Effect of obesity on resection margins in patients with pancreatic ductal adenocarcinoma treated with neoadjuvant chemotherapy.

Abstract

e16229 Background: Obesity has been associated with decreased survival in patients with pancreatic ductal adenocarcinoma (PDAC). However, exact reasons remain unclear. Reduced response to chemotherapy because of obesity-induced desmoplasia has been proposed as a mechanism for the suboptimal response to treatment and therefore worse outcome. To this end, we attempted to determine the effect of obesity on the efficacy of neoadjuvant chemotherapy in patients with resectable and potentially resectable PDAC who underwent surgical resection. We assessed rates of microscopic tumor-free margins as a surrogate for treatment response. Methods: We performed a retrospective review of all patients diagnosed with PDAC from 2017-2019 at Allegheny Health Network. Obesity was defined as BMI > 30 kg/m2. Patients with resectable and potentially resectable disease who eventually received surgical treatment were included.Demographics, treatment details, and surgical pathology results were reviewed. Two-sided Mann-Whitney U test and Fischer’s exact test were used to evaluate differences between groups with continuous and categorical variables, respectively. A p value of < 0.05 was considered as level of significance. Results: Out of 121 patients who received and completed treatment at our institution, 29 patients underwent neoadjuvant chemotherapy followed by surgical resection. Most patients were female (61%), Caucasians (90%), had stage I (76%) and potentially resectable disease (72%). Eleven (38%) patients were categorized as obese and remaining non-obese. Among patients who underwent surgery after neoadjuvant chemotherapy, 10 out of 11 patients (90.9%) had microscopic tumor-free margins in the obese group when compared to 17 out of 18 patients (94.4%) in the non-obese group. (Table). Conclusions: Our study revealed no significant difference in obese patients compared to non-obese patients in terms of tumor-free margins assessed microscopically after surgical resection. Our study is limited by its small sample size, retrospective nature, and unidentifiable confounding factors that could potentially affect outcomes. Larger scale studies are needed to investigate the effect of obesity on treatment outcomes in resectable and potentially resectable pancreatic cancer patients treated with neoadjuvant chemotherapy.[Table: see text]