact of obesity on survival in patients diagnosed with locally advanced or metastatic pancreatic cancer.

Methods: In a multicentre, retrospective study, we included all patients with advanced or metastatic pancreatic cancer treated at four Swiss hospitals between 1994 and 2004. We categorized patients into four body mass index (BMI) groups (<18.5, 18.5 - 25, ≥ 25 - 29, ≥30 kg/m2) and used multivariable Cox regression to investigate the impact of BMI on survival. Missing data were handled using multiple imputations.

Results: 483 patients were included. Median age was 66 years (range 59-74), 47% were female, 82% had stage IV disease, 72% had an ECOG below 2, and 84% were treated with gemcitabine-based first-line chemotherapy. After a median follow-up of 8.5 months, 6 and 12-month survival probabilities of the whole cohort were 67% (95% CI 63% - 71%) and 37% (95% CI 33% - 42%), respectively. Unadjusted 12-month survival rates in each BMI group were: 48% (95% CI 33% - 62%), 42% (95% CI 36% - 48%), 30% (95% CI 22% - 38%), and 11% (95% CI 4% - 24%), respectively. In multivariable analysis, increasing BMI (HR 1.22, 95% CI 1.04 - 1.41, p = 0.012) and CA 19-9 (HR 1.07, 95% CI 1.02 - 1.11, p = 0.003) were significantly associated with worse survival prognosis. Patients with a good clinical performance status (ECOG < 2) had a better prognosis (HR 0.76, 95% CI 0.65 - 0.96, p = 0.019).

Conclusions: Obese patients diagnosed with advanced pancreatic cancers have a worse prognosis compared to non-obese patients. BMI should be considered for risk stratification in future clinical trials.