Is a Pathological Complete Response Following Neoadjuvant Chemoradiation Associated With Prolonged Survival in Patients With Pancreatic Cancer?

Abstract

Objectives: To describe the survival outcome of patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma (BR/LA-PDAC) who have a pathologic complete response (pCR) following neoadjuvant chemoradiation.

Background: Patients with BR/LA-PDAC are often treated with neoadjuvant chemoradiation in an attempt to downstage the tumor. Uncommonly, a pCR may result.

Methods: A retrospective review of a prospectively maintained database was performed at a single institution. pCR was defined as no viable tumor identified in the pancreas or lymph nodes by pathology. A near complete response (nCR) was defined as a primary tumor less than 1 cm, without nodal metastasis. Overall survival (OS) and disease-free survival (DFS) were reported.

Results: One hundred eighty-six patients with BR/LA-PDAC underwent neoadjuvant chemoradiation and subsequent pancreatectomy. Nineteen patients (10%) had a pCR, 29 (16%) had an nCR, and the remaining 138 (74%) had a limited response. Median DFS was 26 months in patients with pCR, which was superior to nCR (12 months, P = 0.019) and limited response (12 months, P < 0.001). The median OS of nCR (27 months, P = 0.003) or limited response (26 months, P = 0.001) was less than that of pCR (more than 60 months). In multivariable analyses pCR was an independent prognostic factor for DFS (HR = 0.45; 0.22-0.93, P = 0.030) and OS (HR=0.41; 0.17-0.97, P = 0.044). Neoadjuvant FOLFIRINOX (HR=0.47; 0.26-0.87, P = 0.015) and negative lymph node status (HR=0.57; 0.36-0.90, P = 0.018) were also associated with improved survival.

Conclusions: Patients with BR/LA-PDAC who had a pCR after neoadjuvant chemoradiation had a significantly prolonged survival compared with those who had nCR or a limited response.

FIGURE 1.

A) Kaplan-Meier estimates of overall survival in patients with BR/LA-PDAC treated with neoadjuvant chemoradiation followed by pancreatic resection based on histological response. B) Kaplan-Meier estimates of overall survival in patients with BR/LA-PDAC treated with neoadjuvant chemo-radiation followed by pancreatic resection based on histological response. pCR v nCR (P = 0.003), pCR v LR (P = 0.001), LR v nCR (P = 0.773).

FIGURE 2.

Kaplan-Meier estimates of disease-free survival in patients with BR/LA-PDAC treated with neoadjuvant chemoradiation followed by pancreatic resection based on histological response. pCR v nCR (P = 0.019), pCR v LR (P < 0.001), LR v nCR (P = 0.768).