Abstract 342P
Background
Locally advanced pancreatic cancer (LAPC) presents a dismal prognosis due to its unresectability and limited treatment options. Chemotherapy (CT) is the validated treatment, but the role of consolidation radiotherapy (RT) remains debated. We evaluated the oncological outcomes of patients with LAPC treated with RT after induction CT.
Methods
In this multicenter retrospective study, we included 164 patients with LAPC treated with induction CT followed by consolidation RT between 2010 and 2020. Primary outcome was overall survival (OS). Secondary outcomes were progression-free survival (PFS), local control, distant metastases, resection rate, and treatment-related toxicities.
Results
Median OS was 20 months, with 1-year and 2-year OS rates of 85.6% and 33.0%, respectively. OS was significantly better in patients those who underwent surgical resection (p=0.002), but with no difference between FOLFIRINOX or gemcitabine induction (p=0.32). Radiologic (RECIST criteria) and biologic (CA19-9) responses after induction CT could not predict RT benefits (p=0.06 and 0.69, respectively). Median PFS was 13.2 months. Local recurrence and distant metastases rates at 2 years were 42.7% and 65.2%, respectively. Surgical resection was achieved in 11.6% of patients, with a majority of R0 resection. RT was safe, with no grade 4 and few grade 3 toxicities.
Conclusions
This multicenter study was one of the largest cohorts reported to underscore some potential benefits in OS and PFS of consolidation RT for LAPC, with comparable outcomes between FOLFIRINOX and gemcitabine regimens. It highlighted the importance of surgical resection in improving survival, and the current lack of biomarker to predict patients’ outcomes. RT was well-tolerated, with mainly mild toxicity. This study confirmed the results of the previously published smaller studies, both retrospective and prospective.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.