Who could complete and benefit from the adjuvant chemotherapy regarding pancreatic ductal adenocarcinoma? A multivariate-adjusted analysis at the pre-adjuvant chemotherapy timing.

Background: The pre-adjuvant chemotherapy (PAC) status of postoperative pancreatic ductal adenocarcinoma (PDAC) patients has not been studied and elaborated well previously.

Method: The association of PAC variables and prognoses was explored using a multivariable Cox model, restricted cubic spline analysis, and correlation analysis. The main outcomes were overall survival (OS) and progression-free survival (PFS). The secondary outcome was chemotherapy completeness (CHC).

Results: A total of 401 eligible patients were enrolled in sequential surgery and chemotherapy. The chemotherapy regimen, PAC fasting blood glucose (FBG), and elevated fasting blood glucose (eFBG) status were associated with CHC (regimen types: p = 0.005, continuous FBG: p = 0.014, eFBG status: p = 0.012). Early administration of adjuvant chemotherapy (<34 days) was a risk factor for the limited OS and PFS (OS: aHR: 1.61 [1.09-2.38], p = 0.016; PFS: aHR: 1.91 [1.29-2.82], p = 0.001). Patients with higher PAC body mass index (BMI), receiving Gemcap regimen, and with lower PAC tumor marker value were observed with better survival prognoses (PAC BMI: OS: 0.927 [0.875-0.983], p = 0.011; Gemcap: OS: 0.533 [0.312-0.913], p = 0.022; Gemcap: PFS: 0.560 [0.341-0.922], p = 0.023; PAC CA125: OS: 1.004 [1.002-1.006], p < 0.001; PAC CA125: PFS: 1.003 [1.000-1.005], p = 0.031; PAC CEA: OS: 1.050 [1.026-1.074], p < 0.001). The BMI decrease was mainly concentrated in the first 3 months of chemotherapy courses (first 3 months: p < 0.001; latter 3 months: p = 0.097). And CEA, compared to CA125 and CA199, was a better prognostic indicator (CEA: first 3 months: PFS p = 0.011, OS p < 0.001; latter 3 months: PFS p = 0.024, OS p = 0.041).

Conclusion: PDAC patients should be treated with adjuvant chemotherapy over 34 postoperative days. PAC sarcopenia was a risk factor for OS, but not PFS and limited CHC. Those with higher PAC FBG levels were more likely to finish chemotherapy. CEA, compared to CA125 and CA199, was a better prognostic indicator.