Chemotherapy versus chemoradiotherapy in borderline resectable and locally advanced pancreatic adenocarcinoma

The role of radiotherapy in borderline resectable (BRPC) and locally advanced pancreatic carcinoma (LAPC) remains controversial. In our study, we retrospectively evaluated 48 patients with BRPC (14; 29.2%) and LAPC (34; 70. 8%) who underwent 6-8 cycles of induction mFOLFIRINOX chemotherapy alone (23; 47.9%) or 4-6 cycles of mFOLFIRINOX followed by hypofractionated radiotherapy (up to the total dose of 39.9 Gy in 15 fractions) (25; 52.1%). Survival parameters were evaluated using the Gehan-Breslow-Wilcoxon Test and compared by using the long-rank test. The addition of radiotherapy was not associated with better survival (16.9 months for chemotherapy only versus 15.9 months for the combined therapy; p=0.486), as well as for both subgroups (13.5 months vs. 18.3 months; p=0.679) and (20.7 months vs. 13.8 months; p=0.425) for BRPC and LAPC, respectively. A higher resection rate was seen in the BRPC group compared to the LAPC group (43% vs. 17.6%, respectively). Our study revealed a significantly higher rate of lung metastases in patients after the combination therapy compared to those treated by chemotherapy only (19% vs. 0%, respectively; p=0.045). Such a borderline result, however, prevents us from drawing clear conclusions about whether this is an artifact caused by the low number of patients or whether radiotherapy leads to a selection of stem cells with a predilection to the generalization to the lungs.