Chemotherapy Plus Proton-chemotherapy for Locally Advanced Pancreatic Cancer

The current trend toward using the biology of the disease as it becomes evident over a period of chemotherapy to better select patients who will benefit from chemoradiotherapy (CRT) seems to be the most pragmatic way to proceed, until we have a better means of predicting tumor behavior and more active systemic agents. This has led to increased interest in treatment regimens incorporating induction chemotherapy with target agent followed by CRT and additional chemotherapy for diseases that carry a high risk for systemic relapse. The PA.3 trial was the first phase III trial in advanced pancreatic cancer to show a survival advantage with the addition of a second drug, in this case the oral Epidermal growth factor receptor (EGFR) inhibitor Erlotinib to gemcitabine. The approval provides an important proof of concept regarding the use of newer "targeted" therapies in pancreatic cancer 7. Proton beam therapy may result in lower toxicity, enhanced efficacy and could contribute to improved local control of patients with LAPC. The capecitabine and oxaliplatin ((CapOx)) regimen utilized in this trial has been proven to be active in gemcitabine-pretreated patients with advanced pancreatic cancer. The current trial will provide important data on the recurrence rates and patterns of failure using state of the art target agent, chemotherapy and proton beam technology for patients with LPAC. A median survival of 10 months or greater would be considered evidence of a regimen potentially worthy of further study as a new treatment paradigm in one arm in a future phase III trial. Patients with unresectable or borderline resectable non-metastatic adenocarcinoma of the pancreas, as defined by 2012 National Comprehensive Cancer Network (NCCN) guidelines, were included. Patients received neoadjuvant gemcitabine 1000 mg/m2 IV on days 1, 8, 15, 22, 29, 36, and 43 and erlotinib 100 mg by mouth every day for 1-43 days (GE). If there was no evidence of metastatic disease after GE, then patients preceded with proton therapy to 50.4 Gy in 28 fractions with concurrent capecitabine 825 mg/m2 twice per day (PCT). This was followed with maintenance oxaliplatin 130 mg/m2 on day 1 and capecitabine 1000 mg/m2 twice per day on days 2 to 15 (CapOx) for 4 cycles. The primary study objective was 1-year overall survival (OS). The benchmark was 43% 1-year survival as demonstrated in Radiation Therapy Oncology Group (RTOG/NRG) 98- 12. The Kaplan-Meier method was used to estimate the one-year OS and the median OS and progression-free survival (PFS).