Evaluation of Pathologic Response on Overall Survival After Neoadjuvant Therapy in Pancreatic Ductal Adenocarcinoma.

Objectives: Single-institution studies have shown improved outcomes among patients with a pathologic complete response (pCR) following neoadjuvant therapy. We sought to evaluate the impact of pCR and near-complete response (nCR) on overall survival (OS) using a large national database.
Methods: The National Cancer Database was queried for patients given a diagnosis of pancreatic cancer from 2004 to 2014. A pCR was defined as no tumor identified in the pancreas after surgical resection. An nCR was defined as a primary tumor less than 1 cm without lymph node metastases. The primary outcome was OS.
Results: A total of 5364 patients underwent neoadjuvant chemotherapy and/or radiation followed by pancreatectomy. Forty-one patients (0.8%) had a pCR, 54 (1%) had an nCR, and the remaining 5266 (98.2%) had an otherwise incomplete response. Patients with pCR had a median OS of 43 months compared with 24 months for nCR and 23 months for incomplete response (P < 0.0001). Only pCR was associated with improved OS on adjusted Cox regression.
Conclusions: For patients given a diagnosis of pancreatic cancer who underwent neoadjuvant treatment and surgical resection, achieving a pCR was associated with improved OS compared with those with residual tumor. An association between nCR and improved survival was not observed.