Prognostic impact of abutment to the branches of the superior mesenteric artery in borderline resectable pancreatic cancer.

ABSTRACT

PURPOSE: The clinical impact of abutment to an artery and its branch on resectability and prognosis in patients with borderline resectable pancreatic cancer is unclear. METHODS: Patients diagnosed with borderline resectable pancreatic cancer due to artery abutment between April 2012 and December 2018 were enrolled. Contact between arteries and the tumour was assessed by computed tomography (CT). RESULTS: A primary lesion was resected in 63 patients (R group) and unresected in 19 patients (UR group). Overall survival (OS) was worse in the UR group than in the R group (P < 0.001). Multivariate analysis showed that abutment to the superior mesenteric artery (SMA) branches (P = 0.001) was an independent predictor of poor OS after surgery. Regarding the initial recurrence pattern, abutment to the SMA branches was significantly associated with high incidence of distant metastasis (P < 0.001). According to the most distal SMA branch attached on CT, significant differences in RFS were found between absent-J1A (P = 0.017), J2A-J3A (P = 0.0313) and J3A-middle colic artery (MCA, P = 0.0476) but not between J1A-J2A (P = 0.8207). Significant prognostic differences in OS after initiation of the treatment were found between absent-J1A/J2A (P = 0.006) and J1A/J2A-J3A/MCA (P = 0.033) but not between J3A/MCA-UR (P = 0.494). CONCLUSION: Abutment to the SMA branches was associated with high incidence of distant metastasis after resection and a poor survival. Especially, abutment to the J3A or MCA was associated with poor prognosis comparable with that of the UR group.