221 Background: While the clinical response from induction chemotherapy followed by stereotactic body radiation therapy (SBRT) has been reported for borderline resectable pancreatic cancer (BRPC) patients, response from a histopathologic standpoint has not been described. Methods: This single-institution retrospective review evaluated BRPC patients who completed induction gemcitabine-based chemotherapy followed by 5-fraction SBRT. All patients were restaged and underwent resection. A pathologist (B.C.) specializing in pancreatic cancer reviewed each surgical specimen and assigned two Tumor Regression Grade (TRG) scores, one from the College of American Pathologists (CAP) and one from the MD Anderson Cancer Center (MDACC). Overall survival (OS) and progression free survival (PFS) were correlated to TRG score using the Kaplan-Meier method. Results: This study evaluated 35 resected BRPC patients with a median follow up of 13.8 months (range, 6.1-24.8). All received induction gemcitabine-based chemotherapy, most commonly GTX (gemcitabine, docetaxel, capecitabine) (82%), followed by 5-fraction SBRT with a median 35 Gy (range, 30-40). TRG scores according to the CAP were as follows, from best to worst response: 0 (n=3), 1 (n=13), 2 (n=15), and 3 (n=4). TRG scores according to MDACC were as follows, from best to worst response: IV (n=3), III(M) (n=6), IIB (n=11), IIA (n=10), and I (n=5). Any neoadjuvant treatment effect according to MDACC scoring (IIA-IV vs. I) was associated with improved OS and PFS (both p=0.019). Conclusions: This study demonstrated a significant pathologic response with a gemcitabine based neoadjuvant regimen containing SBRT and suggests a survival benefit based on response as measured by the MDACC scoring system.
Neoadjuvant treatment for borderline resectable pancreatic cancer
