Resection of Locally Advanced Pancreatic Cancer without Regression of Arterial Encasement After Modern-Era Neoadjuvant Therapy.
INTRODUCTION
Modern-era systemic therapy for locally advanced pancreatic adenocarcinoma (LAPC) offers improved survival relative to historical regimens but not necessarily improved radiographic downstaging to allow more patients to undergo resection. The aim of this study was to evaluate the survival, progression, and pathologic outcomes after resection of LAPC that did not regress from > 180 degrees arterial encasement after neoadjuvant therapy.


METHODS
Sixty-one LAPC patients were brought to the operating room after neoadjuvant therapy for NCCN-defined unresectable pancreatic cancer between 2012 and 2017. Pts were explored with intent of pancreatectomy and irreversible electroporation for margin extension; 5 (8%) had metastatic lesions on exploratory laparoscopy and were excluded from analyses. Imaging was re-examined to confirm LAPC prior to surgery. Data were analyzed from a prospective pancreatic cancer database.


RESULTS
Patients had arterial involvement of the celiac axis (37.5%) and/or superior mesenteric artery (42.9%) and/or an extended length of the common hepatic (n = 44.6%) artery. Twenty-nine males and 27 females, median 65 years of age, received neoadjuvant gemcitabine-based (58.9%) or FOLFIRINOX (35.7%) chemotherapy and stereotactic body (42.9%) or intensity-modulated (51.8%) radiation therapy. Median months from initiation of neoadjuvant therapy to surgery was 7.5. Sixty-one percent underwent Whipple, 21% distal, and 18% modified Appleby procedures; 57% patients underwent venous reconstruction. Ninety-day mortality was 2%. An R0 margin was achieved in 80%, and 53% were N0. Median overall and progression-free survival was 18.5 (95%CI 12.27-32.33) and 8.5 months (95%CI 6.0-15.0), respectively. One- and 3-year survival from surgery was 68.5% (95%CI 53.0-79.7) and 39.0% (95%CI 23.7-53.8), respectively.


CONCLUSION
With modern-era neoadjuvant therapy, R0 resections can be achieved in a majority of non-metastatic patients with locally advanced, unresectable disease based on cross-sectional imaging.
['Kluger|Michael D|MD|0000-0003-4311-078X', 'Rashid|M Farzan|MF|', 'Rosario|Vilma L|VL|', 'Schrope|Beth A|BA|', 'Steinman|Jonathan A|JA|', 'Hecht|Elizabeth M|EM|', 'Chabot|John A|JA|']
D000230:Adenocarcinoma D000368:Aged D000971:Antineoplastic Combined Chemotherapy Protocols D001158:Arteries D002445:Celiac Artery D059186:Chemoradiotherapy, Adjuvant D003841:Deoxycytidine D018450:Disease Progression D004338:Drug Combinations D005260:Female D005472:Fluorouracil D006499:Hepatic Artery D006801:Humans D000077146:Irinotecan D002955:Leucovorin D008297:Male D017538:Mesenteric Artery, Superior D008875:Middle Aged D020360:Neoadjuvant Therapy D018365:Neoplasm, Residual D016609:Neoplasms, Second Primary D009942:Organometallic Compounds D000077150:Oxaliplatin D010180:Pancreatectomy D010190:Pancreatic Neoplasms D000077982:Progression-Free Survival D016634:Radiosurgery D050397:Radiotherapy, Intensity-Modulated D015996:Survival Rate
Locally advanced Neoadjuvant therapy Pancreatic adenocarcinoma Downstaging Irreversible electroporation Surgery Chemotherapy