Surgical outcomes of histopathological stage I pancreatic cancer with special reference to oncological differences between pStage I and ypStage I cases.

Objective: Histopathological stage I pancreatic cancer (PC) consists of four entities according to the Union for International Cancer Control (UICC) 8th staging system: pStage IA (cases underwent up-front surgery, pT1 [tumor size ≤20 mm] pN0), pStage IB (cases underwent up-front surgery, pT2 [20 mm < tumor size ≤40 mm] pN0), ypStage IA and IB (i.e., underwent neoadjuvant treatment [NAT]). This study aimed to evaluate surgical outcomes in patients with histopathological stage I PC ((y)pStage I).

Methods: Patients with PC who underwent resection and were diagnosed with (y)pStage I were included in this study (n = 121). We evaluated and compared recurrence-free survival (RFS) and overall survival (OS) among these four categories: pStage I vs. ypStage I, (y)pStage IA vs. IB, ypStage IA vs. IB, and pStage IA vs. IB.

Results: There was no difference in the prognosis between pStage I and ypStage I cases, even though ypStage I included more advanced cases at NAT initiation. For pStage I (n = 25), no differences in prognosis were noted between pStage IA and IB (median RFS, 24 vs. 21 months, p = 0.871; median OS, 49.5 vs. 35.5 months, p = 0.213). However, in the ypStage I cohort (n = 96), there was significantly better RFS in ypStage IA (median RFS, 42 vs. 14 months, p = 0.0114; median OS, 52 vs. 36 months, p = 0.250).

Conclusions: Survival was comparable between pStage I and ypStage I cohorts, although the subcategories within each cohort (IA vs. IB) had different clinicopathological characteristics and outcomes.