Neoadjuvant Early Stereotactic Body Radiotherapy Followed by Chemoimmunotherapy in Borderline Resectable and Locally Advanced Pancreatic Cancer

Background Optimal neoadjuvant therapy for borderline resectable/locally advanced pancreatic cancer (BRPC/LAPC) remains undefined. This study evaluated the efficacy and safety of neoadjuvant nab-paclitaxel and gemcitabine plus camrelizumab, with or without early stereotactic body radiotherapy (SBRT), among patients with BRPC/LAPC. Methods This single-center, prospective trial enrolled adults with previously untreated BRPC/LAPC. Patients were assigned to an SBRT cohort, receiving early SBRT (25 Gy in 5 fractions) followed by nab-paclitaxel (125 mg/m²) plus gemcitabine (1000 mg/m²) on days 1 and 8 with camrelizumab (200 mg every 3 weeks), or to a non-SBRT cohort treated with the same chemoimmunotherapy alone. A multidisciplinary team determined whether patients underwent surgery or continued first-line therapy. Objective response rate (ORR) served as the primary endpoint. Results A total of 22 patients were enrolled (11 in each cohort). The ORR was 36.4% (8/22) and disease control rate was 100% (22/22). Six patients (27.3%) underwent surgery, and all achieved clinical-to-pathologic downstaging and R0 margins (6/6). With a median follow-up of 30.0 months (95% CI, 23.3–36.7), median progression-free survival (PFS) was 12.5 months (95% CI, 9.6–NA) in the SBRT cohort and 6.6 months (95% CI, 6.4–NA) in the non-SBRT cohort in an exploratory between-cohort analysis (P=0.003). Median overall survival (OS) was 20.8 and 13.9 months in the SBRT and non-SBRT cohorts, respectively (P=0.261). Toxicity profiles were similar across cohorts, with grade ≥3 treatment-related adverse events occurring in 36.4% of patients. Conclusions Neoadjuvant nab-paclitaxel and gemcitabine plus camrelizumab, with or without early SBRT, showed encouraging efficacy and acceptable tolerability for BRPC/LAPC. The potential benefit of early SBRT warrants further investigation. Trial registration Chinese Clinical Trial Registry (ChiCTRXXXX; Registration date: XXXX)