Treatment of primary or recurrent non-resectable pancreatic cancer with proton beam irradiation combined with gemcitabine-based chemotherapy.

Abstract

Pancreatic cancer accounts for around 4.6% of cancers deaths worldwide per year. Despite many advances in treatment regimes, the prognosis is still poor. Only 20% of tumors are primarily resectable. Recurrences-both with distant metastasis as well as locoregional-are frequent. For patients with primary nonresectable localized disease or localized recurrences, we offered chemoradiation to achieve local control over along period of time. We here report our results on combined chemoradiation of pancreatic tumors and local recurrences using proton beam therapy. We report on 25patients with localized nonresectable pancreatic cancer (15patients) or local recurrent disease (10patients). All patients were treated with combined proton radiochemotherapy. Overall survival, progression-free survival, local control, and treatment-related toxicity were analyzed using statistically methods. Median RT dose was 54.0 Gy (RBE) for proton irradiation. The toxicity of treatment was acceptable. Four CTCAE gradeIII and IV adverse events (bone marrow disfunction, gastrointestinal [GI] disorders, stent dislocation, myocardial infarction) were recorded during or directly after the end of radiotherapy; two of them were related to combined chemoradiation (bone marrow disfunction, GI disorders). Six weeks after radiotherapy, one additional gradeIV toxicity was reported (ileus, caused by peritoneal carcinomatosis, not treatment related). The median progression-free survival was 5.9months and median overall survival was 11.0months. The pretherapy CA19‑9 level was astatistically significant prognostic factor for enhanced overall survival. Local control at 6months and 12months were determined to be 86% and 80%, respectively. Combined proton chemoradiation leads to high local control rates. Unfortunately, PFS and OS are driven by distant metastasis and were not improved compared to historical data and reports. With this in mind, enhanced chemotherapeutical regimes, in combination with local irradiation, should be evaluated.