Original Article
Long-term outcomes by response to neoadjuvant chemotherapy or chemoradiation in patients with resected pancreatic adenocarcinoma
Abstract
Background: Response of pancreatic adenocarcinoma to neoadjuvant chemotherapy (nCT) or chemoradiotherapy (nCRT) may be associated with prognosis, but long-term outcomes based on response to neoadjuvant therapy have not been well evaluated to date.
Methods: The National Cancer Database was queried for patients with pancreatic adenocarcinoma receiving nCT/nCRT. To evaluate response to nCT/nCRT, comparisons were made from cT and cN stage to the respective post-neoadjuvant therapy ypT and ypN stages. Based on these comparisons, patients were classified as responders, progressors, or non-responders. Statistical analyses included estimation of survival using Kaplan-Meier analysis, as well as multivariable Cox proportional hazards modeling.
Results: Of 2,028 patients, 30% had a response, 32% progressed, and 38% had no response; 1% of patients experienced pathologic complete response (pCR). Responders were more likely to have received multi-agent chemotherapy (P=0.0001) as well as radiotherapy (RT) (P=0.02) in the neoadjuvant setting. Response to nCT/nCRT was also associated with a higher R0 resection rate (P=0.02). At a median follow-up of 49 months, median overall survival (OS) was higher in responders than non-responders or progressors (29.9 vs. 24.3 vs. 22.2 months, P<0.001). The mean OS for patients experiencing pCR was 55.5 months. On multivariable analysis, treatment response was independently associated with OS (P=0.02).
Conclusions: Response to nCT/nCRT independently predicts long-term outcomes following resection of pancreatic adenocarcinoma; higher rates of treatment response were observed for patients receiving neoadjuvant RT as well as neoadjuvant multi-agent chemotherapy. These results may have implications on strategies to improve response rates.
Methods: The National Cancer Database was queried for patients with pancreatic adenocarcinoma receiving nCT/nCRT. To evaluate response to nCT/nCRT, comparisons were made from cT and cN stage to the respective post-neoadjuvant therapy ypT and ypN stages. Based on these comparisons, patients were classified as responders, progressors, or non-responders. Statistical analyses included estimation of survival using Kaplan-Meier analysis, as well as multivariable Cox proportional hazards modeling.
Results: Of 2,028 patients, 30% had a response, 32% progressed, and 38% had no response; 1% of patients experienced pathologic complete response (pCR). Responders were more likely to have received multi-agent chemotherapy (P=0.0001) as well as radiotherapy (RT) (P=0.02) in the neoadjuvant setting. Response to nCT/nCRT was also associated with a higher R0 resection rate (P=0.02). At a median follow-up of 49 months, median overall survival (OS) was higher in responders than non-responders or progressors (29.9 vs. 24.3 vs. 22.2 months, P<0.001). The mean OS for patients experiencing pCR was 55.5 months. On multivariable analysis, treatment response was independently associated with OS (P=0.02).
Conclusions: Response to nCT/nCRT independently predicts long-term outcomes following resection of pancreatic adenocarcinoma; higher rates of treatment response were observed for patients receiving neoadjuvant RT as well as neoadjuvant multi-agent chemotherapy. These results may have implications on strategies to improve response rates.
