Risk factor analysis for duodenal margin positivity following gastrectomy for resectable gastric cancer.

Background: Duodenal margin positivity is a poor prognostic factor following gastrectomy for resectable gastric cancer. Intraoperative frozen section (IFS) analysis allows radical resection to be achieved in a single operation but is time- and resource-consuming. Hence resection is usually performed based on surgeon's judgment and palpation.

Aim Of Study: To determine risk factors for duodenal resection margin (RM) positivity following gastrectomy for resectable gastric cancer.

Materials And Methods: We retrospectively analyzed prospectively maintained data of 376 patients admitted with diagnosis of gastric cancer from August 2011 to January 2020 in JIPMER, a tertiary center in Puducherry, India. Of these, 146 patients underwent gastric resection with curative intent and were the subject of this study. RM status was assessed by definitive histopathology examination. The potential risk factors were compared between patients with positive margin on definitive histopathology examination and a control cohort of similar patients with negative margins.

Results: Of the 146 patients, 16 patients (10.9%), 11 men and 5 women, had positive duodenal margin. The mean age of study group was 59 years. None of the patient characteristics like age, sex, comorbidities, or addictions were statistically significant with regard to duodenal margin positivity. Among tumor characteristics, locally advanced tumors and pyloroantral tumors were found more frequently in the margin-positive group. High-risk features for duodenal margin positivity were extensive nodal disease, oligometastatic disease, lymphovascular invasion, and perineural invasion. Neoadjuvant chemotherapy and types of surgical access did not have significant impact on RM. Interestingly, both proximal and circumferential resection margin positivity had a linear association with distal margin positivity suggesting that tumor biology may have a significant role in margin positivity. However, none of these factors were statistically significant on multivariate analysis using logistic regression model. Among oligometastatic patients, survival was dependent on R0 resection and was not different from patients without metastases though our study was not powered for survival analysis (mean survival of 11.040 months) and expectedly, duodenal margin positive patients had lower overall survival compared to margin negative patients (mean survival of 5.188 vs. 11.763 months, p = 0.12).

Conclusions: Locally advanced tumors and pyloroantral tumors are associated with an increased risk of duodenal margin positivity after gastrectomy for carcinoma stomach and may benefit from intraoperative frozen section analysis as survival is negatively affected by positive RM. Patients with high-risk features like extensive nodal and oligometastatic disease have a greater propensity for positive duodenal margin. A prospective study with a large sample size is needed to further validate these results.